太湖流域坡地茶园径流流失规律

Surface Runoff in Tea Gardens on Slope Land in Taihu Lake Region

在太湖流域坡地茶园进行小区试验,研究自然降雨条件下坡地茶园径流流失的基本规律。结果表明,在常规种植条件下,茶园的平均年径流水量为98.29L·m-2,随径流流失的氮素量为11.685kg·hm-2,其中硝态氮(NO3--N)流失量为8.918kg·hm-2,占总氮的76.320%;可溶性总磷(TDP)流失量为0.128kg·hm-2,磷酸根(PO43-)流失量为0.104kg·hm-2,占磷总流失量的65.823%;径流携带泥沙量为181.13kg·hm-2,其中泥沙携带氮为0.272kg·hm-2,泥沙携带磷为0.030kg·hm-2;氮、磷流失系数分别为1.008%和-0.087%,氮、磷肥流失率分别为5.686%和0.190%。说明试验区域坡地茶园径流量少,氮、磷流失较少,产生农业面源污染的风险较小。

A field experiment was carried out in a tea garden sitting on a hill slope in the Taihu Lake Region to study basic rules of runoff therein under natural rainfall conditions.Results show that in tea gardens under conventional tea cultivation,the annual volume of runoff reached 98.29 L·m-2,carrying away a total of 11.685 kg·hm-2 N,which was dominantly NO3--N,about 76.320% ;0.128 kg·hm-2 dissolved P,which was dominantly PO43-about 0.104 kg·hm-2;and 181.13 kg·hm-2 of sediments,which contained 0.272 kg·hm-2 N and 0.030 kg·hm-2 P.The loss coefficient of N and P was 1.008% and-0.087% and the loss rate of fertilizer N and P was 5.686% and 0.190%,respectively.Comparatively,cultivation of tea on slope land produces less runoff and lowers soil N and P loss,thus reducing the risk of agricultural non-point source pollution.