The impact of agricultural socialized services on the reduction of fertilizer: double inspection based on panel data of 31 provinces in China
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摘要: 实现化肥减量是我国农业走向高质量发展的重要举措, 也是实现农业绿色发展的关键所在。基于专业分工理论, 利用2011—2020年统计年鉴数据, 采用中介调节模型和工具变量模型实证分析了农业社会化服务对化肥减量的作用机制。研究发现, 农业社会化服务对化肥使用总量和单位面积使用量具有显著负向影响, 即农业社会化服务产值每增加1%, 化肥使用总量和单位面积化肥使用量分别能降低0.055%和0.443%。中介和调节分析发现, 农业社会化服务通过资源配置和科技进步两条路径实现化肥减量, 分工深化和政府主导分别对该路径存在0.039的促进作用和−0.017的抑制作用。进一步研究发现, 农业社会化服务可以显著降低服务规模小、农业发展程度高和东部地区省份的化肥使用量, 而对中西部地区省份化肥减量未能发挥作用。其中, 监管体系的缺失和分工深化的不足是目前我国农业社会化服务面临的主要问题, 也是阻碍化肥减量实现的重要因素。Abstract: In the face of the real dilemma that traditional small farmer management cannot meet the sustainable development of agriculture, the reduction of chemical fertilizers is an important measure for China’s agriculture to move towards high-quality development, and it is also the key to the development of green agriculture. Based on the theory of professional division of labor, a theoretical model of “service outsourcing”, a division of labor economy, and the reduction of chemical fertilizer is constructed. Using statistical yearbook data from 2011 to 2020, this study empirically analyzed the affacting mechanism of agricultural socialized services on the reduction of chemical fertilizer by using an intermediary adjustment model and an instrumental variable model. The study found that agricultural socialized services had a significant negative impact on the total use of chemical fertilizer and the use per unit area; that is, for every 1% increase in the output value of agricultural socialized services, the total amount of fertilizer used and the amount of fertilizer used per unit area can be reduced by 0.055% and 0.443%, respectively. The robustness test of the tool variables also confirmed the positive effect of socialized agricultural services on the reduction of chemical fertilizer. At the same time, resource allocation, technological progress, and disaster areas had a negative impact on the use of chemical fertilizers. While deepening the division of labor and grain output had a positive role in promoting the total use of chemical fertilizers, with impact effects of 0.063 and 0.266, respectively. From the perspective of the mechanism, agricultural socialized services reduced the application of chemical fertilizer through resource allocation and scientific and technological progress. The deepening of the labor division had a 0.039 promotion effect on this path, and the government had a negative impact of 0.271 and an inhibition of 0.017 on the reduction of chemical fertilizers and this path, respectively. Further research found that there were differences between agricultural service scale, agricultural development degree, and geographical location in the impact of agricultural socialized services on reducing chemical fertilizer. Provinces with small service scales had a greater impact on the reduction of chemical fertilizers. Agricultural provinces have a higher impact on the reduction of chemical fertilizers than non-agricultural provinces on the premise of a more complete agricultural infrastructure and a more mature industrial chain. Socialized agricultural services in the central and western province had no significant impact on the use of chemical fertilizers. Among them, the lack of a supervision system and the lack of a deepening division of labor are the main problems faced by China’s socialized agricultural services, and they are also important factors that hinder the realization of fertilizer reduction. Therefore, we should continue to play the positive role of agricultural socialized services in reducing the amount of fertilizer, expanding the market demand for socialized services and green agricultural products, improving the deepening and supervision system of socialized service division, establishing a sound service outsourcing and green production standard system, strengthening risk management and control, promoting rational allocation of resources, and realizing an increase in both the income and productivity of farmers.
