关键词: 生物炭, 玉米生育期, 土壤微生物量碳, 土壤微生物量氮, 玉米产量

Abstract: A field experiment was carried out to determine the effects of biochar on the dynamics of soil microbial biomass carbon and nitrogen during maize growing season, and the yields of maize were also studied after harvest. Biochar was applied by 0 (BC0), 10 (BC1), 20 (BC2) and 30(BC3) t·hm-2, and each biochar treatment reached same rates of chemical fertilizers. Results showed that soil microbial biomass carbons were generally increased with the increase of biochar application rates compared with the control in each soil layer. Compared with BC0, soil microbial biomass carbon in BC3 before planting were significantly increased 103.2%, 91.8% and 158.5% in 0—10, 10—20 and 20—30 cm soil layers, respectively. Soil microbial biomass nitrogen and the ratio of microbial biomass carbon to nitrogen were changed during the maize growing season. In addition, soil microbial biomass carbon and nitrogen were low before maize plating and reached a peak at the jointing stage, then decreased slowly and remained stable. The increase of microbial quotient in BC3 reached 59.5% before planting, while no significant effects  on microbial quotient were observed at other growing stages. The yields of maize were increased with increasing biochar rate, the increases of yield in BC2 and BC3 reached 11.2% and 14.1%. In summary, the application of biochar in the soil could generally increase soil microbial biomass, improve soil fertility and crop yield. The present research provided a  scientific basis for rational application of biochar in this studied area.

Key words: biochar, maize growth stage, soil microbial biomass carbon, soil microbial biomass nitrogen, maize yield