山核桃林坡地氮磷流失年动态规律初步研究

Preliminary Study on Annual Dynamics of Nitrogen and Phosphorus Losses at Carya cathayensis Stand on Slope

2016年6月至2017年5月,在浙江省临安市山核桃林闭合区底部沟壑出口处设置水土流失卡口,监测山核桃林坡面氮磷径流的年动态变化。结果表明,(1)山核桃林坡面径流量和降水量存在显著的线性正相关(y=1.351 0x+126.040 5,R^2=0.797 9),降水量越大,产生的径流量越大;(2)径流总氮(TN)浓度在2.50~3.21 mg·L^(-1),硝态氮(NO_3^--N)浓度变化幅度为0~2.26 mg·L^(-1),TN和NO_3^--N浓度的在6-8月呈递增趋势,而后下降,并保持相对稳定;径流氮元素浓度较高。(3)径流总磷(TP)浓度变化范围为0.01~0.09 mg·L^(-1),磷酸盐(PO_4~^(-3))浓度变化幅度为0.01~0.02 mg·L^(-1),径流磷元素浓度较低。

A monitoring station was established in May2016at the closed zone of Carya cathayensis stand on slope in Lin'an,Zhejiang province,and investigation was carried out during June2016to May2017on annual changes of nitrogen and phosphorus losses.The results showed that it had significant linear positive correlation between runoff and precipitation(y=1.3510x+126.0405,R2=0.7979),meaning that the greater precipitation,the greater runoff.The range of total nitrogen(TN)was2.54-3.47mg·L-1,of the nitrate nitrogen(NO-3-N)concentration was0-2.79mg·L-1.TN and NO-3-N concentration increased during June to August,then declined and remained relatively stable.The concentration of N in runoff was determined higher.The total phosphorus(TP)concentration ranged from0.01to0.09mg·L-1,and phosphate(PO3-4)from0.01to0.02mg·L-1.The concentration of P in runoff was determined lower.