Response Of Complex Erosion And Physical And Chemical Properties In Northeast China To Soil And Water Conservation Measures On Slope

The soil erosion in the north black soil area is complicated,which is eroded by freezing and thawing in spring and then eroded by rainfall in summer.A variety of soil and water conservation measures have been adopted in some regions to prevent and control soil erosion in sloping farmland.In the studies of various scholars,the soil and water conservation measures under the combined influence of spring thawing period and summer precipitation period on the soil erosion status of sloping cultivated land slope have seldom been studied.Because of the farmland soil and water conservation measures mainly horizontal ridge,hedgerows,level terraced fields is given priority to,and measures to deploy more on the slope above or below,therefore this article selects three slope as the research object,respectively is: soil and water conservation measures above setting slope?MUS?,soil and water conservation measures below setting slope?MBS?and no measures to control slope?CK?.Based on the methods of field observation,laboratory test,¹³⁷ Cs tracer technology and GIS spatial technology,the effects of different soil and water conservation measures on soil bulk density,organic matter,aggregates and soil erosion rate were studied.The following are the main research conclusions of this paper:?1?The influence of different soil and water conservation measures on slope soil erosion rate is analyzed.Three average slope surface erosion rate is respectively 1101 t km-²a^-1?MBS?,937 t km-²a^-1?MUS?,3866 t km-²a^-1?CK?,three slope are given priority to with erosion,but there are two soil and water conservation measures of slope average slope soil loss rate are far below no measures,shows that the construction and no measures of soil and water conservation measures of slope compared has certain effect for the prevention and control of soil erosion.Compared with the two controlled slopes,the average soil loss rate of MUS slopes is lower than MBS,and the MUS variation coefficient is smaller than MBS.?2?The effects of different soil and water conservation measures on the physicochemical properties of slope soil were studied.In terms of soil bulk density,the effect of soil and water conservation measures on changing soil bulk density of slope after spring thawing period and then experiencing summer rainfall erosion is not obvious.In terms of soil organic matter,the arrangement of soil and water conservation measures can significantly reduce the decline of soil organic matter content on the slope,so as to reduce the nutrient loss on the slope and make the soil organic matter distributed evenly.The spatial variation of organic matter content in the measured slope is more uniform through Kriging interpolation graph.In terms of soil aggregates,compared with the untreated slopes along the ridge,the slopes laid by soil and water conservation measures experienced precipitation in summer after the spring thaw period,and the change in the content of >0.2mm aggregates was more stable than that of CK.In the two slopes with measures,the >0.2mm aggregate content is more regular in the vertical movement when compared with the lower slopes with measures and the upper slopes with measures.The stability of soil aggregates on three slopes in summer rainfall period was better than that in spring thaw period,and the stability of soil aggregates on the lower slope was better than that on the upper slope.?3?The response of soil organic matter and aggregates to soil erosion rate on different slopes was studied.The higher the soil erosion rate,the lower the soil organic matter content.However,in the specific changes of soil mass,there was no obvious rule between soil erosion rate and > 0.2mm aggregate content on each slope.