Next Article in Journal
Effects of Planting Density—Potassium Interaction on the Coordination among the Lignin Synthesis, Stem Lodging Resistance, and Grain Yield in Oil Flax
Previous Article in Journal
Humic Acid and Selenium Supplementation Modulate the Growth and Antioxidant Potential of Chili under Cadmium Stress
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agronomy
Volume 13
Issue 10
10.3390/agronomy13102555
agronomy-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Management and Reduction Techniques Strategies of Ammonia Emission in Agricultural Sectors in China

by
Jing Li
1,2,*,†,
Weibin Zeng
1,2,† and
Xiaoming Wan
1,2
1
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
2
University of Chinese Academy of Sciences, Beijing 100049, China
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Agronomy 2023, 13(10), 2555; https://doi.org/10.3390/agronomy13102555
Submission received: 17 August 2023 / Revised: 28 September 2023 / Accepted: 30 September 2023 / Published: 4 October 2023
Browse Figures
Review Reports Versions Notes

Abstract

:
Agricultural ammonia (NH3) emissions (including farmland, livestock and poultry) are China’s main sources of NH3 emissions. China’s government has proposed a national strategic goal to reduce NH3 emissions. Excessive protein feeds, unreasonable manure treatments and agricultural fertilizer applications result in large emissions of NH3. Agricultural activities such as the breeding of livestock and fertilization in farmlands are the main sources of atmospheric NH3 emissions. This article discussed the progress and characteristics of typical NH3 emission inventory, calculated the nationwide NH3 emissions and analyzed the NH3 emission control strategy in the past 40 years in China. There was also an integration analysis of national documents on emission reduction technologies (including government reports) in China. The results showed that there existed single calculation methods and insufficient localization of emission factors in the estimation of domestic NH3 emissions. NH3 emission inventories varied greatly influenced by meteorology, planting structure and breeding pattern. The control strategy of NH3 emission in China has transformed from emission standards to technical guidelines to national strategic control, and it involves the coordination and cooperation of the Ministry of Agriculture and Rural Affairs departments. Current domestic NH3 emission management strategy needs scientific emission verification specification, multi-department and inter-provincial regional coordination mechanisms, and suggestions for further improvement have been put forward. It is urgent to evaluate precise NH3 emission inventories at different regional scales, followed by intensive NH3 emission controls in the key regions (such as North China). Government, agriculture, and breeding industries should vigorously promote low-protein feeds, large-scale livestock farming (including poultry), and pilot projects on closed negative pressure farming. Also, agriculture-related NH3 emission reduction measures should be fully implemented by providing technical support for NH3 emission control in domestic agricultural farms.

1. Introduction

Ammonia (NH3) is one of the main alkaline gases in the atmosphere. It reacts easily with acidic gases such as sulfur dioxide (SO2) and nitrogen oxides (NOx) to form salts such as ammonium sulfate and nitrate. These substances form an important component of PM2.5 [1,2] and NH3 emission accounts for 8–30% of fine particulate matter formation [3]. During heavy atmospheric pollution, low NH3 emission effectively reduces PM2.5 concentration, especially nitrate ion concentration in PM2.5. The main sources of NH3 emissions in China are farmland ecosystems and livestock (including poultry) farming [4,5,6]. Although there is a dominant use of nitrogen (N) fertilizers in farmland ecosystems, nitrogen-fixing plants and straw composting are also critical sources.
In addition to being absorbed by crops for growth, N fertilizers in farmlands are converted into NH3 and then volatilized. As well, leaching and denitrification are among the pathways of nitrogen loss. After urea-nitrogen fertilizer application, soil urease enzymes quickly hydrolyze the urea. This process increases soil pH and enhances NH3 emissions [7]. Reducing the nitrogen application rate by 22–44% drops NH3 loss via volatilization by 20.2–35.3% [8,9]. Nitrogen-containing substances (such as protein) ingested by livestock and poultry from feeds are metabolized in the body and excreted in other forms as part of feces and urine [10,11]. Amino acids produced by the decomposition of protein can produce NH3 and lower fatty acids after the deamination reaction. Under anaerobic conditions, the microbial decomposition of amino acids produces large amounts of intermediate products, including NH3. Other non-protein nitrogen compounds, such as urea and uric acid, are further decomposed into CO2, NH3, H2O and other substances under the action of enzymes.
Estimates of NH3 emissions rely primarily on the multiplication of activity levels of emission sources with emission factors [12]. Data on the activity level of a single source are easier to obtain, while data on local emission factors are more difficult to obtain. The emission factor method, widely used in early research, often used a single emission source activity level, such as multiplying the year-end inventory of livestock and poultry, such as cattle and sheep, by the corresponding emission factor in the statistical yearbook. The emission factors are directly calculated using foreign data or the average values of multiple foreign ammonia emission factors [12,13]. The uncertainty in the results generated by this calculation method mainly comes from the differences between foreign and actual emission factors in various regions of China.
Various policy measures have been proposed for the control of ammonia emissions. This includes clear provisions in the National Law Air Pollution Prevention and Control Law of the People’s Republic of China [14] and the special action plan Three-Year Action Plan to Fight Air Pollution [15] to address air pollution control. In terms of measures, technical guidelines such as the Technical Guidelines on Environmental Safety Application of Chemical Fertilizer [16] provide a basis for ammonia emission cases. However, it can be observed that in implementing ammonia emission control, although the goal of reducing ammonia emissions has been proposed, this goal has not been quantified, and the implementation of specific emission reduction measures also needs further improvement. The effectiveness of ammonia emission control in various regions needs to be evaluated.
Based on this, the research objectives of this paper are (1) to briefly sort out China’s goals and policies on ammonia emission control and the relationship between government departments in the decision-making system; (2) to summarize the methods and results of ammonia emission inventories at different regional scales in recent years, and to understand the changes in China’s ammonia emissions during the period of 1980–2019; and (3) to propose emission reduction measures in the areas of livestock and poultry farming and fertilizer application to farmland based on the goals and policies and the results of the ammonia emission inventories.

