To account for sequence read depth variation per sample, the fungal OTU table was normalized by rarefying to equal fungal sequence reads , using the ‘rarefy’ command in VEGAN in R to account for uneven sequencing depth across samples.Our study demonstrates that greater crop diversity in intensive agricultural systems drives a richer and more diverse AMF community. We observed nearly twice as many AMF taxa in poly cultures than in mono cultures, while accounting for variation in soil properties that also significantly affected AMF richness. The AMF community composition in poly culture sites was also distinct from that in monoculture field sites, but soil properties played a stronger role in structuring the AMF community. Contrary to our expectations, we also show that AMF colonization of roots is probably driven by plant host identity rather than farm management practices . For both AMF diversity and colonization responses, soil properties were important factors that influenced the outcomes, but did not dominate relative to the important effect of higher crop diversity. Overall our findings indicate that managing for crop diversity in agricultural landscapes can strongly influence AMF community composition, including richness and diversity, across heterogeneous soils. Further, our results support the notion that plant diversity is key to below ground biodiversity, which in turn could support multifunctional agroecosystems , including those that have been intensively managed in the past. We show that poly culture fields harbor a richer and more diverse AMF community than do monoculture fields, suggesting that poly culture plantings may promote recovery of AMF richness following a long period of monoculture farming, which is known to be associated with decreased AMF diversity . Our poly culture sites were formerly farmed intensively as mono cultures, as recently as 7 yr before sampling, and thus were likely to have had a depauperate AMF community.How to build a vertical hydroponic system? Soil properties also contributed to explaining some of the variance in AMF richness and diversity, but overall they played a minimal role. While AMF are ubiquitous across landscapes, AMF are obligate symbionts with a degree of host specificity; thus, AMF associations with plant hosts are typically not random . Variation in plant traits, including phenology, root architecture and other factors, impacts the distribution and composition of AMF,and thus functionally different plants can associate with distinct AMF communities.

In our study, we found evidence that different AMF taxa occur in poly cultures vs mono cultures. A Rhizophagus taxon was the top indicator of mono cultures, whereas the top indicator taxon in poly cultures was in the genus Glomus. While research on AMF functional traits is still emerging , these taxonomic differences , coupled with greater AMF diversity in poly cultures, could indicate differences in AMF community functionality with implications for plant performance and ecosystem processes. Future research should focus on these possible functional differences among AMF taxa. In poly cultures, functionally distinct plant hosts are planted across space and time, creating a mosaic of diverse microhabitats, varying in microclimatic and microedaphic properties, as evidenced by our finding that poly cultures have a more heterogenous soil environment compared with mono cultures. Across poly culture fields in our study system, crop type can be distinct row by row in space, but single rows can also shift from crop to crop at different times throughout the year. For example, annuals and perennial crops are grown together at the same time, grasses and tubers can be grown adjacent to each other, and leafy greens and legumes could be grown sequentially in poly culture fields in this study system. In fact, the presence of perennials and legumes has been shown to increase AMF diversity. In the poly culture field sites, not only are legumes present, but functionally distinct leguminous species and cultivars are planted . Therefore, the likely mechanism that fosters a richer and more diverse AMF community in poly cultures is the heterogeneity in plant composition: over space, across time within a space, and as different species or varieties across and within functional types such as legumes. Arbuscular mycorrhizal fungi communities also depend, in part, on the composition and pattern of past plant communities . This may explain why in poly cultures we do not find a more diverse AMF community in the more plant-rich transects when compared with the single species transects. Instead, the legacy of poly culture management, specifically the temporally, spatially and functionally heterogeneous plant community, leads to an overall richer and more diverse AMF community in poly cultures than in mono cultures. Poly cultures also harbored a distinct AMF community from mono cultures. However, AMF communities were quite heterogeneous across both monoculture and poly culture field sites, reflecting a high turnover among sites. The heterogeneity and high turnover of the AMF community are evident in the fact that average site-level AMF richness is much lower than total AMF richness recorded across all sites: the average AMF richness was c. 5 in monoculture and 10 in poly culture field sites, compared with a total AMF richness in the whole study of 244. Arbuscular mycorrhizal fungi communities tend to be heterogeneous even at fine scales.

Our expectation that AMF communities on poly culture farms would be more heterogeneous at a fine scale than those on mono cultures was not borne out; specifically, we found no interaction between farm management and transect for composition. This is further evidence that poly cultures may impart a legacy effect on AMF communities. Despite possible AMF compositional differences between mono cultures and poly cultures, our results show that soil properties played a larger role in explaining AMF community composition than farm management, with pH being a significant predictor, consistent with other studies , especially at finer spatial scales . The greater heterogeneity in soil edaphic properties in poly cultures than mono cultures suggests that crop diversity may indirectly underlie these edaphic-driven patterns of AMF community structure. Regardless, these findings suggest a role for soil properties in structuring AMF community composition across farms and a role for farm management in shifting the available AMF community into more or less diverse communities at the site level. The role of plant diversity vs plant host identity on AMF associations was most evident in our measurements of AMF colonization in roots. Our study design allowed us to explore whether crop diversity impacted AMF colonization in the same crop species, and also whether different crop plant hosts in poly cultures play a role in determining AMF colonization. Contrary to our expectation, we found no difference in AMF colonization across the same crop host when planted in poly culture or monoculture fields. In part, this may be explained by fertilizer usage across all farms, which may mask or suppress changes in AMF root colonization as a result of increasing crop diversity because fertilization decreases the dependency of plants hosts on AMF . But AMF colonization has been shown to increase in plant host roots within more diverse plant communities , especially when highly mycorrhizal plants are present . Instead, we found similar degrees of AMF colonization on the focal crop host between poly culture and monoculture farms, but greater degrees of AMF colonization on other crop hosts on poly culture fields. Recent research has found mixed results about the extent to which plant host identity determines the quantity of AMF colonization. Some studies show that plant identity rarely plays a role , while others, like this study, demonstrate that plant host identity does impact AMF colonization, especially at local scales.

Thus, our study strengthens the body of research showing that AMF colonization is dependent on specific AMF–plant host associations. While this finding could suggest that agricultural systems with higher plant diversity may not benefit from greater AMF colonization, AMF colonization may not actually be the most important indicator of AMF benefits and functions for crops in agricultural systems . Colonization does not indicate the extent of nutrient transfer or the degree of ecosystem services provided by AMF . Instead,vertical plant growing there is a growing understanding that AMF composition is an important determinant of the benefits received by ecosystems from AMF communities . A richer and more diverse AMF community could indicate differences in ecosystem functioning between monoculture and poly culture farming, with important implications for agricultural management. Previous research has shown that mono cultures contribute to reducing AMF richness and can change community composition to favor less beneficial AMF taxa, in turn contributing to yield declines . Although empirical evidence from field studies on AMF remains rare, a positive relationship between AMF diversity and ecosystem functioning is expected because AMF taxa differ in their functions . For example, studies have shown differential plant productivity responses to different AMF taxa or communities . Other studies have demonstrated that productivity, phosphorus uptake, soil aggregation and pathogen protection increase with AMF diversity . In short, as AMF taxa are functionally heterogenous,a more diverse community could provide a wider array and/or stability of functions.Therefore, crops grown in poly cultures may benefit from the enhanced and/or stabilized ecosystem functions and services of a richer and more diverse AMF community.As pressures from habitat loss increase, there is growing interest in agricultural landscapes as potential habitat or movement areas for wildlife. Agricultural landscapes are potentially rich in structure, food, and cover, and many native species forage and reproduce in these landscapes. These lands can support moderate diversity of birds, mammals, arthropods, and plants, depending on the intensity of agriculture and on configuration of natural land cover. Mammalian carnivores are frequent targets of conservation efforts, and they play a key role in food webs, for example via mesopredator release or trophic downgrading. Because carnivores are typically wide-ranging, it is especially important to consider agricultural landscapes as well as protected areas when forming conservation plans for these species. Wildlife managers and conservation planners currently have little knowledge of carnivore use of agricultural landscapes, but this subject will become increasingly important as agricultural systems continue to expand and protected areas become more isolated. Connectivity between habitat patches is especially critical in human-dominated landscapes, but most connectivity models focus on natural vegetation types, not on differences between human-dominated land cover types within such landscapes. When evaluating landscape connectivity for large carnivores, conservation planners have often relied on expert opinion and considered all agriculture as having uniformly low connectivity value . Many members of the order Carnivora are omnivorous and feed, in part, on anthropogenic food sources. Scat analysis has identified cultivated fruit in the diets of carnivores, particularly foxes and stone martens, and Borchert et al.found that at least one orchard type – avocado – was regularly used by carnivores in California. California is a major producer of avocados, with 23,500 hectares of orchards spread across five southern counties. Because avocados grow well on steep slopes, they are planted in a variety of landscape contexts, including hill slopes adjacent to native vegetation as well as valley bottoms adjacent to other types of crops. We examined the use of avocado orchards by mammalian carnivores across agricultural-wild land gradients in southern California. We assessed whether occupancy of carnivores at motion-activated camera stations was a function of surrounding land cover, and in particular, whether area of orchards influenced carnivore occupancy. If orchards constitute poor quality carnivore habitat relative to natural areas, we would expect to observe carnivores less frequently in orchards than in nearby wild lands.Coastal southern California is highly urbanized and contains about two thirds of California’s 38 million residents; it also has relatively little remaining undeveloped land, yet is experiencing rapid population growth. This region has a Mediterranean-type climate, and the dominant natural vegetation types areoak woodland, riparian woodland, sage scrub, and annual grassland. Eleven native members of the order Carnivora occur in this region: American badger , American black bear , bobcat , coyote , gray fox , long-tailed weasel , mountain lion , raccoon , ring tail , striped skunk , and Western spotted skunk . Our study area included avocado orchards and wild lands in Santa Barbara and Ventura counties selected for their position in the landscape and for landowner cooperation .

This is the chief evidence supporting our general finding that growth originating in different sectors has different effects on households in different parts of the expenditure distribution. Re-estimating this relationship with different unobserved effects strategies yields results that are slightly weaker but broadly consistent—in any event a joint test of the equality of coefficients across sectors for all deciles leads to a rejection of the null hypothesis of equality. The third thing to notice is that while growth from agriculture has a positive and significant finding effect on expenditure growth for the bottom five deciles, growth from other sectors is never significant. One cannot reject the null hypothesis that no decile benefits from non-agricultural sources of GDP growth.13 Point estimates associated with growth from non-agricultural sectors are in fact negative for the bottom eight deciles, but little should be made of this fact, both because none of these coefficients are significant and because even if significant these negative coefficients would only be an indication that non-agricultural income growth reduced expenditure growth relative to the positive mean levels reported in Table 2, not that it actually makes it negative. Taken together these results suggest a progressive effect of income growth originating in agriculture: a one percentage point increase in GDP due to agricultural income growth is associated with a 6.8 percentage point increase in the growth rate of expenditures of the bottom decile, declining to 4.4 percentage points for the fifth decile, and with no effect at all on the highest decile. Note the differences between our instrumental variables and OLS results. Estimated coefficients associated with agriculture are much higher in Table 5, suggesting that the OLS coefficients were attenuated by measurement error,potted blueberries in line with our discussion above in Section 4.2. At the same time coefficients associated with non-agricultural income growth are lower finding and have considerably higher standard errors than in the OLS case.

