阴山北麓马铃薯喷灌圈土壤风蚀机制研究

Under the background of potato food strategy in China and regional characteristic development, large scale potato were planted using pointer sprinkler in Inner Mongolia. But at the same time the quality and yield of potato were improved, also there have been problems such as soil wind erosion hazard is aggravating. Cultivated land suffered wind erosion in wind season after losing vegetation protection, not only soil desertification and grain size coarsening would be happened in farming area, but also surrounding ecological fragile areas had a serious impact by its sand wind. Circular spray irrigation and continuous deep harvest were the special characteristics of the soil erosion of potato sprinkler cultivation, which soil wind erosion and principle of wind erosion control were different of other kind of cultivated land. Soil wind erosion will be study of potato sprinkler cultivation in the north area of Yinshan Mountain by field investigation and computer simulation. Characteristics of soil wind erosion in potato sprinkler cultivation which build on sandy grassland and fixed sand and surrounding areas of sprinkler cultivation will be studied, and mechanism of soil erosion of potato sprinkler cultivation, relationship of saturated sand flow path length and bare land, effects of harvesting methods on soil loss, temporal and spatial evolution rule of surrounding areas will all be systematic studied, then mastering principle of soil erosion control and proposing reasonable suggestion, providing reference for protecting potato sprinkler cultivation of sandy area.

在我国马铃薯主粮化战略新形势及内蒙古区域特色产业发展的背景下，内蒙古采用指针式喷灌机大规模种植马铃薯，但是在提高了马铃薯质量及产量同时，也出现了土壤风蚀危害加重等问题。由于喷灌圈耕作区缺少植被保护，在风季内变为开放式沙源地，不但自身土壤沙化与粒径粗化，而且产生的风沙对周边生态脆弱区产生严重影响。圆形喷灌圈及连年深翻采收是马铃薯耕地土壤风蚀特殊性所在，进而造成其土壤风蚀规律、防治原理区别于其他耕地。本项目拟对阴山北麓马铃薯喷灌圈土壤风蚀开展研究，采用野外调查及计算机模拟的方式，研究基于沙质草地、固定沙地建立的马铃薯喷灌圈耕作区及周边区域土壤风蚀特征，探寻弦长裸地与风沙流饱和路径的关系，系统研究马铃薯种植作业驱动土壤风蚀机制，掌握采收方式对沙物质流失的影响，摸清圆形喷灌圈开放沙源地时空演变规律。总结分析阴山北麓马铃薯喷灌圈土壤风蚀机制，探明其土壤风蚀控制原理，并提出控制喷灌圈土壤风蚀的合理性建议，旨在为沙区马铃薯喷灌圈耕地保护提供参考依据。

指针式喷灌机高效节水方式在干旱、半干旱地区得到了大面积推广，内蒙古种植马铃薯等块茎类特色作物，以此喷灌圈耕地得到了大规模营建。此类新型耕地区别于传统零散经营型耕地，其地表均匀的裸露面积更大，缺少渠埂植物阻挡，且多未配套防护林或新建防护林未产生有效作用，导致耕作区内风沙活动剧烈、风蚀严重、地力下降，同时加剧了局地沙尘暴频发、积沙掩埋道路及草场等环境问题发生。但是此类耕地的风蚀规律与机制不明，且缺少治理政策决策及相应的治理措施。针对此实际需求问题，为摸清喷灌圈耕地风蚀时空分布规律，探索此类耕地风蚀防治原理及治理措施。本研究以马铃薯喷灌圈耕地为研究对象，通过野外实地监测结合室内试验，从点（局部风蚀）-线（风沙路径）-面（圆面耕地）尺度系统研究了喷灌圈耕地土壤风蚀及风沙运动规律，并结合当地生产常见的治理技术，提出了防治原则、原理、技术等相关建议。研究结果表明：马铃薯喷灌圈沙质土壤耕地风季内风蚀量可达1.34万t/喷灌圈（400亩），是未开垦固定沙地的103.35倍，风蚀等级可定性为剧烈；沙物质沿风沙路径运移时，其含量呈现先增大后减小再增大的变化趋势，整体表现为圆面状耕地上、下风向部位活动相对较小，中部活动最为剧烈；风季内耕地采收起伏迹地逐渐平坦，空气动力学粗糙度与摩阻速度均在减小，起伏地形显著时，过境风沙流随高度呈现波动减小的趋势，地形逐渐平坦后，呈现单调递减的趋势；风沙作用造成了耕地表层土壤细颗粒大量流失，导致表层土壤平均粒径变大，土壤黏粒、粉粒、细砂颗粒含量分别下降42.14%、48.85%、42.28%，向外环境输出的沙物质形成了堆积，沙埋导致了天然植物生长、分布及多样性均发生显著变化。深翻采收、无残茬防护等因素直接导致了风蚀加剧，喷灌方式下耕地土壤含水量较高，但并未对风蚀产生有效的抑制。建议加强对喷灌圈耕地的中部区域的风蚀控制，春耕期-幼苗期耕地风蚀依然严重，此阶段应加强风蚀防控，而生物（植物）固沙剂风蚀控制技术针对此阶段的风蚀防治，具有广阔的应用前景。