化肥、农药和地膜对甘肃省农业生态环境的影响

依据甘肃省农业生态区划,对5个生态区单位面积化肥、农药和地膜施用量进行了环境影响分析。结果是:甘南区处在低施肥量区,其余4个区化肥施用量均超过了全国高施肥量区的平均值,其中河西区施用量已超过全国平均高施肥的3.22倍,粮食产出率仅4.8kg·kg^-1;全省河西区农药和地膜平均施用量最大(128.9kg·hm^-2、15.1万hm²)。对环境的影响是土壤有效营养元素失衡、土地板结、保水保肥能力下降、地表水和地下水受到污染;农作物品质下降,各种农作物中六六六、滴滴涕的残检率为100%,但已逐年降低,有机磷农药蔬菜检出率为76%;由于地膜使用年限短,覆膜面积较小,未出现地膜残留污染。

Influence of Chemical Fertilizer, Pesticide and Plastic Film on Agricultural Ecology Environment in Gansu Province

Based on agro-ecology regionalization,influence of chemical fertilizer,pesticide and plastic film on the eco-environment in Gansu province were studied.The results showed that except for Gannan region the chemical fertilizer use amount in the other four ecotypes was higher than the mean value of China.Especially in Hexi Corridor,it was 4.22 times of that in the high fertilizer use region of China,but the output rate of food was only 4.8 kg\5kg~(-1).Moreover,the amount of pesticide and plastic film application were also the highest in Gansu province.The application of chemical fertilizer,pesticide made soil available nutrition unbalanced,soil hardened,water and fertilizer conservation capacity lowered,surface water and groundwater polluted,and food quality declined.The DDT and HCH residues in crop were 100% detected,but declined year after year;the organophosphorus pesticide residue in vegetable was 76% detected.As far plastic film,its residual pollution didn't appear because of shorter use duration and smaller mulched area.