The results we have which seem quite robust are finding monotonicity of the effects of agricultural income growth across deciles, indicating a certain progressivity in the effects of agricultural income on the distribution of expenditures; and finding significantly different effects from income originating in different sectors. We next turn our attention to the question of whether the effects of income growth from different sectors on expenditures differ across countries. We are interested in particular in whether there is heterogeneity across different particular observable groups. We might expect such heterogeneity to stem from differences in endowments or social conditions across countries. We consider four ways of dividing countries: the initial level of poverty; the initial level of inequality; the initial level of adult literacy;and conclude with the contrast across continents, which of course may capture many differences in endowments and social structures.Our work so far addresses the question of how income growth from agriculture affects the distribution of expenditures within countries, rather than across them. We are now able to say something about the effects of such growth on the global distribution of welfare by asking whether the effects of income growth from agriculture on distribution are different for poorer and wealthier countries within our sample. We group countries by initial level of finding poverty rates and report results in Table 6. In our sample, the median poverty rate across countries is 15.27%, ranging from a minimum of 0.04% in Bosnia and Herzogovina to 81.32% in Burundi.Because we are interested in whether there is heterogeneity in elasticities across the global ranking of poverty rates, not the ranking within continents, we produce these results without the extra continent dummies that we have used in most of the analysis above. There are several things worthy of note in Table 6. First, one can reject the null hypothesis that there is no heterogeneity by country poverty level.

Specifically, one can reject the hypotheses that coefficients are equal across poorer and wealthier countries in the bottom three deciles finding. Second, the robust pattern of monotonicity observed elsewhere for the coefficients associated with agriculture is preserved for poor countries, but the direction is nearly reversed for wealthy countries. Thus, the progressive effect of agricultural income growth on distribution seems to be confined to the poorer half of the countries in our sample. Third, we can reject the hypothesis that agricultural and non-agricultural coefficients are equal within the poorer half of countries finding for the bottom six deciles, in line with the baseline results of Table 5. However, we cannot reject equality among the richer half of countries. This is additional evidence that the progressive effect of agricultural income growth on the welfare of the poor may be confined to the poor in the poorest countries. Our findings here are related to results found by other authors. For example, Christiaensen et al. finding finds that agriculture growth matters most for poverty reduction when using the poverty line of $1 per capita rather that $2 per capita. Though our results are not directly comparable finding, in our analysis the income level of the deciles nevertheless directly measures the intensity of poverty, since lower deciles in poorer countries are typically poorer than lower deciles in richer countries. All of the three notable findings discussed above turn out to also be true when we look at poverty across countries within a continent, by estimating finding while including continent dummies. However, in this specification the addition of extra controls causes the significance of the individual coefficients seen in Table 6 to disappear. Thus, though income growth from agriculture affects the expenditure distribution differently in poor and wealthy countries, the fact that with the addition of continent effects the individual significance vanishes suggests that the continent finding may matter in understanding these patterns, a question we return to below. One interpretation of the results of last section is that it is not really poorer countries, but less equal countries to which this applies, and we only find our earlier results because less equal countries also tend to be countries with more poor. This certainly isn’t a new idea: Datt and Ravallion finding, Ravallion finding, Suryahadi et al. finding, and Christiaensen et al. finding all argue for the possible importance of initial inequality in understanding the effects of aggregate sectoral income growth on poverty. We do not really have the data to distinguish between these two hypotheses adequately, but we can at least divide countries according to initial inequality and see what happens. We divide countries into groups depending on whether their initial Gini coefficient is above or below the median.

Results from this exercise are reported in Table 7. In contrast with our poverty results, dividing countries by initial inequality preserves our earlier monotonicity results for both more and less unequal countries, with agriculture tending to differentially benefit poorer households in both groups. However, we can no longer reject the hypothesis that coefficients are the same across groups, whether we include continent fixed effects or not, leading us to conclude that initial inequality may be a less salient dimension of heterogeneity across countries than is initial poverty.Soils are an important consideration for individuals, community groups, and local governments becoming involved in urban agriculture. In many situations, urban soil has been contaminated and degraded by past uses and activity, including industry,square plastic pot unauthorized dumping, construction, heavy traffic, and adjacent buildings where lead based paint has been applied. Elevated levels of lead in particular are fairly common in urban soils and pose health risks, especially to young children who can ingest soil while playing or helping in gardens. Ongoing exposure to lead can damage the nervous system, interfere with brain development, and create other health problems. Arsenic, cadmium, copper, zinc, and other naturally occurring trace elements in soils, especially heavy metals, can also be elevated to unsafe levels by past land uses. Although soil degradation and contamination are important concerns and should be addressed, they are not always a problem with urban agriculture sites. A study conducted at several community gardens in the Los Angeles area by University of California researchers found that “in nearly all cases concentrations of trace elements were well within natural ranges” finding. In contrast, a study conducted in San Francisco found that “a majority of the gardens exceeded the California Human Health Screening Level for arsenic, cadmium, and lead” finding.Even where there are elevated levels of lead or other heavy metals or contaminants in soil, relatively little is absorbed by plants that can be harmful to humans, although this depends on soil and other environmental conditions as well as on the plant’s characteristics. Accidentally swallowing or inhaling contaminated soil or dust is the most likely way urban farmers will be exposed to unsafe levels of lead or other contaminants. This can happen easily, for example, when people put their fingers in their mouths without thinking. Beyond heavy metals, other sources of soil contamination and soil hazards might include solvents found at sites with a history of manufacturing use, various petroleum-based chemicals common at former gas stations and other industrial sites, chlorinated pesticides and residual herbicides on former agricultural lands or public landscaped areas, saline soil, and sites where a contaminant may not be harmful to people but may prevent plant growth or production.

Physical debris such as lumber, concrete, wire, broken glass, and discarded syringes can also create hazards for the urban farmer. Clearly, there are no easy answers: each site and situation is unique. However, establishing reasonable policies and encouraging sustainable practices will help to ensure that urban farmers and consumers of urban agricultural products are not exposed to unsafe levels of contaminants, including lead and other heavy metals. This publication outlines strategies for urban soil contamination assessment, testing, and remediation; explains best management practices for urban agriculture; and discusses municipal policy concerning safe soils for urban agriculture. This publication does not cover soil fertility or other important soil science topics in depth; additional resources on these topics are presented in the section “Sources of More Information.”Overall soil conditions should be a consideration when selecting a site for urban agriculture. If plants, even weeds, are growing abundantly on the site, it is a good indication that the soil will be able to support crops. If the soil is reasonably easy to dig, it is a positive sign as well. The presence of plant roots and earthworms can indicate soil health. However, these indicators do not guarantee that soil is uncontaminated. When assessing potential sites, be aware that properties with considerable amounts of trash and rubble or obvious dead spots where plants do not grow may pose challenges.A simple test for evaluating soil fertility is to plant bean seeds in soil from the site, perhaps in a pot or biodegradable paper cup, and compare their germination and growth with an equal number of beans grown in purchased potting soil. It is also advisable to dig a hole 1 to 2 feet deep in several places to assess the presence of debris on the site.Learn as much as possible about the history of a proposed site and how it has been used in the past. Walking around the site may provide some clues. Adjacent older homes with peeling paint, paint chips, or evidence of sandblasting finding indicate potential soil lead contamination. Any building built before 1979 that has old or peeling paint may be a hazard due to use of lead based paint. Proximity to a freeway or a heavily trafficked road is also a source of lead. Although leaded gasoline has not been in use since the 1980s, lead particles in vehicle exhaust may have settled from the air into the soil. Talking to the property owner and neighbors is a good strategy, as neighbors are often familiar with past uses of the property. It may also be necessary to do some Internet or library research. For example, at some public libraries and online sources it is possible to access Sanborn maps, which were used by insurance companies to determine the risk involved with insuring individual properties. These maps can provide information about prior uses of a proposed site. Old aerial photographs, which can also be found in local libraries or online, can help identify a site’s history as well. The local city hall may have aerial photographs accessible in their archives.

Generally, it would be beneficial for society to pollute less than what is observed under a free market system. Yet, eliminating pollution altogether is too costly and regulation is needed to keep it at desirable levels that maximize societal welfare. Regulation, on the other hand, is always defined for, and often differs among, given regions. In the United States, regulation of water quality is guided by the federal Clean Water Act finding. States emphasize designing, imposing, and enforcing the actual regulations imposed at the federal level. When regulating concentrated animal feeding operations finding, for instance, states may establish rules that influence manure-application practices. As our economic analysis will demonstrate, regional regulation has serious caveats. For this study, we create a stylized framework to illustrate regional regulation and its potential failure. Hereby, we establish a need for applied economic analysis to further clarify the problem and help improve existing policies. We examine the effects of regional finding regulation on the generation of residual nitrogen and phosphorus from animal and crop production. We also show that stricter but uncoordinated environmental protection in one region may lead to increased environmental damage in the other. The two main reasons for this are: 1) Measures that reduce nutrient residuals, particularly crop choice, exhibit trade-offs between phosphorus and nitrogen residuals; and, 2) The role of nitrogen and phosphorus in generating externalities differs between regions. The crucial difference between manure and chemical fertilizers is that a farmer is only able to choose the overall level of manure application, which determines the applied amounts of both nutrients. With chemical fertilizers, any combination of nitrogen and phosphorus are commercially available. Nutrient requirements of crops vary significantly. Corn needs about 140 pounds of nitrogen and between 20 and 30 pounds of phosphorus per acre finding.

Soybeans, on the other hand,fodder system can utilize atmospheric nitrogen and recommended phosphorus rates vary between 20 and 45 pounds per acre. Also, the concentration of phosphorus and nitrogen in animal manure differ. Dairy manure contains about 1.5 times more nitrogen than phosphorus, while dry hog manure contains roughly equal amounts of both. To avoid the costs of applying both chemical fertilizers and manure,farmers choose the manure quantities on the basis of one nutrient, often nitrogen; while the other, often phosphorus, is applied excessively. Residual nutrients, often coming in the form of runoff, are harmful for ground and surface waters. Protecting groundwater requires controlling nitrogen loading, and mitigating eutrophication requires reducing loading of either or both of the nutrients, depending on the watershed characteristics. Arid regions with little surface water, like California, tend to suffer from groundwater quality problems but face very little eutrophication. Agricultural regions draining into the Chesapeake Bay, on the other hand, may suffer from both problems. Regions located directly on the Bay may be more concerned with phosphorus than nitrogen, depending on the finding effects nutrients have on eutrophication. This discrepancy may cause one region to emphasize controlling nitrogen and another to control phosphorus. Problems can arise if regions share common surface waters, as one region may undertake measures that mitigate problems they experience but aggravate problems experienced by the other. We consider a stylized model of an upstream and a downstream region.The downstream recreational region has no agricultural production but derives benefits from surface water quality. Nutrient residuals in the agricultural region are the only determinants of nutrient loading in both regions. We assume that the agricultural region suffers from elevated nitrate concentrations in its groundwater and nitrogen-driven eutrophication in its rivers. Hence, its regulation focuses on nitrogen. The downstream recreational region is concerned with regulating phosphorus to protect its coastal waters. The decision-making framework for total livestock and crop production relies on basic economic and technical characteristics. While it does not capture the complexities of economic decision-making or the nutrient loading governed by hydrology, it allows for sufficient details needed to obtain qualitative policy conclusions. The objective in our model is profitability of the farms while accounting for the adverse effects of nutrient loading on the downstream region.

We vary the way that profits and nutrient loading are weighed by assigning four alternative decision makers to conduct the optimization: the crop farmer, the livestock farmer, a regional policy maker, and a global finding policy maker. The farmers’ choices and the associated costs and benefits are presented in Table 1. The dark green color in Table 1 stands for revenues and the light green for costs associated with the choice variable given in the left column. Manure nutrients used as substitutes for chemical fertilizers create economic value. The costs are created by hauling and application. The environmental damage is linked to residual nutrients, i.e., the differences in nutrients applied and nutrient uptake. The literature recognizes that under expected profit maximization of the farms, there will typically be some residuals generated. We want to focus on characteristics of residuals when manure is the source of nutrients and policies differ regionally. Therefore, we assume chemical fertilizers create some residual nutrients, but we normalize this to zero. Furthermore, we assume that manure is applied at least according to crops’ agronomic nitrogen needs but, due to the nutrient phosphorus ratio of manure, phosphorus is always applied excessively. Given these guidelines, what do the choices of our decision makers look like? Table 2 considers three alternative situations representative of Midwestern farms. First, both livestock and field crop farmers interact, pursuing profitability without awareness of nutrient loading to ground and surface waters. This prompts policy makers to intervene. The regional policy maker considers only surface and groundwater quality problems in the agricultural region, while the global policy maker additionally considers the eutrophication of surface waters in the recreational region. We assume a cow produces 12 gallons of fresh manure daily, and 126 pounds of plant-available nitrogen and 115 pounds of phosphate phosphorus annually. The crop choice is between corn and double-cropped soybeans after small-grain silage. The agronomic needs for corn and soybeans are 140 and 85 pounds of nitrogen and 25 and 52.5 pounds of phosphorus per acre, respectively finding. The first row in Table 2 presents the choices of the farmers who do not consider nutrient loading. Considering only profits, the livestock farmer ends up having 1000 animals finding, which generate about four million gallons of fresh manure annually. The most profitable crop choice is the double-cropped soybean. In this case, the farmer substitutes chemical fertilization with manure as long as the costs of hauling and application are below or at the costs of buying chemical fertilizers. Regarding this, the farmer ends up applying manure on all her farmland, but does not import anything. The price received from the crop farm does not cover the costs of hauling and applying for farther distances.

