Soil properties and groundnut (Arachis hypogea L.) responses to intercropping with Eucalyptus camaldulensis Dehn and amendment with its biochar

Abstract

In the South of Senegal, Eucalyptus camaldulensis is being intercropped with groundnut as an effort to avoid further deforestation. Introducing E. camaldulensis in agroforestry systems may have mitigated effects on soil and crop yield. This study was conducted to evaluate the effect of E. camaldulensis intercropping and its biochar amendment on groundnut yield. A factorial block design was set up in three sites (Boucotte Diembering, Boukitingho, Oussouye) in South Senegal in year1 with three treatments: E. camaldulensis intercropped with groundnut (Eucal+GrdNut), groundnut amended with E. camaldulensis biochar (Bioch+GrdNut), and groundnut cultivated alone (control). The study was repeated in two years. In biochar-amended plots, soil became significantly less acid in the site of Oussouye only (p<0.05). For all sites, there was also a significant increase in Ca2+ content and C/N compared to other treatments. Pod, seed, and biomass yield were significantly higher for biochar amended plots in Oussouye and Boucotte Diembering during both year1 and year2 (p<0.05). In Boukitingho also, pod yield was higher for biochar treatment for year1. When E. camaldulensis is intercropped with leguminous crop: groundnut, there was at least a decrease of 35% in seed yield (p<0.001). However, no effect was found for the soil physico chemical properties when E camaldulensis was intercropped for two years. Introduction of E. camaldulensis to agroforestry system may be beneficial only through the use of its biochar