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表 1 农业社会化服务对化肥减量影响机制相关变量的基本统计信息
Table 1. Descriptive statistical of related variables of effects of agricultural socialized service on fertilizer reduction
变量
Variable指标
Index总值
Gross value均值
Average value标准差
Standard deviation最小值
Minimum value最大值
Maximum value${\rm{F}}$ 化肥施用总量
Fertilizer application amount (×104 t)57 625.20 185.89 147.01 4.40 716.10 ${\mathrm{Fi} }$ 单位面积化肥施用量
Fertilizer application rate (kg∙hm−2)112 330.46 362.36 129.26 96.25 750.66 $ \mathrm{S}\mathrm{e}\mathrm{r} $ 农林牧渔服务业产值
Agricultural service industry value (×108 ¥)47 167.81 152.15 146.75 3.00 804.10 $ \mathrm{V}\mathrm{a}\mathrm{l} $ 第一产业增加值
Added value of agriculture (×108 ¥)679 370.60 2191.52 1643.60 66.70 7853.80 $ \mathrm{T}\mathrm{e}\mathrm{c} $ 有效灌溉面积
Effective irrigation area (%)141.11 0.46 0.22 0.17 0.99 $ \mathrm{C}\mathrm{o}\mathrm{n} $ 农林牧渔服务业中间消耗
Agricultural service intermediate consumption (×108 ¥)20 319.97 65.55 66.31 0.80 356.90 $ \mathrm{F}\mathrm{i}\mathrm{n} $ 农林水财政支出
Agricultural financial expenditure (×108 ¥)166 533.95 537.21 271.86 91.78 1339.36 表 2 农业社会化服务对化肥施用量的基准回归结果
Table 2. Benchmark regression results of agricultural socialized service on fertilizer application
变量 Variable 模型(1) Model (1) 模型(2) Model (2) 模型(3) Model (3) 模型(4) Model (4) 模型(5) Model (5) 模型(6) Model (6) $\mathrm{l}\mathrm{n}\left(\mathrm{S}\mathrm{e}\mathrm{r}\right)$ −0.077***
(0.016)−0.075***
(0.019)−0.061***
(0.016)−0.065***
(0.018)−0.068***
(0.016)−0.055***
(0.017)$\mathrm{l}\mathrm{n}\left(\mathrm{V}\mathrm{a}\mathrm{l}\right)$ −0.190***
(0.039)−0.094**
(0.047)$ \mathrm{T}\mathrm{e}\mathrm{c} $ −0.213***
(0.046)−0.192***
(0.044)$\mathrm{l}\mathrm{n}\left(\mathrm{C}\mathrm{o}\mathrm{n}\right)$ 0.094***
(0.017)0.063***
(0.020)$\mathrm{l}\mathrm{n}\left(\mathrm{A}\mathrm{f}\mathrm{f}\right)$ 0.031***
(0.006)0.029***
(0.006)0.027***
(0.006)0.025***
(0.006)0.023***
(0.006)$\mathrm{l}\mathrm{n}\left(\mathrm{P}\mathrm{e}\mathrm{r}\right)$ −0.321**
(0.125)−0.280**
(0.121)−0.289**
(0.121)−0.333***
(0.119)−0.280**
(0.115)$\mathrm{l}\mathrm{n}\left(\mathrm{O}\mathrm{u}\mathrm{t}\right)$ 0.133***
(0.037)0.438***
(0.057)0.128***
(0.036)0.120***
(0.035)0.226***
(0.064)$ \_\mathrm{C}\mathrm{o}\mathrm{n}\mathrm{s} $ 5.066***
(0.057)6.715***
(1.027)6.155***
(0.995)6.552***
(0.991)6.590***
(0.975)6.205***
(0.947)N 310 310 310 310 310 310 F 342.45*** 112.38*** 115.30*** 119.57*** 114.26*** 120.38*** 变量Ser、Val、Tec和Con的解释见表1; Aff、Per和Out为控制变量, 分别表示受灾成灾面积、粮食单位面积产量和种植业总产值。*、**、***分别代表P<0.1、P<0.05、P<0.01; _Cons、N和F分别代表方程的常数项、样本数和统计检定值。非标准估计系数表示自变量改变1个单位时, 因变量的改变量; 标准化估计系数表示自变量改变1个标准差时, 因变量改变量。