The excessive manure application is about two million pounds. The farmers’ overall solution generates residual nitrogen of 72.5 pounds per acre and residual phosphorus of 97.7 pounds per acre. Regional policy standards aim to eliminate nitrogen residues from the upstream region. At the livestock farm level, it leads to a switch to corn, a slight reduction in herd sizes, export of manure to the crop production farm, and reduced profits of the livestock farmer. Since corn consumes less phosphorous than soybeans, transition to corn increases the phosphorous residual. This happens despite the fact that the regional policy maker’s solution utilizes the almost two million pounds of manure that were applied excessively. The global policy maker finding recognizes that rivers carry most of the dissolved phosphorus to the other region, and places more weight on phosphorus loading. She concurs with the regional policy maker’s slight cut on animal numbers but maintains the farmers’ initial choice of crops. She requires farmers to incur high costs from hauling manure to the crop production area,fodder system for sale but allows some excessive application of manure. This creates about 15 pounds per acre of residual nitrogen and about 40 pounds of residual phosphorus per acre. As a summary, the regional policy maker’s intervention always improves surface and groundwater quality in the upstream region, but may simultaneously worsen surface water quality downstream. This follows from reductions in residual nitrogen but potential increases in residual phosphorus, which occur because the agricultural regional decision maker does not account for the phosphorous loading problem in downstream regions and simply focuses on the nitrogen loading problem of the agricultural region. In the United States, nutrient management plans finding are key to mitigating the impacts of excess nutrients from animal waste. Concentrated animal feeding operations finding, i.e., large animal facilities, have to conduct and follow NMPs to balance the application and uptake of nutrients. NMPs follow either nitrogen or phosphorus standards and, in most cases, only apply to farmland controlled by the livestock facility. In accordance with the Clean Water Act, each state has created a list of impaired waters and defined their critical pollutants. A phosphorus standard should be followed if local waters are designated phosphorus-critical and if there are significant risks for phosphorus loading. Otherwise, a nitrogen standard is often followed due to its lower compliance costs. If it is designated as critical for certain downstream waters to be free of phosphorous loading, a regional approach may aggravate downstream pollution. In our example, the regional policy maker’s solution coincided with a nitrogen standard. Our framework could be used to assess manure regulation in California. Here, two relevant pollutants for NMPs and environmental concern would be nitrates and other salts. Choosing techniques that allow nitrogen to evaporate in compliance with a nitrogen standard might aggravate problems of salt sequestration in soils and groundwater.

If these techniques allow farmers to meet regulatory standards while applying more manure per acre, more salts per acre would be applied. This paper raises further questions for economic and empirical analysis. Since NMPs are controlling the manure applications only on livestock farms, will tighter nutrient-use limitations as a result of residual effects induce unwanted and even illegal manure-handling practices? Dairy management plans in the San Jac into watershed report manure as being both imported and exported from the region. They also suggest that illegal dumping is taking place. The challenge is not only to introduce regulation but also to enforce it; and the more costly the regulation, the more incentives there are for noncompliance. Furthermore, there are suggestions that NMPs should be applied not only to livestock farms, but also to all farmland utilizing manure. This, too, might have unintended consequences. Crop farmers’ willingness to accept manure as a substitute for chemical fertilizers depends, for instance, on his/ her perceptions of its nutrient content. If these do not coincide with those set by NMPs, crop farmers’ willingness to substitute manure would decrease. This would force the livestock farmers to either directly subsidize crop farmers’ manure applications or to find manure application areas farther away. Both practices would increase livestock farms’ compliance costs–and strengthen the desire for noncompliance. Finally, introducing policies based on a global perspective may be very beneficial to the United States or the state as a whole, but could have negative impacts in some of the affected regions. An example of this would be seen if the upstream region is forced to take uncompensated actions that improve the downstream region’s water quality. This distributional conflict may lead to the use of political processes to prevent enactment of certain policies. Lobbying by different regional groups could carry major implications for policy formation. Therefore, policy design may require incorporation of compensation mechanisms that will reduce the loss to upstream producers as they modify their actions to improve water quality downstream. The incorporation of political-economic considerations is becoming an important part of environmental policy design, and will have major effects on total societal welfare as well as the welfare of individual groups. Given the size of the Korean economy and the high trade barriers now being erased, the agreement with Korea is considered the most important U.S. trade agreement since the North American Free Trade Agreement finding. Throughout this article, we refer to the Republic of Korea simply as Korea; isolationist and communist North Korea is a separate country for which no free trade agreements could be applicable.

Qualitative interview suggest that sellers often posted prices that reflected strategic price offers, fishing for higher prices, much in the way that one would typically make offers in more traditional, in-person negotiations. In fact, sellers often posted prices that were not only higher than their local market price, but even in excess of what was being paid in hubs or super hubs. As a result, ask prices were on average substantially above bid prices.Buyers’ average bid prices, on the other hand, track hub market prices very well. Figure B.8 plots these values over time for maize, and Figure B.9 provides a box-and-whisker plot of bid and ask prices within each season, in which we can see that the median bid price is typically at or below the 25th percentile of ask prices Nonetheless, about 7,300 tons of grain were successfully transacted, worth about ✩2.3 million USD. 22% of treated traders and 2% of treated households successfully traded on the platform. Figure B.10 shows the cumulative sales over the platform during the duration of the study. We now turn the impacts of the platform. We first explore the effects on market integration and trade flows. Figure 2 presents impacts of the platform on several outcomes: whether any trade is occurring between sub-counties, the number of traders engaged in trade between sub-counties, the volume of trade flowing between sub-counties, and price dispersion between markets. The first three of these outcomes is drawn from our panel survey of traders, in which we asked detailed questions about their trading behavior at the sub-county level finding. The last is drawn from our market-level price surveys and is therefore at the market dyad level. Within these dyads, we analyze the experiment using indicator variables for dyads in which both markets are treated and dyads in which one market is treated,dutch buckets using no-treatment dyads as the control.

Figure 2 presents Fan regressions of each outcome on the distance between the pair, estimated separately for our three treatment groups. Distance is measured as the road distance of the shortest route connecting the two. Before examining treatment effects, we first note some important patterns observed among our control-only pairs. In the upper left panel, we see that while the probability of any trade is high for nearby sub-counties, this diminishes rapidly with distance. The probability of any trade occurring between the sub-counties is close to zero beyond 200km distance. Consistent with this, the number of traders finding and total trade volumes finding also falls quickly with distance.These increasing trade costs with distance lead to notably higher price dispersion between markets located at further distances, as shown in the bottom right panel. What is the effect of introducing a mobile clearinghouse? In Figure 2, we see increases in the probability of any trade occurring, the number of traders engaged in trade between sub-counties, and the volume of trade flowing between sub-counties. We also see a drop in price dispersion.Again, we see increases in the probability of trade occurring finding, increases in the number of traders operating between sub-counties finding; increases in trade volumes finding, and reductions in price dispersion finding.Returning to Figure 2, we also note a striking pattern by distance. Treatment effects are strongly concentrated among nearby markets. In fact, we see almost no treatment effect beyond 200km, the point at which the probability of trade drops close to zero. The one exception to this is price dispersion, which continues to drop in our treated market pairs beyond 200km, albeit at a slower rate. This may be due either to treatment effects on large, long-distance traders not included in our sample as resident in study markets. Alternatively, we may observe transitive convergence finding or to transshipment finding. Table 2 explores this further, estimating Equation 1 separately for market pairs above and below the median distance observed in our sample finding.

We again see that treatment effects for all outcomes are concentrated in nearby sub-counties and markets, with significant increases in the probability of trade occurring finding, significant increases in the number of traders operating between sub-counties, significant increases in trade volumes finding, and significant reductions in price dispersion. In contrast, we see almost no effect of the platform on direct trading outcomes finding for markets that are at above median distance, though the point estimates suggest that price convergence results may persist along a farther distance, albeit at a smaller rate. The platform is therefore quite successful in generating additional short-distance trade. However, it falls to live up to the often-touted promise of such online marketplaces to directly connect remotely-located farmers and markets with urban consumers finding. While perhaps initially surprising, this pattern of large effects over the shortest distances is consistent with Figure 1, which shows that very little of the existing price dispersion at short distances is explained by transport costs. Given the ubiquity of mobile phones even in the control group, it is likely that the very large price gaps necessary to motivate long-distance trade are already arbitraged away, meaning that the more marginal improvements in information revealed by our system typically only exceed the pecuniary of trade over shorter distances.We have already seen in the previous section that the platform encouraged greater intermediary activity in treated sub-counties and markets. Here, we explore in greater detail trader take-up of the platform and effects on their businesses. Table 4 presents trader take-up results. We see that, by the endline survey, 91% of treated traders report having heard of Kudu, while only 32% of control traders have heard of the platform. Therefore, while Kudu was not restricted to be operational only in treated areas, we do see a significant and large difference in awareness of the platform generated by our encouragement design. We also observe a 42 percentage point increase in the likelihood of receiving any price information via SMS finding. However, in terms of knowledge of prices, we do not see a substantial treatment effect. We ask traders to report their best guess of the current market price in their local market, their hub market, and their superhub market, which we then compare the the actual price as measured by our market surveys. We call the absolute value of the gap the “error” in price knowledge. Although traders’ knowledge of nearby local and hub markets is slightly better than their knowledge of superhub prices, we see no differences between treatment and control traders in knowledge for any market type.

This may be because knowledge in our control is already quite high, as demonstrated by the relatively small error size. We do, however, see strong treatment effects in terms of self-reported impacts on negotiations, both with farmers from whom traders buy and with buyers to whom they sell. Treated traders are more likely to report that they are aware of farmers and buyers receiving price information via SMS. They are also more likely to state that this information changed how they negotiated with their trading partner. Finally, in terms of Kudu take-up, 80% of treated traders used Kudu finding, while 22% successfully completed a deal on the platform. In comparison, only 12% of control traders tried Kudu, and only 3% successfully completed a transaction. This appears to come mainly from a reduction in trader markups finding; point estimates suggest a reduction of about 8%, though this effect is measured with imprecision and is not significant finding. Volumes traded appear to increase, perhaps sizably, though again, this point estimate is not significant finding. Columns 4-5 present effects on the price at which traders sell maize, while Columns 6-7 present treatment effects on the price at which traders purchase maize. Similar to results presented in Table 3, we see no significant effects on the level of prices finding. However, looking at heterogeneity by relative deficit and surplus areas finding, we see that in relative deficit areas finding, treatment results in trader sale prices that are significantly lower finding. Conversely, in areas that are relative deficit finding, we observe that treated traders sell at higher prices. We see similar, albeit slightly muted, effects for the trader purchase price in Column 7. We will return later to discuss the relative magnitudes of the sale vs. purchase price treatment effects. Finally, we explore treatment effects based on baseline heterogeneity. Figure 4 presents treatment effects on profits, markups, and trade volumes based on their baseline levels finding. The top panels plot Fan regression estimates of the outcome at endline on baseline levels separately by treatment and control, while the bottom panel presents the difference finding, along with the 90% and 95% confidence intervals. Density in the baseline measure is presented in red. While the negative effects on profits and positive effects on volumes traded appear fairly consistent across their baseline distribution, we do interestingly see that markups are higher among treated traders at the low end of the baseline markup distribution and lower among treated traders at the high end of the baseline markup distribution. These estimates therefore suggest that the introduction of the mobile marketplaces appears to lead to convergence in markups, helping low markup traders and harming high markup traders. This is consistent with the idea that trading in the absence of our intervention is skill- and human capital-intensive,grow bucket in which case those with stronger trading networks and superior information can reliably reap greater profits.

