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| Micro-relief characteristics of loess sloping farmland under different tillage practices and its effects of soil and water conservation |
| Zhao Longshan, Song Xiangyang, Liang Xinlan, Zhang Qingfeng, Wu Faqi |
| College of Resources and Environment, Northwest A&F University, 712100, Yangling, Shaanxi, China |
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Abstract The spatial distribution of micro-topographical features of loess sloping farmland and its effects of soil and water conservation were studied using GIS under simulated rainfall conditions. The results showed that the descending order of the changes of micro-relief is contour tillage, artifical dig, artiilcal hoe, and CK, and the mean changes of different type of tillages (CK, artifical hoe, artifical dig and con-tour tillage) decreased as 0. 015，0. 014 , 0. 018 and 0. 015 m after simulated rainfall conditions, respec-tively ,and also despression storage went down except CK. The runoff yield of contour tillage, artifical hoe, artifical dig decreased by 38. 17% , 17. 88%，9. 43% compared to CK, respectively, and the a-mount of sediment yields were 65. 6% , 36. 3%，23. 4% . The descending order of the changes of runoff time is contour tillage, artifical hoe, artifical dig, and CK, there was a sharp increase of runoff yield at the beginning of rainfall, and then has a smooth upward trendency ； the initial sediment yield increased,then decreased and gradually developed to a stable process. The impact of slope on runoff and sediment showed that the greater the slope degree the earlier of runoff generation and the more the runoff and sedi-ment yield. In conclusion, the effects of soil and water conservation of tillage practice are related obvious-ly with soil surface micro-relief.
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Received: 24 March 2010
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