不同施肥制度下褐土结合态腐殖质动态变化

通过8年定位试验,研究了不同施肥制度下褐土结合态腐殖质动态变化规律。结果表明,不同施肥制度主要影响松结态腐殖质碳含量,对稳结态和紧结态的影响较小。采用有机肥(物)料配施常量NPK化肥,土壤有机碳和结合态腐殖质碳表现为以递减速率持续上升;不施肥和单施常量NPK化肥则造成土壤有机碳和结合态腐殖质碳不断降低,其下降速率亦表现为递减。在试验的不同阶段,土壤有机碳的亏损或盈余向结合态腐殖质碳分配比例的变化态势各异,不施肥处理随时间的延长渐增,而施用有机肥(物)料配施化肥则呈相反趋势。

Dynamic Change of Soil Combined Humus in Cinnamon Soil under Different Fertilizer Regimes

Eight years' experiment under different fertilizer regimes on dynamic change of soil combined humus quality in cinnamon soil was conducted.The results showed that there were obvious effects on soil loose-combined organic carbon and little effect on stable combined organic carbon and tight-combined organic carbon.Using organic fertilizer in combination with constant NPK chemical fertilizer not only raised continually the soil organic carbon but also combined organic carbon,but with decreasing rate.No fertilizer or mono-element chemical fertilizer not only decreased soil organic carbon but also decreased combined organic carbon progressively.The dynamic change of combined organic carbon under different fertilizer regimes showed asymptotic curve and imitated with asymptotic function.In different experimental period,the proportion of soil combined organic carbon loss or profit was different,increasing for the no fertilizer regime and decretasing for fertilizer regime.