摘要
针对荒漠草原退化已经由植被退化演变到土壤退化的特征,采用野外调查取样和人工模拟降雨相结合的研究方法,探讨不同放牧强度下荒漠草原的土壤紧实度、容重、总孔隙度、水分及其侵蚀量的变化情况,研究结果表明:(1)不同放牧强度下0~10cm土层土壤紧实度受放牧的影响差异显著,且随放牧强度加重而呈明显的增加趋势,对深层土壤的影响有限;(2)0~10cm土层土壤容重差异性显著,且随放牧强度的增加而不断增大,与对照未放牧草地相比,不同放牧强度草地土壤容重增加幅度为5.1%~11.7%;(3)放牧强度对0~20cm深度的土壤含水量影响显著,放牧强度越大,土壤含水量越小,与对照未放牧草地相比,不同放牧强度草地土壤含水量降低12.5%~35.4%;(4)雨强一定时,坡度与放牧强度越大,其土壤侵蚀量明显增加,雨强、坡度条件相同情况下,重度放牧的土壤侵蚀量可达到对照样地4.9~13.6倍;(5)土壤容重与土壤紧实度、土壤总孔隙度之间存在显著正相关,土壤紧实度与不同坡度、降雨、放牧强度的土壤侵蚀量均存在显著正相关,且均为幂函数关系。
The aim of the present research is to study alterations of the soil compaction, bulk density, total porosity, water content and erosion amounts of the desert steppe under different grazing intensities through a combination of field survey sampling and artificial simulated rainfall. All results are showed in the following contents. First, the soil compaction of 0-10 cm soil layer was significantly affected by grazing intensity, which was significantly increased with the elevation of grazing intensity. However, grazing intensity had a limited impact on deep soils;Second, the bulk density of 0-30cm soil showed significant differences under different grazing intensities. And the increasing trend of the bulk density was along with the increased grazing intensity. Compared with the enclosed grassland, the soil bulk density of grassland under different grazing intensity was increased by 5.3%-11.9%;Third, grazing intensities had a significant effect on the water content in 0-20 cm soil. The greater grazing intensity, the less soil water content was. Compared with the enclosed grassland, the soil water content of grassland under different grazing intensity decreased by 12.5%-35.4%;Fourth, when the precipitation is steady, the greater slope and grazing intensity, the more soil erosion was. Under the same condition of precipitation and slope, the soil erosion amount of heavy grazing was 4.9-13.6 times more than the control plot. Fifth, there was a significant positive correlation between soil bulk density, soil compaction and soil total porosity. Furthermore, there was a significant positive correlation between soil compaction and soil erosion within different slopes, precipitation and grazing intensities, and they were all power functions.
作者
郭建英
董智
李锦荣
王合云
刘铁军
GUO Jian-ying;DONG Zhi;LI Jin-rong;WANG He-yun;LIU Tie-jun(Institute of Water Resources for Pastoral Area of the Ministry of Water Resources of China, Hohhot 010020, China;Forestry College of Shandong Agricultural University, Tai’an 271018, China)
出处
《中国草地学报》
CSCD
北大核心
2019年第3期74-82,共9页
Chinese Journal of Grassland
基金
国家自然科学基金面上项目(51879155、41301302、51779156)资助
关键词
放牧强度
荒漠草原
土壤物理性质
土壤侵蚀
模拟降雨
Grazing intensity
Desert steppe
Soil physical properties
Soil erosion
Simulated rainfall