The explanation of variables of Ser, Val, Tec and Con is shown in the table 1. The variables of Aff, Per and Out mean the disaster affected area, crop yield per cultivated land area, and total output of planting industy. *, ** and *** indicate significance at P<0.1, P<0.05 and P<0.01 levels. _Con, N and F are constant of the equation, samples number and equality of variances. The nonstandard estimation coefficient represents the change of dependent variable when the independent variable changes one unit; the standardized estimation coefficient represents the change of dependent variable when the independent variable changes one standard deviation. 表 3 农业社会化服务对化肥施用量影响的稳健性检验结果
Table 3. Robustness test results of effect of agricultural socialized service on fertilizer application
变量
Variable模型(7)
Model (7)模型(8)
Model (8)模型(9)
Model (9)$\mathrm{l}\mathrm{n}\left(\mathrm{S}\mathrm{e}\mathrm{r}\right)$ −0.443**
(0.212)−0.533*
(0.270)−0.416***
(0.727)$\mathrm{l}\mathrm{n}\left({\mathrm{S}\mathrm{e}\mathrm{r} }_{{t}-1}\right)$ 0.110*
(0.056)$\mathrm{l}\mathrm{n}\left({\mathrm{S}\mathrm{e}\mathrm{r} }_{{j}{t} }\right)$ 2.163***
(0.323)C YES YES YES N 310 310 310 F 146.32*** 4.26 25.71*** $ \mathrm{F}\mathrm{i}\mathrm{r}\mathrm{s}\mathrm{t}\_{F} $ 4.31 44.61*** $ \mathrm{C}\mathrm{h}\mathrm{i}2 $ 40.54*** Ser表示农林牧渔服务业产值, j和t分别表示变量和年份。*、**、***分别代表P<0.1、P<0.05、P<0.01; C、N和F代表控制变量、样本数和统计检定值。标准化估计系数表示自变量改变1个标准差时, 因变量的改变量。Ser is the agricultural service industry value, j and t indicate the variable and year. *, ** and *** indicate significance at P<0.1, P<0.05 and P<0.01 levels. C, N and F are the control variable, number of samples and equality of variances. The standardized estimation coefficient represents the change of dependent variable when the independent variable changes one standard deviation. 表 4 农业社会化服务对中间变量的检验结果
Table 4. Test results of agricultural socialized service on intermediate variables
变量
Variable模型(10)
Model (10)模型(11)
Model (11)模型(12)
Model (12)$\mathrm{l}\mathrm{n}\left(\mathrm{V}\mathrm{a}\mathrm{l}\right)$ $ \mathrm{T}\mathrm{e}\mathrm{c} $ ln($ \mathrm{C}\mathrm{o}\mathrm{n} $) $\mathrm{l}\mathrm{n}\left(\mathrm{S}\mathrm{e}\mathrm{r}\right)$ 0.073***
(0.027)0.046*
(0.024)−0.071
(0.065)$ \_\mathrm{C}\mathrm{o}\mathrm{n}\mathrm{s} $ −2.955*
(1.509)−0.767
(1.308)1.341
(3.521)C YES YES YES N 310 310 310 F 22.84*** 12.83*** 21.21*** Ser、Val、Tec和Con的解释见表1。*、**、***分别代表P<0.1、P<0.05、P<0.01; _Con、C、N和F分别代表方程的常量、控制变量、样本数和统计检定值。非标准估计系数表示自变量改变1个单位时, 中间变量的改变量; 标准化估计系数表示自变量改变1个标准差时,中间变量的改变量。The explanation of Ser, Val, Tec and Con is shown in the table 1. *, ** and *** indicate significance at P<0.1, P<0.05 and P<0.01 levels. _Con, C, N and F indicate the constant of equation, contral variable, number of samples and equality of variances. The nonstandard estimation coefficient represents the change of intermediate variable when the independent variable changes one unit; the standardized estimation coefficient represents the change of intermediate variable when the independent variable changes one standard deviation. 表 5 分工深化和政府主导在农业社会化服务对化肥使用量影响中的调节作用
