雨强与水土保持措施对西南植烟红壤Cu、Mo和Zn流失的影响

降雨强度和水土保持耕作措施对坡面径流、侵蚀泥沙及土壤微量元素影响显著。采用野外降雨观测的方法研究植烟红壤在不同雨型、整地方式和覆被情况下,Cu、Mo和Zn 3种微量元素的流失特征。结果表明：(1)降雨强度对植烟土壤3种微量元素的流失具有显著作用,随着降雨强度的增加,Cu、Mo和Zn 3种微量元素的总流失量均呈表现为大雨>中雨>小雨;(2)秸秆覆盖和横坡种植措施虽然能够有效减少因侵蚀性降雨而产生的侵蚀泥沙,但泥沙中Cu、Mo和Zn 3种元素的富集比均有所提高;(3)与无秸秆覆盖处理相比,秸秆覆盖处理的Cu、Mo和Zn 3种微量元素在径流中分别减少44.99%,47.42%和62.24%;在泥沙中分别减少67.35%,56.88%和67.85%,且秸秆覆盖处理对微量元素总流失量的减小具有显著作用(p<0.05);(4)横坡种植处理较顺坡种植处理的Cu、Mo和Zn 3种微量元素在径流中分别减少43.31%,46.39%和45.62%;在泥沙中分别减少66.34%,53.95%和59.66%,横坡种植处理显著减少3种微量元素的流失量(p<0.05);(5)Cu、Mo和Z...

Effects of Rain Intensity and Soil and Water Conservation Measures on the Loss of Cu, Mo and Zn in Tobacco Planting Red Soil in Southwest China

Rainfall intensity and soil and water conservation tillage measures have a significant impact on slope runoff, erosion sediment and soil trace elements. We studied the loss characteristics of Cu, Mo and Zn in tobacco planting red soil under different rain patterns, land preparation methods and cover conditions through field rain-fall observation methods. The results showed that:(1) Rainfall intensity had a significant effect on the loss of the three trace elements in the tobacco planting soil. With the increasing of rainfall intensity, the total loss of Cu, Mo and Zn followed the order of heavy rain>moderate rain>light rain. (2) Although straw covering and cross slope planting measures could effectively reduce erosion sediment caused by erosive rainfall, the enrichment ratio of Cu, Mo and Zn in sediment increased. (3) Compared with the treatment without straw mulch, Cu, Mo and Zn in runoff decreased by 44.99%, 47.42% and 62.24%, respectively, and the total loss of trace elements in sediment decreased by 67.35%, 56.88% and 67.85%, respectively, and straw mulching treatment had a significant effect on the reduction of total loss of trace elements (p<0.05). (4) Cu, Mo and Zn in the runoff of the cross slope planting treatment decreased by 43.31%, 46.39% and 45.62%, respectively, compared with the slope planting treatment. The three trace elements in the sediment decreased by 66.34%, 53.95% and 59.66%, respectively. The cross slope planting treatment significantly reduced the loss of the three trace elements (p<0.05). (5) The total loss of Cu, Mo and Zn in sediment was significantly higher than that in runoff, and the loss of Cu, Mo and Zn in runoff and sediment followed the order of Zn>Cu>Mo. This study results could provide theoretical basis and data support for effectively reducing and controlling the loss of trace elements caused by soil and water loss of typical tobacco planting red soil in southwest China and for soil and water conservation in tobacco planting red soil.