| Chemical fertilizer has played an important role in promoting grain production,but the constant high input of chemical fertilizer with low utilization rate restricts the development of grain production and declines the international competitiveness of grain.The amount of fertilizer applied in rice production in the middle and lower reaches of the Yangtze River is generally higher than the national average level.The issue of excessive and blind application of chemical fertilizer is becoming more and more serious,which not only increases the production cost and wasting resources,but also having negative effect on the environment.Promoting the reduction of fertilizer and efficiency in the middle and lower reaches of the Yangtze River is an important content of the green development of rice production.Based on the macro perspective,this study focused on fertilizer application in rice production in the middle and lower reaches of the Yangtze River,analyzed the characteristics of fertilizer application,the intensity and driving factors of fertilizer application in rice production in the middle and lower reaches of the Yangtze River from 2004 to 2020,and quantitatively analyzed the environmental effects of fertilizer application in rice production based on the nitrogen footprint.From the perspective of micro level,analyzed the main effects of individual and family characteristics and land management characteristics on fertilizer application of rice farmers.Based on demand orientation,investigated the cognition and demand of fertilizer reduction technology of rice farmers were,intended to provide reference for the government to formulate a scientific fertilizer management and technology extension and application system.The main contents and conclusions of this study are as follows:(1)Variation of rice production and total fertilization in the middle and lower reaches of the Yangtze River.This study systematically reviewed the current situation and main characteristics of rice production in the middle and lower reaches of the Yangtze River from 2004 to 2020 and analyzed the types and nutrient composition of rice fertilizer application in the middle and lower reaches of the Yangtze River.Based on the total amount of fertilizer application in rice production in each province,the total amount of rice fertilizer application was decomposed from three aspects:sowing area,structural adjustment and fertilization intensity.And the study measured the contribution rate of each part.The results showed that:(a)At present,compound fertilizer was the main fertilizer used for rice in the middle and lower reaches of the Yangtze River,and the amount of fertilizer used accounted for more than 60%of the total fertilizer applied,and the amount of compound fertilizer increased year by year,while the amount of elemental fertilizer decreased.(b)From 2004 to 2019,the total amount of rice fertilization in the middle and lower reaches of the Yangtze River increased from 4.063 million t to 5.524 million t,an increase of 36.0%.The contribution rates of increased fertilizer intensity,increased sown area and variety structure adjustment to the total increase of rice fertilizer in the middle and lower reaches of the Yangtze River were 76.1%,18.2%and 5.7%,respectively.The increase of fertilizer intensity was the main reason for the increase of total fertilizer application.(2)Variation and influencing factors of fertilization intensity in rice production in the middle and lower reaches of the Yangtze River.From the perspective of the change of fertilizer application intensity,this study analyzed the characteristics of fertilizer application in rice production in the middle and lower reaches of the Yangtze River,compared and analyzed the differences of fertilizer application intensity in rice production among different varieties,different regions and different provinces.The fixed-effect model was used to analyze the influence of regional economic development level,urbanization level and other factors on the intensity of rice fertilizer application,and to identify the main driving factors for the change of fertilizer application intensity in rice production.The results showed as follows:(a)From 2004 to 2019,the fertilizer application intensity of japonica rice was the highest,followed by middle indica rice and late indica rice,and early indica rice was the lowest due to its short growth period.The fertilization intensity of indica rice in the middle and lower reaches of the Yangtze River was significantly higher than that in southwest China,and that of japonica rice was significantly higher than that in northeast China.The fertilizer application intensity of early indica rice in Jiangxi and Anhui was relatively high,the fertilizer application intensity of middle indica rice in Jiangsu was the highest,the fertilizer application intensity of late indica rice in Anhui was the highest,the fertilizer application intensity of japonica rice in Jiangsu was the highest.(b)The influence of regional economic development level and urbanization development level on the intensity of rice fertilizer application was significantly positive,while the influence of rural residents’ disposable income on the intensity of rice fertilizer application was significantly negative.