论文部分内容阅读
采用风洞实验对祁连山东段天祝高寒地区天然放牧草地、退耕自然恢复草地、翻耕地、免耕留茬地和人工种植多年生草地5种土地利用方式下的原状土抗风蚀能力进行了研究。结果表明,多年生草地的临界侵蚀风速最大,免耕留茬地和天然草地次之,翻耕地和退耕自然恢复地最小;风蚀速率与风速变化成正相关,随着风速增大,风蚀速率相应增加;风蚀速率和风速变化服从幂函数变化关系。在近地表0-20cm范围内,降尘量总量依次为退耕自然恢复地>翻耕地>天然放牧草地>多年生草地>免耕留茬地;土壤抗风蚀能力表现为退耕自然恢复地>天然放牧草地>多年生草地>免耕留茬地>翻耕地。
Wind tunnel experiment was conducted to study wind erosion resistance of undisturbed soil under five land use types: natural grazing grassland, returning farmland to natural grassland, tillage land, no-till stubble land and artificial planted perennial grassland in the Tianzhu alpine region of Qilian Mountains. The results showed that the wind speed of critical erosion of perennial grassland was the highest, followed by no-till stubble field and natural grassland, and the minimum value of plowed field and returned farmland was the smallest. Wind erosion rate was positively correlated with wind speed. With the increase of wind speed, the wind erosion rate increased accordingly. Wind erosion rate and wind speed obey power function change relationship. In the range of 0-20 cm near the surface, the total amount of dustfall followed by natural returning land> tillage> natural grazing grass> perennial grass> no-till stubble field; soil anti-wind erosion performance is natural grassland for returning farmland> natural grazing grassland > Perennial lawn> no-till stubble> tillage.