2. Progress of the NH3 Emission Inventory

The NH3 emission inventory is the list of NH3 emissions in a certain geographical area in a certain time span. This list contains emission time, source, and amount [17,18]. Compared with Europe and the United States, Chinese scholars and environmental authorities started NH3 emission inventory studies much later. From 1980 to 1999, the main concern was primary pollutants such as sulfur dioxide and nitrogen oxides from coal combustion, with little research on NH3 emission inventories. The period was characterized by activity data from Statistical Yearbooks, using single emission factor methods to estimate NH3 emission, emission factors reliant on foreign data, small field test results and descriptive evaluation of results [12,13,19].
However, regional and national NH3 emission inventories have significantly increased in the last decade. Besides the methods of single calculation by simple emission factors and model applications designed by outside institutions for inventory analysis, researchers also developed models localized to the conditions in China [20,21] and improved emission factors [20,22,23]. Based on government environmental protection departments, China’s environmental protection agencies realized in the early 1990s that NH3, as an odorous gas, needed to be controlled. It was therefore considered in the scope of control of odorous gases in some industries [24]. However, no corresponding recommendations existed on the preparation and release of NH3 emission inventories. It was not until 2014 that China’s Ministry of Environmental Protection issued Technical Guidelines for Compilation of Atmospheric NH3 Source Emissions Inventory—Guidelines [25]. This provided recommendations on estimation methods and emission factors for livestock and poultry breeding and farmland cultivations involving NH3 emissions (Figure 1).
Studies on air pollution emission inventories in Europe and the United States started much earlier, evidenced by the involvement of environmental authorities in NH3 emission inventories in the regions [26]. As early as 1996, the European Environmental Protection Agency issued a guidebook on NH3 emission inventories (Joint EMEP/CORINAIR Atmospheric Emission Inventory Guidebook—First edition, 1996 https://www.eea.europa.eu/publications/emep-corinair-atmospheric-emission-inventory (Accessed: 27 November 2021)). In the early 1990s, the U.S. Environmental Protection Agency (EPA) established a national emission source inventory that included an assessment of NH3 [27,28]. A global calculation of NH3 emission by Bouwman et al. [29] reported that the highest emission densities were in northern Europe, the eastern Indian subcontinent and eastern China. Bash et al. [30] coupled the air quality model with agro-ecosystem model to evaluate changes in NH3 emissions in the United States.
Precise calculation methods are critical in building NH3 emission inventories. The emission factor method is now widely used in calculating NH3 emission inventories (Figure 2). Using emission factor methods, several models have been developed, including NARSES, RAINS, and IAP-N models [21,31,32]. In the Guidelines, the following method (Equation (1)) is recommended for calculating NH3 emissions based on the emission factor method. In this method, total NH3 emission is obtained as the product of activity data and emission factor. The formula for the calculation is summarized as follows:
E i , j , y = A i , j , y × E F i , j , y × γ ,
where i is region (province, government-level municipality, autonomous region, or county); j is emission source; y is emission year; Ei,j,y is emission from source j in region i and year y; A is activity level; EF is emission factor; and γ is nitrogen-atmosphere NH3 conversion coefficient.
This method’s main concern is ensuring emission factor (EF) accuracy, i.e., choosing the appropriate emission factor. Using the case of nitrogen fertilizer application, for example, NH3 emission is calculated relative to soil pH, land use pattern, fertilizer application rate, rainfall and temperature [33]. As these factors vary with geographical location, the emission coefficient used for an area should match the accuracy of the emission result. In the absence of local emission coefficients, studies in China directly used average emission coefficients for Europe and America [13]. For higher accuracies, some studies [4,21] corrected the emission factors using model methods, with the correction process taking into account the effects of several factors.
There is a significant increase in the range of studies on NH3 emission inventories nationwide. The estimated geographical scope has also expanded to include provincial, inter-provincial and the entire country. As in Table 1, various methods (including the CHEN, NARSES, IAP-N and emission factor methods) have been used in NH3 emission studies in different areas, with different methods yielding different results. The emission factor method used by Ma [4] yielded a national anthropogenic NH3 emission in 2015 of 12,580 Gg and that of livestock and poultry of 2560 Gg (20% of the total). Farmland emission was 5580 Gg (44.4%), and NH3 emission from waste treatment was 1810 Gg (14.4%). Zhang et al. [6] used the Coupled Human and Natural Systems (CHANS) model to estimate national NH3 emissions in 2015 of 15,600 Gg, of which 5870 Gg (37.6%) was from farmlands and 6650 Gg (42.6%) from livestock and poultry farming. The latter had significantly higher NH3 emissions from livestock and poultry farming, mainly because a higher NH3 emission rate was used. Furthermore, Fu et al. [20] noted that although agriculture was the main source of NH3 emissions, non-agricultural NH3 emissions were also increasing.
Based on aggregated literature data [22,36,37,38,39], China’s NH3 emission changes every month (Figure 3). Due to limited availability, NH3 emission data were collected for different years. It suggested differences in year-to-year NH3 emission. But on average, however, different data had similar monthly variations. March to October of each year was the time with relatively high NH3 emissions. Starting in March, NH3 emission gradually increases and reaching the highest point between June and August, and then gradually decreases. This trend is closely related to agricultural production activities. This is mainly caused by changes in nitrogen fertilizer application and NH3 emission from livestock and poultry farming [22]. In terms of nitrogen fertilizer, application increases in April, after the start of spring planting, and the warming temperature gradually increases NH3 emissions. As most crops are harvested in autumn, NH3 emission gradually decreases during this period [36]. For livestock and poultry breeding the relatively higher temperatures could also be due to the gradual increase in NH3 emission from livestock and poultry breeding.
The difference in emission factor is the main reason for the significant difference in calculated results. When calculating emissions across the country, NH3 emission factor should consider regional differences. This is so because emission coefficients are calculated based on provincial administrative divisions. In various studies, however, the values of emission factors for the same province are inconsistent. For example, in calculating NH3 emissions in 2015, Zhang et al. [6] used an emission factor of 14.3% for NH3 emission from nitrogen fertilizers in Henan Province, while Ma [4] used 15.1% for the same year and area. These emission factors are calculated in reference to different literature values. The emission results for the latter two studies are also quite different. This difference shows the relevance of the parameters used to calculate NH3 emissions in China. NH3 emission accuracy should be ensured for the effective implementation of reduction measures. This implies that NH3 emission reductions, environmental protection agencies or other government agencies should evaluate existing data to provide guidance.

