横坡垄作对坡耕地产流产沙及氮磷养分流失过程影响研究OA北大核心CSTPCD
Study on the Effects of Counter Tillage on Runoff and Sediment Yield and Process of Nitrogen and Phosphorus Nutrient Loss on Sloping Farmland
横坡垄作是一种常见的水土保持耕作措施,它通过增大坡面拦蓄和入渗能力,进而影响坡面土壤侵蚀过程.为揭示黄土坡耕地养分流失特征,通过人工模拟降水试验,利用投影面积为4.5 m×1.5 m的径流小区,设计降雨强度(90 mm·h-1)、5个地表坡度(3°、5°、10°、15°、20°)以及横坡垄作和平整坡面两种坡面处理,探究横坡垄作对不同坡度坡耕地产流产沙特性及其携带的氮磷养分流失情况.结果表明:(1)坡面坡度小于20°时,横坡垄作能明显降低降雨过程中坡面的产流产沙量,产流量和产沙量最大分别可降低95%和99%;而当坡度增大至20°时,横坡垄作坡面发生断垄,横坡垄作对径流和泥沙的控制效应随之减弱,产流和产沙量会接近或大于平整坡面.(2)横坡垄作对养分流失浓度的影响较小,但对养分流失量具有明显影响.坡面坡度小于 20°时,横坡垄作具有较好的控制坡面养分流失量的效果;当坡度增大至 20°时,横坡垄作控制养分流失的作用减弱.径流中全氮的流失量始终大于全磷的流失量;除横坡垄作10°坡面外,泥沙中全磷的流失量均大于全氮的流失量.(3)坡面养分流失量主要由坡面径流量和泥沙量决定.径流养分流失率和产流速率、泥沙养分流失率和产沙速率满足线性正相关关系.横坡垄作对径流和泥沙中养分减少效益分别可以达到45%～100%、59%～100%.整体而言,横坡垄作是控制坡面土壤侵蚀及减少养分流失的一种有效方法.
Counter tillage is a common soil and water conservation tillage practice,which can influence the soil erosion process by increasing storage and infiltration capacity on sloping farmland.However,studies about the effects of counter tillage on nutrient losses during soil erosion processes on sloping farmland are still limited.[Objective]Therefore,this study aimed to reveal the characteristics of nutrient loss on sloping farmland.[Method]In this study,the rainfall simulation was conducted with a rainfall intensity of 90 mm·h-1,five slope gradients(3°,5°,10°,15°,20°)and two types of slope treatments(counter tillage and flat slope)on runoff plots with projection length 4.5 m and projection width 1.5 m to explore the effects of counter tillage on the characteristics of soil erosion and nitrogen and phosphorus nutrient losses on sloping farmland of different slope gradient.[Result]The results showed that:(1)When the slope gradient was less than 20°,counter tillage significantly reduced the amount of runoff and sediment on the sloping farmland and the amount of runoff and sediment reduced by a maximum of 95%and 99%respectively.When the slope gradient increased to 20°,a break in the ridge occurred on the counter tillage and the control effect on the runoff and sediment was gradually weakened.Also,the amount of runoff and sediment was close to or greater than that of the flat slope.(2)The effect of counter tillage on the concentration of nutrient loss was small,but it had a significant effect on the nutrient losses.When the slope gradient was less than 20°,the counter tillage had a better effect on controlling the nutrient losses on the sloping farmland.However,when the slope gradient increased to 20°,the effect of counter tillage on controlling nutrient losses was weakened.Additionally,TN losses were always greater than TP losses in runoff;except for the 10° slope gradient on CT,while TP losses were greater than TN in sediment.(3)The nutrient losses were mainly determined by the amount of runoff and sediment,while the nutrient loss rate and runoff rate or sediment production rate satisfied a linear positive correlation.In addition,the reduction benefits of nutrient losses on counter tillage in runoff and sediment can reach 45%to 100%and 59%to 100%,respectively.[Conclusion]Our results show that counter tillage is an effective tillage practice to control soil erosion and nutrient losses.
陆淑宁;李荣融;姚冲;吴发启
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||西北农林科技大学水土保持研究所,陕西杨凌 712100西北农林科技大学资源环境学院,陕西杨凌 712100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||西北农林科技大学资源环境学院,陕西杨凌 712100
农业科学
横坡垄作坡度产流产沙养分流失
Counter tillageSlope gradientRunoff and sediment yieldNutrient loss
《土壤学报》 2024 (005)
1271-1283 / 13
国家自然科学基金项目(41977065)和国家重点实验室开放基金项目(K3050219171)资助Supported by the National Natural Science Foundation of China(No.41977065),and the Open Fund of State Key Laboratory(No.K3050219171).
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