In the non-certified case studies, rather small percentages of farms fully followed the rules of OA. In KE-NC1, the case study with the most promising approach, up to 42% of farmers worked organically, without any certification, while in GHNC and KE-NC2 only 16% and 28% did, respectively. Remarkably, in four case studies, the share of smallholder farmers in the control group that did not use conventional inputs was below or around 10%. In KE-NC1, the rate was about 21% . This is contrary to literature, where organic-by-default is often indicated to be common among smallholder farmers in SSA . This indicates the increasing availability and usage of conventional inputs as found by De Bon et al. and Andersson and Isgren . Especially pesticide use among smallholders is far more widespread than commonly assumed . Getting accustomed to conventional input use may lead to a decreased willingness of smallholder farmers to convert to an entirely organic system and agroecological principles . However, input use in SSA varies substantially between countries , therefore these results cannot be extrapolated to other countries. Farmers replacing conventional inputs with either preventive or curative agroecological practices can address nutrient and pest management issues under organic management. These practices include, among others, applications of botanical pesticides, such as neem; preventive practices can involve a more diverse rotation, agroforestry or intercropping systems.We specifically analysed whether the interventions led to an increased uptake of a) practices substituting conventional inputs for pest, disease and weed management, b) practices for substituting mineral fertilisers, and c) further agroecological practices.

Looking at the effect of the interventions on the uptake of AOM practices, our data shows no widespread systematic adoption in any of the case studies.Among the agroecological practices,hydroponic barley fodder system only the diversity of crop rotations was affected positively in GH-NC and KE-NC1 while it was even less diverse in KE-C and KE-NC2. For the remaining components of AOM, we did not find consistent differences between the intervention and control groups. While at least one of the interventions led farmers to adopt POM, AOM was not adopted widely in any of the case studies, despite that all of the interventions aimed at such an adoption. This shows the importance of considering innovation dynamics and transition time frames when introducing organic agriculture to smallholder farmers, as their decision-making is dynamic, multi-dimensional and contextual . Transferring information and skills to famers via group trainings is an important component of capacity development, but needs to be embedded in a long-term process and governance structure, which allows a group of smallholder farmers to learn and explore practices on their own farms and identify ways of combining practices that fit into their specific production system. Compared to applying mineral fertilisers, herbicides and pesticides, agroecological practices are usually knowledge-intensive and require understanding of complex ecological principles . In order to understand the low uptake rates of organic farming practices by farmers in the organic intervention groups, we analysed a) motivations to convert to organic agriculture and b) the implementation challenges as perceived by the farmers. In the two certified organic case studies , high potential economic returns motivated farmers to practice organic farming , while non-financial reasons were less apparent. In the non-certified case studies, the primary motivation to practice organic farming was non-financial with the exception of GH-NC, where 54% of the responding farmers had primarily financial reasons. The differences in motivations and expectations are partly driven by the implementation approach of the intervention. For instance, in KE-NC1, much time was prior invested to make farmers aware of the non-financial benefits of organic farming such as human and environmental health.

While in most case studies, little difference between the responses of adopters and non-adopters could be observed, farmers adopting organic management practices in KE-NC2 and GH-NC had a higher share of financial motivations . The most prominent challenges that the organic intervention farmers faced were: pest and disease damage during crop cultivation and post harvest stages , lack of stable markets , inadequate training and extension services , unavailability of inputs and additional labour required due to weeding . The importance of the challenges was perceived differently in the various case studies. Generally, the Ghanaian farmers perceived the agronomic challenges as more important than the Kenyan ones. Furthermore, our assessment of uptake of farmers is reflected in severity of the challenges, as farmers in KE-C and KE-NC1 who were exposed to these interventions perceive the challenges as overall less severe . While there is only little empirical evidence reported in literature about motivations and challenges of organic farmers in SSA , the technical challenges, such as weed infestation and damage by pests and diseases, are similar to those found in Switzerland by Home et al. although the Swiss farmers in their study reported that these barriers were less severe than they had estimated before conversion to organic. Following the analysis of the effects of the interventions on the adoption of practices, we analysed how OA, as a production system, performed. For this, we compared all farms in each case study, those who worked organically with those who did not, regardless of whether they were part of the intervention group or not . We analysed the differences in yields, inputs, labour and gross margins of the four most widely grown crops in each of the five case studies, using an entropy balancing approach for estimating a sound counterfactual . Among the total of 20 crops analysed from the five case studies, we found four organically managed crops with significantly higher and four crops with significantly lower yields . Input cost was significantly higher for three crops each, while inputs were significantly lower for eight crops and labour was lower for six crops . This resulted in higher gross margins for four organically managed crops, while only one crop had significantly lower gross margins under organic management . Comparing the two certified case studies, farmers practicing OA performed very differently in their productivity and profitability.