3. China’s Agricultural NH3 Emission Management Strategy

3.1. Goals and Policies

China’s NH3 emission control did not start at the national level but with emission standards in some industries. It has gone through three stages: first, industry emission standards, then technical guidelines, and finally, national strategic control [40]. The emission standards for odorous pollutants [24] promulgated in 1993 stipulated the concentration of odorous pollutants, including NH3 concentration, in farm boundaries. On this basis, the Environmental Quality Standards for Livestock and Poultry Farms [41] promulgated in 1999 further restrict the concentration of NH3 in livestock and poultry farms. This applies to different areas of the farm (buffer and housing zones) and also considers the difference between pig (25 mg/m3) and cow (20 mg/m3) pens.
Based on the proposed technical guidelines, the National Standard of Slow Release Fertilizers [42] was issued in 2009. It regulates the nutrient content of nitrogen fertilizers, compound fertilizers and other slow-release fertilizers. In 2010, the Ministry of Environmental Protection issued the Pollution Prevention and Control Technology Policy for Livestock and Poultry Farming [43] and Technical Guidelines for Environmental Safety in Fertilizers [16]. The former put forward specific requirements for the prevention and control of air pollution at livestock and poultry breeding sites. Including the technical measures to be taken against malodorous gases, the structure of the breeding farms and the different scales of breeding farms should adopt different air pollution prevention and control measures. The latter recommended the use of compound fertilizers and slow-release fertilizers and made provisions for fertilizer application methods, scientific dosages, and measures to reduce the loss of chemical fertilizers to ensure environmental friendliness.
With regard to national strategic control, the Action Plan for the Prevention and Control of Air Pollution [44] promulgated in 2013 put forward the idea of “actively developing new varieties of slow-release fertilizers and reducing NH3 emissions during application of chemical fertilizers”. This was the first time China put forward requirements for NH3 emissions from agricultural sources at the national level. Article 74 of the Air Pollution Prevention and Control Law emphasized improved fertilizer application methods to reduce NH3 emissions. Then, Article 75 made provisions for the prevention and control of pollution from livestock and poultry breeding, a requirement to control NH3 emissions from agricultural sources at the highest legislative level. In 2018, the central government department issued another relevant document, “Guidance on Comprehensively Strengthening Ecological Environmental Protection and Resolutely Fighting the Tough Battle of Pollution Prevention and Control”. The guideline proposed strengthening the management of unorganized emissions from industrial enterprises, promoting comprehensive remediation of volatile organic compound emissions, and launching pilot projects to control atmospheric NH3 emissions. The same year, the State Council of PRC issued the Three-Year Action Plan to Win the Blue Sky Defense War, emphasizing the control of NH3 emissions from agricultural sources (Figure 4).
To validate the results of existing emission inventories, this study calculated NH3 emissions from 1980–2019 using agricultural data from the National Bureau of Statistics and emission factors from the literature. A 40-year nationwide variation of NH3 emissions was obtained and plotted in Figure 4. For the calculations of the NH3 emission, please refer to Equation (1). Then, the specific parameters and emission factors were from the research conducted by Zeng and Li [47].
Figure 4 shows an overall growth trend, with a more apparent rapid growth in 1980–1999. By 1999, the national NH3 emissions reached 9902.52 Gg; an increase of 69.05% in 1980 (5857.61 Gg). In 1999–2015, the growth was relatively slow. By 2015, the national NH3 emissions increased to 10,346.21 Gg; an increase of 4.48% over 1999. For a 40-year period, NH3 emissions reached the maximum amount in that year. After that (2015–2019), the national NH3 emission gradually declined. The national NH3 emission in 2019 dropped to 9512.92 Gg.
Here, the calculated results are compared with other emission inventory results for the same period [4,6,20]. One worthy point to note is that the trends in the results of several studies are similar, showing a rapid increase in the early period. This is especially true for 1980–2000, after which it slows down but with small fluctuations. The reason is that the NH3 emissions from different studies in a certain period differ. For example, anthropogenic sources NH3 estimated by Kang et al. [36] for the nationwide emission increased by 65.34% (from 5851 Gg to 9674 Gg) from 1980–2012. NH3 emission from agricultural sources (8623 Gg) was lower than the 2012 emission (10 230.48 Gg) calculated in this study. In another study [20], anthropogenic emissions of NH3 increased 2.4-fold; from 4700 Gg in 1980 to 11 000 Gg in 2016. Zhang et al. [6] calculated NH3 emissions in 2000–2015 and concluded that the estimations in China were underestimated. The study concluded that the underestimation was mainly in the areas of both mineral fertilizer and livestock. The calculations showed that NH3 emissions from agricultural sources were 9680 Gg in 2000 and increased to 12,760 Gg in 2015. But NH3 emissions calculated in this study were 9709 Gg in 2000 and 10,346 Gg in 2015.
Figure 5 shows the NH3 emission intensity in each province in 2019. The method of calculating NH3 emissions refers to Equation (1) and the research conducted by Zeng and Li [47]. Shandong, Henan, and Jiangsu are the three provinces with the highest NH3 emission intensity, which are respectively 4531.74, 4664.05 and 3355.96 kg/km2. This is followed by Hebei, Liaoning, Anhui, Hubei, Hunan, and Guangdong provinces, with an emission density of 1819.91–2787.05 kg/km2. The emission intensities of the other provinces are relatively low. Most NH3 emissions are contributed by livestock and poultry farming and nitrogen fertilizer. The total amount of NH3 emission in Jiangsu Province is not high and is even lower than that of other provinces such as Sichuan and Inner Mongolia. When combined with the area of Jiangsu Province, the NH3 emission density of Jiangsu Province is still second only to Henan and Shandong. Similarly, Fu et al. [20] noted that the agricultural NH3 emission intensity of Henan and Jiangsu provinces was significantly higher than that of other provinces, with the highest NH3 emission intensity of 6000–8000 kg/km2. Ma [4] also showed that Henan and Jiangsu have high NH3 emission intensity in the country, including Sichuan and Chongqing.

3.2. Administration and Supervision

NH3 emission management is within the scope of the environmental protection departments, including the central-level Ministry of Environmental Protection and local environmental protection departments (Figure 6). It also involves the coordination and cooperation of other departments, such as the Ministry of Agriculture and Rural Affairs.
The Technical Policy on Pollution Prevention and Control in Livestock and Poultry Breeding [43], for example, is issued by the Ministry of Ecology and Environment to the local environmental protection departments in accordance with the Environmental Protection Law, Air Pollution Prevention and Control Law, and Livestock Law of China. This technical policy is mainly aimed at the livestock and poultry farming industry nationwide, providing technical basis and advice on possible pollution. This gives the supervision and management of livestock and poultry breeding and planting to the Ministry of Agriculture and Rural Affairs, but the renovation and construction of livestock and poultry housing involves the Ministry of Housing and Urban-Rural Development. This means that the management of NH3 emissions and the process of pollution prevention need to be coordinated by multiple departments. Since these departments are equal-level institutions, this coordination work is led by higher-level central government officials. In addition, they are not directly affiliated with environmental departments at different levels. For example, the Ministry of Ecology and Environment at the central level provides business guidance to the Department of Ecology and Environment at the provincial level but does not have direct decision-making power over the latter’s personnel appointments and finances. In other words, the provincial-level Department of Ecology and Environment is under the jurisdiction of the local government rather than the environmental protection department at the central level. This relative independence of local (e.g., at the provincial level) environmental authorities is not sufficiently effective to address environmental problems across provincial boundaries.
This has led to the setting up of inter-provincial regional coordination mechanisms [48], typically including the “Beijing-Tianjin-Hebei and Surrounding Area Air Pollution Prevention and Control Team” and the “Yangtze River Delta Region Air Pollution Prevention and Control Team”. These inter-provincial regional cooperation groups consist of local governments in the region and the Development and Reform Commission under the State Council, the Ministry of Ecology and Environment, and the Ministry of Finance, all led by central-level officials. The coordination mechanisms mainly deal with comprehensive prevention and control of air pollution in the regions and are more oriented towards internal decision-making. This means that these mechanisms are relatively vague for the public in dealing with air pollutant management. While NH3 emission management is still more dependent on central and various local governments and their subordinate environmental and agricultural departments, the role of existing regional coordination mechanisms is not obvious. There is, therefore, a need to refine and augment the existing regional coordination mechanisms and allow them to play a greater role in NH3 emission management. This is especially good for issuing NH3 emission inventories and localization of emission reduction measures within regional environments.

