东北黑土区裸露坡地土壤侵蚀特征

Characteristics of Soil Erosion in Bare Slope Land of Black Soil Region in Northeastern China

2012—2018年,采用野外试验和室内分析相结合方法,对东北黑土区裸露坡地水土流失量和土壤物理化学性状进行连续监测和分析。结果表明:裸露坡地水土流失量受年限、月份侵蚀性降水量和产流次数的影响,存在显著的回归关系,特别是与产流次数的相关性高于侵蚀性降水量。2012年和2013年产流次数最多,年径流模数和年产沙模数也最大,分别为3.7710^(4),2.9710^(4) m^(3)/km^(2)和228.9210^(4),271.5910^(4) m^(3)/km^(2);2016年产流次数和产流量最少,2018年则产沙量最少;不同年份月产流量和产沙量大小也受到侵蚀性雨量分布和产流次数的显著影响,雨季早期土壤侵蚀的危害大于其他时期;土壤理化性质与径流量和泥沙量之间均存在显著的回归关系,除土壤容重随侵蚀年限逐年升高,呈显著负相关外,土壤孔隙度、有机质、全氮和全磷则均逐年降低且呈显著正相关关系;试验小区土壤有机质、全氮、全磷均随侵蚀年限增加而下降并趋于稳定,早期下降显著但降幅逐年缩小,侵蚀年限对坡地土壤结构和肥力退化影响较大。研究结果有助于揭示黑土区坡地年降雨侵蚀规律和水土保持措施布设规划,并对其地力提升和培育有借鉴意义。

A combination of field experiments and indoor analysis was used to continuously monitor and analyze the amount of soil erosion and soil physicochemical properties of bare slope land in the black soil region of Northeast China from 2012 to 2018.The results showed that:the annual soil erosion was significantly affected by erosive precipitation and runoff times of years and months,and there was a significant regression relationship between runoff,sediment yield and erosive rainfall,runoff times,respectively.In 2012 and 2013,times of runoff producing were the highest,and the annual runoff amount and sediment amount were also the largest,being 3.7710^(4) and 2.9710^(4) m^(3)/km^(2),228.9210^(4) and 271.5910^(4) m^(3)/km^(2),respectively.Times of runoff production and the annual flow were the least in 2016.The amount of sediment production was the smallest in 2018.The distribution of monthly runoff production and sediment yield in different years were similar as erosive precipitation and runoff times,and the hazard in earlier monsoon was higher than other periods.There was a significant positive regression relationship between soil organic carbon content,total nitrogen and phosphorous content,porosity and soil erosion,while bulk density was negative.Soil organic matter,total N and total P of the experimental plot decreased first and then tended to be stable with the increase of erosion years,and the decreasing range reduced year by year.Erosion time had a great effect on the degradation of soil structure and fertility on slope land.The results will provide useful reference for further revealing the law of soil erosion on black soil slope land,constructing soil and water conservation measures,and improving land quality.