Residual Effect of Biochar and Legumes on Soil Fertility, Yield and Yield Components of Wheat

Abstract

Biochar and the use of legumes in cropping systems are considered sustainable approaches to boost crop yield and preserve soil fertility. In the current study, the effects of leftover biochar and previously planted legumes on wheat yield and soil N status were examined at various nitrogen (N) levels. The experiment included testing two levels of previously applied biochar (0 and 50 tons ha^-1), three legumes under four levels of N (0, 60, 90, and 120 kg ha^-1), cowpea (Vigna unguiculata) for fodder, Sesbenia (Sesbenia grandaflora) for green manuring, and mung bean (Vigna radiata) for grain. Results showed that biochar application enhanced wheat tiller m^-2, spikes m^-2, grains per spike, thousand grain weight, grain yield, biological yield, and soil total N status by 3%, 6.5%, 3.7%, 1.8%, 7.8%, 9.5%, and 11%, respectively. Moreover, applying nitrogen at a rate of 90 kg ha^-1 increased the amount of wheat spike m^-2 by 20%, grain spike^-1 by 10%, grain yield by 70%, biological yield by 48%, harvest index by 27%, and the N content of the grain, straw, and soil by 13%, 14%, and 36% respectively. Meanwhile, 1000 grain weight resulted higher by 6.17%. Legumes that had been previously seeded outperformed fallow and increased spikes m^-2, grain yield, biological yield, grain N content, and soil total N content by 8.2%, 11%, 6.78%, 25%, and 42%, respectively. It is determined that applying biochar to the summer gap left by legumes can increase soil fertility and wheat output.