荆门市小麦地稻草覆盖增产作用及机理

在荆门市白散土(黄棕壤发育的水稻土)上进行的田间小区试验表明,稻草覆盖小麦田后,土壤速效钾含量大幅提高,并能改善土壤理化性状,显著增加土壤含水量,调节地温,提高土壤肥力。覆草与对照相比,可明显增加小麦有效穗和千粒重,产量由不覆盖的2899 5kg/hm2增高到3558kg/hm2。实验室淋溶试验可看出,3小时后稻草中84%的钾就被淋溶出来。而在大田试验中4个月后,有90%的钾进入土壤。所以秸秆还田是缓解钾肥资源不足的一项有效措施,值得推广应用。

Production increase effect and mechanism for straw covering of wheat field in jingmen city

The field experiment that carried out in Bai San soil(Paddy soil derived from yellow brown soil) in Jing-men showed, after rice straw overlaying the wheat farmland, there was significant alteration on the content of available potassium in soil. In addition, the rice straw overlay could improve the physical and chemical properties of the soil, and increase the amount of water content in soil, regulate the soil temperature. Compared with the check treatment, the soil covered with rice straw could increase the valid seed and the weight of seed in wheat obviously, the yield increased from 2899.5kg/hm~2 of uncovered to 3558kg/hm~2 covered. The 84% potassium in the rice straw was poured out within only 3 hours. But after 4 months in field trial, 90% potassium entered the soil. Therefore, the returning rice straw to farmland is an effective method to alleviate the fertilizer resources in potassium shortage, deserving expansion application in the soil region that lacks potassium.