4. NH3 Emission Reduction Techniques Strategy

4.1. Livestock and Poultry

The characteristics of the excrement of different livestock and poultry are different [49]. Studies found that housing structure, ventilation, and manure treatment influence NH3 emission [50]. For example, the degree of enclosure of the barn affects the internal temperature, humidity, and other factors [9]. NH3 emission is positively correlated with the surrounding temperature. Temperature can directly affect NH3 emission and urease activity and promote the decomposition of nitrogenous substances in feces to release NH3 [51].
NH3 emission is linked with livestock and poultry breeding through feeding, storage, manure and urine treatment, and housing structure [9]. Protein feed is used not only to provide needed nutrients for livestock and poultry growth but also serves as an important source of nitrogen in livestock and poultry. A study on nitrogen input-output in China for 1960–2010 showed that nitrogen input in pig breeding increased from 204 Gg in 1960 to 5718 Gg in 2010. Corn and soybean accounted for an increase in total nitrogen input from 9 Gg to 2095 Gg [52]. Another study showed that from 1980–2005, nitrogen input in the livestock and poultry breeding industry increased to 9400 Gg [53]. Generally, only 20–50% of nitrogen in feeds is absorbed and used by animals, with the remaining 50–80% of nitrogen excreted in feces and urine [54]. For higher yield, excessive protein feed is used in livestock and poultry breeding. This increases NH3 emissions at livestock and poultry breeding sites [55]. In livestock housing, the interaction between urease in excreted feces and urea in urine produces significant NH3. The subsequent treatment of excreta influences NH3 emission. Also, the open barn structure makes it difficult to collect and process discharged NH3. For example, NH3 emissions from livestock and poultry in the Beijing-Tianjin- Hebei region account for over 50% of total agricultural NH3 emissions. The nitrogen in the excrement of livestock and poultry is the basis for ammonia production. Treating feces and urine has become an important challenge [56].
To control NH3 emission, promoting low-protein feed and bio-treatment of livestock and poultry manure can be considered. Also, the construction of airtight breeding enterprises and NH3 emission purification devices could help. Specifically, low-protein feed techniques include replacing high-protein components in feeds with low-protein ones and using synthetic amino acids to partially replace crude protein [55]. Test results in Europe show that low-nitrogen feeds reduce NH3 emissions by 4.1% [57]. Another study [58] shows that feeding dairy cows on feeds with protein content increased from 15 to 21%, and urine nitrogen content increased linearly from 153.5 to 465.2 mg/dL. A similar increase occurs in pig breeding. When crude protein level in feed is reduced by 1%, total nitrogen and ammonium nitrogen content in the manure drop respectively by 8.5% and 10% [59], reducing NH3 volatilization by 10% [60].
In addition to low-protein feed, which controls NH3 emission in terms of nitrogen input, it is also possible to treat livestock manure to reduce NH3 emission from manure. Volatilization of NH3 will be higher when urine is in prolonged contact with feces. Therefore, to reduce the potential for NH3 volatilization, urine and feces should be separated quickly to reduce the contact between urease in feces and urea in urine [55]. Studies have shown that flushing every 2–3 h using the water-flush technique can reduce ammonia volatilization by 14–70% [61]. Composting is one typical way of bio-treatment of animal manure. In composting, nitrogen in feces is converted to ammonium nitrogen through NH3 and then volatilizes as NH3. Controlling the C/N ratio, ventilation, and additives can reduce NH3 emissions [62]. When a composting exhaust filter is used during the composting process, the emission reduction efficiency of NH3 is between 36% and 94% [63]. For large-scale aquaculture enterprises, waste gas can be collected by acid scrubbers or bio-trickling filters to convert NH3 into ammonium sulfate or nitrate substances, with an NH3 reduction rate of over 70% [64].
Regarding internal and external exhaust gas from housing, most large-scale breeding enterprises in China have airtight housing facilities. A negative pressure environment is maintained in the housing, and NH3-containing waste gas is collected and discharged after pickling. However, since acidic chemicals are currently controlled, the actual operation of pickling equipment is not ideal [65].

4.2. Farmland Ecosystem

Physical and chemical properties of soil affect NH4+ concentration in the surface soil liquid phase by regulating adsorption-desorption effects or directly changing conversion reaction systems of NH4+ and NH3, thereby affecting NH3 volatilization in the soil [9,66]. In addition, temperature, wind speed, precipitation and sunlight in the field environment are the factors that need consideration.
In China, commonly used nitrogen fertilizers include urea and ammonium bicarbonate; accounting respectively for 69% and 26% of total nitrogen fertilizer use [9]. NH3 emission in farmlands is mainly driven by the huge amount of urea use [67]. Slow-release fertilizer is a newer fertilizer that can delay urea dissolution and reduce NH3 emission by blocking water movement in and out of the membrane by coating or slowing the dissolution of substances. Based on research, NH3 volatilization of coated slow-release fertilizers is 30% lower than that of ordinary fertilizers [66]. China’s Air Pollution Prevention and Control Action Plan also points out that it is necessary to actively develop new varieties of slow-release fertilizers to reduce NH3 emissions due to fertilizer application. Also, fertilization methods affect NH3 emissions. Spreading fertilizers on the soil surface makes it difficult for crops to absorb [9]; causing severe NH3 emission and low utilization. Application of soil covers brings nutrients closer to the roots of crops and reduces the contact of fertilizers with air [55], thereby reducing fertilizer loss via NH3 emission [68,69]. The Technical Guidelines for Environmental Safety in the Use of Chemical Fertilizers also point out that when nitrogen fertilizer is applied deep in the soil, ammonium ion adsorption by colloidal soil particles reduces volatilization loss via NH3 [16].
In this regard, it is necessary to test the soil and formulate fertilization to guide farmers in scientific farming. In February 2015, the Ministry of Agriculture and Rural Affairs issued the Action Plan for Zero Growth in Fertilizer Use by 2020. This plan proposes the principles and implementation methods of fertilization in different regions, vigorously promoting soil testing and formula fertilization and farmers’ scientific fertilization awareness and skills. Fertilizer application equipment needs to be developed. Techniques such as surface and spread applications should be changed to mechanical deep application, water-fertilizer integration, and time-bound fertilization. For organic fertilizers, the action plan identifies three keys, including using organic fertilizers and straws in the field and planting green manure based on local conditions. Two years of targeted experiments conducted in fields in northern China have shown that urease inhibition can reduce NH3 emissions from wheat corn rotation systems by 41.4% to 96.4%, while also alleviating the emissions of nitrous oxide and nitrogen oxides to some extent [63,70]. Large-scale domestic cultivation is realized through deep mechanical application of nitrogen fertilizers. Mechanical deep application for wheat and rice fertilization is also used in some rural areas. While in some areas where there are labor shortages, fertilizers are still applied by direct spreading.

