地表覆被因子对华北寒旱区土壤抗风蚀力的影响

Effect of Farmland Surface Cover Factors on the Ability of Soil Anti-erosion in Cold and Arid Region of North China

为了明晰不同类型土壤的抗风蚀力特征与华北寒旱区农田地表覆被因子减降土壤风蚀的效果,采用国家发明专利"土壤风蚀测定装置",通过室内模拟与田间实证研究,分析砂砾、垡片覆被以及耕作措施、残茬存留等地表覆被因子对不同类型农田土壤抗风蚀力的影响。结果表明,砂质栗钙土抗风蚀能力高于壤质草甸栗钙土,在连续吹蚀下地表土壤吹蚀量呈"L"形下降特征;砂砾与垡片覆被可显著增强土壤抗风蚀能力,随覆被度增加土壤吹蚀量呈近线性指数型下降特征。华北寒旱区多年免耕的燕麦留茬农田,地表土壤吹蚀量较传统翻耕田降低70.28%～88.42%,多年免耕的地表砂砾覆被对增强砂质栗钙土农田的抗风蚀力起重要作用;而留茬覆被的粗糙度效应对增强壤质草甸栗钙土农田抗风蚀力更为重要。壤质草甸栗钙土秋耕立垡覆被,较传统翻耕田地表土壤吹蚀量降低92.21%。研究表明,生物性残茬覆被、非生物性砂砾与垡片覆被具有显著提高土壤抗风蚀力效应;在华北寒旱区农田,燕麦留茬免耕覆被可显著降低土壤吹蚀量;对无植被存留条件的壤质草甸栗钙土农田,秋耕立垡覆被同样具有显著提高土壤抗风蚀力效果。

In order to clarify the characteristic of anti-erosion ability of different soil types and the effect of farmland surface cover factors reducing soil wind erosion in cold and arid region of north China. A soil wind erosion measurement device, a product with national invention patent, was used. The effect of farmland surface cover factors including gravel, furrow slice, tillage, and stubble remaining on anti-erosion ability of different soil types were studied by the indoor simulation and field empirical research. The results showed that the anti-erosion ability of sandy chestnut soil was higher than that of loam meadow chestnut soil. The amount of wind erosion of surface soil showed ＂L＂ type drop characteristic under the continuous wind blowing conditions; the ability of soil anti-erosion could be significantly enhanced by cover of gravel and furrow slice, and the amount of wind erosion decreased to an exponential pattern with the increase of coverage. In cold and arid regions of north China, the amount of surface soil wincl erosion of no-tillage stubble farmland was 70.28~88. 420//oo lower than that of traditional tillage method. Surface gravel cover in farmland with sandy chestnut soil played an important role in increasing anti-erosion ability under years of no-tillage conditions; and it was very important for the roughness effect of stubble cover on the increase of anti-erosion ability of farmland with loam meadow chestnut soil. The amount of wind erosion of surface soil in autumn furrow slice coverage method reduced to 92.21% of that in traditional tillage method in farmland with this kind of soil. The research showed that, biological stubble and abiotic gravel and furrow slice covered on the top of farmland had significant effect of increasing the ability of soil anti-erosion; in cold and arid region of north China field, no-tillage with stubble cover could significantly reduce the soil wind erosion amount; for farmland without vegetation remaining of loam meadow chestnut soil conditions, the ability of soil anti-erosion could also be significantly enhanced by autumn furrow slice cover method.