稻草编织物覆盖对坡耕地红壤侵蚀及理化性质的影响

Effect of Rice Straw Mat Mulch on Soil and Water Loss and Soil Physical and Chemical Properties of Slope Arable Red Soil

通过田间小区试验,研究稻草编织物覆盖对云南省坡耕地红壤水土流失以及土壤理化性质的影响。于2008-2012年雨季期间,对不同覆盖方式下径流小区的径流量、侵蚀量及降雨强度进行监测,对玉米整个生长期前后的土壤理化性质进行测定。5年的试验结果表明,覆盖处理小区年均径流量为244.78m3/hm2,年均侵蚀量为4.16t/hm2,分别比无覆盖小区减少了67.60%和93.29%;覆盖处理小区径流中土壤全氮、全磷流失量分别比无覆盖小区减少63.98%和49.69%;经T检验,当降雨为中强度降雨（I30为0.25-0.30mm/min）时,稻草编织物覆盖对坡耕地蓄水保土的作用最为显著;不同处理pH在雨季后均有降低,且无覆盖处理小区降低幅度大于覆盖小区;不同处理土壤容重雨季后均有降低,但不同坡位变化趋势不同;侵蚀土壤的主要成分是细砂粒和粘粒,含量依次为细砂粒〉粘粒〉粉粒〉粗砂粒。

In order to prevent soil and water loss and improve the quality of farmland,a field experiment was conducted to study the role of natural fiber textiles made of rice straw on soil and water loss on slope arable red soil in Yunnan province.The runoff,soil loss,and physical and chemical properties of soil were investigated from 2008to 2012.The results showed that the mean annual runoff and erosion rate were 244.78m3/hm2 and 4.16t/hm2 from the covered plot,which reduced by 67.60% and 93.29% respectively compared with non-covered plot.The total nitrogen（TN）and total phosphorus（TP）contents in runoff from the covered plot reduced by 63.98% and 49.69% respectively compared with non-covered plot.The rice straw mat covering was more effective on water and soil conservation by T-test for middle-intensity rainfall events,i.e.I30 between 0.25mm/min and 0.30mm/min.The pH value decreased more from the non-covered plot than that from the covered plot.Soil bulk density reduced after the rainy season with different changes in different slope positions and treatments.The main sediments were fine sand and clay with the order of fine sandclay siltcoarse sand.