黄土丘陵沟壑区坡耕地与草地不同配置方式的侵蚀产沙特征

基于黄土丘陵沟壑区安塞实验站小区实验研究，以4种土地利用组合方式，包括全谷子（a）、2／3谷子-1／3柳枝稷（ab）、2／3谷子-1／3撂荒地（ac）、2／3谷子-1／3苜蓿（ad），探讨坡耕地与草地不同配置方式的侵蚀产沙特征。结果表明：1）产沙量主要集中在降雨比较集中的7、8月份，高降雨量和高降雨强度是影响产沙量的主要因素；2）组合方式ab、ae、ad与a相比，具有不同程度的减沙效应，其中ac的减沙效应最好；3）随着坡度从100、200变化到25°，各土地利用组合方式的产沙量并不是逐渐增大，而是呈现先增大后减少的趋势，但250坡的产沙量依然大于10°坡的产沙量。研究结果可以为土地利用对水土流失的影响评价提供参考。

Characteristics of soil loss under different land use combination of sloping farmland and grassland in the Hilly-gully region of Loess Plateau

Based on the experiment plot research in Ansai Integrated Experiment Station on Soil and Water Conservation,the effects of different land use combination of sloping farmland and grassland on soil loss was discussed.Four kinds of land use combination were designed,including setaria italica only(Pattern a),twothirds setaria italica and one-third panicum virgatum(Pattern ab),two-thirds setaria italica and one-third abandoned land(Pattern ac),two-thirds setaria italica and one-third Allgangin(Pattern ad).The research results indicated that:1) Most of the sediment yields mainly happened in July and August,which had close relationships with high rainfall amount and rainfall intensity.2) Comparing with pattern a,the other three land use combinations (ab,ac,ad) had positive effects on reducing soil loss with different degrees,in which land use combination ac was the best one.3) With the slope degree varied from 10°,20° to 25°,the sediment yields of each land use patterns decreased after increased,and descending order of the sediment yield for different slope degree was 20°,25°,10°.The results could provide reference for evaluation the effect of land use on soil and water losses.