不同施肥处理对土壤团聚体和硝态氮含量的影响

在25年长期定位试验研究基础上,分析了无肥、N、NP、NPK、N+有机肥和N+秸秆6个不同施肥处理土壤的团聚体含量和NO3-N含量。结果表明:施用有机肥以及NPK化肥合理配施可以增加土壤团聚体含量,提高团聚体的稳定性。水稳性团聚体含量与有机质含量呈r2=0.9251的正相关关系。6个不同施肥处理在施N量相同的条件下,单施N肥土壤的NO3-N含量最高,分别是N+有机肥、NPK、NP处理的2.9倍、1.8倍和1.6倍。不平衡施肥是引起土壤NO3-N大量累积的重要原因,施用有机肥以及NPK合理配合施用可明显地减少土壤NO3-N的残留。

Effects of Different Fertilization Treatments on the Soil Aggregate and NO3-N Content

On the base of 25-year located study, analysis was made on soil aggregate and NO3-N content treated with N, NP, NPK, N+organic, N+straw and no fertilizer respectively. Organic and NPK chemical fertilizer could increase the soil aggregate content and enhance the stability. Water-stability aggregate was positive correlated with organic content at r2 =0.9251. By six kind of fertilization treatments with equivalent N content, NO3-N content with only N fertilizer utilization were 2.9, 1.8 and 1.6 times higher than that in N+ organic fertilizer, NPK and NP treatments. Unbalanced fertilization was the key reason for NO3-N accumulation, reasonably fertilization, organic manure and NPK could reduce the NO3-N residual.