应用GLEAMS模型评估我国东南地区农业小流域硝态氮的渗漏淋失

Assessing Nitrate Leaching With GLEAMS Model in an Agricultural Small Catchment in Southeast China.

应用GLEAMS模型估算我国东南亚热带地区农业小流域硝态氮的渗漏淋失。在五川流域8种不同土地利用方式的农田中埋设渗漏监测装置,每月采集水样分析硝态氮含量。用2002年4—12月作物生长季节的实测数据进行模型校验的结果表明,模型对水稻田除外的其他土地利用方式下硝态氮渗漏淋失模拟效果较好。五川流域2002年硝态氮淋失模拟计算结果表明,不同土地利用方式下硝态氮淋失时空差异显著,全年渗漏量(以氮计)为4.6438.39 kg.hm-2,流域面积加权平均为29.99 kg.hm-2。甘蔗地、香蕉地和蔬菜地的年硝态氮渗漏量最高,渗漏峰值一般出现在7—8月。降雨、土地利用和化肥施用等人类活动是影响硝态氮渗漏淋失的主要因素。

GLEAMS model was introduced to calculation of nitrate leaching in an agricultural small catchment in Southeast China. Field experiments were carried out in farmlands under different land uses, such as paddy, banana, and vegetable cultivation, at Wuchuan catchment, Fujian Province. Lysimeters were set up in 8 plots different in land use to monitor nitrate leaching from April to December in 2002. After calibration and validation, the model displayed an acceptable performance in simulating nitrate leaching in all plots, except for the plot of paddy field. Results of the simulations show that nitrate leaching in the catchment varied from 4.64 to 38.39 kg · hm^-2 with land uses. Sugarcane, banana and vegetable fields had maximum nitrate leaching and peaked in July and August. Rainfall, land uses and management were significant factors influencing nitrate leaching in the catchment. The model simulations can be used to specifically establish best management practices for nutrient management and pollution mitigation in the catchment.