Regulation of nitrogen balance and yield on greenhouse eggplant under biochar addition in Mollisol

Maintaining nitrogen (N) balance and inhibiting N leaching loss in the soil-crop system is crucial to maintaining yield reducing environmental pollution. This study investigated effects of soil NO3?-N content accumulation, eggplant yield, response biochar addition, including regular fertilisation irrigation (W + F), addition with F B), 20% reduction (0.8W 0.8F B) treatments. Compared W F, B 0.8W increased 0–40 cm accumulation 0–20 cm, raised harvest index, surplus balance. Simultaneously, compared enhanced use efficiency partial factor productivity, conversely, it decreased dry matter production efficiency, Stepwise regression analysis demonstrated that effect lasted 60 under first year, 20 without application next year. Altogether, most suitable management strategy decrease leaching, maintain uptake a two-year cycle on greenhouse vegetables Mollisols.