Understanding nutrient responses and response heterogeneity from on-farm and on-station fertiliser trials

Cocoa currently yields substantially less than its potential, leading to low incomes for farmers and, in some cases, the expansion of cocoa areas at the expense of forests. Proper and site-specific fertiliser recommendations could increase yields and, in turn, increase farmers’ incomes and potentially avoid deforestation. However, to achieve an appropriate formulation, it is essential to understand the nutrient needs of cocoa trees at different development stages, and how these can be met through better management of cocoa plantations. Opportunities exist for better recycling of nutrients and for balanced fertilization to address the crop’s nutrient needs through integrated soil fertility management, including efficient use of mineral and organic inputs. Moreover, it is important to understand the mechanism of cocoa nutrient uptake and identify the specific traits that can influence fertiliser uptake.

To this aim, there is a need for on-farm trials to assess the impact of management practices and fertiliser recommendations under different environmental conditions. Also, long-term multi-factorial fertiliser response trials to assess cocoa yield responses in various management practices, environments, and soil types. And socioeconomic analyses to understand the pros and cons of fertiliser recommendation from a farmer’s perspective and profitability assessments for a successful fertiliser recommendation.