Except for reduced cocoa input costs , no significant differences in yields and gross margins between organically and conventionally grown crops could be observed in GH-C. Contrary, we observed higher yields for the economically most relevant crops , while banana yields were lower in KE-C. Input cost was reduced or stayed similar, while labour cost was increased for coffee and macadamia nut in KE-C. Despite labour cost was higher, the gross margins of coffee and macadamia nut increased by 336% and 185%, respectively. Less pronounced differences were found in the non-certified case studies: in GH-NC, yields of organic farms were similar to conventional farms for the four crops, almost no purchased inputs were used and labour was reduced for maize , groundnuts and millet . Gross margins of organically managed crops were at similar levels to their conventional counterparts, except in the case of maize . In KE-NC1, however, organically managed brassica and maize yields were lower than for conventional farmers but other crops were not significantly affected. Maize input cost was significantly lower while labour costs were lower for beans, maize and roots. Overall, no significant differences in gross margins were observed in KE-NC1. On the other hand, in KE-NC2, pea yields were higher, while the other crops remained unaffected by organic management. In this case study, organic farmers significantly reduced input cost for mango while labour cost for peas was higher. In terms of gross margins, there were no significant differences, except for peas . Except for macadamia nut in KE-C,livestock fodder system the organically grown crops in our case studies were not sold with/did not generate a price premium. To assess the importance of local and international markets for organic produce, we therefore tested the impacts of a general 20% price premium for the organic farmers for sensitivity analysis . Assuming an organic price premium, POM gross margins would be higher than the conventional counterpart for bananas in GH-C, coffee in KE-C, beans and maize in GH-NC, roots in KE-NC1, and beans and peas in the case of KE-NC2. The high variability of organic yields and gross margins through organic farming is mostly consistent with findings of meta-studies that are mainly based on data from high-income countries . The methodological difficulties of comparing organic smallholder producers in low-income countries and the resulting uncertainty resulting from the definition of a sound counterfactual led even to a higher uncertainty of impacts of organic agriculture on smallholder yield and profits. Some authors identify strong yield increases due to organic agriculture , while others criticise methodological flaws.

We observed positive effects of organic farming practices at farm level productivity in one of the five case studies . Higher farm level gross margins could neither be achieved in the other certified case study nor in the three non-certified case studies . As, at least in GH-C, organic price premiums were originally supposed to be realised, the farm-level gross margins were analysed under the assumption that at least 20% of price premium could be realised due to the organic management. For the pooled sample over all five case studies, OA had significantly positive impacts on gross margins . Under such an assumption, the organic farmers in four of the five case studies would have realised higher gross margins than the farmers who managed their farms conventionally. Besides KE-C, GH-C , GH-NC and KE-NC1 would also have performed better, while for KE-NC1, there was no significant difference observed. For the pooled sample, OA had significantly positive impacts on gross margins . Our results show that there is no one silver bullet for increasing profitability among smallholder farmers . Profitability increasing effects observed over all the five case studies can be associated with labour input in general and specifically with the number of hours spent on pruning as one of the key specific good agricultural practices for the perennial crops such as macadamia nut, mango and cocoa. When used, the application of organic fertilisers had significantly positive impacts, while conventional fertilisers and pesticides affected the revenues rather negatively. Organic insecticides did not have significant yield effects while copper did. Contrary to findings from field trials , further organic and agroecological management practices resulted mostly in no remarkable economic benefits assessed for the farmers in our study . This could signify that the levels of inputs and practices applied by farmers in our study were still low and not optimal as supported by on-station long-term trial findings in Kenya . Contrary to results from field studies and meta-studies, which report the productivity of organic agriculture crop-specifically , our study shows that contextual factors such as the governance and capacities of smallholder cooperatives are important factors determining the agronomic and economic performance of OA, too.

Many authors suggest that capacity development measures, which are implemented alongside organic projects, are responsible for a large share of the revenue increases that were observed in other studies . In our study, we therefore, controlled for the number of training events from both government and non-governmental organisers. Overall, organic farms had similar numbers of training events and extension visits by NGO and government agents in all case studies, except in KE-C, where the number of governmental and total trainings was even lower than for conventional farms . Government trainings were generally rated lower by organic farmers than by conventional farmers in KE-NC1 and KE-C. On average, NGO trainings were rated better in terms of effectiveness compared to the governmental-based trainings. This indicates a potential for improvement and strengthening of trainings and extension services offered by governmental agents. This further indicates that there are large differences in the perceived quality of NGO training provided to the farmers. There is a great diversity of smallholder farmers in Africa. Much of the on-going controversial discussion about OA is due to a lack of a clear classification and the very heterogeneous characteristics and performances that one can realise on farms that may all be called “organic” on a superficial level . Therefore, based on the results from our study, we propose a terminology for organic farms that can bring more transparency in the debate and can be used to assess the current situation and design tailored public and private policy interventions. Fig. 4 distinguishes organic farming systems according to a) the degree they follow the principles of OA  and b) the intention to work organically .