Organic farming with smallholder input rates cannot close the yield gap in Central Kenya

Agricultural productivity is the key to global food security. Modern conventional farming has substantially increased food production, but at the expense of serious environmental harm [[1][1]]. By contrast, organic production is regarded as a suitable and more sustainable alternative owing to its

This review provides an introduction to organic farming, its history and concepts, organic certification systems and governmental support, impacts to the environment and food security, the quality of organic food, and the impact of organic farming on human health. Organic farming is a holistic approach to agriculture and food systems that is based on agroecosystem health, soil fertility, reduction of inputs, and locally to regionally adapted farming systems. The first organic ideas were developed after World War I in Europe as an alternative to the existing conventional farming systems which induced rapid and crucial social and environmental changes in rural areas. Today, organic farming is growing rapidly on a global scale, with around 370 million hectares currently under certified organic management and a turnover of organic products amounting to 60 billion US dollars. Given that organic farming has environmental benefits, some governments are subsidizing organic farmers, while others establish legally valid organic standards that must be followed to enhance consumer trust in organic labeling.Many recent studies comparing organic and conventional farming have been performed, although almost exclusively in North America and Europe. These studies show that environmental impacts of organic farming are less than those from conventional farming, but the conclusions depend on the different farming systems used for comparison and on the parameters that were assessed. For soil parameters such as organic matter or aggregate stability, the effect from organic farming systems was positive compared to conventional farming systems, although contrary results exist in some cases. For nitrate leaching, study results are diverse and depend on production systems (animal husbandry, crop production, proportion of legumes). For greenhouse gas emissions, organic farming provides lower emissions on a per hectare basis compared to conventional farming, but the same or higher emissions on a product basis because of lower yields. If the yield gap between organic and conventional farming systems could be reduced, the potential for a reduction of greenhouse gas emissions would rise. Organic farming performed better with regard to biodiversity compared to conventional farming for most taxa assessed. The impact of organic farming on food security cannot be clearly assessed because studies on the performance of organic farming in developing countries are lacking. Currently, some authors argue that organic farmers in developing countries profit from organic production if they can realize a price premium for the products and reduce input costs.One of the most important consumer motivations for the purchase of organic products is their health benefits. Organic products performed better than conventional products for different food compounds by containing less pesticide residues that are harmful to human health, having more desirable bioactive substances, and in the case of organic meat and milk, having more desirable fatty-acid composition. Animal experiments have shown positive health impacts from organic food. Several studies conducted on rats have indicated higher immune system reactivity in organically fed rats compared to conventionally fed animals. Similar results have been obtained for chickens and cows.The rapid growth of organic farming also can be a threat to future development if the organic sector cannot maintain its integrity and credibility. Organic products are available not only in farmer markets but in on-farm shops and organic food stores and are becoming increasingly present in conventional supermarkets. This involves long supply-chains, large suppliers, as well as processing, distribution, and trade via conventional processors and wholesalers. This conventionalization of organic food-chains may challenge the credibility of the organic sector as an environmentally friendly and socially fair form of agriculture. As the organic sector depends very much on this credibility, the question of how to retain this authenticity will be a major concern for the future.

Crop yield gap and stability in organic and conventional farming systems

For decades, there has been debate about the possibility that organic farming can feed the world’s population. The most recent studies, analyzing the yields of individual crops, show a yield gap between organic and conventional farming. The rotations and the intensity of soil use are also different between systems and the impact of this factor on productivity has not been assessed. A meta-analysis of the yield data of organic and conventional crops and the intensity of soil use (years with harvest crop in relation to rotation duration) was carried out using studies published in peer-reviewed journals. The yields under organic farming were on average 25% lower than the conventional ones, reaching a yield gap of 30% for cereals. The intensity of soil use was also lower in organic systems, the size of the reduction depending on the type of study: field experiments (7%) or on-farm studies (20%). Combining the yield gap with the reduction in the number of crops harvested in the rotation, a productivity gap of 29% to 44% was estimated depending on the type of crops included in the rotation. These results show that the productivity gap is greater than the yield gap between organic and conventional farming.