Our intervention, by reducing the cost of information to a symmetric low level appears to have removed a substantial portion of the heterogeneity in trader markups. We have seen thus far that the introduction of a mobile clearinghouse platform induces greater market integration and lowers intermediaries’ profits. These results are often seen as stepping stones along a causal chain ending in the ultimate goal of improving the welfare of smallholder farmers. We turn now to effects of the platform on farmers. First, we explore measures of awareness and take-up of the platform among farmers. Table 6 presents these results. We see that 52% percent of farmers in treated sub-counties have heard of Kudu, compared to only 12% in control sub-counties. Similarly, 55% of treated farmers have received price information via some form of an SMS-based platform, compared to only 16% of control farmers. Next, we explore impacts on price knowledge. We first note that overall price knowledge is lower among farmers than among traders, with error rates that are 42-84% higher than observed among traders. This is consistent with the presence of information asymmetries between farmers and traders. Similar to those of traders, farmers’ error rates grow with distance. In contrast to traders, however, we do find some suggestive evidence that information to farmers improves their knowledge of prices; errors rates are smaller among treated farmers than among control farmers, albeit not quite significantly so finding. 23% of farmers in treated sub-counties report using price information received via SMS when negotiating prices in the past year, compared to only 1% in control sub-counties. Turning to take-up of Kudu itself, we see that 26% of treated farmers have ever used Kudu finding, compared to 2% of control farmers. However, the success rate for study farmers managing to transact on Kudu is relatively low; only 2% of treated farmers completed a transaction on Kudu. Though this rate is significantly higher than the 0% observed in the control group, this low adoption of Kudu is notable, and suggests that farmers either see low benefits or high barriers to adoption of the platform. We will explore determinants of adoption below. Columns 2, 4, 6, and 8 of Table 7 present results. The coefficient on β2 helps to characterize likely adopters. Who is likely to adopt Kudu depends on who faces the largest benefits to adoption, relative to the cost. One might predict that smaller, poorer farmers who currently receive low prices would have the most to gain from access to a new platform on which to sell their crops. However, one could also imagine that the platform would have a hard time finding a buyer for farmers who sell relatively small surpluses, and therefore that it may be the larger, wealthier farmers who are best positioned to use Kudu. Consistent with Allen finding, our evidence suggests the latter interpretation. We see that take up is significantly higher among farmers with higher total revenues and higher prices received, as evidenced by the statistically significant correlation between the propensity score and these outcomes.

Such a pattern of findings is consistent with a story that although the focus of the CG system on tropical and subtropical wheat and maize varieties has limited its impact on China productivity as a whole, it has played a role in increasing technology in poor areas, a chronic weakness of China’s research system.Our results for the TFP equation, presented in Table 4, also generally perform well.The goodness of fit measures range from 0.80 to 0.85, quite high for determinants of TFP equations.In other work, in India for example, the fit of the specification was only 0.17.The signs of most of the coefficients also are as expected and many of the standard errors are relatively low.For example, the coefficients of the weather indices are negative and significant in the TFP equations in the rice, wheat, and maize specifications.Flood and drought events, as expected, push down TFP measures, since they often adversely affect output but not inputs.Perhaps the most robust and important finding of our analysis is that technology has a large and positive influence on TFP.The finding holds over all crops, and all measures of technology.The positive and highly significant coefficients on both measures of the rate of varietal turnover show that as new technology is adopted by farmers it increases TFP.Following from this, the positive contributions of China’s research system and the presence of CG material both imply that domestic investments in agricultural R & D and ties with the international agricultural research system have contributed to a healthy agricultural sector.Further analysis is conducted to attempt overcome one possible shortcoming of using VT as a measure of technological change.As varieties age, the yield potential may deteriorate.We add a variable measuring the average age of the varieties to isolate the age effect from the new technology effect.Although we find no apparent negative age impact on TFP in any of the equations,hydroponic nft channel in a number of the regressions, the coefficient ofVT variable in the TFP equation actually rises, a finding that reinforces the basic message of the importance of technology.The role of extension is less simple.

The impact of extension can occur through its effect on spreading new seed technologies and through its provision of other services enhancing farmer productivity.The positive and significant coefficients on the extension variable in all of the VT technology equations for all crops demonstrate the importance of extension in facilitating farmer adoption.Extension, however, plays less of an independent role in increasing the yield potential of varieties that have been adopted by farmers, perhaps an unsurprising result given the reforms that have shifted the extension from an advisory body to one that is supporting itself, often through the sale of seed.In recent years, both growers and consumers have become increasingly interested in direct marketing as an alternative to conventional marketing outlets.Further, as more consumers develop an appreciation for fresh food produced close to home, they’re turning to farmers markets and other direct markets that offer not only locally grown food, but a connection with those who grow it.In the search for alternatives to the current food system, Community Supported Agriculture offers an increasingly popular option.In the CSA arrangement, consumers get much of their weekly produce by picking up a box of organic, fresh-picked fruits and vegetables grown on a farm in their community.A farmer commits to growing food for a group of people , and the people support the farmer by paying for their shares of produce ahead of time, often at the beginning of the season.CSA members thus ideally share both the risks and the bounty of farming.Although community supported agriculture farms have only been operating in the U.S.since the mid 1980s, there are now between 800 and 1,000 CSAs in the United States.As CSAs have proliferated in this country and elsewhere, CSA and sustainable agriculture advocates have professed a number of hopes and dreams for this approach to farming and marketing.Many see CSA as a vehicle for increasing small farm viability and for encouraging the use of ecologically sound farming practices.CSAs have also been promoted as a way to connect people to their food and each other by building personal relationships between farmers and consumers, as well as by educating people about the food system and its issues.

In 2001, the social issues staff of the Center for Agroecology and Sustainable Food Systems at UC Santa Cruz initiated a study of California central coast CSAs, Research Brief #1 covering Monterey, San Benito, San Mateo, Santa Clara, and Santa Cruz Counties.This research aims to: 1) describe how the CSA model has been implemented on the central coast, 2) determine the extent to which CSAs on California’s central coast are manifesting the hopes that people hold for them, and 3) identify constraints and opportunities to reaching these ideals.The project was designed to contribute to the small number of studies focusing on CSAs in California, and to provide information to people interested in understanding, supporting, or furthering CSAs.This research brief focuses on one aspect of the CSA study: the profiles and experiences of CSA members.Member attitudes, experiences and perceptions are summarized, and then used to explore the extent to which CSAs are meeting the ideals that many hold for them and to identify some opportunities and challenges that they face in meeting these goals.The survey asked members to write in their most important reasons for joining the CSA.As shown in table 1, the most frequently reported “important reasons” members expressed were to purchase organic3 , fresh produce.The members also wanted to buy local produce or support “local”.When focus group members were asked why they wanted to “support local,” several themes were mentioned.Some people felt that local farms benefit the community in some way, such as by adding jobs, green space, and diversity.Other reasons mentioned include that local farms allow for connection—to the farmers, other people, the land, or farming itself.Finally, others think that supporting local is more ecological, in that less resources are used shipping the food to distant outlets, and having a farm nearby allows people to make sure their farmer is actually using ecological farming methods.Considering that several of the primary reasons given for becoming a CSA member could also be met by going to the farmers market, focus group members were asked what they receive by participating in a CSA rather than by shopping at a farmers market.Although not everyone participated in a CSA to the exclusion of farmers markets, there were still themes regarding their preference.Convenience was frequently mentioned by focus group members—that CSA is less work than going to the farmers market.Some preferred CSA because it allowed them direct contact to a farm, which, as one member said, is “…much different than going to a farmers market and just seeing the produce on the table—you see…the whole process.” Others mentioned that it helped support eating habits that they wanted to have.These responses show some of the unique aspects of CSA, and offer insights for promoting this new aspect of the food system.One goal of this study was to see how people’s habits around shopping and cooking changed as a result of joining a CSA.We assumed that CSA membership would create another task for people; in addition to picking up their weekly share, they would still have to go to the store for food that the CSA did not supply as well as process the food.

Interestingly, we found that half of the respondents’ households reported that they spent less time obtaining food after becoming members than they did before joining.Based on our conversations with CSA members, it is possible that they actually spend more time, but that it ‘feels’ like less.On the other hand, most people reported that they spent more time preparing food than they did before, since CSA produce is usually minimally processed.Participating in a CSA appears to decrease the amount of time spent on some food-related household tasks while increasing the time spent on others.Changes in eating habits was another area we explored.Survey results show that 81% said that they had some type of eating habit change; 79% of the 221 noted that they eat more vegetables or eat a greater variety of vegetables.This finding is encouraging since eating more fruits and vegetables, including a wider variety, has been suggested as a sound way to address and prevent health problems.The next most frequently cited eating habit changes are behaviors related to better health.Shareholders noted that they are eating healthier , eating at home more and out less,nft growing system and eating better quality food.Focus group participants partially explained this phenomena.The CSA structure helped to support these types of eating habits: for example, some people felt compelled to eat the produce that they had already paid for, and others just couldn’t stand throwing vegetables away.We also wanted to identify what people learned from their experiences with the CSA farm, and how their lives changed.We asked members if there have been any other changes in their own or their household’s life since participating in CSAs.The most frequent responses were that people cook differently.This includes people who say they now plan their meals around the vegetables, cook more creatively, enjoy cooking more, and use different recipes/try new things.As one woman said, “I usually plan a week’s menu in advance of going shopping.With CSA I planned the menu around the CSA produce, e.g., ate more stuffed chard and cabbage, fruit desserts, etc.” Some members also noted that they now have a connection with the farm or the farmers , that they are more aware of agricultural or environmental issues , and that they are more active regarding agricultural issues.These effects—learning more about the food system, and doing something to improve it—are changes that some CSA advocates hope will take place as a result of CSA membership.Although the numbers are low, CSA participation does appear to lead to an increased awareness of food system and environmental issues.In addition to exploring why members may leave, we also looked at factors that are related to returning to the CSA.

Respondents appeared more likely to re-join when they were satisfied with the quality, quantity, and product mix of the produce; when picking up the box was convenient; and when people felt the share price was fair.Also, members were more likely to return the next year if the payment schedule did not pose a financial hardship, and they were not throwing away or composting more produce than before they joined the CSA.One interesting finding is that those who said they or their household experienced a change as a result of participating in a CSA were also more likely to rejoin.For example, 82% of households that experienced a change in eating habits would sign on again, whereas 65% of those without such a change were not likely to rejoin.It appears that learning to incorporate or adapt to the new way of eating and cooking helps increase the likelihood of staying with the CSA, as well as encouraging desirable/valuable lifestyle changes.The CSA member survey and focus group findings reveal both positive results and future challenges for those running CSAs or growers who are considering starting a CSA.On the positive side, CSA farms have succeeded in producing high quality produce, have helped people develop healthier eating habits, appear to have addressed some ecological issues , and have connected some people back to their food source.Conversely, the data point to several challenges, particularly regarding long-term CSA viability.Addressing the issue of choice appears to be a persistent dilemma.Most people leave the CSA due to lack of choice, yet the idea of “receiving what is available when it is available” is an integral part of the CSA concept.Therefore, turnover is likely to always be an issue, and thus finding new members will continually be required.Some people look at the small number of members currently participating in CSA and see a huge untapped market.However, there are also several indicators that point to obstacles to CSA growth.The limited demographics of people participating, the availability of organic food from other sources , a culture based on convenience and choice, and having to spend more time preparing food and eating what is seasonally available could limit the number of potential members available for both current and future CSAs.Ultimately, it appears that while CSA is not a quick answer to problems in the food system, it definitely offers a needed alternative.Providing fresh, local, and organically grown produce; a connection to where food is grown; and education about agricultural and environmental issues are important and necessary services for those seeking options in today’s food system.

