生物炭与氮肥配施对土壤生物特性和烤烟氮素吸收的影响

  目的  研究生物炭与氮肥减量配施对土壤生物特性和烤烟氮素分配的影响。  方法  采用盆栽试验, 氮肥为15N标记肥料, 测定生物炭与不同用量氮肥配施条件下烤烟生长不同时期土壤中肥料氮的残留量、土壤酶活性、微生物量碳含量和烤烟对不同氮源氮素的累积量。  结果  与对照相比, 不减氮时, 生物炭与氮肥配施使土壤酶活性提高了8.8%~19.5%, 微生物生物量碳含量提高了13.3%, 减少了烤烟生长前期肥料氮的流失, 提高了烤烟氮素累积量; 适量减氮时过氧化氢酶活性提高了7.8%, 蔗糖酶、脲酶活性和微生物量碳在中后期也有所提高, 氮素累积量提高了21.0%。  结论  生物炭能提高植烟土壤酶活性和微生物量, 减少肥料流失, 提高氮素累积量。生物炭与氮肥配施时适量减氮是可行的。 

Effects of mined biochar and nitrogen fertilizer on biological characteristics of soil and nitrogen absorpti on of flue-cured tobacco

In order to study the effects of mined biochar addition combined with nitrogen fertilizer on biological characteristics of soil and nitrogen absorption of flue-cured tobacco, pot experiment was unde rtaken with 15N trace technique. Fertilizer nitrogen residue, enzyme activity and soil microbial biomass carbon (SMBC) in soil, different sources nitrogen accumula tion of flue-cured tobacco at 90 days after transplanting were analysed. Compared with CK, enzyme activity of biochar addition combined with nitrogen fertilizer improved by 8.8%-19.5%, SMBC increased by 13.3%, 15N residue promoted o n early stage, and nitrogen accumulation of flue-cured tobacco also increased. When the amount of nitrogen reduced moderately, biochar addition combined with nitrogen fertilizer improved catalase activity and nitrogen accumulation. Sucrase and urease activity were promoted at mid and late stages. It was concluded that biochar significantly promoted activity of urease, sucrase and catalase, and improved fertilizer nitrogen soil residue and nitrogen accumulation in tobacco. It proved feasible to reduce the amount of nitrogen moderately when biochar combined with nitrogen fertilizer was added during tobacco planting.