摘要
为了深入了解降雨历时对黑土坡面养分流失的影响特征,探寻降雨历时对黑土坡面养分流失的规律,在沈阳农业大学水利试验基地,进行室内人工模拟降雨试验,对不同降雨历时条件下的黑土坡面养分流失进行研究。结果表明:降雨历时是影响坡地溶质迁移以及坡面降雨产流产沙的重要因素。降雨历时越长,表土养分流失越严重,N、P、K流失量越大,降雨后的养分含量越低,且累计径流量与泥沙量和降雨历时呈正相关变化,当降雨历时增加至90min后,土壤入渗率趋于稳定,径流量增加幅度减缓,且由于土壤发生沟蚀,泥沙量急剧增加。径流水样中N、P、K流失呈现出不同特征,当降雨历时<90min时,随着降雨历时的增加,径流硝态氮迅速衰减,20min后逐渐趋于稳定,土壤养分含量均降低;当降雨历时进一步增大至120min时,硝态氮含量趋于稳定,基本没有变化,而磷离子和钾离子则由于土壤发生沟蚀,下层土壤中的PO_4^(3-)和K^+被浸提出进入径流中,导致其含量仅一步增加,磷离子增加幅度较钾离子相比更为明显,且随泥沙流失的养分与之呈现出相似规律。不同降雨历时条件下降雨前后土壤剖面养分含量垂直分布情况也有明显差异,随着降雨历时的增加,磷离子以及钾离子的浓度峰值变化不大,多出现在10cm表层土壤内,而硝态氮浓度峰值不断加深。30,60,90,120 min降雨后,硝态氮浓度峰值分别位于土层7,8,10,14cm处;土层的湿润峰也随降雨历时增大而增加,分别位于土层以下10,12,16,19cm处,降雨120min后,土层全部湿透。试验结果表明,降雨历时对硝态氮流失的影响比对磷和钾离子更为显著。
In order to better understand the influencing characteristics of rainfall duration on the nutrient loss of black soil slope,and explore the regulation of nutrient loss on the black soil slope,indoor artificial rainfall experiments were conducted in the experimental base of water conservancy in Shenyang Agricultural University to study the nutrient loss of black soil slope under different conditions of rainfall duration.The results showed that：Rainfall duration was an important factor that influenced solute transport and slope runoff and sediment yield.The longer rainfall lasted,the more severely the topsoil nutrient lost,the larger N,P,K loss amount was,the lower the nutrient content after rainfall was.The cumulative amount of runoff and sediment was positively correlated with the change of rainfall duration,when rainfall duration increased to over 90 min,the soil infiltration rates were stable,the increase amplitude of runoff slowed down,and soil and gully erosion occurred,followed by a sharp increase in the amount of sediment.Meanwhile,N,P,K loss in runoff water samples presented different characteristics.When rain lasted less than 90 min time,with the increase of rainfall duration,nitrate nitrogen content in runoff decreased rapidly,gradually stabilized after 20 min,with all soil nutrient contents lowering;when rainfall duration was further increased to 120 min,the nitrate nitrogen content became stable and unchanged,and phosphorus and potassium ions further increased in the contents due to gully erosion of soil,PO4^（3-） and K~＋in subsoil being leached into the runoff;in addition,the increasing amplitude of phosphorus ions was more obvious than that of potassium ions,the same was the loss of nutrients with sediment.Next,there was obvious difference in the vertical distribution of nutrient content of the soil profilebefore and after rainfall under different rainfall durations.With the increase of rainfall,the peak concentration of phosphorus ions and potassium ions changed little,mostly within 0—10cm layer of topsoil,but the peak concentration of nitrate continued to deepen in the soil;after 30 min,60min,90 min and 120 min rainfall,soil nitrate concentration peaks were located at 7cm,8cm,10 cm and 14 cm,respectively;soil moist peaks also increased with the increase of rainfall duration,located in the soil below 10 cm,12cm,16 cm and 19 cm,all soil wetted after 120 min of rainfall.And the results also showed that the rainfall duration had more significant effect on nitrogen loss than on phosphorus and potassium ions.
出处
《水土保持学报》
CSCD
北大核心
2016年第2期97-101,共5页
Journal of Soil and Water Conservation
基金
辽宁省自然科学基金项目(20102197)
关键词
降雨历时
模拟降雨
养分流失
黑土坡面
rainfall duration
simulated rainfall
nutrient loss
black soil slope
作者简介
沈奕彤（1992-）女，硕士，主要从事土壤侵蚀规律及其治理研究。E-mail：646708284@qq．com.
通信作者：郭成久（1964-）男，教授，主要从事土壤侵蚀规律及其治理研究。E-mail：chengjiuguoll@163．com
