Soil fertility status as influenced by the carryover effect of biochar and summer legumes

There are numerous benefits of biochar and summer legumes in the soil fertility status enhancement, so, keeping in consideration these benefits, a research study was designed to investigate the soil fertility status influence with the carryover effect of biochar and summer legumes at the UAP Research Farm, during winter 2016-2017. An experiment in the rotation was conducted in summer 2016 having three summer legumes for a specific purpose i.e. mungbean (grain), sesbania (green manuring), and cowpea (fodder), control was also comprised. Biochar synthesized domestically in a furnace from small wood cuttings on a pyrolysis temperature (400–500◦C) and applied once to legumes @ 0, 5 and 10 tons ha-1. When the legumes were harvested, the residues of sesbania remained in the soil, while the residues of the other two legumes were taken away. The test for soil fertility status investigation was performed on subsequent wheat in RCBD with three replicates on the previous field layout of legumes. Significantly maximum soil total nitrogen, extractable P, K, Fe, Zn, Mn were obtained in the plots previously incorporated with sesbania. However, Cu was not significantly affected. While, in the case of preceding biochar, maximum soil total nitrogen, extractable P, K, Cu, Fe, Zn, and Mn were obtained on 10 tons ha-1. The biochar-legumes interaction was significant for macronutrients while non-significant for micronutrients. Thus, it is concluded that preceding legumes and previously applied biochar showed a significant carry-over effect on soil fertility status.