Table 5. Regulatory effect of deepening division of labor and government leadership in the impact of agricultural socialized services on fertilizer production
变量
Variable模型 (13)
Model (13)模型 (14)
Model (14)模型 (15)
Model (15)$\mathrm{l}\mathrm{n}\left(\mathrm{S}\mathrm{e}\mathrm{r}\right)$ −0.146***
(0.055)−0.220***
(0.067)−0.181***
(0.070)$\mathrm{l}\mathrm{n}(\mathrm{S}\mathrm{e}\mathrm{r}\_\mathrm{C}\mathrm{o}\mathrm{n})$ −0.017*
(0.010)−0.021*
(0.011)$\mathrm{l}\mathrm{n}(\mathrm{S}\mathrm{e}\mathrm{r}\_\mathrm{F}\mathrm{i}\mathrm{n})$ 0.029***
(0.010)0.039***
(0.011)$ \_\mathrm{C}\mathrm{o}\mathrm{n}\mathrm{s} $ 6.159***
(0.944)5.712***
(0.956)5.953***
(0.961)N 310 310 310 C YES YES YES F 121.23*** 126.21*** 127.12*** Ser、Ser_Con和Ser_Fin分别表示农业生产性服务产值、农业生产性服务产值与农业服务业中间消耗的交互项和农业生产性服务产值和农林牧渔财政支出的交互项。*、**、***分别代表P<0.1、P<0.05、P<0.01; _Con、C 、N和F分别代表方程的常量、控制变量、样本数和统计检定值。标准化估计系数表示自变量改变1个标准差时, 因变量的改变量。Ser, Ser_Con and Ser_Fin indicate agricultural service industry value, interaction between Ser and agricultural service intermediate consumption, interaction between Ser and agricultural financial expenditure. *, ** and *** indicate significance at P<0.1, P<05 and P<0.01 levels. _Con, C, N and F indicate the constant of equation, contral variable, number of samples and equality of variances. The standardized estimation coefficient represents the change of dependent variable when the independent variable changes one standard deviation. 表 6 农业社会化服务对化肥施用量的异致性分析结果
Table 6. Analysis results of heterogeneity of effect of agricultural socialized service on fertilizer application
变量
Variable模型(16) 模型(17) 模型(18) 规模化
Large-scale agricultural
socialized service非规模化
Small-scale agricultural
socialized service农业大省
Agricultural
province非农业大省
Non-agricultural
province东部省份
Eastern
provinces中西部省份
Central and western
provinces$\mathrm{L}\mathrm{n}\left({\rm{Ser}}\right)$ −0.182***
(0.026)−0.378***
(0.053)−0.2621***
(0.052)−0.019***
(0.008)−0.175***
(0.382)−0.006
(0.159)$ \_\mathrm{C}\mathrm{o}\mathrm{n}\mathrm{s} $ 3.302***
(0.920)2.916***
(1.191)4.093***
(1.180)5.243***
(1.086)8.139***
(1.264)1.236
(1.023)N 171 139 100 210 130 180 C YES YES YES YES YES YES F 475.35*** 105.54*** 107.59*** 455.27*** 207.16*** 164.05*** Ser表示农林牧渔服务业产值。*、**、***分别代表P<0.1、P<0.05、P<0.01; _Con、 C 、 N 和 F 分别代表方程的常量、控制变量、样本数和统计检定值。标准化估计系数表示自变量改变1个标准差时, 因变量的改变量。Ser is the agricultural service industry value. *, ** and *** indicate significance at P<0.1, P<05 and P<0.01 levels. _Con, C , N and F indicate the constant of equation, contral variable, number of samples and equality of variances. The standardized estimation coefficient represents the change of dependent variable when the independent variable changes one standard deviation. -
