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

ABSTRACT

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.

KEYWORDS:

• Biochar
• bio- inoculant
• mode of N fertilization
• N use efficiency
• microbial biomass
• grain yield

Acknowledgements

The authors thank Dr. Takashi Kenjo and Mr. Tomotaka Asano, Asahi Industries Co., LTD., Japan for providing TUAT-1 bio-inoculant used in this study. The authors would like to acknowledge Dr. Kaworu Ebana, The Institute of Agrobiological Science, NARO, (Tsukuba, Ibaraki, Japan) for the technical support during this study. Special thanks are also addressed to Ms. Minako Tanimura for her technical assistance with the experiment.

Disclosure of potential conflicts of interest

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by grants from the Project of the NARO Bio-oriented Technology Research Advancement Institution: the special scheme project on regional developing strategy (Grant No.16822446).