基于化肥施用控制的稻田生态补偿标准研究——以南京市溧水区为例

农田生态补偿作为一种控制化肥用量与面源污染的公共政策工具,其补偿标准将决定政策内化外部效应的实际效果。以南京市溧水区水稻种植户为对象,综合运用成本收益法、能值分析法和双边界二分式CVM法,测定基于政府和农户双重视角下的稻田化肥减施生态补偿标准。研究结果表明:化肥污染环境成本量化视角下南京市水稻种植过程中的折纯化肥投入参考值为268.75 kg hm~(-2)a~(-1),相比2017年南京市的实际化肥用量312.48 kg hm~(-2)a~(-1)仍有约14%的下降空间;绝大多数种植户愿意在接受平均补偿标准为882.49元hm~(-2)a~(-1)的前提之下减少化肥投入至参考用量;受教育程度越高、家中务农人数越多、化肥投入成本越高的稻农更倾向于接受生态补偿,而种植面积较大的农户以及年长男性种植户对减施化肥持更谨慎的态度。研究结果为南京市农业面源污染防治和稻田生态补偿标准制定提供了一定的理论支撑,在实际补偿发放过程中,单一的补偿标准无法保障公平公正,需建立与作物种植类型、化肥减施成效相挂钩的分级生态补偿制度,从而激励农户尽可能减少化肥投入。

Ecological compensation standards for paddy fields based on the control of chemical fertilizer application-Lishui District, Nanjing as an example

Ecological compensation is a public policy tool that can be used to cope with excessive fertilizer application and agricultural non-point source pollution; the amount of compensation significantly influences the actual level of policy implementation. This study examined government compensation for a reduction in the amount of fertilizer applied by rice farmers in Nanjing. We used cost income, energy value analysis, and double-boundary contingent valuation methods and constructed a fertilizer reduction compensation standard using the dual perspectives of the government and the farmers.. The results showed that from the perspective of environmental cost quantification resulting from chemical fertilizer pollution, the reference value for application of pure fertilizer to rice cropping systems in Nanjing is 268.75 kg hm^-2 a^-1, which is still approximately 14% lower than the actual amount of fertilizer applied 312.48 kg hm^-2 a^-1 in 2017 in Nanjing. The vast majority of growers were willing to reduce the amount of fertilizer to the reference dosage on the premise of accepting an ecological average compensation standard of 882.49 yuan hm^-2 a^-1. Finally, rice growers with higher education, larger households, and higher fertilizer input costs tended to accept ecological compensation as well as related obligations, whereas older male farmers and those with larger planting areas tended to be more cautious about reducing fertilizer use. Our results provide theoretical support for the prevention and control of agricultural non-point source pollution in Nanjing and the formulation of an ecological compensation standard for paddy fields. In the actual compensation and distribution process, the single compensation standard cannot guarantee fairness and justice and it is necessary to establish a hierarchical ecological compensation system that is linked to the crop planting type and the effects of chemical fertilizer reduction. Farmers should reduce the input of chemical fertilizer as much as possible.