棉花-油菜轮作制中磷·钾肥合理分配研究

目的]探讨了棉花-油菜轮作制中磷、钾肥的合理分配,为相关区域棉花和油菜合理施用磷、钾肥及土壤磷、钾平衡调控提供参考。方法]采用田间4年定位试验并结合农户肥料使用情况调查,研究湖北东部潮土区棉花-油菜轮作制中磷、钾肥的合理分配问题。结果]棉花增施钾肥后增产显著,施钾4年平均增产27.3%,并对油菜有明显后效;油菜施磷4年平均增产约10%,增施钾肥的增产幅度较低;如果每年每季作物施磷肥(P2O590 kg/hm2)、钾肥(K2O 120 kg/hm2),土壤磷素盈余率为68.2%,钾素亏缺率约35.0%,且油菜季土壤K素亏缺量明显高于棉花季。结论]根据研究区域磷、钾肥料使用情况,兼顾肥料的增产效果和土壤肥力的维持与提高,提出"棉花增钾、油菜增磷增钾"的施肥措施。

Study on Assignment of Phosphate and Potassium Fertilizer in Cotton-Canola Rotation System

Objective]The research aimed to explore the rational distribution of P and K fertilizer in cotton-canola rotation system,and provide the references for the rational application of P and K fertilizer to cotton and canola and balanced control of P and K in soil in relevant region.Method] Combining with the investigation on applying condition of farmers' fertilizer,4-year location test was adopted to study the rational distribution issue of P and K fertilizer in cotton-canola rotation system on the moist soil district of eastern Hubei.Result] The cotton yield raised significantly after increasing application of K fertilizer,the average yield was increased by 27.3% for 4-year K fertilizer applying,and had evident aftereffect on canola.The average canola yield increased about 10% for 4-year P fertilizer application,the yield increasing range of P fertilizer application was less;if P fertilization on crop was 90 kg/hm2 P2O5 and K fertilization was 120 kg/hm2 K2O per season of every year,soil surplus of P was 68.2%,and soil K deficit rate was 35.0%,and the soil K deficient amount for canola season was obviously higher than that of cotton season.Conclusion] Considering on the yield increasing effect of fertilizer and the maintenance and improvement of soil fertility according to the study on the applying condition of P and K fertilizer in tested region,the fertilization measures of "K increasing application for cotton,and P and K increasing application for canola" were proposed.