Residual efficacy of biochar and organic-inorganic nutrient sources on growth efficiency and yield potential of green gram (Vigna radiata L.) under a wheat-green gram cropping system

Abstract

The present investigation was carried out at the research farm of Lovely Professional University, Jalandhar, Punjab. The wheat–green gram field experiment was conducted to evaluate the residual effect of different biochar sources and nutrient management on growth and yield potential of green gram. The experiment was laid out in split plot design with three biochar sources i.e., paddy straw biochar (B1), red gram stover biochar (B2) and cotton stover biochar (B3) as main plot and four nutrient management practices as sub-plots, which were 100 % recommended dose of fertilisers (RDF) (N1), 70 % RDF + foliar spray (FS) of liquid compost (N2), 70 % RDF + FS of nano diammonium phosphate (DAP) (N3) and control (N4) with three replications. The results revealed that B3 recorded higher plant height, higher accumulation of biomass, leaf area index (LAI), chlorophyll index and yield attributes than other biochar sources. Similarly, the residual effect of 100 % RDF (N1) recorded significantly higher growth and yield attributes than other nutrient management practices. Therefore, the interaction treatment B3N1 recorded the significantly highest grain yield (21.92 q ha-1) and straw yield (40.52 q ha-1). However, 70 % RDF with liquid compost or nano DAP can also be used to supplement or partially substitute for synthetic fertilisers and act as a sustainable crop production system. These findings highlight the potential of biochar blended nutrient management in optimising green gram productivity while reducing dependence on synthetic fertilisers.