等高犁耕对黄土坡耕地坡形与坡度的影响  

Effect of Contour Ploughing on the Slope Shape and Slope of Loess Sloping Farmland

作　　者：张泽瑜 陆淑宁 黄淑娴 姚冲 吴发启 ZHANG Zeyu;LU Shuning;HUANG Shuxian;YAO Chong;WU Faqi(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Yangling,Shaanxi 712100;Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100;College of Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100)

机构地区：[1]黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100 [3]西北农林科技大学资源与环境学院,陕西杨凌712100

出　　处：《水土保持学报》2023年第5期94-102,共9页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41977065);国家重点实验室开放基金项目(K3050219171)。

摘　　要：为了明确等高犁耕条件下黄土坡耕地地形与坡度的变化特征,基于6个坡度(3°,5°,10°,15°,20°,25°)和5个耕作强度(6,12,18,24,30次)的组合,开展模拟耕作试验,利用测针法获取耕作后地表高程数据,探讨耕作强度和坡度对黄土直线形坡演化特征的影响。结果表明,在等高向下犁耕条件下,不同坡度的直线坡随着耕作强度的增加逐渐向“∽”形复合坡演化。同一坡度下,随着耕作强度的增加,坡脚延伸,整体小区投影坡长增大,坡脚高程增加幅度大,堆积现象明显,坡度大幅度减小;坡中高程增加,逐渐抬起坡度减小;坡顶形成的新分水岭的高程和位置随之减小和向下推移,直接侵蚀速率逐渐减小且趋于稳定。坡度通过影响土壤运动能力控制耕作时土壤的分布。因此坡度越大,单次耕作后坡形的变化越明显,直接侵蚀速率越大。研究结果有助于更加深入了解耕作侵蚀对坡耕地地形的影响,为控制坡耕地土壤侵蚀提供理论依据。In order to clarify the characteristics of slope shape and slope changes in loess slope farmland under contour ploughing conditions,a simulated tillage experiment was conducted based on a combination of six slopes(3°,5°,10°,15°,20°and 25°)and five tillage intensities(6,12,18,24 and 30 times).The influence of tillage intensity and slope gradient on the evolution characteristics of loess linear slope was discussed by using the needle method to measure the surface elevation before and after ploughing.The results showed that under the conditions of contour downward ploughing,the straight slopes with different slope gradients gradually evolved into“∽”type composite slopes with the increasing of tillage intensity.Under the same slope,with the increasing of tillage intensity,the slope toe extended,the projected slope length of the whole plot increased,the slope toe elevation increased significantly,the accumulation phenomenon was obvious,and the slope gradient decreased significantly.The elevation of the middle of the slope increased and gradually lifted the slope.The elevation and position of the new watershed formed at the top of the slope then decreased and moved downward,and the direct erosion rate gradually decreased and tended to be stable.The slope gradient controlled the distribution of soil during tillage by affecting the soil movement ability.Therefore,the greater the slope,the more obvious the change in slope shape after single tillage,and the greater the direct erosion rate.The results of the study were helpful for a deeper understanding of the impact of tillage erosion on the topography of slope farmland,and provide a theoretical basis for controlling soil erosion in slope farmland.

关 键 词：耕作侵蚀 耕作强度 坡耕地 坡形 

分 类 号：S157.1[农业科学—土壤学]