The majority of producers in the Sacramento River Valley have opted to join the SVWQC, the area’s most encompassing watershed-management coalition, because it allows them to share the costs of the monitoring program, facilitates local oversight, takes advantage of local knowledge and is less intrusive on individuals. Such coalitions also focus on the watershed, attempt to consider the cumulative effects from multiple operations and try to integrate some of the elements of collaborative policy at the local level . However, some producers in the Sacramento River Valley have criticized the non-voluntary nature of the program as an unnecessary regulatory burden. The critical role of diffusion networks is illustrated by the SVWQC’s nested watershed approach, which divides the larger watershed into 10 sub-watershed groups, based on county and hydrological boundaries . The sub-watershed groups are typically headquartered locally with organizations such as the county agricultural commissioner, the county farm bureau or a previously established watershed group. The sub-watershed leadership collaborates with other local stakeholders, such as resource conservation districts, UC Cooperative Extension and the federal Natural Resource Conservation Service. The exact structure of the partnerships is different in each sub-watershed, reflecting the unique configuration of networks, political interests, policy expertise, leadership and individual personalities in each area. Regional coordination among the sub-watershed groups is achieved by three main organizations: the Northern California Water Association , Ducks Unlimited and the Coalition for Urban Rural Environmental Stewardship . These organizations ensure professional oversight of the water-quality monitoring program,what is vertical growing and the timely preparation of required documents and reporting of water-quality monitoring results.

The regional coordinators are headquartered in the Sacramento area and serve as a liaison between the Regional Board and producers in the more distant, rural areas of the Sacramento River Valley. These networks of sub-watershed and regional actors represent each of the three pathways for sustainable agriculture. They inform producers about the requirements of the program, opportunities for participation, and appropriate management practices for protecting and enhancing water quality. They are a main source of social capital and trust, and they help build inter agency cooperation as well as encourage producer participation. They encourage cultural change by demonstrating the success of various water-quality programs and practices, as well as providing public awareness about individual producers who are outstanding examples of stewardship. Whether the Conditional Waiver program is viewed as collaborative or regulatory policy, the diffusion networks involved with the SVWQC make a positive contribution to sustainability to the extent that they facilitate producer participation in water-quality management.To examine the role of diffusion networks, we conducted a mail survey of 5,073 producers from nine Sacramento River Valley counties: Butte, Colusa, Glenn, Shasta, Solano, Sutter, Tehama, Yolo and Yuba. The sample list was constructed mainly from agricultural commissioner pesticide-permit lists. The standard Dillman methodology of delivery was used to encourage response. The respondents were divided into a group of known orchard producers and a group of other producers for whom the specific commodities were not known beforehand . A 12-page survey was mailed to growers, which included 68 questions about their views on water quality management, political values and farm characteristics; most of the responses were yes/no or 7-point Likert scales. The orchard respondents received several additional questions about orchard management practices. The survey was administered from November 2004 to February 2005, about 2 years after the introduction of the waiver program. A total of 1,229 producers responded to the survey , including 408 from the orchard group and 821 from the nonspecific group. Except for the analyses of orchard practices , the results presented here apply to the combined 1,229 respondents.

The survey population adequately reflected the diversity of land tenure, operation size, commodity types and operator characteristics in the nine counties. To further validate our survey, we conducted follow-up telephone interviews of mail survey non-respondents in seven of the nine original counties, which targeted 1,078 non-respondents for whom telephone numbers could be found. Of these, 44.7% were determined as owners of irrigated land and thus eligible for the survey, 16.2% were considered ineligible and 39.1% could never be reached. A total of 300 non-respondents were interviewed by telephone, and the results suggest that the mail survey respondents were more likely to own instead of lease their land and to have slightly higher rates of participation in the coalition groups. This means that we do not have a complete picture of the least-engaged producers, and reflects the difficulty of communicating with smaller and part-time producers. However, the survey does sufficiently represent the economically and politically significant segment of producers who will have the most influence on policy decisions and eventually, the behavior and attitudes of less active producers.We asked producers about the number of times they had contacted different organizations in the last year, as well as the average level of trust that they had in these organizations based on an 11-point Likert scale . In the case of the Conditional Waiver, the Regional Board is considered the most important regulatory agency because it has the authority to manage and enforce the program. The diffusion network consists mostly of local agencies that deliver information about policies and practices to individual producers, as well as the regional organizers of the SVWQC. The agricultural commissioners are considered a diffusion agency because despite having formal regulatory duties, they are usually viewed as ombudsmen who help producers comply with pesticide laws. The diffusion network agencies received much higher levels of trust and contact than the regulatory agencies . Trust and contact were also positively correlated. Even diffusion agencies with fairly low levels of contact, such as the California Department of Food and Agriculture and two of the regional coalition organizers , had higher levels of trust than might be expected, given their lower frequency of contact by growers. Just the basic descriptive data about trust and contact shows how the local diffusion network interacts most effectively with farmers with respect to water-quality management.

