Agricultural Non-Point Source Pollution in China：Causes and Mitigation Measures

AMBI02012,41:370-379 D0110.1007/s13280-012-0249-6 REVIEW PAPER Agricultural Non-Point Source Pollution in China: Causes and Mitigation Measures Bo Sun,Linxiu Zhang,Linzhang Yang,Fusuo Zhang,David Norse, Zhaoliang Zhu Received:28 September 2010/Revised:31 December 2011/Accepted:12 January 2012/Published online:5 February 2012 Abstract Non-point source (NPS)pollution has been now the largest user of synthetic nitrogen fertilisers in the increasingly serious in China since the 1990s.The increases world.However,this agro-chemical-based intensive agri- of agricultural NPS pollution in China is evaluated for the culture has contributed substantially to the emission of the period 2000-2008 by surveying the literature on water and very powerful greenhouse gases CH,and N2O,and the entry soil pollution from fertilizers and pesticides,and assessing of pollutants(excessive nitrogen and phosphorus,pesticide the surplus nitrogen balance within provinces.The main and heavy metals)into water bodies and soils(Smil 1997). causes for NPS pollution were excessive inputs of nitrogen These pollutants have adverse effects on environmental fertilizer and pesticides,which were partly the result of the quality and public health,for example,eutrophication of inadequate agricultural extension services and the rapid lakes and streams,soil contamination by heavy metals and expansion of intensive livestock production with little of the accumulation of pesticide residues in food. waste management.The annual application of synthetic The response to these problems since the 1960s has been nitrogen fertilizers and pesticides in China increased by to shift agricultural policies and R&D programmes towards 50.7 and 119.7%,respectively,during 1991-2008.The a more sustainable growth path.This has led to the devel- mitigation measures to reduce NPS pollution include:cor- opment of many new techniques and integrated resource rect distortion in fertilizer prices;improve incentives for the management practices that can mitigate the adverse effects recycling of organic manure;provide farmers with better of intensive farming on the environment (Conway 1994, information on the sound use of agro-chemicals;and tighten 1997).However,controlling NPS pollution at the regional, the regulations and national standards on organic waste national and local scale is a complex and difficult problem disposal and pesticides use. which can take decades to overcome,for example,reduc- tion of nitrate pollution in the EU.This study analyses the Keywords Non-point source pollution. reasons for increasing NPS pollution in China,then put Synthetic nitrogen fertilizers.Organic manure. forwards mitigation measures for NPS pollution control that Agricultural policy.Mitigation strategy are primarily for crop production and need to be comple- mented by other measures to control NPS pollution from the livestock sector. INTRODUCTION China is facing the challenge of feeding her large and STATUS OF NON-POINT SOURCE POLLUTION increasing population with a limited and decreasing culti- FROM CROP PRODUCTION IN CHINA vated land while achieving a clean and safe environment(Fu 2008).After the onset of the green revolution in the 1950s, Water Pollution from Crop Fertilization increasing inputs of inorganic fertilisers,organic manures and pesticides became the principal means globally and in Water bodies in China have become seriously polluted China of attaining high-crop yields and,indirectly,greater since the 1990s and there have been no marked improve- livestock production(FAO 2008).Consequently,China is ments in recent years.China has 4880 lakes,covering a Royal Swedish Academy of Sciences 2012 Springer www.kva.se/en

REVIEW PAPER Agricultural Non-Point Source Pollution in China: Causes and Mitigation Measures Bo Sun, Linxiu Zhang, Linzhang Yang, Fusuo Zhang, David Norse, Zhaoliang Zhu Received: 28 September 2010 / Revised: 31 December 2011 / Accepted: 12 January 2012 / Published online: 5 February 2012 Abstract Non-point source (NPS) pollution has been increasingly serious in China since the 1990s. The increases of agricultural NPS pollution in China is evaluated for the period 2000-2008 by surveying the literature on water and soil pollution from fertilizers and pesticides, and assessing the surplus nitrogen balance within provinces. The main causes for NPS pollution were excessive inputs of nitrogen fertilizer and pesticides, which were partly the result of the inadequate agricultural extension services and the rapid expansion of intensive livestock production with