谷子不同生长时期水土及养分流失规律研究

Study on Soil and Nutrient Loss in Different Growth Periods of Millet

通过室内人工模拟降雨的方法,研究了谷子不同生长时期片麻岩坡面水土流失和养分流失特征。结果表明:谷子不同生长时期产流产沙量不同,总体流失量呈现出0d>20d>40d>60d,与对照(0d)相比,谷子60d坡面产流量减少了33%,产沙量减少了43%;谷子不同生长时期坡面养分流失量随谷子生长天数的增加而减少,与对照(0d)相比,60d坡面氮磷钾养分流失量分别减少了75%,45%,70%,降雨过程中硝态氮流失量始终高于铵态氮流失量;谷子不同生长时期坡面养分流失量表现为钾流失总量>氮流失总量>磷流失总量,养分流失总量与产沙量之间方程拟合系数均达0.85以上,有着显著的正相关性;谷子不同生长时期片麻岩坡面磷钾的流失主要以泥沙结合态为主,氮素流失为溶解态氮与泥沙态氮共存。

An indoor rainfall experiment was conducted to evaluate the effects of millet at different growth stages on the soil and nutrient loss on the slope surface of gneiss area.The results showed that the yield of runoff and sediment during different growth periods of millet were different,and the general loss amount was sequenced by 0d〉20d〉40d〉60d.Compared with the control（0d）,under the 60-day old millet,the slope runoff yield decreased by 33%,and the sediment yield decreased by 43%.The loss of nutrients on the slope surface decreased with the increase of the growth days of millet.Compared with the control（0d）,the losses of nitrogen,phosphorus and potassium on the 60 th day decreased by 75%,45%and 70%,respectively,and the loss of nitrate during the rainfall was always higher than that of ammonium.The loss amounts of different nutrients in the different growth stages of millet listed in the following order：potassium〉nitrogen〉phosphorus.The fit coefficient of the equation between total nutrient loss amount and sediment yield were higher than 0.85,and there was a significant positive correlation between them.In the different growth stages of millet,nutrient losses on the slope surface of gneiss area were mainly in the form of sediment combination state especially for phosphorus and potassium,and nitrogen loss was mainly in the form of dissolved nitrogen or both dissolved nitrogen and sediment-associated nitrogen.