植被覆盖条件下纳米碳对黄土坡面养分流失调控的试验研究

将纳米材料应用于坡面养分流失调控对减少黄土坡面养分流失等有着重要意义。基于神木六道沟流域上的坡面人工模拟降雨试验,分析了不同纳米碳含量(质量百分比分别为0%,0.1%,0.5%,0.7%,1.0%)对黄土坡面养分迁移过程的影响。结果表明:(1)同一作物的小区添加不同纳米碳含量对养分流失影响不明显;5种下垫面条件下,养分流失量均呈随纳米碳含量增加而降低的趋势,其中纳米碳含量为0.5%及0.7%对降低径流养分流失量的效果最好。不同纳米碳含量条件下,径流中的养分流失量从小到大为:空地玉米柠条绿豆苜蓿。(2)人工模拟降雨条件下,土壤表层养分在0—5cm内均有明显减少。而大于5cm深度的土壤中的养分值在降雨后有所增加,但随着深度增大养分增加量减少,而且添加不同浓度纳米碳导致养分值减少的速率不同。(3)不同纳米碳含量下与不同植被覆盖下径流中各离子的养分流失调控效果评价是径流中不同离子的平均浓度与平均流失率均随纳米碳含量的增加而减小,规律性较为明显。

Experimental Study on the Regulation of Nano Carbon to Soil Nutrient Losses Under Different Vegetation Cover Conditions

The nanometer materials applied in the nutrient loss control could improve the utilization rate of soil water and improve soil physical structure.Based on the artificial simulated rainfall experiment in Shenmu County,Shaanxi Province,we analyzed the different contents of nano carbon (0.0％,0.1％,0.5％,0.7％,1.0％ in mass) on the nutrient affect the migration process on loess slope.The results showed that planting the same crop community adding different concentration of nano carbon has not the obvious effects on nutrient losses.Five kinds of underlying surface conditions,the nitrogen,phosphorus and potassium loss amounts in runoff on the slope all present a decreasing trend with the increase of nano carbon contents,when the nano carbon contents are 0.5％ and 0.7％,the effect of reducing nutrient loss amount in runoff is more significant.Under the conditions of different nano carbon contents,the nitrogen,phosphorus and potassium loss amounts decrease in the order:bare land＞corn＞Korshinsk Peashrub＞green bean＞alfalfa.Regulation effect in runoff under different nano carbon contents and different vegetation coverage were consistent with different nutrient losses.After artificial simulation rainfall,nutrients in top soil profile under different types of vegetation decreased significantly,but with the increase of the depth,the nutrient loss became decreased,which indicated that rainfall runoff could take soil nutrient of the surface layer,but most of them would be leached into the deep soil.Nutrient content decreased with the increase of depth of the soil profile,moreover,the nutrient loss was quite different due to different applied nano carbon.The average concentration and the average loss rates of different nutrients in runoff decreased when the nanometer carbon concentration increased,the regularity is obvious.