little of waste management. The annual application of synthetic nitrogen fertilizers and pesticides in China increased by 50.7 and 119.7%, respectively, during 1991-2008. The mitigation measures to reduce NPS pollution include: cor￾rect distortion in fertilizer prices; improve incentives for the recycling of organic manure; provide farmers with better information on the sound use of agro-chemicals; and tighten the regulations and national standards on organic waste disposal and pesticides use. Keywords Non-point source pollution Synthetic nitrogen fertilizers Organic manure Agricultural policy Mitigation strategy INTRODUCTION China is facing the challenge of feeding her large and increasing population with a limited and decreasing culti￾vated land while achieving a clean and safe environment (Fu 2008). After the onset of the green revolution in the 1950s, increasing inputs of inorganic fertilisers, organic manures and pesticides became the principal means globally and in China of attaining high-crop yields and, indirectly, greater livestock production (FAO 2008). Consequently, China is now the largest user of synthetic nitrogen fertilisers in the world. However, this agro-chemical-based intensive agri￾culture has contributed substantially to the emission of the very powerful greenhouse gases CH4 and N2O, and the entry of pollutants (excessive nitrogen and phosphorus, pesticide and heavy metals) into water bodies and soils (Smil 1997). These pollutants have adverse effects on environmental quality and public health, for example, eutrophication of lakes and streams, soil contamination by heavy metals and the accumulation of pesticide residues in food. The response to these problems since the 1960s has been to shift agricultural policies and R&D programmes towards a more sustainable growth path. This has led to the devel￾opment of many new techniques and integrated resource management practices that can mitigate the adverse effects of intensive farming on the environment (Conway 1994, 1997). However, controlling NPS pollution at the regional, national and local scale is a complex and difficult problem which can take decades to overcome, for example, reduc￾tion of nitrate pollution in the EU. This study analyses the reasons for increasing NPS pollution in China, then put forwards mitigation measures for NPS pollution control that are primarily for crop production and need to be comple￾mented by other measures to control NPS pollution from the livestock sector. STATUS OF NON-POINT SOURCE POLLUTION FROM CROP PRODUCTION IN CHINA Water Pollution from Crop Fertilization Water bodies in China have become seriously polluted since the 1990s and there have been no marked improve￾ments in recent years. China has 4880 lakes, covering a 123 Royal Swedish Academy of Sciences 2012 www.kva.se/en AMBIO 2012, 41:370–379 DOI 10.1007/s13280-012-0249-6

AMBI02012,41:370-379 371 A Seven main river systems B Twenty-eight major lakes 100% 100% 80% 80% ▣Grade V plus Bnb 60% 60% ▣Grade IV-V 40% 40% Grade I-mI 200 20% 0% 0% 2000 00 2000 1008 Year Year Fig.1 Water quality in (a)seven main river basins and (b)28 major lakes (in different grades) total area of 83 400 km2 and accounting for 0.8%of the The national groundwater resources assessment in 2000- country.According to an evaluation of eutrophication in 2002 showed less than 5%of the total resources of 131 major lakes in 2000,about 50%of them were eutro- 350 thousand million m'per year suffered from serious phic (Yuan 2000).and for 75%of these lakes the eutro- pollution,so most of it could be used in agriculture and phication is getting worse.Over half of the rivers and about industry after the conventional treatment.The shallow two-thirds of the lakes in the seven river systems and 28 groundwater resources polluted by nitrate are mainly in the major lakes were assessed to be of poor quality (Grade IV North China Plan.the Northeast Plain.the Jianghan Plain and above')during 2000-2008 (Fig.1)(SEPA 2000- (in the middle reach of Yangtze River)and the Yangtze 2008).Lake eutrophication has been showing a rapidly Delta region (Zhang and Li 2004). increasing trend since 2000,with serious algal bloom crisis Projections suggest that the future nitrogen surplus from in Dianchi Lake in 2001 and in Taihu Lake in 2007(Qin crop production will increase from about 154 kg ha in et al.2007;Gao and Zhang 2010).Nitrogen concentrations 2004 to 179 kg ha in 2015,and hence the risk of non- in large rivers,especially the Yangtze and Yellow river, point source pollution will increase (Shen et al.2005). have been increasing in recent years (Li et al.2007;Yu During 2005-2008,the