关键词: 农业气象灾害, 农业气象灾害, 灾情调查, 分级规范

Abstract:

To further study the effects of returning wheat straws to fields directly on raising the yield of crops and fertilizing soil, and to find out farming methods which are suitable to this area and that can raise the yield of crops and improve soil fertility, a comparative test was conducted by fertilizing only, returning wheat straws to fields without fertilizing, and returning wheat straws to fields plus applying a certain quantity of fertilizer. The results showed that returning wheat straws to fields directly could raise the yields of succession crops significantly; returning wheat straws to fields directly plus fertilizing could raise the yields of succession crops more significantly than just returning wheat straws to fields and than just fertilizing; moreover, returning wheat straws to fields directly could increase organic matter, total nitrogen, total phosphorus, soil nitrogen, and rapidly available phosphorus and potassium of soil in various degrees; meanwhile, it could help reduce soil bulk density, increase soil porosity and permeability rates, and improve soil microbial and soil enzyme activity. Returning wheat straw to crop fields directly plus fertilizing should be popularized and it has far-reaching effects.