有机肥部分替代化肥对土壤微生物生物量及矿质态氮含量的影响

Influence of Partial Replacement of Chemical Fertilizer by Organic Manure on Soil Microbial Biomass and Mineral Nitrogen Content

土壤矿质态氮是植物有效养分的重要来源，土壤微生物量碳（SMBC）、微生物量氮（SMBN）是土壤微生态系统的重要组成部分，对土壤矿质态氮含量及作物养分吸收具有重要影响。试验通过盆栽的方法研究了有机肥部分替代化肥对土壤微生物量碳、微生物量氮及矿质态氮含量的影响。结果表明，施肥能提高土壤微生物量碳、微生物量氮和矿质态氮含量；小麦拔节至开花期，有机肥部分替代化肥处理的土壤微生物量碳、微生物量氮、矿质态氮含量明显高于化肥、纯有机肥和对照处理，其中以配施20％-30％有机肥的土壤微生物量碳、微生物量氮、矿质态氮含量最高；收获期纯有机肥处理的土壤微生物量碳、微生物量氮、矿质态氮含量略高于有机肥与化肥配施处理。可见有机肥部分替代化肥有利于提高小麦生育盛期土壤微生物量碳、微生物量氮和矿质态氮含量，更好地满足作物对养分的需求。

Soil mineral nitrogen （SMN） is an important source for plant nutrition. Soil microbial biomass carbon （SMBC） and soil microbial biomass nitrogen （SMBN） are the basilic components of soil microbial ecosystem, and can influence the content of SMN directly. SMBC, SMBN and SMN are significant to plant nutrient uptake. A pot experiment was carried out to study the effects of partial replacement of chemical fertilizer by organic manure on the content of SMBC, SMBN and SMN. The results obtained were as follows ： fertilization could enhance the content of SMBC, SMBN and SMN. At the stage from jointing to flowing of wheat, the treatment with partial replacement of chemical fertilizer by organic manure could increase the content of SMBC, SMBN and SMN remarkably in comparison with the other treatments. Combined application of 20% - 30% organic manure and 70% - 80% chemical fertilizer had the highest content of SMBC, SMBN and SMN. At harvest stage, the pure organic manure treatment had slightly higher content of SMBC, SMBN and SMN than the other treatments. It could be inferred that partial replacement of chemical fertilizer by organic manure could increase the content of SMBC, SMBN and SMN in the rapid growth period of wheat, and help to meet the nutrients demand of wheat better.