high-risk area for fertilizer appli- et al.2010).The estuaries and coastal water near cities are cation included five coastal provinces and three munici- seriously polluted,and the annual frequency of red tides palities in the east region and four provinces in middle has increased from 28 in 2000 to 68 in 2008 with a region.There will be three more provinces (Hainan,Anhui cumulative area of 13,738 km2(SEPA 2000-2008). and Hebei)and one municipality (Chongqing)facing high The NPS problem is not restricted to surface water risks in 2020 if current policies and trends continue bodies.The shallow groundwater in intensive vegetable (Fig.2). growing areas generally suffers from very serious nitrate pollution.A survey of 16 counties in the Yangtse Delta Pollution from Pesticides region (i.e.Jiangsu Province,Zhejiang Province and Shanghai City)found 38%of the drinking water wells had Long-term intensive application of pesticide has caused a nitrate-N content 20 mg L-(Zhang 1999).Another contamination of soil,surface water,groundwater and farm survey of 14 counties in three cities in North China(i.e. products.In the period 1950-1983,soil pollution was Beijing,Tianjin and Tangshan)found that 50%of the mainly caused by organochlorine pesticides (OCPs),with a sampling sites had nitrate-N levels>11.3 mg L-(the total consumption of 4.46 Mt of Lindane (HCH)and 0.435 Europe Union limit for drinking water)in nitrate-N con- Mt of dichlorodiphenyltrichloroethane(DDT)in 33 years tent-the highest reached 68 mg L(Zhang et al.1996). Conventional treatment for water includes physical and biological IThere are five grades in the national environmental quality treatments.The solid pollutants are removed first by sand sedimen- standards for surface water (MEP 2002).There are 24 items to tation;then the colloidal and dissolved organic pollutants (BOD. evaluate the water quality.such as pH,COD,BOD.N,P,heavy COD)are removed by biological treatment including the biological metal,petroleum,Faecal Coliform Bacteria,etc.From Grades I to IV, filter biofilm,biological dial,bio-contact oxidation and fluidized bed. the threshold value for total N is 0.2.0.5.1.0,1.5 and 2.0 mg L-, Advanced treatment is to remove the refractory organic matter, respectively.The standards also set limits for the content of different nitrogen and phosphorus by biological nutrient removal,coagulation pesticide in surface water with the highest value of 0.08 mg L-for precipitation,sand filtration,activated carbon adsorption,ion dimethoate. exchange and electrodialysis method. Royal Swedish Academy of Sciences 2012 www.kva.se/en ②Springer

total area of 83 400 km2 and accounting for 0.8% of the country. According to an evaluation of eutrophication in 131 major lakes in 2000, about 50% of them were eutro￾phic (Yuan 2000), and for 75% of these lakes the eutro￾phication is getting worse. Over half of the rivers and about two-thirds of the lakes in the seven river systems and 28 major lakes were assessed to be of poor quality (Grade IV and above1 ) during 2000-2008 (Fig. 1) (SEPA 2000- 2008). Lake eutrophication has been showing a rapidly increasing trend since 2000, with serious algal bloom crisis in Dianchi Lake in 2001 and in Taihu Lake in 2007 (Qin et al. 2007; Gao and Zhang 2010). Nitrogen concentrations in large rivers, especially the Yangtze and Yellow river, have been increasing in recent years (Li et al. 2007; Yu et al. 2010). The estuaries and coastal water near cities are seriously polluted, and the annual frequency of red tides has increased from 28 in 2000 to 68 in 2008 with a cumulative area of 13,738 km2 (SEPA 2000-2008). The NPS problem is not restricted to surface water bodies. The shallow groundwater in intensive vegetable growing areas generally suffers from very serious nitrate pollution. A survey of 16 counties in the Yangtse Delta region (i.e. Jiangsu Province, Zhejiang Province and Shanghai City) found 38% of the drinking water wells had a nitrate–N content[20 mg L-1 (Zhang 1999). Another survey of 14 counties in three cities in North China (i.e. Beijing, Tianjin and Tangshan) found that 50% of the sampling sites had nitrate–N levels[11.3 mg L-1 (the Europe Union limit for drinking water) in nitrate–N con￾tent—the highest reached 68 mg L-1 (Zhang et al. 1996). The national groundwater resources assessment in 2000- 2002 showed less than 5% of the total resources of 350 thousand million m3 per year suffered from serious pollution, so most of it could be used in agriculture and industry after the conventional treatment.2 The shallow groundwater resources polluted by nitrate are mainly in the North China Plan, the