Flower scarcity outside coffee flowering periods leads to a decline of pollinators' abundance and diversity possibly through death or migration. The objective of this study was to assess whether other flowering plants within and around coffee farms act as alternative floral resources that may impact on abundance and diversity of pollinators of coffee flowers. Bee pollinators of coffee were assessed and identified for a period of 27 months. Their abundance and diversity were examined within and around organically and conventionally managed coffee farms in Kiambu District in Kenya. This study provides evidence that 42 plant species from 19 families were alternative floral resources for bees that pollinate coffee. Bee pollinators of coffee were observed to visit coffee flowers as well as other flowering plants close by. Significant relationship existed between plant species and bee species richness in the organic farming (R2=0.5918; P<0.0001) and in conventional farming (R2=0.6744; P<0.0001). Therefore in coffee monocultures, presence of other flowering plants should be encouraged to support bee pollinators when coffee is not flowering and to enhance abundance and diversity of bees visiting coffee flowers.

The European Commission's Farm to Fork (F2F) strategy, under the European Green Deal, acknowledges that innovative techniques, including biotechnology, may play a role in increasing sustainability. At the same time, organic farming will be promoted, and at least 25% of the EU's agricultural land shall be under organic farming by 2030. How can both biotechnology and organic farming be developed and promoted simultaneously to contribute to achieving the Sustainable Development Goals (SDGs)? We illustrate that achieving the SDGs benefits from the inclusion of recent innovations in biotechnology in organic farming. This requires a change in the law. Otherwise, the planned increase of organic production in the F2F strategy may result in less sustainable, not more sustainable, food systems.

Organic agriculture is one of the most widely known alternative production systems advocated for its benefits to soil, environment, health and economic well-being of farming communities. Rapid increase in the market demand for organic products presents a remarkable opportunity for expansion of organic agriculture. A thorough understanding of the context specific motivations of farmers for adoption of organic farming systems is important so that appropriate policy measures are put in place. With an aim of understanding the social and biophysical motivations of organic and conventional cotton farmers for following their respective farming practices, a detailed farm survey was conducted in Nimar valley of Madhya Pradesh state in central India. The study area was chosen for being an important region for cotton production, where established organic and conventional farms operate under comparable circumstances. We found considerable variation among organic and conventional farmers for their social and biophysical motivations. Organic farmers were motivated by the sustainability of cotton production and growing safer food without pesticides, whereas conventional farmers were sensitive about their reputation in community. Organic farmers with larger holdings were more concerned about closed nutrient cycles and reducing their dependence on external inputs, whereas medium and small holding organic farmers were clearly motivated by the premium price of organic cotton. Higher productivity was the only important motivation for conventional farmers with larger land holdings. We also found considerable yield gaps among different farms, both under conventional and organic management, that need to be addressed through extension and training. Our findings suggest that research and policy measures need to be directed toward strengthening of extension services, local capacity building, enhancing availability of suitable inputs and market access for organic farmers.

This article provides a comprehensive analysis of the productivity of organic farming systems in comparison to conventional agricultural practices. Amidst the growing emphasis on sustainable agriculture, organic farming has gained prominence for its environmentally friendly methods. However, the efficiency and productivity of organic farming remain subjects of debate. This analysis focuses on key aspects such as land usage, crop yield gaps, and the challenges faced by organic farming in maintaining productivity. Studies indicate that organic farming typically requires 2-3 times more land than conventional farming to produce the same amount of food, highlighting a significant efficiency challenge. Additionally, the yield gap between organic and conventional farming, estimated at 29 to 44% depending on crop types, further underscores the productivity challenges in organic systems. Despite these challenges, the environmental benefits of organic farming, such as reduced pollution, enhanced biodiversity, and improved soil health, are notable. The article concludes that while organic farming faces hurdles in achieving the productivity levels of conventional methods, its environmental sustainability and potential contributions to climate change mitigation are significant. Future advancements in organic farming practices, focusing on innovative pest control, soil fertility management, and crop variety development, are crucial for enhancing its productivity and overall sustainability.

