Fertilizer Use in China: The Role of Agricultural Support Policies

Review of current trends in chitosan based controlled and slow-release fertilizer: From green chemistry to circular economy

The demand for food is increasing rapidly with the growth of the global population. To ensure global food security, fertilizers are essential. Controlled-release fertilizers (CRFs) are a highly effective type of fertilizer that have been developed to meet this need. While CRFs offer significant advantages over traditional fertilizers, their use has been limited due to high production costs and negative impact on the environment. CRFs are manufactured and applied without considering the resource-use efficiency of the production process or the potential ecological consequences of fertilizer application. To tackle these issues, biopolymer-based CRFs have been developed. These innovative fertilizers are created by coating granules with biodegradable and eco-friendly biopolymers (chitosan, starch and cellulose). In addition, these groundbreaking fertilizers align with the tenets of the circular economy, which involve formulating products that enable a gradual and steady dispensation of nutrients over an extended period. Our objective in embracing these fertilizers is to transcend the traditional linear "take, make, dispose" approach and transition towards a more sustainable and circular model. This approach not only enhances nutrient delivery efficiency but also contributes significantly to reducing the environmental impact associated with conventional fertilizer use. Afterward, the research explored various aspects of controlled-release fertilizers (CRFs), including the mechanisms of nutrient release, the types of coating materials used, and the techniques employed for coating. The study also examined the benefits and challenges associated with CRFs and analyzed how specific parameters influence the nutrient release mechanisms.

Impacts of chemical fertilizer reduction on grain yield: A case study of China

Reducing fertilizer usage is a crucial measure for achieving high-quality development in Chinese agriculture. Utilizing panel data from 31 Chinese provinces spanning from 2004 to 2019, this study empirically analyzes the dynamic relationship between fertilizer application and grain production, exploring the underlying mechanisms. The study findings reveal that the application of fertilizers maintains a positive impact on grain production. The two variables will demonstrate a dynamic alternation between "strong decoupling" and "retreat decoupling," suggesting that grain production may either increase or gradually decline, while fertilizer application exhibits a decreasing trend. Mechanism analysis reveals a distinct substitution relationship between fertilizer use efficiency and application quantity. Increasing fertilizer use efficiency while reducing application quantity still facilitates the stable and increased production of grains. Heterogeneity analysis indicates that the efficiency of fertilizer use has a more pronounced impact on grain yield in the eastern and western regions. Increasing fertilizer quantity is detrimental to wheat yield but has a promoting effect on corn yield. However, in the main grain-producing areas, increasing fertilizer quantity can enhance wheat yield but is unfavorable for the overall grain yield. Additionally, nitrogen fertilizer input has exceeded the optimal level compared to potassium fertilizer. Continuously increasing nitrogen fertilizer input will hinder the increase in grain yield. Therefore, there is a need to shift from the notion of "more fertilizer is better" and focus on improving fertilizer use efficiency to transition from the emphasis on "quantity" to "quality" of fertilizer application.

The effect of agricultural subsidies on chemical fertilizer use: Evidence from a new policy in China

This study uses a nationally representative rural household survey from China, the difference-in-difference, three-step approach, and Seemingly Unrelated Regression methods to assess the impacts of China's new agricultural subsidy on chemical fertilizer use, heterogeneity effect, and mechanism. The results show that, first, the new agriculture subsidy reduces the use of chemical fertilizer by about 7.2 percent. A series of robustness tests confirm the finding. Second, the heterogeneity analysis shows that the subsidy's negative impact on fertilizer use is substantially greater among younger farmers than among older farmers. The negative effect also is significantly more in the main grain-producing areas than in non-grain-producing regions in China. Third, the mediating effect analysis shows that farmland scale mediates 8.3 percent of fertilizer use, and the adoption of agricultural machinery mediates 48.6 percent of fertilizer use. Our findings underscore the positive role that reforming the agrarian subsidy policy plays in sustainable development.

Decomposition of green agricultural productivity gain under a multiple-frontier framework

This paper investigates structural variation of agricultural productivity growth in China using a multiple-frontier approach. Agricultural productivity gain in Sichuan province is decomposed into technological progress, technical, mix and scale efficiency changes in terms of economic and environmental performance. The results show that agricultural Luenberger productivity indicator in Sichuan presents a significant increase trend with annual growth rate of 2.5% over the period of 1997-2017. The agricultural green growth in Sichuan is most driven by technological progress. Of the decline in the OI changes, over 90% results from the decline of environmental inefficiency. The technological progress is the main driven force of the economic growth while the TEC (technical inefficiency) incumbers its growth. The structural effects (mix and scale components) incumber environmental growth. The results imply that policymakers should pay more attention to new agricultural technological development and resource misallocation to improve agricultural green growth in Sichuan.

