不同种植制度下长期施钾与秸秆还田对作物产量和土壤钾素的影响

Effect of Long-Term Application of K Fertilizer and Wheat Straw to Soil on Crop Yield and Soil K Under Different Planting Systems

【目的】研究施钾和秸秆还田对华北地区不同种植制度下作物产量和耕层土壤钾素状况的影响。【方法】在华北平原的河北潮土和山西褐土上进行连续13年的施钾和秸秆还田试验。【结果】施钾和秸秆还田能增加小麦和玉米产量,处理之间表现为:NPK+St>NPK>NP+St>NP,施钾处理的作物产量与NP处理的产量差异显著,轮作制度下玉米的施钾效应高于小麦。与山西单作制度相比,河北轮作制度下的土壤钾素损耗严重,除NPK+St处理外土壤钾素均表现亏缺。秸秆还田和施用钾肥较NP处理可不同程度提高河北潮土和山西褐土耕层土的水溶性钾、非特殊吸附钾、非交换性钾、矿物钾及全钾含量,且降低矿物钾比例的同时提高其余几种形态钾的比例。与定位开始相比,两种类型土壤各形态钾含量和比例随时间变异特点不同,两定位点土壤矿物钾和全钾含量均表现下降。【结论】整体看直接施用化肥钾的效果优于秸秆还田。但从提高作物产量和缓解土壤钾素下降来看,小麦秸秆还田是一个有效的补钾措施。

[ Objective ] Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in plough layer under different planting systems was studied. [Method] Experiment on long-term application of K fertilizer and wheat straw to soil experiments in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992. [Result]The results showed that K fertilizer and straw could improve yields of wheat and maize, and treatments showed： NPK＋St〉NPK〉NP＋St〉NP, and treatment of K fertilizer made a significant difference to NP, and efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei. In contrast with Shanxi, soil potassium wastage of rotation system in Hebei was more serious, only potassium in treatment of NPK＋St showed a surplus and others showed a wane. K fertilizer and straw could improve content of water-soluble K, non-specifically adsorbed K, non-exchangeable K, mineral K and total K in contrast to NP, however reduce proportion of mineral K and improve those of others in the two locating sites. Compared with the orientation＇s beginning, temporal variability character of soil K content and proportion showed a difference between two soil types, further more content of mineral K and total K behaved a decrease accordantly in two locating sites. [Conclusion] As a whole, effect of K fertilizer applied to soil directly was excelled to wheat straw to soil. In order to increase crop yield and retard decrease of soil K, wheat straw to soil was an effective measure to complement potassium.