Organic agriculture is a production system that aims at sustaining healthy soils, ecosystems and people by prohibiting the application of synthetic pesticides and fertilisers in crop production and by emphasising animal welfare in livestock breeding. This article shows that organic agriculture is characterised by higher soil quality and reduced nutrient or pesticide leaching compared to nonorganic agriculture, but that positive effects on biological control services or emission of greenhouse gases are less evident. Yield gaps between organic and nonorganic agriculture are on average 20%, but vary between crops and regions. Given the environmental risks that are associated with intensive, nonorganic agriculture, farming practices should be modified to decrease risks. Organic agriculture can be a more environmentally friendly alternative, but individual farming practices need improvement to meet the demands of a growing human population. Further growth of the organic farming sector will contribute to reduce the negative environmental impact of agriculture. Key Concepts Organic agriculture leads to higher soil quality and reduced nutrient and pesticide leaching compared to nonorganic agriculture. Organic agriculture may lead to a higher provision of ecosystem services and reduced soil erosion compared to nonorganic agriculture, but more research is needed to address these impacts. Organic agriculture leads to higher greenhouse gas emissions if considered per unit product and, on average, has 20% lower yields than intensive, nonorganic agriculture. The current situation of nutrient supply to crop plants in organic agriculture is often not optimal and this is a major challenge for future research. Intensive, nonorganic agriculture is based on the application of pesticides that cause risks to human health, and organic agriculture can act as an environmentally friendly alternative.

This article presents a comparative analysis of organic farming practices and their implications for soil health, crop yield, and environmental sustainability. Organic farming, characterized by the exclusion of synthetic fertilizers and pesticides, emphasizes the use of natural resources and processes. The analysis focuses on the impact of these practices on key aspects of agricultural sustainability. For soil health, organic farming has been found to enhance soil fertility and biodiversity through the use of natural compost, green manure, and crop rotations. In terms of crop yield, while organic farming traditionally faces perceptions of lower productivity, advancements in techniques are narrowing the yield gap between organic and conventional farming. Additionally, the quality and resilience of organic produce are often higher, especially under environmental stressors like drought. The environmental sustainability of organic farming is a signi icant bene it, contributing to biodiversity, reducing pollution, and mitigating climate change through lower carbon emissions and enhanced carbon sequestration. However, the transition to and broader adoption of organic farming practices are not without challenges. These include the need for labour-intensive management, comprehensive knowledge of organic methods, and the complexities of certi ication. The article concludes that while organic farming faces certain limitations, its bene its in promoting sustainable agriculture are substantial. Embracing organic farming practices could be crucial in addressing contemporary environmental and food security challenges, paving the way for a more sustainable agricultural future.

Raising awareness about the benefits of organic food has spurred consumer demand and organic farming practices. However, organic farming often criticized for its lower productivity than conventional farming. Poorly adapted varieties are partially responsible for the lower yields in organic farming. Therefore, it's crucial to identify suitable varieties for organic farming to minimize the yield gap between organic and conventional farming practices. To address this, a field experiment was conducted at Indian Council of Agricultural Research (ICAR)-Central PotatoResearch Institute (CPRI), Regional Station, Shillong, during the kharif seasons of 2020 to 2022. The study evaluated the performance of six potato varieties viz., Kufri Jyoti, Kufri Megha, Kufri Giriraj, Kufri Kanchan, Kufri Himalini and Kufri Girdhari under organic farming. The findings indicated that Kufri Himalini is suitable for organic cultivation, exhibiting the highest total tuber yield (14.44 t ha-1) combined with marketable tuber yield (10.89 t ha-1). This variety has moderate resistant to late blight and medium tuber dormancy. Storage behaviour varied among the varieties.Tubers of Kufri Girdhari and Kufri Kanchan were exhibited excellent keeping quality with long tuber dormancy and minimum storage losses, indicating their suitability for low-cost country storage for six months.

