玉米季坡耕地地表糙度的变化及其对土壤溅蚀的影响

Changes of Soil Surface Roughness and Its Effects on Soil Splash Erosion in Sloping Cropland During Maize Growing Season

通过野外人工模拟降雨试验,开展横垄条件下玉米全生育期紫色土坡耕地地表糙度变化及其对土壤溅蚀影响的研究。结果表明:随着玉米生育期的推进,地表糙度逐渐衰退,在抽雄期或成熟期达最小,而地表糙度变幅在玉米拔节期或抽雄期时最大,雨强对地表糙度变幅的影响表现出20°坡面>15°坡面。不同坡面的向上、下坡溅蚀量及溅蚀总量,在雨强为2.0mm/min时,玉米苗期最大,1.0mm/min和1.5mm/min雨强下,最大溅蚀量出现在玉米抽雄期;玉米全生育期溅蚀量随雨强的增大而增加。在玉米苗期,各坡面雨强、糙度比率和溅蚀量间呈极显著线性正相关关系;玉米成熟期,仅在20°坡面雨强和糙度比率与溅蚀量呈显著线性关系,可知玉米冠层对各坡面溅蚀影响较大。

Through field artificial rainfall simulation experiment,the research was carried out to study the land surface roughness change in the whole stages of maize cultivated with purple soil under the condition of the transverse ridge and its effects on soil splash erosion.The results showed that：With the advance of corn growing period,the surface roughness was gradually recession,and reached the minimum in tasseling or mature stage,and the change of surface roughness was maximum in maize jointing and tasseling stage,the influence of rainfall intensity on the surface roughness change in the 20°slope was greater than that in the 15°slope.The upward and down splash erosion slope and total splash erosion of the slope surface were maximum in the 2.0mm/min of rainfall intensity in corn seedling stage,and the largest splash erosion was appeared in corn tasseling stage with 1.0 mm/min and 1.5 mm/min of rainfall intensity,splash erosion in the whole stages of corn was increased with the increasing of rainfall intensity.In the corn seedling,the rainfall intensity,slope roughness and splash erosion rate had a significant linear positive correlation relationship.In the corn mature period,the rainfall intensity and roughness ratio had significant linear relationship with splash erosion quantity only in the 20°slope,this indicated that corn canopy had a greater influence on the splash erosion in the slope.