黄土高原春玉米保护性耕作农田土壤养分时空动态变化研究

试验以传统耕作(CT)为对照,连续3 a研究了保护性耕作(NT),传统耕作+秸秆还田(TS)处理下黄土高原春玉米田土壤养分含量的动态变化。结果表明,与传统耕作相比,保护性耕作处理各土层土壤有机质含量随春玉米生育期推进呈上升趋势,其中收获后耕作层土壤有机质含量增加明显;保护性耕作使得土壤碱解氮有向表面富集的趋势,保护性耕作下土壤速效磷略显增加趋势,其中在玉米收获后表现较明显,且较TS和CT处理差异显著;速效钾含量保护性耕作处理要显著低于其它处理,但有增加趋势。

Spatial and temporal changes of soil nutrients of spring maize field in the Loess Plateau under conservation tillage

Three kinds of farming measures were adopted, such as no tllage (NT), conventional tillage + straw returming (TS) and conventional tillage (CT), to study the effects of different tillage treatments on soil nutrient content of spring maize field in the Loess Plateau for three consecutive years. The results show that soil organic matter content turns a rising trend under conservation tillage with the growing period, in which the soil organic matter content in arable layer was significantly higher than that under other two treatments; Conservation tillage makes the soil nitrogen enrichment up to the surface of soil; The available phosphorus is increasing slightly under conservation tillage , which is obvious in the harvest time and is significantly diferent from that under TS and CT treatments; The available potassium under conserva-tion tllage treatment is significantly lower than that under other treatments, but there is an increasing trend.