东北黑土区不同地形垄向坡度的相对水土保持效益研究

垄作是东北黑土区一种非常普遍而重要的耕作措施，具有一定的水土保持效益，但几乎没有学者对其进行研究。探讨黑土区不同地形垄作方向在空间上的分布规律及其具有的水土保持效益具有重要研究价值。以黑龙江省宾县为研究区，用分层抽样的方法提取168个野外调查单元并进行实地填图调查，根据坡度因子和垄向坡度计算公式，利用ArcMAP、SPSS和Excel等软件进行了室内数据分析统计，结果表明:平原区、丘陵区、山区的平均地面坡度分别为1.92°，6.20°，8.27°；平均垄向坡度分别为1.33°，4.52°，6.45°，分别为平均地面坡度的70%，73%，78%；垄作坡度引起的平均土壤流失相对量分别为地面坡度的55%，69%，67%，垄作的相对水土保持效益明显。在此基础上，对垄作现状的原因进行了分析，并提出一些改进措施。研究成果有助于了解东北黑土区不同地形耕地垄作方向的分布情况及其水土保持效益状况，对当地水土保持措施的布设也具有重要的指导意义。

Study on Relative Soil and Water Conservation Benefits in Different Terrain Conditions in Black Soil Area of Northeast China

Ridge tillage, which is a very common and important tillage measure in black soil area of northeast China has some water conservation benefits, but has received little attention. It is very important to explore the spatial distribution of the ridge direction of the arable land and its water conservation benefits in different terrain conditions in black soil area. So Binxian County of Heilongjiang Province was selected as the study area, and 168 field cells were extracted by stratified sampling method and investigated. According to slope gradient factor equations and tillage-induced directional slope gradient equation, and based on the software of ArcMap, SPSS and Excel, the investigation data were analyzed and counted. The results were as follows. The average land slope gradients in plain, hilly and mountain are 1.92°, 6.20°, 8.27°, respectively. The average tillage-induced directional slope gradients in plain, hilly and mountain is 1.33°, 4.52°, 6.45°, respectively, which are 70%, 73%, 78% of the average land slope gradient in the same terrain condition. The relative soil erosion in the present ridge tillage condition is about 55%, 69% and 67% of that in down-slope ridge tillage conditions in plain, hilly and mountain and ridge direction, respectively, so present ridge tillage has obviously relative water conservation benefits. Based on these results, the reasons for the present ridge tillage status were analyzed, and some reform measures were proposed. The result could help to comprehend the spatial distribution and soil and water conservation benefits of ridge tillage in black soil area of northeast China, and it could be used to guide the local soil and water conservation measures too.