Northeast Plain, the Jianghan Plain (in the middle reach of Yangtze River) and the Yangtze Delta region (Zhang and Li 2004). Projections suggest that the future nitrogen surplus from crop production will increase from about 154 kg ha-1 in 2004 to 179 kg ha-1 in 2015, and hence the risk of non￾point source pollution will increase (Shen et al. 2005). During 2005-2008, the high-risk area for fertilizer appli￾cation included five coastal provinces and three munici￾palities in the east region and four provinces in middle region. There will be three more provinces (Hainan, Anhui and Hebei) and one municipality (Chongqing) facing high risks in 2020 if current policies and trends continue (Fig. 2). Pollution from Pesticides Long-term intensive application of pesticide has caused contamination of soil, surface water, groundwater and farm products. In the period 1950-1983, soil pollution was mainly caused by organochlorine pesticides (OCPs), with a total consumption of 4.46 Mt of Lindane (HCH) and 0.435 Mt of dichlorodiphenyltrichloroethane (DDT) in 33 years Fig. 1 Water quality in (a) seven main river basins and (b) 28 major lakes (% in different grades) 1 There are five grades in the national environmental quality standards for surface water (MEP 2002). There are 24 items to evaluate the water quality, such as pH, COD, BOD, N, P, heavy metal, petroleum, Faecal Coliform Bacteria, etc. From Grades I to IV, the threshold value for total N is 0.2, 0.5, 1.0, 1.5 and 2.0 mg L-1 , respectively. The standards also set limits for the content of different pesticide in surface water with the highest value of 0.08 mg L-1 for dimethoate. 2 Conventional treatment for water includes physical and biological treatments. The solid pollutants are removed first by sand sedimen￾tation; then the colloidal and dissolved organic pollutants (BOD, COD) are removed by biological treatment including the biological filter biofilm, biological dial, bio-contact oxidation and fluidized bed. Advanced treatment is to remove the refractory organic matter, nitrogen and phosphorus by biological nutrient removal, coagulation precipitation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis method. AMBIO 2012, 41:370–379 371 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123

372 AMBI02012.41:370-379 2005-2008 2020 Risk class Low Potential High Fig.2 Evaluation of the risk of NPS pollution within province from and livestock manure,and biological N fixation by legumes.The N excess nitrogen application during 2005-2008 and in 2020.The risk output is the crop N export by harvest.The potential and high-risk of NPS pollution is evaluated by annual surface nitrogen balances regions in China were identified as those with more than 100 and which is the difference between N inputs and outputs for the agro- 180 kg ha-of surface N balance surplus,respectively.The N surplus ecosystems within the province.The N inputs include synthetic single is projected by non-seasonal Box-Jenkins model and compound N fertilizers,crop straw returned to the field,human before they were banned in 1983.About 14 million ha of REASONS FOR NON-POINT SOURCE POLLUTION farmland suffered from OCPs pollution in 1985,with a FROM CROP PRODUCTION IN CHINA residual amount of 0.181-0.254 and 0.222-0.273 mg kg- for HCHs and DDTs in the surface soil,respectively(first Huge Losses of Inorganic N Fertilizers grade limitation is 200 000 tonnes from underground Royal Swedish Academy of Sciences 2012 Springer www.kva.se/en

before they were banned in 1983. About 14 million ha of farmland suffered from OCPs pollution in 1985, with a residual amount of 0.181-0.254 and 0.222-0.273 mg kg-1 for HCHs and DDTs in the surface soil, respectively (first grade limitation is \0.05 mg kg-1 in National Soil Envi￾ronmental Quality Standards, GB15618-1995) (Lin et al. 2000). NPS pollution from pesticides is still serious in many regions although residue levels have declined since 1983. The average concentrations of DDTs and HCHs were 60 lg kg-1 (ND3 *2910 lg kg-1 ) and 8.7 lg kg-1 (ND *131 lg kg-1 ) in 2000s, respectively. The regional dif￾ferences were very large. The average concentration of DDTs in the soils of East China was 14- and 5-fold of that of South and Southwest China, while the ones of HCHs in South and Southwest China were 4- and 2-fold of those in North China (Cai et al. 2008). A survey during 2003–2004 of 217 reservoirs and 406 rivers and lakes in seven major river basins revealed that surface waters in China also suffered from moderate pol￾lution by OCPs (Gao et al. 2008). Lindane (c-HCH) and p,p0 -DDT were detected in 84 and 63% of sites, with a mean