荒地不同压砂年限对土壤微生物区系、酶活性与土壤理化性状的影响

以宁夏中卫市香山地区荒地压砂3,8,15,25 a和邻近未压砂(对照)的土壤为研究对象,研究了压砂对土壤微生物区系、酶活性和土壤理化性状的影响.结果表明,与对照相比,压砂后微生物总数减少;土壤脲酶活性随着压砂年限的延长呈下降趋势;前15 a压砂地土壤有机碳、全氮、碱解氮和速效钾随着压砂年限的延长呈下降趋势;压砂地土壤含水量高于对照;压砂地全盐含量远远低于对照;说明荒地压砂种植能蓄水保墒,防止土壤次生盐碱化,但连续种植肥力下降,微生物量减少.

Effects of Gravel Mulch on Soi l Microbial Population, Enzyme Activity and Physicochemical Properties in Wasteland

The effects of gravel mulch on soil microbial population, enzyme activity, and physicochemical properties were evaluated on the wasteland in Xiang shan area, Zhongwei City, Ningxia Hui Autonomous Region. Four typical sites were selected as a chronological sequence ( 3, 8, 15, and 25 years) and an adjacent no n-mulched gravel land was taken as the control. Results indicated that compared with the control, the number of microbes in the gravel mulched field was decreased. With the increased year of gravel mulched field, soil urinary enzyme activity presented a declined trend. The contents of soil organic carbon, total nitrogen, available nitrogen, and potassium declined for the sites of 3, 8, and 15 years. The soil water content in gravel mulched field was higher than the control, but the total salt content was much lower than the control.It is suggested that gravel mulch on wasteland can restore vegetation through preserving water, but soil fertility and microbial biomass are low .