Our knowledge about the past is fragmentary for a number of reasons, and there are many challenges facing our approach.Many of these are by no means unique to the study of agricultural systems, and relate to the nature of the historical and archaeological records.Firstly, we must deal only with the limited material remains of past societies , or the marks they left on the world around them.Features of behavior and practice are not preserved directly but instead have to be inferred from what does remain.Secondly, some regions and time periods are better-studied than others, and this reflects a number of factors, including ecological conditions, that make some regions easier to excavate than others, the personal interests or theoretical persuasions of researchers, and broader social and historical factors that shape which countries and institutions have the money to conduct such research.In other words, there are certain biases in our records of the past of which we need to be aware when attempting to draw broader inferences.One potential source of error comes from the fact that although our units of analysis are the NGAs and the societies that have inhabited them in the past, we often only have information from a small number of archaeological sites or a limited set of historical records.For example, our inferences about the early stages of agriculture in the Kachi Plain, discussed above, are extrapolated from the single site of Mehrgarh.A potential risk here is that this site may not be representative of what was going on in the wider NGA.On a practical point, there is not much that can be done here except to recognize that we must work with whatever information we have, be aware of the potential limitations and sources of error, and be ready and willing to update our understanding as and when new information is discovered.Our general strategy is to make as clear as possible the assumptions involved in defining and coding these variables,ebb and flow trays and in how they will get incorporated into further inferences about the productivity of past agricultural systems.

One way to make sure we are using the best available data and are aware of its limitations is by engaging fully with academic historians and archaeologists who are experts on our focal regions and time periods.Such experts enter into the process in a number of ways.Firstly, they help us navigate what is known already, identifying the most relevant literature, aiding in the design of the codebooks, and advising on what information is or is not feasible to obtain.Secondly, they verify that the information being collected is based on the most up-to-date knowledge and scholarship.Finally, as we move forward and begin analyzing these data statistically, experts will also be able to provide important background information and context that can help in the interpretation of the results.It should be noted that researchers can sometimes come to different conclusions about how historical and archaeological records should be interpreted.In other words, there is often conflicting evidence, or a lack of consensus about what the data are telling us.We try to avoid imposing any kind of typological scheme or monolithic theoretical perspective on the data, and the coding framework allows us to indicate where there are disagreements.Another practical step we have taken in dealing with how to interpret the information that is present in the archaeological and historical records is to try and make the coding process as objective as possible.This is done by focusing on presence/absence-type features, which are often much easier to code with certainty, and almost by definition are more consistent across different situations than quantitative estimates or judgments.We have found it often helps to break things down into component parts that can be more readily coded in a presence/absence manner, particularly for societies known only archaeologically.For example, rather than simply asking whether irrigation was practiced or not, we can ask if certain features related to irrigation systems were present or not.In our experience, certain features, such as the presence or absence of metal tools or food storage facilities have proven relatively straightforward to code.

Other variables have proven more challenging because, due to their annual or cyclical nature, many agricultural practices can be quite hard to discern archaeologically.A solution to this is to have very specific criteria about justifying the presence of such techniques.For example, for crop rotation, a sensible justification could be that within a particular site, a spectrum of crops were grown that is compatible with the rotation of crops.The point here is not that these justifications are without error, or cannot be challenged, but rather, that the reason given should be made clear.Attempting to code data systematically across different regions highlights that, for many variables of interest, there will be many cases in which not much, if anything, is known.Because this project is primarily interested in the broad patterns and processes of human history, the issue of missing data or scholarly disagreement perhaps matters less than if we are trying to find the particular details of a given time or place.In other words, as long as we have information on enough variables and enough regions then major trends should still be discernible.On a practical level, we are able to incorporate such sources of uncertainty into any statistical analyses that we perform, and we can explore whether making different assumptions about the data affects our overall results and conclusions.Although sometimes frustrating from an analytical perspective, highlighting where there are gaps in our understanding also serves a useful purpose in the wider sense in that it highlights those areas where future research efforts can be productively targeted.Having outlined out the general factors that will be important in assessing potential productivity in past societies, in this section, we sketch out how we are combining earth system science approaches with historical and geographical information to create a model of carrying capacity in past societies.Our general approach is to take estimates of productivity based on the output of simulations of modern crop growth and then modify these estimates based on the kind of historical information discussed above.

A variety of process-based models have been developed to simulate crop growth and productivity using detailed physical and biological processes.The details of the inputs required by these models can vary greatly depending on the question being addressed and the scale at which a simulation is being applied.For this project, we are making use of the LPJmL global crop model of , which simulates the productivity of a limited number of broad crop functional types through an explicit model of crop growth and development based on the features of such plants, their ecophysiology, and the management techniques applied to them.The model uses inputs relating to climate and weather in order to assess productivity under a variety of scenarios.One of the advantages of LPJmL for our purposes is that it is constructed at a suitable level of abstraction, with a limited number of inputs, which is suitable for projecting back into the past.A downside of simulations is that they are often time consuming to run and require specialist expertise to develop.To overcome this constraint, emulators have been developed that are computationally fast, statistical representations of process-based models.6 In previous work, developed an emulator of the LPJmL model.It generates a spatial map of maize, rice, cereal, or oil crop yields at approximately 50 km resolution.The crop emulator allows for variable management levels, allowing us to capture the effects of developing agricultural technologies.The emulation framework takes a matter of minutes to derive a global map of crop yield for a specified climate input and crop management level.This speed compares to several days of computing that would be required if we were using its underlying simulators.We are, therefore, using this emulator approach for reasons of tractability, flexibility, and to facilitate the analysis of modelling uncertainties.To date, LPJmL has been used primarily to simulate current and future conditions.However, the emulation approach allows us to take the modelled associations between climate and crop productivity and project these back into the past using information about past climate.For this project, we have developed a crop-modelling framework that uses emulation of a crop simulator and a paleo climate simulator.This paleo climate emulator generates spatially and seasonally resolved fields of temperature, precipitation,4×8 flood tray and cloud cover as functions of the Earth’s orbital configuration.

The climate data is then passed to an emulator of the LPJmL crop model.As with the original emulator, the outputs of this crop emulator are spatial maps of crop yields, but this time, those maps are derived from the estimated climate at defined periods in the past.To make the outputs more relevant to past societies, the suite of crops being considered will be extended beyond the maize, rice, cereal, or oil crops of the original emulator to take into account additional important classes of crops, such as tropical cereals and tropical roots.The simulator and the emulator also estimate productivity under rain-fed and irrigated conditions, which can help inform our historical estimates of productivity based on knowledge about the presence of irrigation techniques in the past.With these estimates of productivity in hand, we can set about adjusting them based on the historical data on past agricultural systems described above.The basic idea is that within a Geographical Information System framework, we can take the initial coverage maps supplied as output from the emulator and apply a formula that shifts the estimated yields up or down depending on the particular crops, agricultural techniques and practices, and other relevant factors at different points in time and in different regions.As a first step in adjusting the emulator output, our data can tell us when agriculture began being practiced in different regions and which crops are most important to assess for different regions.Adjustments will have to be made based on the human-induced biological improvements that crop varieties have undergone.For example, was able to estimate the improvement in maize yields that occurred over time in Oaxaca, Mexico, based on the increase in the length of ears of corn evident in the archaeological record.Furthermore, information about variables, such as the size of fields and whether land is farmed permanently or more sporadically , will affect the amount of land that could be devoted to food production and, therefore, the carrying capacity under that system.The effects of other variables can also be assessed with reference to the literature about the degree to which techniques such as fertilizing, mulching, or crop rotation affect crop productivities.This process can be conducted at several scales.Firstly, because the historical data relate directly to particular NGAs, we can make adjustments at this level to estimate productivity and carrying capacity at the NGA level.

However, because our NGAs are well-sampled geographically, we can use this information in conjunction with other sources to make reasonable extrapolations out from these points to assess potential productivity on regional and global scales.The relative efficiency of private and state-owned enterprises has been a subject of interest throughout recent history, and has gained attention in recent decades following a wave of privatizations that began with the Thatcher government in the UK in the 1980s, and escalated after the collapse of the Soviet Union.While theoretical literature in the last 3 decades has been nearly unequivocal in favoring the productive efficiency of private firms, results in the empirical literature have been less conclusive.Boardman and Vining survey 54 studies that examine the effects of ownership on performance, and find that 32 of them conclude that private firms outperform state-owned firms, and 22 of them are either inconclusive, or find that public firms outperform private firms.More recently, Megginson and Netter find greater evidence that the empirical literature favors the efficiency of private firms, but cite important exceptions.In addition, measures of efficiency vary greatly between studies, and may have important implications to findings.In this paper, I explore whether the variation in findings on the effect of firm ownership on productive efficiency can be partially explained by differences in the level of industry competition faced in each setting.In addition, I identify the elements of “competitiveness”that theoretically matter in determining efficiency differences between state-owned and private firms, to shed light on what elements seem to matter most, and how strongly these elements are tied to standard measures of competitiveness.

For a landowner, the decision to sell or donate an agricultural conservation easement is a momentous one that is not made lightly or quickly. Negotiated voluntarily with a nonprofit or public land-trust agency, conservation easements restrict the use of a particular parcel; the landowner can continue farming after the easement is purchased, but the land can never be subdivided or developed. Land in easements can be bought or sold, but the restrictions remain in perpetuity. The decision to sell, then, depends on the landowner’s willingness to forego the profitable option of selling the land for urban development in return for more modest economic gains and other benefits. While cash or tax advantages provide immediate benefits to the present landowner, future generations and owners carry the costs in terms of restrictions and limited opportunities.Based on extensive interviews with 46 owners of easement-restricted farms in three counties , we have examined landowner motivations for selling easements and their experiences with local programs that acquired the easements . The landowners in most cases were enthusiastic sellers of the easements. Their main motivations were cash, family ownership and conservation, and they reported generally satisfactory experiences with the easement programs. To a lesser degree they expressed concerns about certain aspects of the process, especially negotiations and monitoring, and suggested ways that easement programs can improve their relationships with landowners. Most of the landowners interviewed are located in two North Bay counties, the region that contains most of California’s farmland easement acres and easement programs. Given the unique conservation, landscape and agricultural characteristics of this region, it’s not yet clear what the prospects are for easement programs statewide and in the agriculturally rich Central Valley,flood table where they are much less well-established .The landowners who participated in this study are involved in three of the most active agricultural easement programs in California.

The programs are countywide in scope. The Marin Agricultural Land Trust and Yolo Land Trust are private, nonprofit organizations, chartered under state law to engage in conservation activities. The Sonoma County Agricultural Preservation and Open Space District is a public district formed by a county ballot initiative in 1990 and operated by a county government agency. Their easements total more than 53,000 acres, nearly half of all agricultural easement acres in California. Both the Marin and Sonoma county programs are among the six largest local agricultural easement programs in the nation . We surveyed 46 landowners in the Sonoma, Marin and Yolo county programs by phone and in person from February to August 1999, using a standardized interview guide. The interviews ranged from 15 minutes to 1 hour and were taped and later transcribed for analysis. Interview topics included questions about motivations, negotiations with land trusts, perceptions about program success and other experiences related to their conservation easement. The 46 landowners represented 44% of the total of 105 landowners participating in the three programs. Thirty-seven had sold such easements in recent years; the other nine owners had recently purchased parcels with easements already in place . Their parcels represented a majority of the total 53,000 easement acres held by the three programs at that time. The average parcel size was 530 acres.The survey revealed some common threads about why landowners made the decision to sell development rights . While the 37 original sellers of easements gave seven discrete reasons, there were obvious similarities and overlaps. Combined, three major motivations surfaced: to preserve land for farming and/ or open space ; to provide cash for savings and retirement, for farm improvements or to reduce debt ; and to serve family needs such as estate settlements and generational transfers.Most respondents cited a combination of at least two of these motivations. Certainly cash was a powerful incentive, since giving up development rights typically meant that the landowners received at least several hundred thousand dollars per transaction and more than a million dollars in a few cases.

