Impact of Integrated Soil Fertility Management Practices on Cocoa Yield and Food Security in Ghana

Abstract

Integrated Soil Fertility Management (ISFM) combines the use of inorganic fertilizers, organic inputs, and aboveground practices like pruning, weeding, pest control, and shade management, tailored to local conditions to improve soil fertility and boost crop yields. This study assesses the impact of ISFM practices on cocoa output and food security among smallholder cocoa farmers in Ghana as a strategy for sustainable cocoa intensification. The study aimed to achieve three key objectives: (1) identifying factors influencing the extent of ISFM adoption among smallholder cocoa farmers, (2) estimating the impact of ISFM adoption on cocoa yields, and (3) assessing the effects of ISFM adoption on farm income and food security. Data was collected from 442 cocoa farmers (221 in treatment and 221 in control groups) across Ghana’s Ashanti, Western North, and Western Regions using a multistage sampling technique with additional qualitative data collected from fifteen key informants (elites) to provide insights into various aspects of ISFM adoption and its effects on cocoa yield, farm income(gross margin), and food security. The analysis applies a multinomial logit model to evaluate adoption factors, and uses Propensity Score Matching (PSM) and Inverse Probability Weighted Ratio Adjusted (IPWRA) models to measure ISFM's impact on yields, income, and food security. The findings reveal that factors such as household size, land tenure security, access to credit, and extension services play significant roles in influencing ISFM adoption. Larger households, due to their labour capacity, are more likely to adopt ISFM practices, while factors such as decision-making autonomy and secure land tenure encourage the adoption of inorganic fertilizers. Cocoa farming as a primary occupation significantly enhances the likelihood of adopting organic fertilizers, while marital status and livestock ownership promote the use of aboveground ISFM practices. These results emphasize the importance of financial resources, land tenure security, and technical knowledge in facilitating ISFM adoption. Econometric analyses show that ISFM adoption significantly enhances cocoa yields. PSM and IPWRA results indicate that inorganic fertilizer uses alone boosts yield by 69.80% and 61.54%, respectively, while organic fertilizer alone increases yield by 63.50% and 47.88%. The highest yield improvements are observed when complete ISFM practices are carried out (inorganic fertilizer, organic fertilizer and aboveground), resulting in increases of 93.87% (PSM) and 71.02% (IPWRA), demonstrating the efficacy of an integrated approach. In terms of income (gross margin), the PSM analysis shows that combining inorganic fertilizer and aboveground ISFM practices leads to an income (gross margin) rise of GH₵ 1,281.11, while aboveground practices alone increase income (gross margin) by GH₵ 2,807.37. The IPWRA model supports these findings, though the income (gross margin) rises are slightly smaller, with the combined ISFM practices (inorganic fertilizer and aboveground) yielding GH₵ 744.36. Additionally, PSM analysis reveals that using inorganic fertilizer alone reduces food insecurity by 17.1%, while combining it with aboveground practices results in a 11.8% reduction in food insecurity. The IPWRA model confirms these results, though the reductions are slightly smaller. Hence, ISFM practices significantly improve cocoa yields, farm income (gross margin), and food security. To enhance ISFM adoption, the study recommends strengthening agricultural extension services, improving access to credit, and ensuring secure land tenure. Additionally, introducing subsidies and labour-saving technologies helps to overcome barriers to ISFM adoption among smallholder cocoa farmers.