We conducted a series of regression analyses to estimate how many times a grower would need to have contact with the diffusion network before leading to a change in three dependent variables associated with successful water-quality management: participation in coalition activities; satisfaction with coalition group policies; and the number of orchard BMPs on a particular farm. The participation measure was a count of the number of watershed activities producers had engaged in, varying in intensity from reading brochures to committee membership. The satisfaction measure took the average level of agreement to four questions about coalition effectiveness for addressing water-quality problems, encouraging the participation of other producers, pooling resources and facilitating BMP adoption. The orchard BMP measure was a count of 11 different practices considered to be protective of water quality. To measure the density of network contacts, we counted the number of organizations contacted by the producer from the diffusion network and the regulatory network . The analysis controlled for a range of other variables that are considered by diffusion-of innovation models, which are typically used to predict the adoption of agricultural practices. These variables included the producer’s education level, their operation’s income and the total number of acres farmed . For the non-orchard sample, we measured perceptions about the severity of water-quality problems, the likelihood that agricultural sources are causing a problem, and the availability of information about the coalition groups. Due to non-response on the attitude and belief questions, multiple imputation by chained equations was used to estimate missing data on these variables . For the orchard sample, we asked if the respondent was aware that pesticides have been detected in the Sacramento River and if they have been informed of water-quality management practices .Before reporting the results of the regression analysis, we summarize the rates of practice adoption . The results suggest that adoption rates partly reflect the combination of experience with each practice and the balance between economic risks/costs to crops and environmental protection. For example, some of the conventional pest-management practices, such as basing the time of spraying on weather/wind , have been a part of agricultural research and education since the 1960s, and more is known about how to adapt these practices to specific farm settings to protect water quality while simultaneously controlling pests and reducing overall input costs . Alternative pest-management practices, such as providing beneficial insect habitat ,what can you grow in vertical farms on the other hand, are relatively new and are more complex in terms of their research development and adaptation to on-farm use. There is more uncertainty about their readiness for use, and about balancing their efficacy at reducing pests and associated crop risks with their environmental benefits . Respondents reported moderate adoption rates of runoff-control practices, such as filter strips . These practices are thought to pose few economic risks to crops, but to have fairly clear benefits for reducing the amount of agricultural contaminants entering surface water from dormant-season orchard sprays . An exception is that orchard floor vegetation, depending upon how it is managed, influences orchard temperatures and may increase the potential for freeze damage in orchard crops . Tables 2 and 3 summarize the results of the regression analysis by presenting unstandardized coefficients, which are interpreted as the expected change in the dependent variable for a one-unit change in an independent variable , controlling for the other independent variables.

Diffusion networks have an important influence on all three dependent variables; the estimated diffusion network coefficients are positive and are statistically different from zero in all models . Unlike correlation coefficients, regression coefficients are not constrained to the range between negative and positive one ; their importance must be judged relative to the scales of the variables. To assess their influence on each dependent variable, it is useful to calculate how many additional diffusion network contacts are required to increase the dependent variables by one unit. The fewer the contacts needed, the more power each contact has for changing the relevant outcome. In our survey, we found that the number of contacts needed to change different measures of policy effectiveness was highest for satisfaction with coalition group policies — it takes 20 diffusion network contacts to increase policy satisfaction by 1 point on the 7-point scale. However, the influence of diffusion networks was quite strong for coalition participation and BMP adoption. It took 9.0 additional diffusion network contacts for the adoption of an additional orchard BMP, and 3.7 contacts for another act of coalition participation. Overall, diffusion networks had the strongest influence on coalition group participation, followed by BMP adoption, and weakest for policy satisfaction. Contact with the regulatory network, on the other hand, had zero influence on the three dependent variables. The coefficients for the other independent variables — such as operator characteristics and attitudes and beliefs toward water quality — were largely consistent with classic diffusion-of-innovation models . Producers who thought that agriculture influences water quality and who had information about coalition group practices had higher levels of policy satisfaction. Producers who had more education and higher incomes were more likely to participate, and higher income producers also had implemented more BMPs. Because there was a strong correlation between agricultural income and size of operation, the total-acres variable became significant in regressions that omitted the income variable. This suggests that larger and wealthier operations were more likely to participate in watershed management and to adopt BMPs.The most incongruous finding was that producers who thought that water quality is not a problem were more likely to participate in the coalition group activities, and more-educated growers were less satisfied with coalition policies. This suggests that an important motivation for participation by educated growers was to prevent the implementation of costly new policies for water-quality problems, which many producers perceived to be of lesser importance than other issues, such as urbanization. According to our personal interviews , this type of “policy skepticism” is likely to shift toward problem-solving if water quality monitoring conducted by the coalition clearly establishes a relationship between agricultural practices and water pollution.