片麻岩坡面花生不同生长时期水土及养分流失规律

Study on Soil and Nutrient Losses on Gneiss in Different Growth Periods of Peanut

通过室内人工模拟降雨的方法,研究了花生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:花生不同生长时期产流产沙量不同,总体流失量均呈现出0d>20d>40d>60d,与对照(0d)相比,花生60d坡面产流量减少了38%,产沙量减少了47%;不同生长时期坡面养分流失量随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;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0.98以上,有着显著的正相关性;花生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。

Indoor simulation rainfall experiment was conducted to evaluate the effects of peanut at different growth stages on the surface soil and nutrient losses in gneiss area.The results showed that the yields of runoff and sediment during different growth periods peanut were different,and the loss amounts decreased in the order：0d〉20d〉40d〉60d.Compared with the control（0d）,runoff slope with 60-day-peanut decreased by 38%,sediment production slope with 60-day-peanut decreased by 47%.The losses of nutrients during different growth stages decreased with the increase of the growth days,compared with the control（0d）,the losses of nitrogen,phosphorus,potassium in the 60 days decreased by 75%,45%,70%,respectively,the loss of nitrate during the rainfall was always higher than ammonium.The amounts of nutrient loss at the different growth stages represented the cumulative loss order：potassium〉nitrogen〉phosphorus.The equation fitting factor of total nutrient loss and sediment yield was more than 0.98,and there was a significant positive correlation;nutrient losses from gneiss area were mainly in the form of sediment combination state especially for phosphorus and potassium,nitrogen loss was mainly in the form of dissolved nitrogen or both dissolved nitrogen and sediment-associated nitrogen.