But in many cases the cash was valued mainly as a vehicle for accomplishing one or another of the other objectives. Personal attachment to a parcel was another widely held sentiment, with many respondents noting a long history of family ownership and the importance of their farms as home sites. Several landowners spoke about the need to facilitate an intergenerational transfer. The immediate goal for some was to overcome a fragmented family ownership that made continued farming uncertain. The cash from the easementsale could help the younger family members purchase the parcel from the older generation or prepare for the transition by paying down existing farm debt or improving the farm operation. In one situation, the farm operator used the proceeds from the easement sale to secure full control of the land by buying out the ownership shares of his siblings. Surprisingly, the permanence of a deed restriction — the issue of keeping the land in agriculture in perpetuity, essentially forever — did not discourage landowners from selling easements. However, this sample includes only participating landowners and not those who might have chosen not to sell because of this restriction. Only five respondents expressed some discomfort with the permanent nature of their easement. In fact, for the majority of landowners, perpetuity was considered an advantage because their goal was to pass the land on, undeveloped, to future generations. One respondent did argue for less-than-permanent easements because he felt they were more compatible with the economic fluctuations in agriculture. For most of the nine landowners in the three counties who purchased their properties after the development rights had been removed, having an easement in place was considered an advantage. The principal reason, they said, is that it made the purchase more affordable. By eliminating the possibility of development, an easement in effect reduces the market value from a speculative to a farm production level.Discussions between the landowner and the conservation organization usually focus on two areas: the price, and changes in the use and character of the covered parcel that the easement will allow. One area of landowner concern was the time it took in some cases to negotiate and complete a transaction. Various factors can complicate and lengthen the process: disagreements over price that require more than one appraisal, landowner consultations with attorneys or consultants, or delays until the land trust receives the funds to close the deal. One landowner in Yolo County, who purchased a parcel after the easement was in place, had no idea that he wouldn’t be able to build a home because of specific restrictions named in the deed. Landowners suggested that programs should seek ways to clarify and expedite easement negotiations and terms.

They felt that if programs provided complete information upfront, and made sure purchasers understood the easement terms including the conditions of monitoring and use restrictions, misunderstandings and negative feelings would be reduced. The most frequent sticking point seemed to be the construction of additional residences or farm outbuildings. Landowners wanted the flexibility to house family members or farm workers. Several landowners expressed the opinion, when asked if they would participate again, that they would revise their easement deeds to provide more flexibility for family housing. This included the location, size and number of buildings allowed. While the conservation organization generally tries to tailor these terms as closely as possible to the expressed needs of individual landowners, we found that some organizations were more lenient than others in defining the parameters of an easement.Contact between the landowner and the conservation organization does not end at completion of the easement transaction. The easement terms require that the relationship continue indefinitely to ensure that landowners adhere to the restrictions that have been placed on the property. Program staff or volunteers periodically monitor the uses and conditions of the property, typically through annual site checks and other forms of data collection. Monitoring of easements was controversial among some of those we interviewed. Of the 33 respondents who commented on the subject, 14 reported negative experiences or perceptions of the process. Landowners do not like intrusions on their property regardless of whether they agreed to them on paper. Landowners suggested that programs monitor easement-restricted parcels as a cooperative rather than adversarial process. They suggested that the personnel responsible should be sensitive to local circumstances,rolling benches be knowledgeable about local agricultural practices and provide more practical assistance with improving land management practices.Easements are unquestionably a flexible tool for advancing the individual, family and business goals of farmland owners, as suggested by the owners who sold easements in three California counties. They liked the economic and conservation benefits of the transactions, and were largely positive about the negotiations and other experiences with conservation agencies. Nonetheless, while the easement programs seemed to work for farmers in the northern Bay Area counties and Yolo County, it’s not clear that they will appeal to landowners in other parts of the state and, in particular, the agriculturally rich Central Valley. This region differs from the three counties we surveyed in having a greater diversity of agricultural crops, no coastal zones to justify the protection of farmland as open space, less apparent community support for land preservation programs and perhaps a more conservative agricultural community.We captured a snapshot of vineyard worker satisfaction in 2018; some employers had already adopted strategies to improve job satisfaction and some had not, which may account for some of the variability in the levels of satisfaction among workers.

Future studies may seek to evaluate which strategies are most effective by assessing changes in worker perceptions before and after the introduction of new practices, using tools such as the AJSS.In addition to reducing turnover, improving job satisfaction can also increase work performance and worker health outcomes.Therefore, the satisfaction categories that did not predict turnover should not be dismissed, as dissatisfaction in these areas can contribute to other negative consequences.The AJSS tool overall proved reliable, but it contains four categories with low reliability that require further adjustment and retesting in future studies.In the long term, we are confident that adoption of this tool by the industry could support improvements in productivity, worker health and happiness, and promote the sustainability of the agricultural workforce.Prior to European contact, the Hawaiian Archipelago supported a diversity of highly intensive agricultural systems—in keeping with the high degree of social and cultural complexity of Hawaiian society , and the exceptional environmental heterogeneity of the islands.The most widespread of these agricultural systems have been separated into two major classes—irrigated pond fields in which taro was the major crop, and rainfed uplands based on sweet potato , dryland taro, and yams.Pond Fields were established earlier in Hawaiian history; there is clear evidence for their existence by AD 1200 , and organized systems of pond fields were developed by AD 1400.In contrast, rainfed systems largely developed after AD 1400, and show evidence for increased intensification after AD 1650.These two classes of agro-ecosystems have profoundly different environmental requirements, and they were distributed unevenly across the archipelago at the time of European contact.Pond Fields depend upon reliable sources of irrigation water and gentle slopes; they were developed extensively in well-watered alluvial and colluvial soils.Streams develop and the cumulative effects of erosion and sediment deposition increase with increasing rainfall and substrate age across the Hawaiian archipelago—and consequently pond fields largely were restricted to older northwestern islands, and to the oldest and wettest portions of the younger southeastern islands.In contrast, intensive rainfed systems require at least moderate rainfall and relatively fertile soils.Soil fertility on stable geomorphic surfaces decreases with increasing rainfall and substrate age ; hence, rainfed systems developed primarily in leeward portions of the younger Hawaiian Islands, in environments very different from irrigated pond fields.The spatial and environmental separation between these two modes of intensive agricultural production could have played a substantial role in the dynamics and interactions of Hawaiian societies occupying the younger versus older islands in the archipelago.Despite the opposing nature of the conditions favoring irrigated and intensive rainfed systems, examples of what appear to be integrated systems including both the modes have been reported in valleys on older islands in the archipelago, with irrigated pond fields in valley bottoms and dryland agricultural features on lower slopes just above them.

They documented Old World cultigens, including wheat , barley , and peach , in a hearth associated with an usnu, or ceremonial platform, and suggest that those items were incorporated into changing ritual practices of the Hispanic-Indigenous period, although those foods were not recovered in other domestic contexts. Throughout the period of Spanish conquest, a common cultural exchange that occurred between Europeans and Indigenous peoples involved food, especially cultigens. Jamieson and Sayre’s recovery of barley and quinoa from eighteenth century artisan households from a marginal neighborhood in Riobamba in highland Ecuador suggests that lower-class households consumed both Old World and New World domesticates. They argue that indigenous highlanders may have readily adopted barley, an Old World cultigen, as the grain would have fit well into existing food-processing systems and grain-based cuisine that included quinoa . While the impact of European contact on native subsistence systems has been a prominent theme in historic archaeology in North America , historic archaeology in the Andes has been more limited . Aside from ritual offerings themselves, paleoethnobotanists have examined the settings in which ritual events took place—namely, feasting, including memorial feasting as well as feasting that was more explicitly tied to the political economy . Many scholars have emphasized the political and economic roles of prominent types of ritual negotiation—feasts—in creating and reinforcing power and status differences. However, scholars are now questioning the simple association between the emergence of social hierarchies and food production linked to status competition occurring in the context of feasting. Rather than having a causal role in the emergence of social hierarchies,led grow lights changes in plant food cultivation likely were embedded in the changing social relations that eventually led to the development of those hierarchies.

Across the world and through time, while many groups certainly engaged in hierarchical negotiations involving food ways to emphasize power or status differences, others likely participated in commensal events that reinforced shared group identities and traditions . Neither scenario is mutually exclusive; attempts at increasing solidarity within communities and emphasizing differences among its members through commensal activities likely happened simultaneously in the formation of early complex societies, including early Andean polities. Some recent scholarship in the Andes has moved away from ideas of food production as an economic foundation for accumulation on the part of leaders,and instead favors views of community events and the ritual significance of food in the formation of sociopolitical inequalities. At the site of Buena Vista in the Chillón Valley of central Peru, Duncan et al. discuss macro and micro-botanical remains from the Fox Temple, a special purpose ritual feature that dates to ca. 2200 B.C. In addition to a diverse suite of macrobotanical remains, gourd and squash artifacts yielded starch grains of manioc , potato , chili pepper , arrowroot , and mesquite, or algarrobo . The authors argue that these remains likely represent refuse from small feasting events. In the Preceramic period , multiple small-scale construction events appear to have been preceded by feasting rituals hosted by informal leaders who lacked the social power to organize large amounts of labor for more massive building events. Drawing on work by Vega-Centeno,they argue that the limited and weakly formalized leadership of this time needed to be constantly reinforced through ritual practices or events. For the Tiwanaku polity of western Bolivia and southern Peru, Goldstein argues that there were no specialized chicha brewing facilities , and that the distribution of keros, the emblematic Tiwanaku serving vessel, indicates that feasting was organized at an ayllu-like level and not at the grandiose large scale of Inka state feasting. In this view, chicha consumption, including amongst Tiwanaku colonies, contributed to the development of community cohesion and a panregional identity across areas that had previous lacked unifying features, including the Atacama region, the Azapa Valley, Cochabamba, and Moquegua.

In all of these areas, ceramic assemblages for making and consuming chicha are associated with Tiwanaku expansion and came to predominate over open-mouth pots more suited for the preparation of stews. The adoption of chicha at the household level, using Tiwanaku drinking vessels and designs, signals the depth of Tiwanaku influence as it affected commoners’ daily practices instead of being restricted to feasting or elite contexts . Recent research also questions assumptions about the role of maize as an important element of ritual practice within emerging political institutions. Microbotanical analyses by Zarillo et al. suggest that maize was initially used as ritual beverage, rather than a quickly-intensified staple, at the Early Formative/Valdivia period Real Alto site on the Santa Elena Peninsula of coastal Ecuador as early as 3350 B.C. They argue that subsistence change was slow and gradual, rejecting the idea that political competition framed early food production. Recent macro and microbotanical analyses of early maize remains from Paredones and Huaca Prieta, Peru by Grobman and colleagues also lend support to the argument that maize was not a staple food in the Preceramic period . These new findings are significant in that they cast doubt on previous scenarios that consider food production to always be orchestrated by politically savvy elites—rather, political consolidations and social inequalities may have emerged from rituals practiced within traditionally accepted parameters that eventually reached exaggerated scales. Moving beyond the emergence of social hierarchies, other studies continue to draw more explicitly on political economy approaches for understanding changes in plant foodways and social differentiation. Archaeologists typically have examined political economies in terms of class relations, surplus production, and the financing of political institutions. Some Andean models of political economy posit that inequalities resulted as differential control of canals and irrigated land was exploited by elites as a means to co-opt the labor of others, generating agricultural surpluses to achieve power and participate in exchange networks with other communities and ethnic groups ; however, these assumptions largely remain untested with direct subsistence data.