4.3. Country/Regional Comparisons

This work compared and analyzed response strategies of other countries and regions. Total NH3 emission in the United States has changed steadily and not increased significantly in recent years. According to the United States EPA, total NH3 emissions in the United States increased initially and then decreased in 2000–2018. Among these, the range of changes from 2014 to 2018 was relatively small. The control strategy in the United States focused on agricultural sources, comprehensive control of NH3 emissions and implementation of emergency emission reduction measures in key areas. In 1995, the United States EPA issued the “control and pollution prevention options for NH3 emissions” [71]. This provided corresponding measures for key aspects of NH3 emission in the production, animal, and plantation industries. The targeted NH3 suppression measures included anaerobic fermentation, emphasizing comprehensive consideration of soil environment, manure texture, meteorological conditions and application methods that control agricultural NH3 emission.
Based on the establishment of emission reduction targets, the European Union supported corresponding technical guidelines on emission reduction to achieve NH3 emission reduction goals. The “Gothenburg Protocol” was signed by Europe and North America in 1999 and is the earliest international treaty on NH3 emission control [72]. In 2001, the European Union promulgated the National Emission Ceilings Directive and revised it in 2006. This directive directly determined the EU’s total NH3 emissions and sharing targets of individual countries. In 2017, the European Union issued a new proposal that stipulated NH3 reduction based on 2005 values by 6% by 2020 and 27% by 2030 [73]. In terms of emission reduction technologies, Europe has focused on building an agricultural NH3 emission reduction system. This recommends NH3 control technologies and clarifies emission reduction potentials. In 2015, the European United Nations Economic Commission published an NH3 reduction framework system based on optimized agricultural management that details related technical measures [73,74,75]. The livestock and poultry breeding industry mainly introduced livestock feeding technology strategies and low-emission livestock breeding housing, manure storage systems and other emission reduction technologies. For the plantation industry, the effects of plowing and fully mixing straw with soil immediately after urea application, application of urease inhibitors and use of resin-coated urea were introduced.
Although it started late, NH3 reduction in China is now a national program and requirement. Regarding NH3 emission control, national laws require that livestock and poultry breeding and farmland fertilization pay attention to reducing NH3 emissions [44]. Specific action plans also emphasize the importance of NH3 reduction. The Environmental Protection Department and the agricultural department have policy documents that provide such technical advice. Irrespectively, China’s current NH3 emission control is unclear about emission reduction targets and applications of emission reduction measures. Although laws and policy documents stipulate requirements for NH3 emission control, these requirements need further clarification. The practices of the European Union and the United States can provide a reference for China’s NH3 emission reduction. Establishing a complete technical framework for NH3 emission reduction is an important step. The next is to propose effective measures for key emission sources and key regions. In addition, more localized measures should be proposed, considering China’s local soil and aquaculture situation.

5. Conclusions and Expectations

This paper provides an overview of China’s management and reduction strategies for agricultural NH3 emissions. The control of ammonia emissions in China has gone through a process of development from emission standards to technical guidelines to national strategic control. Cooperation among governmental departments based on the national strategy is conducive to promoting the realization of ammonia emission reduction targets. Due to the differences in calculation methods, the results of NH3 emission inventories at different scales across the country vary widely. This makes controlling regional ammonia emissions more difficult, and the current status of NH3 emissions and emission reduction targets are difficult to quantify uniformly. In terms of technical measures to reduce emissions, more detailed technical operation guidelines are readily available. However, the application of these measures in the relevant industries is not obvious enough, and the effectiveness of the reduction technologies in the field needs to be further evaluated.
The strategy of NH3 emission reduction should still be continued. For government departments, a better regional cooperation mechanism should be established. At the same time, the existing mechanism should be made more mature and publicized, including the provision of a complete ammonia emission inventory, emission reduction targets and emission reduction measures in the relevant regions. In addition, more localized experiments need to be conducted to obtain more accurate emission factors. Improvement of localized models needs to be a priority. This will reduce the uncertainty of NH3 emission estimates. Regarding specific emission reduction measures, low-protein feeding technology, large-scale livestock and poultry farming, pilot projects on confined negative-pressure farming, soil-formula fertilization and increasing the proportion of non-ammonium nitrogen fertilizers should be further promoted. The proportion of technology applications, economic benefits and supporting measures need more attention.

Author Contributions

Conceptualization, W.Z. and J.L.; methodology, W.Z. and X.W.; software, W.Z.; investigation, X.W.; writing—original draft preparation, W.Z.; writing—review and editing, W.Z. and J.L.; funding acquisition, J.L. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA28130400 & XDA26050202) and the National Natural Science Foundation of China (‪42271278).

Data Availability Statement

Data will be made available on request.

Conflicts of Interest

The authors declare no conflict of interest. The funders had no role in the study’s design, in the collection, analysis, or interpretation of data, the writing of the manuscript, or the decision to publish the results.