Optimization of a Water-Saving and Fertilizer-Saving Model for Enhancing Xinjiang Korla Fragrant Pear Yield, Quality, and Net Profits under Water and Fertilizer Coupling

To develop an optimal irrigation and fertilization system for Korla fragrant pear in the Xinjiang region, the effects of water and fertilizer coupling on the quality, yield, irrigation water use efficiency (IWUE), fertilizer partial productivity (PFP), and net profits of Korla fragrant pear under the condition of limited water drip irrigation were studied through field experiments by combining multiple regression analysis and spatial analysis. A comprehensive quality evaluation model of fragrant pear was constructed using the principal component analysis, and 12 quality indices were evaluated comprehensively. The experiment adopted a two-factor crossover design with three irrigation levels (W1: 5250 m3 ha−1, W2: 6750 m3 ha−1, W3: 8250 m3 ha−1), accounting for 60%, 80% and 100% of the ETe (where ETe denotes evapotranspiration under sufficient water supply for crops); four fertilizer application levels (F1: 675 kg ha−1, F2: 750 kg ha−1, F3: 825 kg ha−1, F4: 900 kg ha−1), designated F80%, F90%, F100%, and F110%, respectively; and 12 treatments. The results showed that the overall quality of fragrant pear was improved based on the integrated quality of pear. Four principal components were extracted through the fragrant pear comprehensive quality evaluation model, and their cumulative contribution was 89.977%; the best comprehensive quality was obtained in the W3F2 treatment and the worst comprehensive quality in the W1F1 treatment. The spatial analysis showed that when the irrigation range is 7484–8250 m3 ha−1 and the N-P2O5-K2O fertilization range is (181-223-300)–(200-246-332) kg ha−1, the comprehensive quality, yield, IWUE, PFP, and net profits of fragrant pear can reach > 85% of the maximum value. These results provide a scientific basis for water and fertilizer management of fragrant pear orchard with drip irrigation in Korla, Xinjiang.

Effect of agricultural subsidies on the use of chemical fertilizer

Agricultural subsidies lead to changes in the use of chemical fertilizer by farmers. Using data from a household survey conducted annually by the Rural Economy Research Center of the Ministry of Agriculture of China from 2014 to 2018, Control Function (CF) approach and Heteroskedasticity-based identification strategy were employed to analyze the impact of agricultural subsidies on chemical fertilizer use by rice farmers. After addressing the problem of endogeneity, we found that agricultural subsidies have a significantly negative impact on the use of chemical fertilizer. Precisely, every 100% increase in agricultural subsidies would result in an average decrease of 3.4% in chemical fertilizer use. In addition, results of heterogeneity analysis showed that agricultural subsidies had a stronger negative impact on fertilizer use as rice-planting experience increases. But the ability of rice-planting management and off-farm labor within household could reduce this negative impact. We also found that the effect of arable land productivity conservation subsidies policy was short-lived. Furthermore, based on the frame of structural equation model (SEM), the results of mediation analysis showed that agricultural machine and rice-planting area had partial mediation of 5.3% and 41%, respectively. It implied that agricultural subsidies reduced fertilizer use by promoting the adoption of agricultural techniques and expanding the planting area. In brief, agricultural subsidies had both technical effect and scale effect. But the mediating effect of household income was not significant. This study is intended to assist the concerned authority and agriculture sector to understand the positive role of agricultural subsidies in sustainable production, and provides some feasible policy proposals.

Subsidy as An Economic Instrument for Environmental Protection: A Case of Global Fertilizer Use

Fertilizer subsidies may constitute a key economic tool with which to provide food for the growing population. Therefore, this work aimed to (i) assess the effectiveness of subsidized chemical (NPK) fertilizer use in food production by comparing the crop output between developed and developing regions and (ii) examine the benefits of organic fertilizer and the need for its use in developing regions such as Africa. Secondary data from 2000 to 2019 on global subsidized fertilizer use, crop production, income, and other agro-environmental parameters, such as climate and soil, were collected from the international databases of the World Bank, Food and Agriculture Organization (FAO), Forest Resources Assessment (FRA), National Aeronautics and Space Administration (NASA), and World Income Inequalities Database (WID), as well as countries’ national statistics. Data were analyzed using qualitative, quantitative, and geospatial software and techniques, such as SPSS, averages, multivariate analysis, and spatial analytical Geographic Information System (GIS) tools. The results reveal that the total global fertilizer use continuously increased from 79 million tonnes in 2000 to 125 million tonnes in 2019. Subsidized fertilizer use and crop production increased with countries’ economic status. For example, countries or regions with more economic resources tended to have higher fertilizer subsidies. More than 95% of North American and European countries recorded the highest total chemical fertilizer use, ranging from 855,160 to 18,224,035 kg ha−1. In terms of organic fertilizer production, the percentage contribution in Africa relative to global production was only 2%, which was about 932,538 million tonnes below the production yield in North America. More organic fertilizer and less inorganic fertilizer should be encouraged instead of the total eradication of chemical fertilizers. This is especially applicable to developing countries, where food production is low due to poor soil and high food demand owing to a harsh environment and rapid population growth.