One of the most important contributions of paleoethnobotanical data to understanding shifts in political economy in the Andes is Hastorf’s classic case of how the Inka interfered with the local political economy of the Sausa people of the Upper Mantaro River Valley of central Peru. Hastorf’s analysis of plant data from Sausa house floors dating both prior and subsequent to Inka control revealed a shift in plant diet for local elites and non-elites. Prior to Inka domination, elite and non-elite status was clearly marked in plant foodways; the shift to imperial control, however, led to a leveling of local status differences. Hastorf and colleagues extend their analysis to wood use as well, noting a change in wood use that indicates restriction in access, tending, or trade of fuel resources by the local indigenous inhabitants under Inka rule. Goldstein et al. discuss labor extraction in relation to molle chicha production at the Wari site of Cerro Baul in Moquegua . They argue that outside of Wari elite contexts, the local population was not engaged in producing chicha for their own consumption, but that chicha primarily played a role in organizing and legitimizing elite activities, perhaps including the extraction of labor from nonelite households. Their examination of molle remains departs from the traditional emphasis on maize chicha that has dominated the Andean literature for decades note, “paleoethnobotanists excel at diachronic analyses of plant data, synchronic comparisons of different sites/regions, and the use of diverse quantitative techniques, from basic standardizing measures to complex multivariate statistics.” It is still the rare study, however, that examines variability in plant remains from different contexts within a single site , although such an approach has the potential to inform about the organization of food preparation, processing, storage, and disposal, as well as issues of site formation and feature function. Hastorf’s study of Inka conquest, food ways, and gender represents a seminal case of the spatial distribution of plant remains and gender, and is also a key paper that pushed paleoethnobotany toward social archaeology in the first place—drawing on such approaches has good potential for evaluating the organization of Moche Valley society. Understandings of domestic labor,vertical grow system including food preparation and consumption, can shed light on elements of social reproduction and inequalities in daily life that are often downplayed in large-scale, structural histories . By studying the material remains of food ways, this dissertation contributes to further understandings of the diverse social strategies enacted by both highland and coastal groups that profoundly influenced ancient sociopolitical development along the Peruvian north coast. A drought-resistant plant,Trujillo coca probably originated from the adaptation of Huánuco coca to drier habitats.The best growing conditions include hill-slope planting in friable soil, good drainage, and ample shade; coca plants can be harvested 18 months from the time of planting.

A mild stimulant and analgesic, coca is used to combat altitude sickness; assuage fatigue; stave off hunger and thirst; and relieve headaches, stomach aches, and joint pain. Dried coca leaves are chewed , or are steeped in water to make a tea. Coca tea is consumed commonly in the Andean highlands today as a means to prevent altitude sickness, but coca leaves are chewed broadly in coastal and middle valley communities, particularly by day laborers. While prehistoric remains of coca are rarely uncovered by archaeologists or positively identified by paleoethnobotanists because of their fragile nature , Dillehay et al. provide evidence for coca chewing as early as 6050 B.C. in the Nanchoc Valley, Peru, and tie its use to emerging specialists who extracted and supplied calcite and lime to communities for coca chewing during the transition from mobile hunting and gathering to sedentary farming.Indeed, fully domesticated common beans were recovered from deposits in Guitarrero Cave in the Callejón de Huaylas, Ancash, Peru, dated to 6050 B.C. .Common beans were domesticated independently in Mexico as well as the Andes;Andean beans have larger seeds, but Mexican cultivars are better suited to hotter climates.According to Hastorf , beans were the most common crop in coastal Preceramic sites from 6000 to 4200 B.C., eventually becoming widespread throughout the coastal region by the Initial Period . On the Peruvian north coast, beans have been recovered from the earliest levels at the Preceramic component of Huaca Prieta in the Chicama Valley and from the Initial Period site of Gramalote in the Moche Valley . Because beans are highly susceptible to taphonomic processes and consumed in their entirety, the archaeological presence of beans is actually quite remarkable. Common beans are also prominent in the Moche artistic canon . High in protein, common beans are well known comestibles, frequently added to soups and stews, but also have documented medicinal uses, as a diuretic, as an analgesic, to dissolve tumors, and to stabilize menstruation. After beans are harvested, stalks can be used as fodder. Beans tolerate most environmental conditions in tropical and temperate zones, and germinate rapidly at soil temperatures above 18°C. Seed rates are 20–115 kg/ha depending on seed size and row width . Beans are frequently cultivated with maize for their nitrogen-fixing properties; indeed, in Latin America today, ca. 70 percent of beans are inter planted with maize in commercial fields . With maize, beans are usually planted 5–8 cm deep, deep enough to give good coverage and sufficient moisture to promote fast germination and growth. Intercropping Phaseolus beans with maize provides benefits to both plants . VanDerwarker notes that in addition to enriching the growth and yield of maize plants, Phaseolus beans complement maize in terms of nutritional value; maize is deficient in essential amino acids lysine and isoleucine, which beans have in abundance. As a result, eating beans with maize together would have provided benefits as well as cropping beans and maize together. Lima bean/pallaris another Phaseolus species broadly cultivated in the coast and highlands, with a great antiquity of domestication . Like the common bean, there were two independent centers of domestication of lima bean, with smaller varieties domesticated in Mesoamerica and larger varieties domesticated in coastal Peru. Although lima beans are primarily grown for consumption , some medicinal uses include the treatment of styes and smallpox . Like the common bean, lima beans do not require much water for cultivation, and often are intercropped with maize for their nitrogen-fixing properties.

Such a mechanistic understanding could help point to strategies for managing multiple ecosystem functions simultaneously , a key goal for agroecosystem management. The effects of biodiversity on multi-functionality are often context dependent, because different mechanisms govern different ecosystem processes. Therefore, managing for multiple agroecosystem services requires understanding the responses of individual services to changes in environment and management as well as trade-offs that exist among services. Given its mechanistic foundation, a traitbased approach could be used to develop agricultural and land-use management strategies to provide multiple ecosystem services that take into account such trade-offs . To develop generalizable principles of how agrobiodiversity impacts ecosystem processes and services, we propose a trait-based approach to agriculture that adopts recent advances in trait research for multi-trophic and spatially heterogeneous ecosystems . Given that traits can vary with environmental conditions, making the relation between trait diversity and ecosystem functioning context dependent, we argue that trait values should be measured across environmental conditions and agricultural management regimes. This knowledge will help predict how ecosystem services vary with agricultural practices and environment, and could be used to develop particular trait-based management strategies that can be implemented in farming systems to increase multiple ecosystem services as well as to manage trade-offs among ecosystem services in agriculture . A trait-based approach to the study of agroecosystems could transform understanding of the importance of agrobiodiversity from largely context specific and based on species identities to generalizable and predictive. For instance, although it is currently well established that intercropping can increase crop yields through niche complementarity, understanding of intercropping comes from examples of particular species interactions in particular contexts, rather than from principles that can be generally applied across different species compositions and environmental conditions.

The statement that intercropping maize with cow peas increases yield is less generalizable than the finding that,vertical hydroponics under conditions where plant-available NO3 concentrations are lower than a certain threshold, intercropping facultative N2-fifixing species increases staple grain seed set and protein content. The latter statement refers to well-defined, measurable traits , while the former refers to taxonomic affiliations that group multiple traits, thereby masking the mechanisms of how intercropping increases yield. Both approaches predict that intercropping increases yield, but the approach referring to functional traits can guide management strategies over a broad gradient of environmental conditions by pinpointing the general controls, such as abiotic and biotic , on rates of soil nutrient cycling and human nutrition .Important initial steps have been taken to apply a trait based framework to agroecosystems. The bulk of this initial research focused on using traits to understand how biodiversity in agricultural systems responds to environmental conditions and land management, rather than on understanding how biodiversity impacts agroecosystem services. Examples of trait-based response to environmentinclude weeds, pollinators , pasture vegetation, soil macrofauna, and soil microbes. Most work connecting species-based measures of biodiversity to agroecosystem services focuses on pollination and pest control ; however, most research using traits has focused on the plant trophic level, such as intercropping . Research on the contribution of intercropping to productivity has largely focused on functional group classifications. In a recent example, crops of broadly different functional types were planted in different combinations and shown to increase overall production. For weed control, the functional traits of weed seeds and cover crop grasses at the plot level are key predictors of weed seed interception by grasses that prevent weed establishment. Weed traits also have an important role in weed persistence and interaction with crop production, a reminder that functional traits can simultaneously contribute to agroecosystem services and disservices. Some initial work has also applied functional group classifications to pollination and pest control services, yet applying traits to mobile organisms remains a key research priority . The diversity of functional groups of bees explained more of the variance in pumpkin seed set than did species richness.

For pest control, functional group diversity of birds was a significant predictor of arthropod removal. However, in contrast with findings from a pollinator system, bird functional group diversity was not as strong a predictor of ecosystem services compared with species richness. Less work has considered how continuously varying measures of functional traits influence agroecosystem services. Gagic et al.provided an initial step by calculating functional trait diversity based on a mix of continuous and categorical traits to show that functional trait metrics are superior to taxonomic measures in linking diversity to several ecosystem functions. Although this study included some important agroecosystem services , it was not specifically focused on agriculture. In a forage production system, Laliberte´ and Tylianakis showed that resource addition and grazing strongly determine grassland functional trait diversity,which cascades to induce changes in grassland productivity, decomposition, and soil carbon sequestration. Abiotic and biotic factors directly impacted functional diversity, directly impacted ecosystem functioning, and indirectly impacted ecosystem functioning through changes in functional diversity. Wood et al. applied a similar approach to soil microbes on African farms and showed that, although microbial functional diversity can be strongly structured by farm management, functional diversity was a weaker predictor of ecosystem processes than were abiotic factors. This approach that simultaneously assesses the influence of biotic and abiotic controls enables ecologists to determine when functional diversity is a key control on agroecosystem services and when it is not. Many applications of trait-based research to agroecosystems have been conducted at the plot scale, while fewer studies have looked at larger or multiple spatial scales. Remans et al. showed that nutritional functional traits of crops are an important predictor of nutrition related health outcomes at a national scale. For animal nutrition, dry leaf matter content can be an important predictor of forage digestibility across broad climate conditions and management regimes. In pollinator systems, sociality is a strong predictor of pollinator response to fragmentation at the landscape scale. Such landscape fragmentation, and resulting distance between pollinator habitat and crops, can have significant negative impacts on yields.

Given that traits determine the movement of species through a landscape, as well as their effect on that landscape, more research is needed to understand how the influence of a community on ecosystem services scales up to the landscape . A trophic approach can also be crucial to understanding agroecosystem services because many services provided by agriculture are determined by activity within, and interactions across, multiple trophic levels. Some studies apply a trait-based framework to understudied trophic levels, such as birds.Storkey et al. showed overlap in the traits affecting the response of plants to tillage and the effects of plants on abundance of phytophagous invertebrates. Plant communities characterized by ruderal traits were associated with greater invertebrate abundances, suggesting that growth strategy can be linked to plant response to disturbance effects and other trophic levels .Agroecosystems range in complexity of the spatial arrangement of crop varieties, species, fields, and landscape types. This heterogeneity can have important effects on agroecosystem processes by determining the persistence, distribution, dispersal, and interactions of farmland biodiversity. These population- and community-level processes can in turn affect ecosystem services through effect traits. It is well established that the spatial partitioning of agroecosystems has an important consequence for ecosystem services. For example, pollination and pest control services depend on the spatial arrangement of vegetation in the farm scape, where farm scapes with spatial heterogeneity in vegetation types can have higher yields because pollinators and pest predators can access more of the cultivated area of the farm scape. However, pests can also rely on non-crop vegetation types to complete their life cycles; therefore,hydroponic vertical farming systems understanding pest traits could additionally provide valuable insights into ecosystem disservices that can compromise farm yields. Many of these studies on spatial structure implicitly evoke interactions between spatial structure and functional traits, but do not measure those traits explicitly. The research showing the importance of forest habitat for coffee yields assumes, and treats as static, the dispersal traits of pollinators. Given the important inter- and intraspecific variation in response and effect traits, the impact of spatial arrangement on agrobiodiversity and ecosystem services can be highly dependent on trait values and distributions. Thus, explicitly including trait measurements into existing spatial approaches to agricultural research is key. Lonsdorf et al. used a trait-based model to predict pollinator abundances in a spatially complex environment, but did not connect these predicted abundances to ecosystem services.

