论文部分内容阅读
从时空转换的角度出发,采用物理分离的方法,获得宁夏盐池县多年围封区沙漠化逆转过程中不同土壤粒径的组分,并进行了各组分中有机碳和养分含量的测定。结果表明:随沙漠化程度的减小,中粗砂、极细砂和粘粉粒组分中土壤有机碳(SOC)和氮、磷、钾(N、P、K)含量与全土组分中各养分含量的变化一致,均呈增加趋势;其中,与中粗砂和极细砂结合的非保护性颗粒养分对沙漠化逆转的响应和敏感程度较大。沙漠化逆转过程中,颗粒组分SOC和N、P、K养分的含量和富集系数,均为粘粉粒>极细砂>中粗砂,表层土壤中粘粉粒含量的增加对维持SOC和N、P、K养分的固存起着主要作用;沙漠化逆转过程中随着粘粉粒的不断沉积,与粘粉粒结合的相对稳定的SOC和N、P、K养分的相对数量不断增多,与中粗砂和极细砂结合的非保护性颗粒SOC和N、P、K养分的相对数量逐渐减小,SOC和N、P、K养分的稳定性上升。
From the perspective of space-time transformation, the physical separation method was used to obtain the components of different soil particle sizes during the course of desertification reversal in Yanchi County, Ningxia. The organic carbon and nutrient contents of each component were determined. The results showed that with the reduction of desertification, the content of soil organic carbon (SOC), nitrogen, phosphorus and potassium (N, P, K) in the coarse and coarse sand, The changes of nutrient contents were consistent and showed an increasing trend. Among them, the non-protective particulate nutrients combined with the coarse and fine sand had a greater response and sensitivity to desertification reversal. During the process of desertification reversal, the contents of SOC, N, P, K nutrients and enrichment coefficients of the grain fractions were both grit powder> fine sand> gritstone. The increase of sticky grit content in the surface soil contributed to maintaining SOC and N, P, K nutrients play a major role. With the continuous deposition of sticky particles during the process of desertification reversal, the relative amounts of SOC and N, P and K nutrients that are relatively stable with sticky particles are increasing. The relative amounts of SOC and N, P and K nutrients in the non-protective granules combined with the coarse sand and fine sand decreased gradually, and the stability of nutrients of SOC and N, P and K increased.