长期施肥对土壤有机质氧化稳定性动态变化及其与肥力关系的影响

通过连续８年定位试验，研究了不同施肥方式下土壤有机质氧化稳定性的动态变化及其作物产量和肥力水平的关系。结果表明，长期不施肥七施用常量Ｎ、Ｐ、Ｋ化肥，使土壤易氧化有机质含量明显下降，进而引起土壤有机质总量减少，氧化稳定系数（Ｋｏｓ）升高，土壤供肥能力降低；连续施用增量Ｎ、Ｐ、Ｋ化肥，可使土壤有机质及Ｋｏｓ值保持稳定，但投入成本较高；长期施用有机肥（物）料配施常量Ｎ、Ｐ、Ｋ化肥，可明显提高土壤易氧化有机质含量和有机质总量，降低其Ｋｏｓ值，土壤对养分的供、贮能力增强，肥力提高，同时其作物产量显著高于增量Ｎ、Ｐ、Ｋ化肥处理，不同施肥方式主要影响土壤易氧化有机质含量，对难氧化有机质的影响较小。

The effect of long-term fertilization on the relationship between dynamic changes of oxidation stability of soil organic matter and soil fertility

A eight years long-term experiment with five different kinds of fertilizer application treatments were conducted. The relationship between dynamic changes of oxidation stability of soil organic matter and fertility was studied. The results showed that with readily oxidizable organic matter decrease under long term no fertilization or constant N,P,K chemical fertilizer application, total soil organic matter decreased. And soil fertility decreased. With increment N,P,K chemical fertilizer applied successively, soil organic matter and oxidation stability coefficient kept steady with high kos. Under long term organic manure used together with constant N,P,K fertilizer, soil readily oxidizable organic matter and total organic matter increased significantly. Oxidation stablility coefficient decreased.Reserves and supply of soil nutrient improved. And the crop yield was significant higher than incrememnt N,P,K chemical fertilizer treatment. There were obvious effect on soil readily oxidizable organic matter and little effect on difficultly oxidizable organic matter with different fertilization treatments.