To integrate traits and spatial scale, trait-based data could be integrated into existing spatially explicit models of ecosystem services. These modeling approaches would first identify the landscape patches important to the provisioning of certain ecosystem services. Services, key functional traits, and abiotic properties would then be measured in each of the components of the spatially structured landscape. Spatial configuration metrics could then be calculated to determine how space influences functional trait control of ecosystem services. For instance, Biswas et al. demonstrated that fine-scale responses of plant functional trait diversity to environmental disturbance exhibit greater unexplained variance and evidence of local-scale competition than did coarse-scale patterns. Combining such spatial metrics with data on traits and abiotic characteristics would enable the development of spatially explicit models of ecosystem services that use point data to predict the landscape distribution of ecosystem services. Models with and without trait data could then be compared to determine the importance of traits vis-a`-vis environmental properties to particular ecosystem services. Such a spatially explicit representation of traits and ecosystem services would also be important because functional traits, and associated services, can vary through the farm scape over time. For instance, plant matter of N2- fixing plants is often relocated from one field to another to improve soil fertility. Sampling vegetation and soil nutrient status in single plots would fail to identify the effect of N2 fixation on soil nutrient availability in the broader farm scape by ignoring this transfer of plant matter between farm fields.In addition to being focused on small spatial scales, most research on biodiversity–ecosystem functioning has been conducted on single trophic scales. Yet, the ecosystem services provided by agriculture often depend on activity within multiple trophic levels and interactions across trophic levels. For example, rates of symbiotic N2 fixation are determined by the activity of several trophic levels. Leguminous plants regulate carbon and oxygen flow to roots that symbiotic N2-fifixing microorganisms use to fix atmospheric N2. Root-feeding nematodes can suppress N2 fixation by feeding on roots and decreasing the number of root nodules for N2 fixation. Similarly, for pest control, consumptive predator activity traits affects pest populations , which in turn affect crop yields. Thus, it is crucial not only to apply traits to understudied trophic levels, but also to understand the interactions among multiple trophic levels. A trophic, trait-based framework of ecosystem functioning requires quantifying the traits involved in the responses of species to the abiotic environment, effects of species on the environment, and the effects of species on, and their responses to, the presence and activity of species at other trophic levels. Within a given trophic level, traits determine the effect of that trophic level on an ecosystem process and/or service; the response of that trophic level to higher trophic levels; and the effect of that trophic level on lower trophic levels. These latter two types of trait can inform how trait interactions across trophic scales might improve inference about the relation between agrobiodiversity and ecosystem services. Applying trait-based research simultaneously across multiple trophic and spatial scales is essential for predicting ecosystem services because of interactions between trophic and spatial scales. For instance, large monocultures may be worse for pest control when the pest is a better disperser than the predator because the pest can out disperse the predator into the middle of the crop field and then increase in abundance. In this case, response traits interact with mobility traits, landscape context, and trophic traits to determine an ecosystem service. Although previous work in ecology has proposed the adoption of either trophic or spatial approaches to trait research, we argue that predicting agroecosystem services requires both because of interactions between these two frameworks.Previous efforts to integrate functional trait research into ecosystem service assessments have been proposed, but these have stopped short of creating tangible management targets that can be practically implemented by managers.

While not all of these funds were being used on distorting policies or non-productive administration, much of it was. If a good part of the funds is able to be redirected into more productive areas, there is a chance that the agricultural sector can be energized by this new windfall. The policy implications of China’s WTO accession on land use and farm organization also are hotly debated. Many of the concerns have arisen over the ability of China’s small farms to be able to compete after trade liberalization. Although every farm household in China is endowed with land, the average farm size is small, and declining . Leaders are pleased with the equity effects of the nation’s distribution of land as it allays concerns about food security and poverty. Land fragmentation and the extremely small scale of farms, however, almost certainly will in some way constrain the growth of labor productivity on the farm and hold back farm income. The debate has centered on these issues: Some argue that farm size could be expanded and agricultural productivity could rise if policy makers were to advocate more secure land tenure arrangements. Others call for a continuation of policies that allow localities to periodically re-allocated land to the farmers in order to keep land in the hands of all rural residents. Although most policy makers currently seem to favor more secure rights, they still are searching for complementary measures that will not forego all of the pro-equity benefits of the current land management regime. Land ownership in rural areas, by law, is collectively owned by the village or small group and contracted to households . One of the most important changes in recent years has been that the duration of the use contract was extended from 15 to 30 years. By 2000, about 98% of villages had amended their contract with farmers to reflect the longer set of use rights .

Although some were concerned that household and village demographics and other policy pressures often induce local authorities to reallocate land prior to contract expiration,vertical farming technology it has been shown that the area of this reallocated land has been minimal and the effect on investment behavior insignificant . With the issue of use rights, resolved, the government is now searching for a mechanism that permits the remaining full-time farmers to gain access additional cultivated land and increase their income and competitiveness. One of the main efforts revolves around the development of a new Rural Land Contract Law. The Standing Committee of the National People’s Congress has drafted a law and the main body is expected to approve it in the near future. According to this law, although the property rights over the ownership of the land remains with the collective, the Law conveys almost all other rights to the contract holder that they would have under a private property system. In particular, the Law clarifies the rights for transfer and exchange of the contracted land, an element that may already be taking effect as researchers are finding increasing more land in China is rented in and out .Part of the law also allows family members to inherit the land during the contracted period. The goal of this new set of policies is to encourage farmers to use their land to increase their farms and household short and long-run productivity. Although quite controversial, the effort to increase China’s agricultural productivity under trade liberalization also is made through the promotion of large farm enterprises. Many officials in the MOA consider this effort as one of important forces that may help to restructuring China’s agriculture, expand agricultural markets, and increase farmer income. Recently fiscal authorities have supported this effort by making grants and allowing tax reductions for the infrastructure investments of the farms. They also have provided large farms with credit subsidies for input procurement and the financing of their efforts to update their technology at all levels of the food change .

As a result of China’s WTO accession, the support in this area is expected to increase. However, more effort in the future is likely to shift to supplying services that are supposed to be provided by government in areas such as farm infrastructure development, technology adoption, and extension, rather than direct intervention and subsidy. As subsidies through agricultural investment and inputs in China are subject to WTO restrictions on Aggregate Market Support , it is not expected that the extent of these subsidies will restrict such support. China will be limited to its support of large farms to levels that do not exceed its de minimis level of AMS of 8.5%. However, it is much more likely that its ability to finance agricultural subsidies will be more binding than the WTO-imposed rules. The other major attempt to increase farm productivity and agricultural competitiveness under trade liberalization is to promote the development of farmer organizations. The government has now officially cast its support for self-organized farmer groups that focus agricultural technology and marketing . At one time, the creation of farmer organization was a political sensitive issue. Leaders were concerned with the rise of any organization outside the government’s authority. Such restrictions, however, caused a dilemma in reforming the nation’s agricultural and rural economies. Policy makers also are aware that with the small scale of China’s farms there are many increases in economic efficiency that might be gained by the creation of effective rural organizations and that if they were successful in raising incomes, there might be a rise in political stability.It is on this basis, then, that leaders have now decided to allow the organization of China’s 240 million farms. Letting these millions of small farmers competing in a market with globalization requires substantial institutional reforms on farm organization and provisions of government service such as technology extension and marketing information and quality controls. It will be in these areas that farmer organizations will be encouraged. In addition, these types of farm organizations that are supported by the government fall under WTO’s “Green Box” categorization and investments to create such groups will not be counted as part of the nation’s AMS measures. Perhaps more than anything, the government is going to need these farmer organizations to lead the fight against the imposition of trade barriers on China’s agricultural exports.

Because China’s producers have not been organized, when foreign countries, such as Japan, Korea, and the US have levied trade barriers, typically citing dumping. Even when such cases were based on questionable bases, China had no one who had an incentive or ability to contest the cases. Since China Provisions of anti-dumping and safeguards measures against China’s products, such cases will not abate and the nation needs to have a way to protect the interest of those seeking to export.The financial sector has reformed more slowly than some other sector, and government maintains strong control . Among the commitments regarding the banking sector, the Protocol requires China to open the country’s financial markets in a step by step way. The liberalization must allow foreign competition across wider and wider regions and customer base. After a four years transition period, all regional restrictions will be removed and foreign banks will receive national non-discriminative treatment in the area of banking services. Specifically, restrictions on branch banking can not be imposed.International experience shows that in the long run, increased foreign participation in the financial sector will have a positive effect on country’s development as a whole. However, in the period immediately following its WTO accession and the removal of protective measures in the financial sector, China may face one of its biggest challenges. There is a good possibility that the nation’s banks will suffer financially. Hence, it might be expected, the leader’s policy response to reform the current banking system will be a strong one. For example, financial sector officials are already mandating the government interventions fall, state banks recapitalize themselves, and nonperforming loans be transferred to asset management companies . The implications of the above shifts of policies for agricultural development are not clear. While one might think the agricultural sector and poor regions in the rural economy could suffer from liberalization, it is not clear if things will be worse than before the reforms. In the past, agriculture in China was squeezed. Huang and Ma have shown how the financial sector has systematically shifted funds away from faming. Throughout the entire reform period, there was a net capital outflow by means of the financial system. Hence, it is hard to see how a reformed banking sector will treat agriculture any worse. Though, the experience of other countries most likely mean that in the short run small, poor farmers will be rationed out of financial markets. Tax reform also is underway. In 2001, there were three major types of taxes levied on products and services: a VAT levied on goods and services for processing,how to make vertical garden maintenance and assembling; a Consumption Tax levied on some selected consumer products; and a Business Tax on services and the sales transaction involving assets.Both the VAT and Consumption Tax are applied to imported goods.Tax laws, however, have offered producers several exemptions. In many cases, part or all of the VAT is reimbursed when the goods is exported.

All goods to be exported are not subject to the Consumption Tax. Although subject to a number of technicalities, there is some concerns are some of these tax rebates may not be consistent with the requirements of the 1994 GATT rules. Since, China has agreed that it would ensure that its laws, regulations and other measures relating to internal taxes would be in full conformity with its WTO obligations, some adjustments may have to be made. Perhaps the best example of this may be in the area of the assessment of the VAT on agricultural imports and the possibility that such an act may violate the national treatment clauses of the WTO accession agreement. Specifically, while the VAT is charged in full at the border for all imports . Although some observers in China have tried to argue that since farmers in rural areas already pay high land- and head-taxes, they can fairly be exempt, such a tax is not commodity specific and such unequal taxation of imports and domestically procured crops almost certainly violates WTO. If such a tax policy is challenged, China will have two options: assess the VAT on all domestic procurement or eliminate the VAT at the border on agricultural goods. More generally, as China attempts to make it economy more competitive in a post accession world, it has announced that in some areas it will lower taxes. The primary objective would be to lower the burden of domestic enterprises and attract new foreign investment. Tax cuts would also increase the competitiveness of its domestic products in the international markets. Moreover, tax officials also have plans to continue to push on tax reform that shift China from a system that primarily uses a production-based tax system to a more consumer oriented tax regime. While desirable, it should be noted that the timing of implementing this tax reduction necessarily will depend on the impacts that the reform would have on the government’s revenue-earning capacity. An official from the State Council recently claimed that a major move to realign China’s tax system towards a more consumer-oriented one may begin as soon as 2003. To make the rural economy more competitive and to remove a set of institutions that have historically caused a lot of frustration among rural residents, officials have also begun to experiment with rural tax reform. The most bold experiment to date is based on a movement that seeks to “convert fees into taxes.” The earlier experiments began in Anhui province in 2000. The reform was implemented to reduce the burden of various fees imposed on farmers to a maximum level of 5 percent of the income of farmers. By reducing the tax burden of the farmer, officials hope to reduce the cost of agricultural production, since many fees are collected from farmers by local government and village committee on the basis of their sown area or level of livestock production.