秸秆还田与施钾对华北低产潮土区作物产量及土壤钾素的影响

Effect of straw returned to soil and application of potassium fertilizer on crops yield and soil potassium in the low fertility of efluvo-aquic soil in North China

在华北平原的低产田上,研究了3年秸秆还田和施钾肥对小麦-玉米作物产量和耕层土壤钾素状况的影响。结果表明,相对于NP处理,NPK和NPK+秸秆还田(St)处理对小麦和玉米均有显著的增产效果;NPK+St处理增产最为明显,而且降低了年度间的产量变异系数。秸秆还田可以显著增加土壤速效形态钾含量。同季作物种植下,NPK+St处理的钾肥利用率、钾肥农学效率和钾肥偏生产力都高于NPK处理。NPK+St能提高0～20 cm耕层土壤速效钾、非交换性钾、矿物态钾和全钾含量。因此,秸秆还田有利于土壤不同形态钾素的稳定和增加,而NPK+St处理不仅能保证作物高产稳产,还能提高土壤各形态钾素含量。

The effect of three years＇s traw returned to soil and application of potassium fertilizer on winter wheat - summer corn yields and topsoil potassium was conducted in the low fertility of efluvo-aquie soil in North China Plain. The result showed that yields of wheat and corn in treatments NPK and NPK ＋ St were significantly increased in contrast to that in treatment NP; the highest yield increment was achieved in treatment NPK ＋ St which also decreased yield coefficients of variation in different years. Straw returned to soil significantly increased some forms of soil available potassium content. Under the same crop grow- ing, the recovery effeieney of applied potassium, agronomy efficiency of applied potassium and partial factor productivity from applied potassium in treatment NPK ＋ St were higher than that in treatment NPK. Furthermore, these contents of soil available potassium, non-exchangeable potassium, mineral potassium and total potassium in topsoil of 0 ~ 20 cm were increased in treat- ment NPK ＋ St. Therefore, straw returned to soil could be beneficial to stabilize and improve different forms of soil potassium, and treatment NPK ＋ St could not only get high and stable crop yields, but also increase different forms of soil potassium content.