The crop yield gap between organic and conventional agriculture

Although scientists have been researching the impacts of organic agriculture on the environment and animal welfare for decades, the conclusions drawn by the scientific community remain controversial. Against this background, this paper provides a comprehensive assessment of the benefits of organic farming in both areas by analysing results of all relevant scientific comparative studies between organic and conventional farming that have dealt with this topic over the last thirty years. So far, this study is the largest one of its kind and the first one that adds the aspect of animal welfare to a comprehensive array of impact categories. The systematic review of the scientific literature from pairwise comparisons found that organic management showed clear advantages over conventional management in the fields of environmental protection and resource conservation, which can be mainly explained by the system approach pursued in organic farming. No clear conclusion was drawn regarding animal welfare indicating that farm-specific management factors are of greater importance than the production system (organic vs conventional). Consequently, organic farming may contribute to solving current environmental and resource challenges and is rightly considered a key approach for sustainable land use. The positive effects should be further strengthened by decreasing the yield gaps between organic and conventional farming, i.e. by improving yields based on organic principles as well as by altering their relevance through changes in consumption as feed for livestock and food for humans.

Organic farming may improve agroecosystems’ resilience against external stressors, favour below-ground biodiversity, soil health, and increase soil water holding capacity. At the same time, organic farming systems are repeatedly reported to have lower average crop yields than conventional systems. To date, global meta-analyses on organic farming systems include a diverse range of crops, but none of them specifically focus on arable systems with cereal-based rotations. Further, they are not representative for specific European agro-environmental zones and often show weaknesses in the applied meta-analytical methodology.This meta-analysis aimed at quantitatively summarizing existing knowledge and outcomes on soil organic carbon (SOC) in the topsoil (0-20/30 cm) and cereal production (i.e., yields and yield stability) in organic farming systems compared to conventional farming systems across Europe.The database consisted of 43 independent field studies on SOC and 50 field studies on cereal yields across 16 European countries, covering nine European agro-environmental zones. Cereal-based rotations were cultivated organically and conventionally on mineral soils, up to several decades. Yields for winter rye, winter and spring wheat, spring barley and spring oats were annually measured. SOC was measured as stock or concentration at the end of the experiments. Organic farming systems relied either on animal-based or plant-based fertilizers, or on both sources of nitrogen input. Conventional systems received solely mineral fertilization in most experiments. For both farming systems conventional tillage was applied without irrigation. The meta-analysis was conducted by using Meta Win 2.0 and IBM SPSS Statistics 29. As an index of effect size, we used ln (R), i.e., relative SOC, yield or temporal yield variation.  All studies were weighted by inverse variance.The overall effect of organic farming was a 5% increase of topsoil SOC (95% CI: 1% – 9%, n=43) compared to conventional systems. Pedoclimatic factors, such as mean annual precipitation and clay content had a profound impact on SOC response under organic farming (p=0.014). With increasing annual precipitation and clay content, SOC response to organic farming was increasing, and reached 20% in areas with clayey soils and annual precipitation of 700 mm. In addition, the response of SOC to organic farming showed some positive trend with increasing soil pH (p=0.059).Overall, cereal yield in organic farming was about 30% lower compared to conventional farming systems. However, yield performance of organic systems varied statistically significantly across farming types (p=0.021): a 20% yield gap was observed in organic systems using animal-based fertilizers, while a 35% yield gap was shown in organic systems using only legumes or mixed green manure. Moreover, the yield gap decreased with increasing average annual temperature (p=0.002). Overall, the temporal yield variation of organic farming systems was about 50% larger than in conventional systems, which was not related to any pedoclimatic factors studied.In conclusion, organic farming systems had a positive impact on SOC in the topsoil, compared to conventional systems. The magnitude of this influence mainly depended on pedoclimatic characteristics in Europe. In terms of cereal production, organic farming had lower yields and yield stability compared to conventional farming.

Yield gap between organic and conventional farming systems across climate types and sub-types: A meta-analysis