Effects of Different Irrigation Methods on Environmental Factors, Rice Production, and Water Use Efficiency

Rice is one of the most important food crops in China and is also the largest user of agricultural water. Experiments were conducted for two consecutive years at two locations of Jiangsu province to study the effect of four irrigation methods with four replications (shallow water irrigation (FSI), wet-shallow irrigation (WSI), controlled irrigation (CI), and rain-catching and controlled irrigation (RCCI)) on drainage, rainwater utilization rate, pollutant load of N and P, irrigation water, grain yield, and water use efficiency. The results show that FSI treatment used the largest irrigation amount, which is significantly higher than the other three irrigation methods, but the southern part of Jiangsu province especially Nanjing and riverside areas are relatively rich in water resources. It can be seen from our findings that FSI and RCCI are the best irrigation methods in Nanjing area to get a higher yield. However, the yield of CI treatment varies greatly; the annual and seasonal yield changes of CI treatment are higher than those of other treatments; and the risk of yield reduction is greater. Thus, considering water saving and high efficiency, RCCI is a better irrigation strategy than FSI. Combined with the following analysis, it can be seen that RCCI irrigation treatment has less nitrogen and phosphorus pollution load with no significant difference in yield in Lianshui and in 2017 in Nanjing area. Therefore, RCCI is more suitable for irrigation in Lianshui and similar areas.

Clustering Analysis of Soybean Production to Understand its Spatiotemporal Dynamics in the North China Plain

The production gap of soybean (Glycine max L. Merr.) has been expanding in China recently, due to the increasing demand and decreasing production. Identifying soybean production dynamics is contributable to appropriate adjustment of crop rotation system and efficient use of agricultural resources—and thus to ensure food security. Taking the North China plain (NCP) as a case area, this study first analyzed the spatiotemporal dynamics of soybean production during 1998–2015 based on the spatial autocorrelation method, and then calculated contributions to the total production by yield and sown area using the factor decomposition method. The results indicated that total soybean production in the NCP decreased dramatically from 1998 to 2015 and showed a decreasing trend in 80.4% (263) of the counties, mainly (83.9%) contributed by the shrinkage of sown area, largely caused by decreasing benefit. Two regions were found with significantly spatial clustering degree of soybean production. In the south part of NCP, soybean production was highly clustered in Anhui province, and in north it was mainly clustered in western Hebei plain. It was found that soybean production in the NCP was rather sensitive to the return gaps of soybean from maize (Zea mays L.). These imply that the reduced area of soybean production can be restored if the return is improved by adopting appropriate policies such as appropriate subsidies. These findings could be helpful for the policymakers to make soybean production planning in the NCP, contributing to the national revitalization strategy of soybean production.

The Role of Rural Infrastructure in Reducing Production Costs and Promoting Resource-Conserving Agriculture

The development of rural infrastructure plays an essential role in improving rural livelihoods and enhancing sustainable and environmentally friendly agricultural production. However, little is known about whether rural infrastructure enables the promotion of resource-conserving agriculture and reduces production costs. Understanding the relationship between rural infrastructure and production costs can provide significant information for policy-makers in their efforts to promote resource-saving agriculture that is beneficial to environmental performance. This study contributes to the literature by analyzing the heterogeneous effects of irrigation infrastructure and standard and substandard roads on agricultural production costs, using an unconditional quantile regression model and provincial data from China for the period 1995–2017. The empirical results show that the effects of rural infrastructure on production costs are mixed. In particular, irrigation infrastructure affects production costs positively in the lower quantiles, but it negatively affects production costs in the higher quantiles. In the higher 80th and 90th quantiles, standard and substandard roads affect production costs both negatively and significantly. Our findings suggest that improving rural infrastructure enables the promotion of resource-conserving agriculture and enhances environmental performance, especially for those paying high production costs.