花岗岩红壤区不同生草措施果园产流产沙特征

Characteristics of runoff and sediment yield of orchards with different grass growing measures in red soil region with granite

南方花岗岩红壤区果园普遍面临着严重的水土流失问题,采用林下生草措施能有效降低地表产流产沙,减少果园水土流失。本文以江西省兴国县塘背小流域为研究区域,通过设置五种不同生草措施的果园径流小区,研究天然降雨下不同生草措施果园的产流产沙特征。结果表明:(1)不同生草措施果园的产流产沙量具有显著差异,且随降雨量和降雨侵蚀力的增加而增加;(2)不同生草措施果园的产流产沙量,以脐橙+白三叶最小,产流量比脐橙+艾蒿、脐橙+马齿苋、脐橙+草木犀和脐橙清耕,分别减少54.09%、53.15%、58.07%、69.85%,产沙量分别减少61.53%、59.94%、68.88%、87.26%,具有较好的减流减沙效果;(3)不同生草措施对果园侵蚀泥沙的粒径组成具有一定影响,但区别不明显;其中脐橙+白三叶措施的侵蚀泥沙粒径组成中,砂粒平均含量最少,粘粒平均含量最多。因此,在南方花岗岩红壤区果园林下采用生草覆盖措施能有效减少水土流失。

Orchards in granite red soil region of South China are generally faced with serious soil and water loss.Grass planting under forest can effectively reduce runoff and sediment yield and soil and water loss of orchards.Taking Tangbei small watershed in Xingguo county of Jiangxi province as the research area,this paper studies the runoff and sediment characteristics of orchards with different grass growing measures under natural rainfall by setting five orchard runoff plots with different grass growing measures.The results showed that:(1)the runoff and sediment yield of orchards with different grass planting measures were significantly different,and increased with the increase of rainfall and rainfall erosivity;(2)compared with navel orange+Artemisia argyi,navel orange+purslane,navel orange+Melilotus and navel orange clear tillage,the runoff and sediment yield of navel orange+white clover decreased by 54.09%,53.15%,58.07%,69.85%,61.53%,59.94%,68.88%,87.26%,respectively,which had good effect of reducing runoff and sediment;(3)different grass planting measures had a certain effect on the grain size composition of orchard erosion sediment,but the difference was not obvious.Among them,the average content of sand is the least,and the average content of clay is the most.Therefore,grass mulching can effectively reduce soil and water loss under orchard forest in red soil region with granite in Southern China.