Nitrogen Fertilizer Reduction Combined with Biochar Application Maintain the Yield and Nitrogen Supply of Rice but Improve the Nitrogen Use Efficiency

Excessive application of nitrogen (N) fertilizer will cause many adverse consequences in paddy fields, especially for the reduction N use efficiency. Biochar can be used to replace part rice production. A field experiment 2-year/four-season was conducted investigate effects combined with straw biochar on yield, soil fertility, and The contained six treatments: No (CK), customary (N100), 20% (N80), + (N80+BC), 40% (N60), (N60+BC). Compared N100, alone had no significant impact number tillers aboveground biomass rice, exceptfor N60 which slightly reduced grain while incorporation tended obtain higher tillers, biomass, yield compared alone. average contribution basis N80 were 5.8% 7.7%, respectively. Notably, further improved agronomic efficiency (54.5–309.4% over N100) apparent recovery (25.7–150.5% reduction. Furthermore, could not only maintain nutrition level but also improve fertility mainly by increasing pH organic matter. Therefore, integrated mineral is a feasible nutrient management measure increase ecosystem.