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| Optimization of structure of slope-separated terrace based on crop water requirement and control of rainfall runoff |
| Liang Gaige1,2,3,Gao Jian’en1,3,4,Han Hao3,4,Meng Yan3,4,Xing Dingwu4,Zhao Wenjun1,2,3 |
| 1.Institute of Soil and Water Conservation;CAS and MWR,712100,Yangling,Shaanxi;2.Graduate School of Chinese Academy of Sciences,100049,Beijing;3.National Engineering Research Center for Water Saving Irrigation at Yangling,712100,Yangling,Shaanxi;4.Northwest Agricultural and Forestry University,712100,Yangling,Shaanxi:China |
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Abstract In order to solve the problems of drought and water shortage and soil erosion for crops on hilly area of Loess Plateau,this paper calculated the precipitation,runoff,erosion and sediment yield,infiltration,evaporation and soil water for the process of water requirement during Zea mays L.growth period for different terrace modes using WEPP model,basing on crop water demand and control of rainfall runoff.The results showed that the individual slope-separated terrace could not fully solve the dislocation problem in time between the Zea mays L.water requirement and natural runoff,and ordinarily the ratio of terrace width to interval slope length should to be 1∶6 to 1∶8 to collect the rainfall runoff,which seriously wasted the land resources;Combing the water cellar,not only a large number of land resources could be saved to meet the water requirement,but also the annual crop yield,water use efficiency and precipitation use efficiency on slope-separated terrace were higher by more than 50% than that on level terrace,which basically achieved the dual goals of increasing crop yield and reducing soil erosion;The given table of the ratio of terrace width to interval slope length on typical model could provide a reference for the design and planning of the slope-separated terrace on hilly area of Loess Plateau.This study showed that the combination of slope-separated terrace and water cellar was a pattern of control of rainfall runoff on slope suitable for promotion,for the reason that it could not only meet crop water demand during the whole growth period,but also could prevent water loss and soil erosion,and it had an actual meaning in guiding efficient utilization of land and water resources on slope land.
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Received: 29 March 2010
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