Effects of main intercropping practices on the soil biophysical parameters and cashew yield in cashew-based agroforestry systems in Benin
摘要
Several studies have examined intercropping in cashew-based agroforestry systems, but few have focused on its effects on soil biophysical parameters and cashew yields. This study aims to evaluate the influence of major intercropping practices on cashew productivity and key soil fertility indicators in the main producing regions of Benin. The experiment consisted of 48 plots arranged in a Randomized Complete Block Design (RCBD) with four blocks (sites) and four treatments, each with three replicates (farmers) per site. The treatments included the main cashew-based intercropping: cashew-soybeans, cashew-maize, cashew-peppers, and a control (cashew without intercropping). The effects of intercrops on soil cover, soil moisture, and major soil fertility indicators (C, OM, pH, CEC, N, P2O5, K2O, Ca, and Mg), as well as cashew nut yields, were analyzed using appropriate models in R 4.5.1. Results showed that soybeans provided significantly higher soil cover (22–26%) than maize (15–22%) and peppers (5–9%), generally from the 60th to 90th day after sowing (DAS). They also enhanced average soil moisture conservation by 3.4–9.7%. Additionally, soybeans significantly improved key soil fertility indicators (C, OM, N) after two growing years, increasing N by 2.3 times and C and OM by 3.17 times, which may result in approximately 35.7% higher cashew nut yields. Soybeans, which consume less N fertilizer and improve more soil biophysical parameters, could be recommended as a suitable intercrop in agroforestry systems in the context of climate-smart agriculture. However, further research should be conducted to explore which rotation systems could sustain their benefits within cashew orchards.