[1] YU F W. An analysis of the reasons, core and countermeasures of agricultural green development in the new era[J]. Chinese Rural Economy, 2018(5): 19−34 [2] 韩俊. 论“三农”中国梦的实现[J]. 农村经济, 2014(8): 3−6HAN J. On the realization of the Chinese dream of “agriculture, countryside and farmers”[J]. Rural Economy, 2014(8): 3−6 [3] 黄季焜. 新时期的中国农业发展: 机遇、挑战和战略选择[J]. 中国科学院院刊, 2013, 28(3): 295−300 doi: 10.3969/j.issn.1000-3045.2013.03.001HUANG J K. China’s agricultural development in the new era: opportunities, challenges, and strategies[J]. Bulletin of Chinese Academy of Sciences, 2013, 28(3): 295−300 doi: 10.3969/j.issn.1000-3045.2013.03.001 [4] 李春海. 新型农业社会化服务体系框架及其运行机理[J]. 改革, 2011(10): 79−84LI C H. New agricultural social service system framework and operation mechanism[J]. Reform, 2011(10): 79−84 [5] 姜松, 曹峥林, 刘晗. 农业适度规模经营与金融服务创新: 特征现象与演化机制[J]. 世界农业, 2017(7): 67−73, 244JIANG S, CAO Z L, LIU H. Moderate scale management of agriculture and financial service innovation: characteristics and evolution mechanism[J]. World Agriculture, 2017(7): 67−73, 244 [6] 赵昶, 孔祥智, 仇焕广. 农业经营规模扩大有助于化肥减量吗−基于全国1274个家庭农场的计量分析[J]. 农业技术经济, 2021(4): 110−121ZHAO C, KONG X Z, QIU H G. Does the expansion of farm size contribute to the reduction of chemical fertilizers? — Empirical analysis based on 1274 family farms in China[J]. Journal of Agrotechnical Economics, 2021(4): 110−121 [7] WU Y, XI X, TANG X, et al. Policy distortions farm size and the overuse of agricultural chemicals in China[J]. Proceedings of the National Academy of Sciences of the United States of America, 2018(115): 7010−7015 [8] 曹铁毅, 周佳宁, 邹伟. 土地托管与化肥减量化: 作用机制与实证检验[J]. 干旱区资源与环境, 2022, 36(6): 34−40CAO T Y, ZHOU J N, ZOU W. Effects of land trusteeship on fertilizer input reduction: mechanism and empirical test[J]. Journal of Arid Land Resources and Environment, 2022, 36(6): 34−40 [9] 张露, 罗必良. 农业减量化: 农户经营的规模逻辑及其证据[J]. 中国农村经济, 2020(2): 81−99ZHANG L, LUO B L. Agricultural chemical reduction: the logic and evidence based on farmland operation scale of households[J]. Chinese Rural Economy, 2020(2): 81−99 [10] 朱建军, 徐宣国, 郑军. 农机社会化服务的化肥减量效应及作用路径研究——基于CRHPS数据[J/OL]. 农业技术经济, 1−13 (2021-11-29). http://doi.org/10.13246/j.cnki.jae.20211126.002ZHU J J, XU X G, ZHENG J. Research on chemical fertilizer reduction effect of agricultural machinery socialized service and action path— Based on CRHPS data[J/OL]. Journal of Agrotechnical Economics, 1−13 (2021-11-29). http://doi.org/10.13246/j.cnki.jae.20211126.002 [11] 李颖慧, 李敬. 中国农业生产性服务供给效率测算与影响因素研究−基于DEA-Malmquist指数和Rough Set方法[J]. 重庆社会科学, 2021(5): 6−16LI Y H, LI J. Research on the measurement and influencing factors of the supply efficiency of agricultural productive services in China: based on DEA Malmquist index and rough set method[J]. Chongqing Social Sciences, 2021(5): 6−16 [12] 于鸷隆, 刘玉铭. 我国农村科技服务供给方式探析−以科技特派员制度为例[J]. 