Effects of biochar and TUAT-1 bio-inoculant on grain yield and nitrogen efficiency of forage rice 'Monster rice 1' under different N application modes

The application of bio-inoculant and biochar can be an effective strategy for stimulating crop growth, while improving soil fertility in an environmentally friendly manner. A greenhouse experiment was conducted to study the effects of biochar and TUAT-1 bio-inoculant under two N fertilization modes (basal and split) on the yield of forage rice and nutrient distribution in the soil rhizosphere. Positive effects of the biochar and bio-inoculant, either alone or in combination, on growth, photosynthesis rate, and yield components were depended on the mode of N application. There was no change in either microbial biomass carbon (MBC) or microbial biomass nitrogen (MBN) with the treatments of biochar and bio-inoculant with split N fertilization, whereas both these treatments, either alone or in combination, resulted in higher MBC and MBN with basal N fertilization. The NO3--N concentration of surface floodwater under biochar treatment was significantly reduced immediately after soil N fertilization, whereas biochar addition did not reduce the NH4+-N concentration of surface floodwater at each of our monitoring points. The findings indicate that biochar and the mode of N fertilization have the potential to improve forage rice productivity and soil nutrient availability, while minimizing the potential of nitrate (NO3--N) leaching.