陕北农牧交错带荒漠化土壤肥力水平研究

Study on the fertility of desertification soil in the agriculture and animal husbandry interlaced zone of Northern Shaanxi

通过野外调查和室内化验,对陕北农牧交错带荒漠化土壤的理化性质和肥力状况进行了研究。结果表明,荒漠化土壤机械组成为:砂粒含量>784.0g/kg,有机质含量<3.67g/kg,阳离子交换量不超过6.37cmol/kg,氮、磷、钾等营养元素不足,土壤的综合肥力质量低;从沙丘流动到固定沙丘,表层土壤粒径>0.25mm的砂粒降低,5mm以上的团聚体增加,土壤有机质和氮、磷、钾等速效养分增高,离子吸附交换能力增强。可以认为,土壤肥力差异是荒漠化的本质反映,结皮层可作为荒漠化类型土壤鉴定的主要依据。

Integrating field investigation with analysis in laboratory,the physical and chemical characteristics of desertification soil and the status of fertility were studied in the agriculture and animal husbandry interlaced zone of northern Shaanxi.The results showed that:Among the mechanical composition of desertification soil,the contents of sand particle were more than 784.0 g/kg,and that of organic matter less than 3.67 g/kg,CEC (cation exchange capacity) not over 6.37 cmol/kg.The nutrients of nitrogen,phosphorous,potassium etc.were scarce;the total soil fertility was low;from the mobile sand dunes to the fixed sand dunes,the content of sand particle in the soil surface layer,with a diameter of gt 0.25 mm decreased,and that of the aggregate with a diameter of gt 5 mm increased,and that of available nutrients such as organic matter,nitrogen,phosphorous and potassium etc.rose,ion exchange absorption ability was enchanced.The diversity of soil fertility reflects the essence of desertification;and soil crust is the main factors of identifying the type of desertification.