土壤容重对黑土坡面养分流失的影响  

Effect of Soil Bulk Density on Nutrient Loss of Black Soil Slope

作　　者：沈奕彤 郭成久[1] 金珊[1] 董爽[1] 

机构地区：[1]沈阳农业大学水利学院,沈阳110866

出　　处：《水土保持学报》2016年第1期26-30,共5页Journal of Soil and Water Conservation

基　　金：辽宁省自然科学基金项目(20102197)

摘　　要：为深入了解土壤容重对黑土区坡面养分流失的影响,在沈阳农业大学水利试验基地,采用室内人工模拟天然降雨的方法,对不同容重条件下的黑土坡面养分流失进行研究。试验结果表明:土壤容重是影响坡地溶质迁移以及坡面降雨产流产沙的重要因素。土壤容重在0.8~1.3g/cm^3间变化时,随泥沙流失的养分与径流水样中养分的流失呈现出相似规律。随着容重增大,径流系数变大,产流时间提早,入渗率减小,溶质(N、P、K)的流失量增加。在产流初期,径流强度增加显著,径流硝态氮衰减速率快,10min内基本达到本底值,同一时段径流水样中PO_4^(3-)-P和K^+浓度升高,而产流后期,溶质浓度含量由于土壤发生面蚀甚至沟蚀而随容重呈相反变化。土层湿润锋深度随容重增大而变浅,容重为0.8g/cm^3时,湿润锋可达15cm,容重为1.4g/cm^3时,仅淋失到地表11cm深处,且表层土壤容重对硝态氮在土层中流失的影响大于对速效磷和速效钾流失的影响。当容重增大至1.4g/cm^3时,土壤结构坚实,养分浓度有所降低,流失量小,土壤流失情况减弱,说明采用适当的耕作措施改变表层容重可有效控制土壤侵蚀的发生。通过数学模拟分析,也进一步证实了幂函数是较为适于模拟黑土区溶质流失变化过程的模型。In order to better understand the effects of soil bulk density on nutrient loss on slopes in black soil region,the indoor artificial rainfall simulation was conducted in Shenyang Agricultural University Test Base to study the nutrient loss on black soil slopes under different conditions of soil bulk density.The results showed that soil bulk density was an important influencing factor on slope solute transport and runoff and sediment yield.When soil bulk density was in the range of 0.8^1.3g/cm^3,the loss of nutrients in sediment and runoff water showed similar tendency.As the increase of bulk density,the runoff coefficient increased,the runoff yielding time was advanced,infiltration rate reduced,and the loss amount of solute（N,P,and K）reduced.At the early stage of runoff period,runoff intensity increased significantly,and the concentration of nitrate in runoff decreased quickly,which reached the background value within 10 min.In the same period,the concentrations of PO4^（3-）-P and K^＋in runoff water increased,and at later stage of runoff period,solute concentration showed an opposite tendency with soil bulk density due to the sheet erosion and rill erosion on slopes.The depth of soil wetting front decreased with the increasing bulk density,which reached up to 15 cm when bulk density was 0.8g/cm^3.The depth of soil wetting front was 11 cm when the bulk density was 1.4g/cm^3,and the effects of soil bulk density on vertical migration of nitrate in soil were greater than those on vertical migration of phosphorus and potassium in soil.When the bulk density was 1.4g/cm^3,soil was solidlystructured,with lower nutrient concentration and loss amount,and soil erosion was weakened,indicating that applying appropriate tillage measures to change the bulk density of surface soil could effectively control the occurrence of soil erosion.By using mathematical simulation analysis,we also confirmed that the power function was more suitable for simulating solute loss process in black soil zone.

关 键 词：土壤容重 模拟降雨 养分流失 

分 类 号：S152.7[农业科学—土壤学] S157.1[农业科学—农业基础科学]