Enhancing yields and climate resilience through conservation agriculture: multi-year regional on-farm trials in Zambia

Abstract

Abstract Background and aims Conservation agriculture (CA) has gained traction as a climate-smart management strategy to enhance food security and maintain soil quality. However, nearly all investigations are based on controlled experimental studies with few long-term on-farm trials. The objective of the study was to assess the effect of CA on maize yield and soil fertility at smallholder farms in Zambia (2016–2021). Methods About 100 on-farm trials were established. CA plots with maize ( Zea mays L.) in annual rotation with soybean were compared pairwise with conventional plots, with maize monocropping, which were managed in accordance with local practices. Maize grain yield and soil pH, organic carbon, phosphorus and nitrogen were investigated. Results Maize grain yield was significantly higher in CA (+ 24% to + 39%) compared to conventional management, due to early sowing and more effective use of precipitation. However, after 5 years, there was no significant difference in soil fertility between CA and conventional agriculture. Conclusion CA provides a viable option for climate change adaptation due to increased yields and drought resilience. The higher yield under CA provides an opportunity to enhance food security. However, our results do not support that CA enhances soil organic carbon, available phosphorus and nitrogen after 5 years of maize-soybean rotation.