国家农业绿色发展先行区化肥减量效果评估——兼论化肥减量与粮食安全的关系

EVALUATION OF THE EFFECT OF CHEMICAL FERTILIZER REDUCTION IN NATIONAL AGRICULTURAL GREEN DEVELOPMENT PILOT ZONES——WITH A DISCUSSION ON THE RELATIONSHIP BETWEEN CHEMICAL FERTILIZER REDUCTION AND FOOD SECURITY

关键词:  国家农业绿色发展先行区  化肥减量  有机肥  新型肥料  粮食生产安全

Key words:  national agricultural green development pilot zone  chemical fertilizer reduction  organic fertilizer  new-type fertilizers  food production security

摘要:

目的 化肥减量化作为国家农业绿色发展先行区的重点任务之一，是从源头防控农业面源污染、促进农业绿色转型的有力支撑，因此评估先行区政策的化肥减量效果以及对粮食安全的潜在影响具有重要意义。方法 文章使用2011—2020年江苏、浙江、山东、河南和湖北71个地级市面板数据，构建多期双重差分模型评估了国家农业绿色发展先行区化肥减量的政策效果，并使用门槛效应等方法讨论了先行区化肥减量与粮食安全的关系。结果 （1）先行区政策能有效降低化肥施用强度，并且推广有机肥的替代效应以及发展高效肥料的技术进步效应是先行区政策促进化肥减量的重要机制。（2）先行区政策仅对稻区和高财政支农水平地区的化肥减量有显著的促进作用。（3）在有机肥和高效肥料发展水平较高的城市，先行区政策能显著提高粮食总产量。进一步分析发现，随着粮食单产水平提高，先行区化肥减量效果越强。当粮食单产超过6 185.7 kg/hm²的门槛值时，先行区政策的化肥减量效果才开始显现。这说明，先行区基本完成粮食生产任务后，政策重心将由保障粮食产量转向促进化肥减量。结论 应当持续开展国家农业绿色发展先行区成果评估与创建工作，增强先行区的示范带动效应。同时，把握好化肥减量与粮食安全的关系，制定稳步合理的化肥减量目标，加快推广及高效用肥技术和有机肥替代工程。

Abstract:

As one of the key tasks in the national agricultural green development pilot areas, chemical fertilizer reduction serves as a powerful support for preventing and controlling agricultural non-point source pollution from the source and facilitating the green transformation of agriculture. Therefore, it is of great significance to evaluate the effect of chemical fertilizer reduction under the pilot area policies as well as its potential impact on food security. This reseach employed panel data of 71 prefecture-level cities in Jiangsu, Zhejiang, Shandong, Henan, and Hubei from 2011 to 2020, and constructed a multi-period difference-in-differences model to assess the policy effect of chemical fertilizer reduction in the national agricultural green development pilot areas. Meanwhile, it adopted methods such as the threshold effect to discuss the relationship between chemical fertilizer reduction and food security in the pilot areas.The results were listed as follows. (1) The policies of the pilot areas effectively reduced the intensity of chemical fertilizer application. Moreover, the substitution effect of promoting organic fertilizers and the technological progress effect of developing high-efficiency fertilizers were important mechanisms through which the pilot area policies promoted chemical fertilizer reduction. (2) The policies of the pilot areas only had a significant promoting effect on chemical fertilizer reduction in rice-growing areas and regions with a high level of fiscal support for agriculture. (3) In cities with a relatively high level of development in organic fertilizers and high-efficiency fertilizers, the policies of the pilot areas significantly increased the total grain output. Further analysis revealed that as the level of grain yield per unit area rises, the effect of chemical fertilizer reduction in the pilot areas became stronger. Only when the grain yield per unit area exceeded the threshold value of 6 185.7 kg/hm2 , did the effect of chemical fertilizer reduction under the pilot area policies began to emerge. This indicated that after the pilot areas basically complete the grain production tasks, the policy focus would shift from ensuring grain output to promoting chemical fertilizer reduction.Therefore, the evaluation and establishment work of the achievements in the national agricultural green development pilot areas should be continuously carried out to enhance the demonstration and driving effects of the pilot areas. Meanwhile, it is necessary to properly handle the relationship between chemical fertilizer reduction and food security, formulate steady and reasonable targets for chemical fertilizer reduction, and accelerate the promotion of high-efficiency fertilizer application technologies and organic fertilizer substitution projects.