concentration of 0.0313 lg L-1 (ND *0.860 lg L-1 ) and 14.6 lg L-1 (ND *0.368 lg L-1 ), respec￾tively. The concentrations of HCH in the rivers of northern China were usually higher than those of southern China. The surface water with the highest concentrations of HCH and p,p0 -DDT occurred mainly in the Yellow River and Huaihe River basins. REASONS FOR NON-POINT SOURCE POLLUTION FROM CROP PRODUCTION IN CHINA Huge Losses of Inorganic N Fertilizers from Cropland to Surface Waters China’s consumption of synthetic fertilizers has been increasing year by year since the early 1960s to feed her huge population from a limited area of cropland (Fig. 3); however, the growth of crop yields has slowdown since 1990 (EOCSSB 2009). China is now the largest producer and consumer of synthetic N fertilizer in the world. Total fertilizer consumption reached 52 million tonnes in 2008, that is, over one-third of world consumption. The national average annual application rate is about 230 kg N ha-1 cropland, which is the third highest in the world after Korea and Japan. In some provinces, the average is greater than 400 kg N ha-1 and in some counties over 1000 kg N ha-1 for the vegetable lands. Fertilizer use efficiency of inorganic N fertilizer has been decreasing in China since the 1980s. The recovery ratio of N in the harvest crop decreased from 57% in 1979 to 43% in 1998, and the total loss of N increased by about two times (Wu 2005). This decline in nitrogen use effi- ciency has continued since 1998 and now is an issue for almost all cereal and vegetable crops and some tree crops. The national survey of pollution sources in 2007 showed that the total nitrogen loss from cropland was about 1 600 000 tonnes, in which some 320 000 tonnes was from sur￾face runoff and [200 000 tonnes from underground Fig. 2 Evaluation of the risk of NPS pollution within province from excess nitrogen application during 2005–2008 and in 2020. The risk of NPS pollution is evaluated by annual surface nitrogen balances which is the difference between N inputs and outputs for the agro￾ecosystems within the province. The N inputs include synthetic single and compound N fertilizers, crop straw returned to the field, human and livestock manure, and biological N fixation by legumes. The N output is the crop N export by harvest. The potential and high-risk regions in China were identified as those with more than 100 and 180 kg ha-1 of surface N balance surplus, respectively. The N surplus is projected by non-seasonal Box-Jenkins model 3 ND = Not detected at or above the method detection limit. 372 AMBIO 2012, 41:370–379 123 Royal Swedish Academy of Sciences 2012 www.kva.se/en

AMBI02012,41:370-379 373 Fig.3 Grain production and 600 30 synthetic fertilizer consumption in China from 1949 to 2008 oGrain production 500 N 25 OP 400 在K 20 300 15 200 o 100 ooooocooooooooxoooocooo 4444 V9K376000020090000020086444444444444443394444 0 1949 1959 1969 1979 1989 1999 2009 Year Table 1 Estimated N output from synthetic fertilizer N in three main river valleys in China in 1995 River name Major regime Nitrogen loss in river valley (million tonnes) Length Drainage Annual flow Denitrification in N transported NH Total loss (km) area (km) (108m) agricultural soils into water bodies volatilization Yangtze River 6300 1808500 9513 1.77-2.61 2.87 1.32 5.96-6.80 Yellow River 5464 752443 661 0.24-0.53 0.65 0.17 1.06-1.35 Pearl River 2214 453690 3338 0.39-0.49 0.62 0.29 1.30-1.40 leaching.The total phosphorus loss was much less at about Rapid Development of Intensive Livestock 108 000 tonnes (MEP et al.2010).Estimates based on field Production with Limited Treatment of Organic observations on the use of the main nitrogen fertilizers Wastes (urea,ammonium bicarbonate and ammonium sulphate)for the main cereal crops(rice,wheat and maize)and the key Intensive livestock production has developed rapidly in food production provinces of China(Zhu et al.1997;Zhu China during the last two decades (Fig.4)(EOCSSB and Chen 2002)indicated that in the 1990s the total loss of 2009),leading to the generation of large amounts of nitrogen fertilizer from crops to the environment was about organic wastes but the use of these wastes for the pro- 19.1%,of which 5%entered the surface water by runoff, duction of organic fertilizer has received little attention.In 2%passed down to the groundwater by leaching,1.1% 2007,livestock and poultry farms produced 243 mil- entered the atmosphere through denitrification process lion tonnes of organic waste and 163 million tonnes of (largely in the form of N2O)and 11%through ammonia urine;the total N and P discharge from animal