长期减量施肥对设施耕地土壤养分含量的影响

为了研究不同种植制度下长期减量施肥对设施耕地土壤养分含量的影响,对昆明市晋宁区5个土壤养分监测点施肥和土壤养分检测数据进行统计分析,比较不同施肥处理对土壤养分的影响。结果表明：不同观测点长期常规施肥、推荐施肥（减量）下土壤有机质没有发生明显差异,空白不施肥下土壤有机质明显下降。不施肥与施肥处理相比土壤碱解氮、有效磷明显降低,不同观测点方差分析显示达显著水平,推荐施肥（减量）与常规施肥土壤碱解氮、有效磷养分含量之间没有明显差异,但碱解氮有随着减肥幅度增加,土壤养分含量减少的趋势。长期施磷造成设施土壤有效磷有明显累积,不同观测点方差分析显示达显著水平。结果说明长期减量施用氮、磷肥在一定范围内并不会造成设施耕地土壤有机质、碱解氮、有效磷养分的减少,减量施肥是减少设施耕地土壤有效养分累积、保持土壤养分稳定的重要措施。

Effects of Long-term Reducing Fertilization on Soil Nutrient Content in Protected Cultivated Land

To study the effect of long-term reducing fertilization on soil nutrient content in protected cultivated land under different cropping systems, the soil nutrients and fertilization rate of five long-term soil nutrient monitoring points in Jinning County of Kunming City were statistically analyzed, and the effect of different fertilization treatments on soil nutrient was compared. The results showed that there was no significant difference in soil organic matter between long-term reducing fertilizer treatment and conventional fertilizer treatment, but the organic matter in long-term non-fertilization decreased significantly. Compared with those of the fertilization treatment, soil available N and available P of non-fertilization treatment decreased obviously. There was no significant difference in soil available N and available P between reducing fertilizer treatment and conventional fertilizer treatment, but available N decreased as nitrogen fertilizer decreased. Due to the long-term phosphorus fertilizer application, enrichment effect of phosphorus was significant in protected soil. Long-term reducing nitrogen application will not result in the decrease of soil organic matter, available N and available P in protected cultivated land.