保护性耕作下黄土高原作物轮作系统土壤健康评价

摘要：在黄土高原雨养农业区，以4个耕作处理传统耕作(t)、传统耕作+秸秆覆盖（ts）、免耕(nt)和免耕+秸秆覆盖(nts)]的2年3熟粮豆轮作系统为对象，研究了0~5和5~10 cm土壤全碳、有机碳、全氮及微生物生物量碳和氮等指标的变化特征。结果表明，实施保护性耕作7年后，有机碳含量在ts、nt和nts处理下比t处理显著增加22.9%、25.3%和42.6%，0~5 cm层土壤微生物生物量碳和氮含量均以nts最高,t处理最低。在0~10 cm土层内，免耕促进了土壤碳的表聚化，但耕作有助于秸秆有机碳在土壤剖面的均匀分布。研究结果表明，短期尺度下微生物量碳和氮是反映耕作措施的敏感指标，中期尺度下土壤有机碳可以敏感反映土壤健康状况。

The evaluation of soil properties under conservation tillage in a maize-wheat-soybean rotation on the Loess Plateau

The aim of this study was to determine how soil properties changed when conservation tillage was used in a maize-wheat-soybean rotation on the Loess Plateau,China.The four tillage treatments were: t(conventional tillage),ts(conventional tillage with stubble retention),nt(no tillage) and nts(no tillage with stubble retention).Soil total C,organic C,total N and microbial biomass C and N in the 0-5 cm and the 5-10 cm layer was measured over a seven year period in each treatment.Soil organic C was significantly...