References

  1. Gu, B.; Sutton, M.A.; Chang, S.X.; Ge, Y.; Chang, J. Agricultural ammonia emissions contribute to China’s urban air pollution. Front. Ecol. Environ. 2014, 12, 265–266. [Google Scholar] [CrossRef]
  2. Wang, C.; Yin, S.; Bai, L.; Zhang, X.; Gu, X.; Zhang, H.; Lu, Q.; Zhang, R. High-resolution ammonia emission inventories with comprehensive analysis and evaluation in Henan, China, 2006–2016. Atmos. Environ. 2018, 193, 11–23. [Google Scholar] [CrossRef]
  3. Ye, Z.; Guo, X.; Cheng, L.; Cheng, S.; Chen, D.; Wang, W.; Liu, B. Reducing PM2.5 and secondary inorganic aerosols by agricultural ammonia emission mitigation within the Beijing-Tianjin-Hebei region, China. Atmos. Environ. 2019, 219, 116989. [Google Scholar] [CrossRef]
  4. Ma, S. High-resolution assessment of ammonia emissions in China: Inventories, driving forces and mitigation. Atmos. Environ. 2020, 229, 117458. [Google Scholar] [CrossRef]
  5. Yu, X.; Shen, L.; Hou, X.; Yuan, L.; Pan, Y.; An, J.; Yan, S. High-resolution anthropogenic ammonia emission inventory for the Yangtze River Delta, China. Chemosphere 2020, 251, 126342. [Google Scholar] [CrossRef]
  6. Zhang, X.; Wu, Y.; Liu, X.; Reis, S.; Jin, J.; Dragosits, U.; Van Damme, M.; Clarisse, L.; Whitburn, S.; Coheur, P.F.; et al. Ammonia Emissions May Be Substantially Underestimated in China. Environ. Sci Technol 2017, 51, 12089–12096. [Google Scholar] [CrossRef] [PubMed]
  7. Bittman, S.; Dedina, M.; Howard, C.; Oenema, O.; Sutton, M. Options for ammonia mitigation: Guidance from the UNECE Task Force on Reactive Nitrogen; NERC/Centre for Ecology & Hydrology: Wallingford, UK, 2014. [Google Scholar]
  8. Sun, K.; Mao, X.; Lu, Q.; Jia, A.; Liao, Z. Mitigation effect of several controlled-release N fertilizers on ammonia volatilization and related affecting factors. Ying Yong Sheng Tai Xue Bao = J. Appl. Ecol. 2004, 15, 2347–2350. [Google Scholar]
  9. Wang, W.; Liu, B.; Han, R.; Wang, Y.; Liu, X.; Xu, Q.; Li, W.; Tang, X. Review of Researches on Factors Affecting Emission of Ammonia From Agriculture. J. Ecol. Rural Environ. 2016, 32, 870–878. [Google Scholar]
  10. Hristov, A.N.; Hanigan, M.; Cole, A.; Todd, R.; McAllister, T.A.; Ndegwa, P.M.; Rotz, A. Review: Ammonia emissions from dairy farms and beef feedlots. Can. J. Anim. Sci. 2011, 91, 1–35. [Google Scholar] [CrossRef]
  11. Webb, J.; Pain, B.; Bittman, S.; Morgan, J. The impacts of manure application methods on emissions of ammonia, nitrous oxide and on crop response-A review. Agric. Ecosyst. Environ. 2010, 137, 39–46. [Google Scholar] [CrossRef]
  12. Li, J.; Zeng, W.; Zhou, Y.; Chen, X. A synthetic review of the methods used to estimate agricultural ammonia emissions in China. Acta Ecol. Sin. 2018, 38, 8256–8265. [Google Scholar]
  13. Wang, W.; Lu, X.; Pang, Y.; Tang, D.; Zhang, W. Geographical distribution of NH3 emission intensities in China. Acta Sci. Circumstantiae 1997, 17, 2–7. [Google Scholar]
  14. Air Pollution Prevention and Control Law of the People’s Republic of China; China Legal Publishing House: Beijing, China, 2018.
  15. SCC, State Council of the People’s Republic of China. Three-Year Action Plan to Fight Air Pollution; Standards Press of China: Beijing, China, 2018. [Google Scholar]
  16. MEP, Ministry of Environmental Protection the People’s Republic of China. Technical Guideline on Environmental Safety Application of Chemical Fertilizer; Standards Press of China: Beijing, China, 2010. [Google Scholar]
  17. Hellsten, S.; Dragosits, U.; Place, C.J.; Misselbrook, T.H.; Tang, Y.S.; Sutton, M.A. Modelling Seasonal Dynamics from Temporal Variation in Agricultural Practices in the UK Ammonia Emission Inventory. Water Air Soil Pollut. Focus 2007, 7, 3–13. [Google Scholar] [CrossRef]
  18. Pinder, R.W.; Adams, P.J.; Pandis, S.N.; Gilliland, A.B. Temporally resolved ammonia emission inventories: Current estimates, evaluation tools, and measurement needs. J. Geophys. Res.-Atmos. 2006, 111, 14. [Google Scholar] [CrossRef]
  19. Xu, X. Estimation of Anthropogenic Ammonia Emissions in Jiangsu-Zhejiang-Shanghai District. Rural Eco-Environ. 1997, 13, 50–52. [Google Scholar]
  20. Fu, H.; Luo, Z.; Hu, S. A temporal-spatial analysis and future trends of ammonia emissions in China. Sci Total Environ. 2020, 731, 138897. [Google Scholar] [CrossRef] [PubMed]
  21. Zheng, X.; Liu, C.; Han, S. Description and application of a model for simulating regional nitrogen cycling and calculating nitrogen flux. Adv. Atmos. Sci. 2008, 25, 181–201. [Google Scholar] [CrossRef]
  22. Huang, X.; Song, Y.; Li, M.; Li, J.; Huo, Q.; Cai, X.; Zhu, T.; Hu, M.; Zhang, H. A high-resolution ammonia emission inventory in China. Global Biogeochemical Cycles 2012, 26. [Google Scholar] [CrossRef]
  23. Li, F.-c.; Han, S.-h.; Yang, J.; Zhang, X.; Li, R.-y.; Wei, Y.-s.; Fan, M.-h. Agro-ecosystem ammonia emission in Sichuan-Chongqing region. Huan Jing Ke Xue= Huanjing Kexue 2009, 30, 2823–2831. [Google Scholar]
  24. SEPA, State Environmental Protection Administration of the People’s Republic of China. Emission Standards for Odor Pollutants; Standards Press of China: Beijing, China, 1993. [Google Scholar]
  25. MEP, Ministry of Environmental Protection of the People’s Republic of China. Technical Guidelines for the Compilation of Atmospheric Ammonia Source Emissions Inventory; Standards Press of China: Beijing, China, 2014. [Google Scholar]
  26. Ni, J.-Q.; Heber, A.J.; Cortus, E.L.; Lim, T.-T.; Bogan, B.W.; Grant, R.H.; Boehm, M.T. Assessment of ammonia emissions from swine facilities in the U.S.—Application of knowledge from experimental research. Environ. Sci. Policy 2012, 22, 25–35. [Google Scholar] [CrossRef]
  27. Gilliland, A.B.; Dennis, R.L.; Roselle, S.J.; Pierce, T.E. Seasonal NH3 emission estimates for the eastern United States based on ammonium wet concentrations and an inverse modeling method. J. Geophys. Res.-Atmos. 2003, 108. [Google Scholar] [CrossRef]
  28. Shen, X.; Yin, S.; Zheng, J.; Lu, Q.; Zhong, L. Anthropogenic ammonia emission inventory and its mitigation potential in Guangdong Province. Acta Sci. Circumstantiae 2014, 34, 43–53. [Google Scholar]
  29. Bouwman, A.F.; Lee, D.S.; Asman, W.A.H.; Dentener, F.J.; VanderHoek, K.W.; Olivier, J.G.J. A global high-resolution emission inventory for ammonia. Glob. Biogeochem. Cycles 1997, 11, 561–587. [Google Scholar] [CrossRef]
  30. Bash, J.O.; Cooter, E.J.; Dennis, R.L.; Walker, J.T.; Pleim, J.E. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model. Biogeosciences 2013, 10, 1635–1645. [Google Scholar] [CrossRef]
  31. Fang, X.; Shen, G.; Xu, C.; Qian, X.; Li, J.; Zhao, Z.; Yu, S.; Zhu, K. Agricultural ammonia emission inventory and its distribution characteristics in Shanghai. Acta Agric. Zhejiangensis 2015, 27, 2177–2185. [Google Scholar]