中国行政管理, 2011(4): 69−72YU Z L, LIU Y M. An analysis of China’s rural science and technology service means[J]. Chinese Public Administration, 2011(4): 69−72 [13] ZHANG C, HU R F, SHI G M, et al. Overuse or underuse? An observation of pesticide use in China[J]. The Science of the Total Environment, 2015, 538: 1−6 doi: 10.1016/j.scitotenv.2015.08.031 [14] 卢华, 陈仪静, 胡浩, 等. 农业社会化服务能促进农户采用亲环境农业技术吗[J]. 农业技术经济, 2021(3): 36−49LU H, CHEN Y J, HU H, et al. Can agricultural socialized services promote farmers to adopt pro-environment agricultural technologies?[J]. Journal of Agrotechnical Economics, 2021(3): 36−49 [15] 吕杰, 薛莹, 韩晓燕. 风险规避、关系网络与农业生产托管服务选择偏向−基于有限理性假设的分析[J]. 农村经济, 2020(3): 118−126LYU J, XUE Y, HAN X Y. Risk avoidance, relationship network and preference of agricultural production trusteeship service: analysis based on the hypothesis of limited rationality[J]. Rural Economy, 2020(3): 118−126 [16] 穆娜娜, 周振, 孔祥智. 农业社会化服务模式的交易成本解释−以山东舜耕合作社为例[J]. 华中农业大学学报(社会科学版), 2019(3): 50−60, 160MU N N, ZHOU Z, KONG X Z. Explanation of transaction cost on the mode of specialized agricultural services — A case study of Shungeng Cooperative in Shandong Province[J]. Journal of Huazhong Agricultural University (Social Sciences Edition), 2019(3): 50−60, 160 [17] 谢琳, 胡新艳, 罗必良. 技术进步、信任格局与农业生产环节外包[J]. 农业技术经济, 2020(11): 4−16 doi: 10.13246/j.cnki.jae.2020.11.001XIE L, HU X Y, LUO B L. Technical progress, trust pattern and the outsourcing of agricultural production links[J]. Journal of Agrotechnical Economics, 2020(11): 4−16 doi: 10.13246/j.cnki.jae.2020.11.001 [18] 赵玉姝, 焦源, 高强. 农业技术外包服务的利益机制研究[J]. 农业技术经济, 2013(5): 28−35 doi: 10.13246/j.cnki.jae.2013.05.003ZHAO Y S, JIAO Y, GAO Q. Study on the benefit mechanism of agricultural technology outsourcing service[J]. Journal of Agrotechnical Economics, 2013(5): 28−35 doi: 10.13246/j.cnki.jae.2013.05.003 [19] 庞春. 一体化、外包与经济演进: 超边际-新兴古典一般均衡分析[J]. 经济研究, 2010, 45(3): 114−128PANG C. Vertical integration, outsourcing and economic progress: a new classical infra-marginal general equilibrium analysis[J]. Economic Research Journal, 2010, 45(3): 114−128 [20] YANG X K. Economics: New Classical Versus Neoclassical Frameworks[M]. New York: Blackwell Publishers, 2011 [21] 高晶晶, 彭超, 史清华. 中国化肥高用量与小农户的施肥行为研究−基于1995—2016年全国农村固定观察点数据的发现[J]. 管理世界, 2019, 35(10): 120−132 doi: 10.3969/j.issn.1002-5502.2019.10.011GAO J J, PENG C, SHI Q H. Study on the high chemical fertilizers consumption and fertilization behavior of small rural household in China: discovery from 1995–2016 national fixed point survey data[J]. Management World, 2019, 35(10): 120−132 doi: 10.3969/j.issn.1002-5502.2019.10.011 [22] 魏欣, 李世平, 张丛军. 农户施肥行为及其影响因素分析−基于陕西关中地区不同农作物种植户的调研[J]. 农村经济, 2018(12): 86−92WEI X, LI S P, ZHANG C J. Farmer’s fertilization behavior and its influencing factors — Based on the investigation of different crop planters in Guanzhong area of Shaanxi Province[J]. Rural Economy, 2018(12): 86−92 [23] 卢洋啸, 孔祥智. 