地膜覆盖及不同施肥处理对土壤微生物量碳和氮的影响

采用培养熏蒸-提取法测定了不同施肥处理和长期地膜覆盖条件下土壤微生物量碳和氮的含量。结果表明:长期不同施肥处理对土壤微生物量碳和氮产生显著影响。长期施有机肥和有机无机肥配合施用使土壤微生物量碳平均提高102.6%和60.1%,使土壤微生物量氮平均提高107%和41.2%;施氮肥处理则使土壤微生物量碳平均降低30.8%,使微生物量氮平均降低1.46%。地膜覆盖对土壤微生物量碳和氮影响不显著,不同施肥处理覆膜后变化趋势不同。其中,对照、N4及M4N2P1处理土壤微生物量碳覆膜后平均升高20.4%、44.6%和12.9%,土壤微生物量氮平均升高22.9%、12.7%和56.5%;而M4处理土壤微生物量碳覆膜后平均降低27.5%,微生物量氮平均降低31.2%。另外,长期施用有机肥可以提高微生物对肥料的利用率,而长期施氮肥则降低其利用率;长期地膜覆盖可使土壤微生物对肥料固作用更加明显。

Effect of Plastic Mulching and Different Fertilization Treatments on Soil Microbial Biomass Carbon and Nitrogen

In order to probe into the changes of microbial biomass carbon and nitrogen in the plastic mulching soil and different fertilization treatments, this research determined microbial biomass carbon and nitrogen in the different fertilization treatments and plastic mulching soil at the long - term located brown earth experiment site at Shengyang Agricultural University using the measure of suffocating - extraction. The results indicated that soil biomass carbon and nitrogen were remarkably influenced by fertilization. Applying organic matters and the combination of organic and inorganic matters in long-term increased the microbial biomass carbon 102.6% and 60. 1% averagely and increased the microbial biomass nitrogen 107% and 41.2% averagely. Applying nitrogen fertilizer decreased the microbial biomass carbon 30. 8% averagely and decreased the microbial biomass nitrogen 1.46% averagely. Plastic mulching has significant effect on soil microbial biomass carbon and nitrogen. The changes of soil microbial biomass carbon and nitrogen after plastic mulching wene different with the different fertilizations. The soil microbial biomass carbon of the treatments in CK, N4 and M4N2P1 increased 20.4% ,44. 6% and 12. 9% averagely and soil microbial biomass nitrogen increased 22.9% ,12. 7% and 56. 5% averagely after plastic mulching. The soil microbial biomass carbon of the treatments in N4 decreased 27. 5% averagely and soil microbial biomass nitrogen decreased 31.2% averagely. Otherwise, applying organic matters in longterm enhanced the use efficiency of soil microorganism to fertilizers but applying inorganic matters in long -term decreased the efficiency. Plastic mulching made the increasing action of soil microorganism to fertilizers more remarkably.