【作者】 何丙辉； 谌芸； 马云；

【Author】 HE Bing-hui~1,CHEN Yun~1,MA Yun~2 (1.Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education, College of Resources and Environment,Southwest University,Chongqing 400715;2.Ningxia Department of Water Resources of Hydrology and Water Resources Survey,Ningxia,Yinchuan, 750001)

【机构】 西南大学资源环境学院三峡库区生态环境教育部重点实验室； 宁夏水利厅水文水资源勘测局；

【摘要】 在四川盆地紫色土区通过标准径流小区试验,研究香根草植物篱对不同坡度的坡耕地表层(0-20 cm)土壤容重、颗粒分布及养分流失的影响。结果表明香根草植物篱有利于土壤容重减小,但总体上效果不显著。在植物篱的影响下,土壤细颗粒(粉粒、粘粒)在坡脚、坡腰明显富集,且总体上细颗粒流失减少,所以砂粒含量相对降低。香根草植物篱能有效的控制表土各养分的流失,保持土壤肥力;能减少各养分在坡顶的流失,但全氮的流失依然严重;能加剧各养分在坡脚的富集,其中对有机质的影响最明显;能明显提高篱带前土壤肥力,尤其是总磷和速效钾。有机质、全氮、总磷、有效磷、速效钾的变化量分别与粘粒变化量呈显著线性正相关(r=0.859,0.896,0.821,0.807,0.927),与粉粒相关性不强,所以它们在坡面上的变化趋势与粘粒基本一致。在植物篱小区,坡度对有机质、全氮、碱解氮、全钾的富集影响不明显,但坡度较小时,有效钾、坡顶碱解氮和坡顶有效磷的流失显著减少。所有小区坡面上的全钾含量均增加。因此,该区紫色土坡耕地要注意补充氮肥,减少钾肥,加强坡顶和远篱带处土壤的培肥。更多还原

【Abstract】 Through experiments in standard runoff plots,this paper studied effects of vetiver hedgerows on bulk density,particle distribution and nutrient loss in the surface soil layer(0-20 cm) of different slope farmland in the purple soil area,Sichuan,China.The results showed that vetiver hedgerow can reduce soil bulk density,but the effect was not significant.Under hedgerow’s effect, small soil particles(silt,clay) obviously enriched in the bottom and middle of slope,and the quantity of small particles loss reduced in the whole,so sand percentage decreased.Vetiver hedgerow can effectively control nutrient loss and maintain soil fertility;can reduce the quantity of nutrient loss in the top of slop,but the quantity of total nitrogen loss was still serious;can increase nutrient enrichment in the bottom of slope,especially organic matter;can significantly improve soil fertility in the front of hedgerow,especially total phosphorus and available potassium.Variations of organic matter,total nitrogen,total phosphorus,available potassium and available potassium had positive linear correlation with variation of clay with correlation coefficient of 0.859,0.896,0.821,0.807 and0.927 respectively,so they had the same changing characteristic with clay in slop.In the hedgerow plots,effects of slope on organic,total nitrogen,alkali-hydrolyzable nitrogen and total potassium enrichment were not obvious,but in the gentle slope loss of available potassium,losses of alkali-hydrolyzable nitrogen and available phosphorus of slop top had a significant reduction.Total potassium in different slope positions of all plots increased.Therefore,increasing the amount of nitrogenous fertilizer and reducing the amount of potash fertilizer were important in this area.And strengthen soil fertilities of the top of the slop and portions faraway from hedgerow were also important.更多还原