农业生产托管的形成机制与服务模式分析[J]. 现代经济探讨, 2021(6): 119−125, 132 doi: 10.3969/j.issn.1009-2382.2021.06.014LU Y X, KONG X Z. Analysis on the formation mechanism and service mode of agricultural production trusteeship[J]. Modern Economic Research, 2021(6): 119−125, 132 doi: 10.3969/j.issn.1009-2382.2021.06.014 [24] 李宪翔, 丁鼎, 高强. 小农户如何有机衔接全程机械化−基于农机社会化服务的视角[J]. 农业技术经济, 2021(4): 98−109 doi: 10.13246/j.cnki.jae.2021.04.008LI X X, DING D, GAO Q. How to organically connect small farmers to mechanize the whole process? — Based on the perspective of social service of agricultural machinery[J]. Journal of Agrotechnical Economics, 2021(4): 98−109 doi: 10.13246/j.cnki.jae.2021.04.008 [25] 谢长安, 程恩富. 分工深化论: 五次社会大分工与部门内分工探析[J]. 马克思主义研究, 2016(12): 46−58, 157XIE C A, CHENG E F. The further division of labor: exploration of the five great social division of labor and the internal division of labor within sectors[J]. Studies on Marxism, 2016(12): 46−58, 157 [26] 王拓. 分工经济思想的发展−从亚当·斯密到新兴古典经济学[J]. 当代财经, 2003(11): 13−17 doi: 10.3969/j.issn.1005-0892.2003.11.003WANG T. The development of division economy thought: from Adam Smith to new classical economics[J]. Contemporary Finance & Economics, 2003(11): 13−17 doi: 10.3969/j.issn.1005-0892.2003.11.003 [27] 郑宏运, 李谷成. 城乡政策偏向对农业资源配置效率的影响研究[J]. 农业技术经济, 2020(7): 79−92 doi: 10.13246/j.cnki.jae.2020.07.005ZHENG H Y, LI G C. The impact of urban-rural biased policy on agricultural resource allocation efficiency[J]. Journal of Agrotechnical Economics, 2020(7): 79−92 doi: 10.13246/j.cnki.jae.2020.07.005 [28] 刘晗, 王钊, 曹峥林. 农业要素配置效率及其地区收敛性研究−基于省际面板数据的实证分析[J]. 中南大学学报(社会科学版), 2016, 22(4): 70−78LIU H, WANG Z, CAO Z L. On allocation efficiency and its regional convergence of agricultural resources: based on empirical analysis of provincial panel data[J]. Journal of Central South University (Social Science), 2016, 22(4): 70−78 [29] BARON R M, KENNY D A. The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations[J]. Journal of Personality and Social Psychology, 1986, 51(6): 1173−1182 doi: 10.1037/0022-3514.51.6.1173 [30] 谢琳, 廖佳华, 李尚蒲. 服务外包有助于化肥减量吗? −来自荟萃分析的证据[J]. 南方经济, 2020(9): 26−38XIE L, LIAO J H, LI S P. Does agricultural service outsourcing help reduce fertilizer use: evidence from meta-analysis[J]. South China Journal of Economics, 2020(9): 26−38 [31] 仇焕广, 栾昊, 李瑾, 等. 风险规避对农户化肥过量施用行为的影响[J]. 中国农村经济, 2014(3): 85−96QIU H G, LUAN H, LI J, et al. The impact of risk aversion on farmers’ behavior of excessive fertilizer application[J]. Chinese Rural Economy, 2014(3): 85−96 [32] 刘浩, 韩晓燕, 薛莹, 等. 农业生产性服务的化肥减量逻辑: 替代和匹配−基于东北三省741户玉米种植农户的调研数据[J]. 干旱区资源与环境, 2022, 36(4): 32−38LIU H, HAN X Y, XUE Y, et al. The logic of agricultural productive services affecting fertilizer reduction: substitution and matching[J]. Journal of Arid Land Resources and Environment, 2022, 36(4): 32−38 -