excretion (NH3)volatilization process.These national averages hide reached 1 024 800 and 160 400 tonnes,respectively (MEP considerable regional and cropping system variation in N et al.2010).The N and P discharge in 2007 coming from losses to the environment (Table 1)(Xing and Zhu 2002). human excreta of residents and livestock was larger than For example,leaching losses can be far greater in the high- that from inorganic fertilizers application and has become rainfall areas of southern China,and from irrigated inten- the main cause of NPS in China.This happened because sive vegetable production,and are still increasing.A the lack of national waste discharge standards has led to no review of research on urea utilization efficiency showed or inadequate waste disposal or treatment facilities in 90% that the average N leaching rate in North China was 2.1 and 2.7%of the total urea-N applied for upland and paddy field, respectively,while in South China it was 8.2 and 6.1% 4 The census includes 1963624 discharge sources from medium to large intensive units and do not include discharges from small (Yang and Sun 2008). producers. Royal Swedish Academy of Sciences 2012 www.kva.se/en ②Springer

leaching. The total phosphorus loss was much less at about 108 000 tonnes (MEP et al. 2010). Estimates based on field observations on the use of the main nitrogen fertilizers (urea, ammonium bicarbonate and ammonium sulphate) for the main cereal crops (rice, wheat and maize) and the key food production provinces of China (Zhu et al. 1997; Zhu and Chen 2002) indicated that in the 1990s the total loss of nitrogen fertilizer from crops to the environment was about 19.1%, of which 5% entered the surface water by runoff, 2% passed down to the groundwater by leaching, 1.1% entered the atmosphere through denitrification process (largely in the form of N2O) and 11% through ammonia (NH3) volatilization process. These national averages hide considerable regional and cropping system variation in N losses to the environment (Table 1) (Xing and Zhu 2002). For example, leaching losses can be far greater in the high￾rainfall areas of southern China, and from irrigated inten￾sive vegetable production, and are still increasing. A review of research on urea utilization efficiency showed that the average N leaching rate in North China was 2.1 and 2.7% of the total urea-N applied for upland and paddy field, respectively, while in South China it was 8.2 and 6.1% (Yang and Sun 2008). Rapid Development of Intensive Livestock Production with Limited Treatment of Organic Wastes Intensive livestock production has developed rapidly in China during the last two decades (Fig. 4) (EOCSSB 2009), leading to the generation of large amounts of organic wastes but the use of these wastes for the pro￾duction of organic fertilizer has received little attention. In 2007, livestock and poultry farms produced 243 mil￾lion tonnes of organic waste and 163 million tonnes of urine4 ; the total N and P discharge from animal excretion reached 1 024 800 and 160 400 tonnes, respectively (MEP et al. 2010). The N and P discharge in 2007 coming from human excreta of residents and livestock was larger than that from inorganic fertilizers application and has become the main cause of NPS in China. This happened because the lack of national waste discharge standards has led to no or inadequate waste disposal or treatment facilities in 90% Fig. 3 Grain production and synthetic fertilizer consumption in China from 1949 to 2008 Table 1 Estimated N output from synthetic fertilizer N in three main river valleys in China in 1995 River name Major regime Nitrogen loss in river valley (million tonnes) Length (km) Drainage area (km2 ) Annual flow (108 m3 ) Denitrification in agricultural soils N transported into water bodies NH3 volatilization Total loss Yangtze River 6300 1 808 500 9513 1.77–2.61 2.87 1.32 5.96–6.80 Yellow River 5464 752 443 661 0.24–0.53 0.65 0.17 1.06–1.35 Pearl River 2214 453 690 3338 0.39–0.49 0.62 0.29 1.30–1.40 4 The census includes 1 963 624 discharge sources from medium to large intensive units and do not include discharges from small producers. AMBIO 2012, 41:370–379 373 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123