  32. Webb, J.; Misselbrook, T.H. A mass-flow model of ammonia emissions from UK livestock production. Atmos. Environ. 2004, 38, 2163–2176. [Google Scholar] [CrossRef]
  33. Wu, S.-P.; Zhang, Y.-J.; Schwab, J.J.; Li, Y.-F.; Liu, Y.-L.; Yuan, C.-S. High-resolution ammonia emissions inventories in Fujian, China, 2009-2015. Atmos. Environ. 2017, 162, 100–114. [Google Scholar] [CrossRef]
  34. Guo, X.; Ye, Z.; Chen, D.; Wu, H.; Shen, Y.; Liu, J.; Cheng, S. Prediction and mitigation potential of anthropogenic ammonia emissions within the Beijing-Tianjin-Hebei region, China. Environ. Pollut 2020, 259, 113863. [Google Scholar] [CrossRef] [PubMed]
  35. Hou, X.-H.; Yu, X.-N.; Shen, L.; Zhao, R.-D.; Wang, G.-Z.; Zhang, Y.-X. Establishment and Characteristics of an Artificial Ammonia Emissions Inventory in Jiangsu Province from 2013 to 2017. Huan Jing Ke Xue= Huanjing Kexue 2019, 40, 4862–4869. [Google Scholar]
  36. Kang, Y.; Liu, M.; Song, Y.; Huang, X.; Yao, H.; Cai, X.; Zhang, H.; Kang, L.; Liu, X.; Yan, X.; et al. High-resolution ammonia emissions inventories in China from 1980 to 2012. Atmos. Chem. Phys. 2016, 16, 2043–2058. [Google Scholar] [CrossRef]
  37. Paulot, F.; Jacob, D.J.; Pinder, R.W.; Bash, J.O.; Travis, K.; Henze, D.K. Ammonia emissions in the United States, European Union, and China derived by high-resolution inversion of ammonium wet deposition data: Interpretation with a new agricultural emissions inventory (MASAGE_NH3). J. Geophys. Res.-Atmos. 2014, 119, 4343–4364. [Google Scholar] [CrossRef]
  38. Streets, D.G.; Bond, T.C.; Carmichael, G.R.; Fernandes, S.D.; Fu, Q.; He, D.; Klimont, Z.; Nelson, S.M.; Tsai, N.Y.; Wang, M.Q.; et al. An inventory of gaseous and primary aerosol emissions in Asia in the year 2000. J. Geophys. Res. Atmos. 2003, 108. [Google Scholar] [CrossRef]
  39. Zhang, L.; Chen, Y.; Zhao, Y.; Henze, D.K.; Zhu, L.; Song, Y.; Paulot, F.; Liu, X.; Pan, Y.; Lin, Y.; et al. Agricultural ammonia emissions in China: Reconciling bottom-up and top-down estimates. Atmos. Chem. Phys. 2018, 18, 339–355. [Google Scholar] [CrossRef]
  40. Wang, Y.; Zhao, T.; Zou, G.; Yang, J.; Tian, Z.; Li, X. Research Statues of Ammonia Emission Characteristics and Mitigation Technologies from Livestock Houses. Chin. J. Anim. Nutr. 2017, 29, 4249–4259. [Google Scholar]
  41. MA, Ministry of Agriculture of the People’s Republic of China. Environmental Quality Standards for Livestock and Poultry Farms; Standards Press of China: Beijing, China, 1999. [Google Scholar]
  42. SAC, Standardization Administration of the People’s Republic of China. Slow Release Fertilizers; Standards Press of China: Beijing, China, 2009. [Google Scholar]
  43. MEP, Ministry of Environmental Protection of the People’s Republic of China. Technical Policy on Pollution Prevention and Control in Livestock and Poultry Breeding; Standards Press of China: Beijing, China, 2010. [Google Scholar]
  44. SCC, State Council of the People’s Republic of China. Action Plan for the Prevention and Control of Air Pollution; Standards Press of China: Beijing, China, 2013. [Google Scholar]
  45. SEPA, State Environmental Protection Administration of the People’s Republic of China. Discharge standard of pollutants for livestock and poultry breeding; Standards Press of China: Beijing, China, 2001. [Google Scholar]
  46. GAQSIQ, General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China. Inspection and Quarantine of the People’s Republic of China, Environmental parameters and environmental management for intensive pig farms; Standards Press of China: Beijing, China, 2008. [Google Scholar]
  47. Zeng, W.; Li, J. Spatio-temporal distribution of ammonia (NH3) emissions in agricultural fields across North China. Environ. Sci. Pollut. Res. 2020, 27, 8129–8141. [Google Scholar] [CrossRef] [PubMed]
  48. Suo, L. Strategic Change in the Region, Policy Regionalization and Changes in the Structure of the Collaborative Governance Organization for Air Pollution. J. Tianjin Adm. Inst. 2020, 22, 55–68. [Google Scholar]
  49. de Vries, M.; de Boer, I.J.M. Comparing environmental impacts for livestock products: A review of life cycle assessments. Livest. Sci. 2010, 128, 1–11. [Google Scholar] [CrossRef]
  50. Yang, Z. Estimation of Ammonia Emission from Livestock in China based on Mass-flow Method and Regional Comparison. Master’s Thesis, Peking University, Beijing, China, 2008. [Google Scholar]
  51. Cortus, E.L.; Lemay, S.P.; Barber, E.M.; Hill, G.A.; Godbout, S. A dynamic model of ammonia emission from urine puddles. Biosyst. Eng. 2008, 99, 390–402. [Google Scholar] [CrossRef]
  52. Bai, Z.H.; Ma, L.; Qin, W.; Chen, Q.; Oenema, O.; Zhang, F.S. Changes in pig production in China and their effects on nitrogen and phosphorus use and losses. Environ. Sci Technol 2014, 48, 12742–12749. [Google Scholar] [CrossRef] [PubMed]
  53. Ma, L.; Velthof, G.L.; Wang, F.H.; Qin, W.; Zhang, W.F.; Liu, Z.; Zhang, Y.; Wei, J.; Lesschen, J.P.; Ma, W.Q.; et al. Nitrogen and phosphorus use efficiencies and losses in the food chain in China at regional scales in 1980 and 2005. Sci Total Environ. 2012, 434, 51–61. [Google Scholar] [CrossRef]
  54. Tamminga, S. Gaseous pollutants produced by farm animal enterprises. In Effect of Farm Animals on the Human Environment; CAB International: Wallingford, UK, 1992; pp. 345–356. [Google Scholar]
  55. Cao, Y.; Xing, X.; Bai, Z.; Wang, X.; Hu, C.; Ma, L. Review on Ammonia Emission Mitigation Techniques of Crop-Livestock Production System. Sci. Agric. Sin. 2018, 51, 566–580. [Google Scholar]
  56. Cheng, L. Establlishment and Contral Scheme of Agricultural Ammonia Emission Inventory in Beijing-Tianjin-Hebei Region; Beijing University of Technology: Beijing, China, 2018. [Google Scholar]
  57. Velthof, G.L.; Oudendag, D.A.; Oenema, O. Development and Application of the Integrated Nitrogen Model MITERRA-EUROPE; Task 1 Service Contract “Integrated Measures in Agriculture to Reduce Ammonia Emissions”; Alterra: Wageningen, The Netherlands, 2007. [Google Scholar]
  58. Burgos, S.A.; Embertson, N.M.; Zhao, Y.; Mitloehner, F.M.; DePeters, E.J.; Fadel, J.G. Prediction of ammonia emission from dairy cattle manure based on milk urea nitrogen: Relation of milk urea nitrogen to ammonia emissions. J. Dairy Sci. 2010, 93, 2377–2386. [Google Scholar] [CrossRef] [PubMed]
  59. Rotz, C.A. Management to reduce nitrogen losses in animal production. J. Anim. Sci. 2004, 82 (Suppl. S13), E119–E137. [Google Scholar]
  60. Canh, T.T.; Aarnink, A.J.A.; Schutte, J.B.; Sutton, A.; Langhout, D.J.; Verstegen, M.W.A. Dietary protein affects nitrogen excretion and ammonia emission from slurry of growing-finishing pigs. Livest. Prod. Sci. 1998, 56, 181–191. [Google Scholar] [CrossRef]
