玉米秸秆直接还田配施促腐剂效应研究 Ⅱ.对土壤磷素和钾素时空动态变化的影响

Effects of Maize Straw's Returning Application with Transformation Promoter II.Effects on the Space-time Dynamic Variations of Soil P and K Nutrient

通过2年田间定位试验,研究了冀东地区玉米秸秆连续直接还田对土壤磷素和钾素养分时空动态变化的影响。结果表明,玉米秸秆直接还田可明显提高土壤磷素和钾素供应水平。小麦生长期间,玉米秸秆直接还田后磷素的转化表现为前期净释放、中期净固持、后期净释放;钾素的转化则表现为前期大量释放,中、后期释放量逐次减少。在调节秸秆C/N15∶1～35∶1范围内,调节秸秆不同C/N未改变秸秆还田后的转化进程,其转化对土壤磷素和钾素时空动态变化的影响亦无明显差异。在调节秸秆C/N的前提下配施促腐剂,使秸秆还田后的转化进程明显加快。

A 2-year experiment was conducted in cinnamon soil in the eastern parts of Hebei Province and the effects on the space-time dynamic changes of soil P and K nutrient with returning application of maize straw were studied. The results showed that returning application of maize straw could significantly improve the supply of soil P and K. In the stage of wheat growing, P transformation with returning application of maize straw indicated the characteristics as follows: net release in the previous period, net fixation in the middle and net release in the later period; while K transformation showed huge release in the previous period, but reduction step by step in the middle and later period. Adjusting the proportion of straw C/N from 15∶1 to 35∶1, the course of transformation with application of maize straw did not change, and there was no obvious difference to the space-time dynamic variations of soil P and K. Adjusting the straw proportion of straw C/N with transformation promoter could remarkably quicken the step of transformation of maize straw.