秸秆还田对双季稻产量和土壤钾素平衡的影响

探究秸秆还田对水稻产量和土壤钾素平衡的效应,为安徽双季稻区秸秆还田和钾素合理利用提供科学依据。本试验于2013—2015年在安徽省桐城市进行,试验共设置5个处理,分别为：不施肥(CK)、不施肥+秸秆还田(CK+S)、氮磷钾(NPK)、氮磷钾+秸秆还田(NPK+S)、氮磷+80%钾+秸秆还田(NP+80%K+S)。结果显示：无论是在施肥和不施肥条件下,秸秆还田对水稻产量都没有显著负效应,而且秸秆还田替代20%化学钾肥不会减少水稻产量;CK+S、NPK和NPK+S处理的钾素表观平衡系数分别为0.90、0.48、1.40,说明单施化肥不能减缓作物对土壤钾素的消耗,秸秆还田可以显著提高土壤速效钾含量,有利于土壤钾素的收支平衡,对维持当地土壤钾素水平具有重要意义。

Effect of Straw Returning on Yield and Soil Potassium Balance of Double Cropping Rice

Field experiments were carried out to explore the effects of straw returning on rice yield and soil potassium balance, to provide a basis for straw returning and potassium use in double cropping rice area. The experiments were set in Tongcheng, Anhui in 2013 to 2015 with five treatments, including no fertilization (CK), no fertilization + straw returning (CK+S), fertilization (NPK), fertilization + straw returning (NPK+S) and nitrogen and phosphorus + 80% potassium + straw returning (NP+80%K+S). The results showed that there was no significant negative effect on rice yield among these treatments, and the rice yield under NP+80%K+S was not reduced. The apparent balance coefficient of potassium of CK+S, NPK and NPK+S was 0.90, 0.48 and 1.40, respectively. These results indicate that the application of chemical fertilizer can not inhibit the consumption of potassium by crops. The straw returning can increase the content of soil available potassium significantly, and improve the balance of soil potassium, which is important to maintain the local soil potassium level.