Agricultural pollution pressure in the Taihu Lake Basin

The serious water environment quality deterioration in the Taihu Lake Basin (TLB) has been largely blamed on agricultural pollution. The pollutants were mainly from the processing of plant, livestock and poultry and aquacultural products. This paper developed an agricultural pollution model that calculates the pressure index of agricultural pollution based on the cultivation of plants and the breeding of livestock, poultry and aquaculture. The results showed that nitrogen and phosphorus pollutants largely contributed to water pollution with pollution pressure index value greater than one. Spatial distributions of agricultural pollution pressure index differed not only with different cultivation and breeding practices, but also with region. Although fertilizer and pesticide dose per unit area decreased, it was still far above the upper limit of safety usage. For example, the lowest fertilizer dose in Changzhou City during 2000—2008 was 452.71 kg·hm^-2 (in 2008), which was still above the 225 kg·hm^-2 upper safe limit. The findings in this paper served as important reference for sustainable usage of water resources and water environment management in terms of the influence of agriculture pollution on the water environment.