(3)Environmental effects of fertilizer application in rice production in the middle and lower reaches of the Yangtze River.Based on the main rice-producing provinces in the middle and lower reaches of the Yangtze River,using the method of statistical data analysis and household survey,agricultural nitrogen footprint theory and life cycle assessment method,this study evaluated the nitrogen balance,nitrogen footprint dynamics,distribution and composition of rice production in the middle and lower reaches of the Yangtze River from 2004 to 2020.Then analyzed main reasons for the difference of nitrogen effect in rice production in different provinces and varieties.In the middle and lower reaches of the Yangtze River,the partial nitrogen productivity of rice production showed an increasing trend,and the active nitrogen emission of rice production showed a decreasing trend.Mechanical input and fertilizer application accounted for the largest proportion of potential active nitrogen emission in rice production.Mechanical input and fertilizer application accounted for 23%,28%,25%and 31%of the potential active nitrogen emissions of rice,respectively.There was no significant difference in N footprint per unit yield between small and medium scale farmers,but it was significantly higher than large scale farmers.(4)Fertilizer application behavior and influencing factors of rice farmers in the middle and lower reaches of the Yangtze River.Based on the questionnaire survey data of farmers in the middle and lower reaches of the Yangtze River,analyzed the characteristics of different types of fertilizer quantity input and the main influencing factors of fertilizer input decision.At the same time,under the background of the accelerated development of land transfer,analyzed the influence direction and influence degree of land management scale,land transfer cost,land fragmentation degree and land ownership stability on the amount of fertilizer applied by farmers.The results showed that large-scale land management was helpful to reduce the amount of fertilizer applied,but the scale of land should be controlled reasonably to avoid excessive scale leading to extensive management of farmers.The reduction of land fragmentation is helpful to reduce the amount of fertilizer applied.It is necessary to encourage the realization of concentrated contiguous plots and promote the reduction of fertilizer input.The rising cost of land transfer is not conducive to the rational investment of fertilizer by farmers.It is necessary to strengthen the supervision of land transfer market and standardize the behavior of land transfer.The shortage of rural labor force and the level of household part-time work are not conducive to the reduction of fertilizer input.(5)Knowledge and demand of fertilizer reduction technology among rice farmers in the middle and lower reaches of the Yangtze River.Based on green rice industry development needs of the middle and lower reaches of the Yangtze river region,used the questionnaire to investigate farmers fertilizer reduction degree of synergistic technology agreement,adoption intention and actual demand.Then illustrated the middle and lower reaches of the Yangtze river area in rice production farmers fertilizer applied,the present situation and development trend,and green varieties and technical requirements.It is expected to point out the direction for the government to increase the support of science and technology and introduce relevant policies.The results showed that farmers still paid much attention to rice yield,and fertilizer saving varieties and technologies should give priority to ensuring stable yield and increasing yield.Farmers are in urgent need of fertilizer saving technology,like soil testing formula fertilization,slow and controlled release of new fertilizers,and adjustment of fertilization period and quantity are the most needed techniques for reducing weight at present.It is still difficult to accurately grasp the timing and quantity of fertilization for farmers,which is not conducive to the green and high-quality development of rice industry.(6)Policy implications of reducing fertilizer application in rice production in the middle and lower reaches of the Yangtze River.Based on our results,as well as experience in chemical fertilizer application and green development of agriculture at home and abroad,we put forward the following recommendations for reduction of fertilizer application for rice production in the middle and lower reaches of the Yangtze River,which intend to help the government to formulate scientific fertilization management and technology popularization and application system to provide the reference.Firstly,raise the proportion of double cropping rice area in the total rice area moderately,and optimizing the regional distribution of rice production.Secondly,promote proper scale management of farmland,and regulating the land rental market behaviors.Thirdly,accelerate the application of green varieties and technologies,reducing the intensity of fertilizer application.Fourthly,strengthen technology training for farmers and cultivating highly qualified and professional farmers.(7)There are three main innovations in this study:Firstly,innovation in research perspective,the study measured the total amount of fertilizer applied to rice was decomposed from three aspects,including sowing area,structural adjustment and fertilization intensity,and the contribution rate of each part,identified the main driving factors of the total amount of fertilizer applied.Secondly,in the context of the current accelerated development of land transfer,the paper not only focused on the change of management scale,but also focused on the analysis of the relationship between land transfer cost,land fragmentation degree,land ownership stability and farmers’ input in fertilization,so as to further enrich the research content of farmers’decision-making on fertilization behavior.Thirdly,from the perspective of farmers’demand orientation,this paper analyzed farmers’ cognition degree,demand types and adoption intention of green technologies such as fertilizer reduction,which is conducive to improving the pertinence of the government to increase scientific and technological support and introduce relevant supporting policies. |
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