  61. Ogink, N.W.M.; Kroodsma, W. Reduction of ammonia emission from a cow cubicle house by flushing with water or a formalin solution. J. Agric. Eng. Res. 1996, 63, 197–204. [Google Scholar] [CrossRef]
  62. Huang, X.-D.; Han, Z.-Y.; Shi, D.-Z.; Huang, X.; Wu, W.-X.; Liu, Y.-X. Nitrogen loss and its control during livestock manure composting. Ying Yong Sheng Tai Xue Bao = J. Appl. Ecol. 2010, 21, 247–254. [Google Scholar]
  63. Liu, X.J.; Sha, Z.P.; Song, Y.; Dong, H.M.; Pan, Y.P.; Gao, Z.L.; Li, Y.E.; Ma, L.; Dong, W.X.; Hu, C.S.; et al. China’s Atmospheric Ammonia Emission Characteristics, Mitigation Options and Policy Recommendations. Res. Environ. Sci. 2021, 34, 149–157. [Google Scholar]
  64. Zhang, Z.; Zhang, S.; Han, Y.; Wang, J.; Wang, A.; Bi, H. Preliminary study on control strategies of ammonia emissions from agricultural sources. Jiangsu Agric. Sci. 2016, 44, 439–442. [Google Scholar]
  65. Wang, W. How much pollution can be reduced by controlling agricultural source ammonia. China Environment News, 3 April 2017. [Google Scholar]
  66. Shan, L.; He, Y.; Chen, J.; Huang, Q.; Wang, H. Ammonia volatilization from a Chinese cabbage field under different nitrogen treatments in the Taihu Lake Basin, China. J. Environ. Sci. 2015, 38, 14–23. [Google Scholar] [CrossRef]
  67. Zhang, Y.; Luan, S.; Chen, L.; Shao, M. Estimating the volatilization of ammonia from synthetic nitrogenous fertilizers used in China. J. Environ. Manag. 2011, 92, 480–493. [Google Scholar] [CrossRef]
  68. Li, X.; Ju, X.-t.; Zhang, L.-j.; Wan, Y.-j.; Liu, S.-q. Effects of different fertilization modes on soil ammonia volatilization and nitrous oxide emission. Ying Yong Sheng Tai Xue Bao = J. Appl. Ecol. 2008, 19, 99–104. [Google Scholar]
  69. Yang, X.; Yang, H. Soil ammonia volatilization under the different fertilization in summer corn farmland in North China. J. Arid Land Resour. Environ. 2016, 30, 137–142. [Google Scholar]
  70. Sha, Z.; Ma, X.; Loick, N.; Lv, T.; Cardenas, L.M.; Ma, Y.; Liu, X.; Misselbrook, T. Nitrogen stabilizers mitigate reactive N and greenhouse gas emissions from an arable soil in North China Plain: Field and laboratory investigation. J. Clean. Prod. 2020, 258, 121025. [Google Scholar] [CrossRef]
  71. Phillips, J. Control and Pollution Prevention Options for Ammonia Emissions; United States Environmental Protection Agency: Washington, DC, USA, 1995. [Google Scholar]
  72. Reidy, B.; Webb, J.; Misselbrook, T.H.; Menzi, H.; Luesink, H.H.; Hutchings, N.J.; Eurich-Menden, B.; Döhler, H.; Dämmgen, U. Comparison of models used for national agricultural ammonia emission inventories in Europe: Litter-based manure systems. Atmos. Environ. 2009, 43, 1632–1640. [Google Scholar] [CrossRef]
  73. Hellsten, S.; Dalgaard, T.; Rankinen, K.; Torseth, K.; Bakken, L.; Bechmann, M.; Kulmala, A.; Moldan, F.; Olofsson, S.; Piil, K.; et al. Abating N in Nordic agriculture-Policy, measures and way forward. J Environ. Manag. 2019, 236, 674–686. [Google Scholar] [CrossRef] [PubMed]
  74. EEA, European Environment Agency. EMEP/CORINAIR Emission Inventory Guidebook— 2007; In Publications Office of the Europe: Luxembourg, 2007. [Google Scholar]
  75. Van Grinsven, H.J.M.; Tiktak, A.; Rougoor, C.W. Evaluation of the Dutch implementation of the nitrates directive, the water framework directive and the national emission ceilings directive. NJAS—Wagening. J. Life Sci. 2016, 78, 69–84. [Google Scholar] [CrossRef]
Agronomy 13 02555 g001
Figure 1. Progress in China’s NH3 emission inventory.
Figure 1. Progress in China’s NH3 emission inventory.
Agronomy 13 02555 g001
Agronomy 13 02555 g002
Figure 2. Sources of generation and emissions of NH3.
Figure 2. Sources of generation and emissions of NH3.
Agronomy 13 02555 g002
Agronomy 13 02555 g003
Figure 3. Monthly variations in NH3 emission in China [22,36,37,38,39].
Figure 3. Monthly variations in NH3 emission in China [22,36,37,38,39].
Agronomy 13 02555 g003
Agronomy 13 02555 g004
Figure 4. National NH3 emission management from 1980 to 2019 [24,41,45,46].
Figure 4. National NH3 emission management from 1980 to 2019 [24,41,45,46].
Agronomy 13 02555 g004
Agronomy 13 02555 g005
Figure 5. NH3 emission intensity of different provinces in 2019. Note that this figure does not include Hong Kong, Macau and Taiwan data.
Figure 5. NH3 emission intensity of different provinces in 2019. Note that this figure does not include Hong Kong, Macau and Taiwan data.
Agronomy 13 02555 g005
Agronomy 13 02555 g006
Figure 6. China’s NH3 emission management mechanism.
Figure 6. China’s NH3 emission management mechanism.
Agronomy 13 02555 g006
Table 1. Summary of NH3 emission inventories at different scales.
Table 1. Summary of NH3 emission inventories at different scales.
No.AreaTimeSourceResolutionMethodActivity DataFactor DifferentiationTotal/GgFarmland/GgLivestock & Poultry /GgHuman/GgUncertainty MethodUncertaintyReferences
1NationalNational2016Anthropogenic1 × 1 kmCHENProvincialYes11,032.006475.003032.00487.00MC(−20%,24%)[20]
National2015Anthropogenic CHANSProvincialYes15,600.005870.006650.00780.00MC(−21%, 32%)[6]
National2015Anthropogenic1 × 1 kmEFProvincialYes12,580.005580.002560.00870.00Literature-based values±30%[4]
2RegionalYangtze River Delta region2014Anthropogenic1 × 1 kmEF, NARSESPrefecture-level cityPartial986.73532.82316.6851.11MC(−55%, 60%)[5,34]
North China2016Anthropogenic EFPrefecture-level cityPartial966.14350.04548.9013.11MC(−17%, 25%)[34]
Sichuan and Chongqing2004Agricultural IAP-NCountyNo698.76374.94219.6098.59Qualitative analysis[23]
3ProvincialFujian2015Anthropogenic1 × 1 kmEF, NARSESCountyPartial228.0289.7498.3711.13MC±16.3%[33]
Jiangsu2017Anthropogenic EFPrefecture-level cityNo562.47250.54212.9133.55Qualitative analysis[35]
Henan2015Anthropogenic3 × 3 kmEF, NARSESPrefecture-level cityPartial1031.60291.00591.5031.60MC; the AuvToolPro tool(−33%, 35%)[2]
Note: EF is the Emission Factor Method, and MC is the Monte Carlo simulation.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Li, J.; Zeng, W.; Wan, X. Management and Reduction Techniques Strategies of Ammonia Emission in Agricultural Sectors in China. Agronomy 2023, 13, 2555. https://doi.org/10.3390/agronomy13102555

AMA Style

Li J, Zeng W, Wan X. Management and Reduction Techniques Strategies of Ammonia Emission in Agricultural Sectors in China. Agronomy. 2023; 13(10):2555. https://doi.org/10.3390/agronomy13102555

Chicago/Turabian Style

Li, Jing, Weibin Zeng, and Xiaoming Wan. 2023. "Management and Reduction Techniques Strategies of Ammonia Emission in Agricultural Sectors in China" Agronomy 13, no. 10: 2555. https://doi.org/10.3390/agronomy13102555

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop