长期减量化施肥对水稻产量和土壤肥力的影响

Effects of Long-term Reducing Fertilization on Yield and Soil Fertility of Rice

为探讨减量化施肥对水稻产量及土壤肥力的影响,对巢湖流域连续10年减量化施肥和秸秆还田定位试验后的水稻产量、土壤有机质、有效氮磷钾、有效铜锌铁锰含量及土壤酶活性进行了测定和分析。结果表明:长期减氮30%或减磷50%处理对水稻产量无明显降低作用,减量+秸秆还田有增产作用,但增产不显著;减氮30%或减磷50%会降低土壤中有机质含量,增加土壤中速效钾、碱解氮含量,减磷50%土壤中的有效磷含量显著降低,减量+秸秆还田会增加土壤中的有机质、速效钾、碱解氮、有效铜锌铁锰含量,对有效磷的增加效果不显著;较不施肥相比,施肥能够明显提高土壤的酶活性,减少氮磷肥会一定程度地降低土壤中的酶活性,减量+秸秆还田对脲酶的增加效果不明显,但会显著增加土壤中性磷酸酶和蔗糖酶活性;土壤酶活性与水稻产量及土壤养分含量之间呈显著或极显著正相关关系。综合考虑减量化施肥对水稻产量和土壤肥力的影响,可提出在巢湖流域实施减量化施肥+秸秆还田处理来代替高产施肥。

To investigate the effect of reduced fertilization on rice yield and soil fertility,the rice yield,soil organic matter,available NPK and effective copper,zinc,iron and manganese content after10years of reduced fertilization and straw returning in the Chaohu Lake Basin were tested.Soil enzyme activity was measured and analyzed.The results showed that long-term nitrogen reduction of30%or50%phosphorus reduction had no significant effect on rice yield,but reduction+straw yield had an effect on yield increase,but the yield was not significant;reducing nitrogen by30%or reducing phosphorus by50%would reduce soil The content of organic matter increased the content of available potassium and alkali-hydrolyzed nitrogen in the soil.The content of available phosphorus in soil reduced significantly by50%of phosphorus reduction,and the amount of available organic matter,available potassium,alkali-hydrolyzed nitrogen,and effective copper and zinc were increased by reducing the amount of straw+returned to soil.The iron and manganese content had no significant effect on the increase of available phosphorus.Compared with no fertilizer application,fertilization could significantly increase soil enzyme activity.Decreasing N and P fertilizers would reduce enzyme activity in the soil to a certain extent.The reduction+straw returning to urease The effect of the increase was not obvious,but it would significantly increase the activity of neutral phosphatase and sucrase in soil.There was a significant or highly significant positive correlation between soil enzyme activity and rice yield and soil nutrient content.Considering the effect of reduced fertilization on rice yield and soil fertility,we can put forward the implementation of reducing fertilization and straw returning in Chaohu Lake Basin instead of optimizing fertilization.