374 AMBI02012,41:370-379 600 o ◆-Beef cattle 口-k 500 △-Goatand Sheep -0-且og (s01 △-Poultry 30 -Poultry Eggs 400 00000000 uo!l! 300 44△△44△4 200 △△△△△△ 100 ◆◆◆◆◆◆◆◆◆ 0 0 19851989 1993 1997200120052009 1985 1989 1993 1997200120052009 Year Year Fig.4 Livestock number and milk and poultry production in China from 1996 to 2008 of the animal farms of China.At the national level,the and aminoformin pesticides accounted for 67.0%of the proportion of animal wastes directly exported to water was total insecticides.Most of them were applied to vegetables, 2-8%for solid wastes and about 50%for liquid wastes in fruit trees and cereals(rice and wheat)(ECCPDR 2005). 2002 (ECCEY 2003).The national average load of poultry A large amount of pesticide enters directly into or is manure in 2002 was 4.19 t ha(based on the total crop- deposited on soil or is moved by wind drift to surface land area),with the highest environmental risk of NPS waters.The average pesticide-use efficiency was only pollution arising from this manure occurring in Shanghai, about 30%of the total pesticide applied,which was caused Henan,Tianjin and Shandong where the load >18 t ha- by the over application,inadequate spray technology and the medium level NPS risk was in Beijing,Jiangsu,Hebei, poor mixing methods(Shao and Zhao 2004).The recovery Anhui and Hunan where the average loads were between 5 of pesticide on the target plant was only 9-16%of the total and 18 t ha (Wu 2005). sprayed to the wide-row crops,such as cotton and oil seed rape (Tu et al.2003). Increasing Use of Pesticides China has been the world largest consumer of pesticides for REASONS FOR UNSUITABLE APPLICATION more than 10 years(EOCASY 2002-2009)with an annual OF FERTILIZER AND PESTICIDE application amount of 1.67 million tonnes (active ingredi- ent)in 2008(Fig.5).The average application rate of pes- The Pressure for High Levels of Food ticide in the east,middle and west part of China is 12.91, Self-Sufficiency 7.26 and 3.43 kg ha(active ingredient)in 2001, respectively,with a mean value of 8.19 kg ha(ECCPDR China is a major agricultural country with 22%of the 2005). world's population (1.3 thousand million)but only 7%of In 2000,insecticides,fungicides,herbicides and plant the cultivated land of the world.Food production has growth regulators accounted for 54.7.25.3.19.3 and 0.7%. increased substantially during the past 50 years,and this is respectively,of the total consumption (Lin et al.2000). largely because of progress in science and technology and The organo-chlorine and organo-phosphorus pesticides institutional reform.Much of the increase in grain pro- accounted for over 39.4 and 37.0%,respectively,of total duction was the result of greater use of synthetic N fertil- pesticide use.The highly poisonous organic phosphorus izers,and there is a significant correlation between the annual fertilizer application and the grain production.The s Insecticides mainly include parathion,parathion_methyl,trichlor- collectives on behalf of central government used to put fon,dichlorvos,dimethoate,omethoate,ethamidophos,isocarbophos, pressures on farmers to increase production to meet local carbamate,pyrethroid,disosultap and chlordimeform.Fungicides and national food self-sufficiency targets,and most of them mainly include copper sulphate,carbendazim,benodanil,kitazin responded by increasing fertilizer use.Since 1978,how- (EBP),iprobenfos(Kitazin P),zineb,tricyclazole and jiangangmycin. ever,when China started to open up its economy,farmers Herbicides mainly include nitrofen,butachlor,2,4-D butylate,chlor- toluron,MCPA,glyphosate,atrazine,prometryn and trifluralin. have become more involved in off-farm activities and Royal Swedish Academy of Sciences 2012 Springer www.kva.se/en

of the animal farms of China. At the national level, the proportion of animal wastes directly exported to water was 2-8% for solid wastes and about 50% for liquid wastes in 2002 (ECCEY 2003). The national average load of poultry manure in 2002 was 4.19 t ha-1 (based on the total crop￾land area), with the highest environmental risk of NPS pollution arising from this manure occurring in Shanghai, Henan, Tianjin and Shandong where the load [18 t ha-1 the medium level NPS risk was in Beijing, Jiangsu, Hebei, Anhui and Hunan where the average loads were between 5 and 18 t ha-1 (Wu 2005). Increasing Use of Pesticides China has been the world largest consumer of pesticides for more than 10 years (EOCASY 2002-2009) with an annual application amount of 1.67 million tonnes (active ingredi￾ent) in 2008 (Fig. 5). The average application rate of pes￾ticide5 in the east, middle and west part of China is 12.91, 7.26 and 3.43 kg ha-1 (active ingredient) in 2001, respectively, with a mean value of 8.19 kg ha-1 (ECCPDR 2005). In 2000, insecticides, fungicides, herbicides and plant growth regulators accounted for 54.7, 25.3, 19.3 and 0.7%, respectively, of the total consumption (Lin et al. 2000). The organo-chlorine and organo-phosphorus pesticides accounted for over 39.4 and 37.0%, respectively, of total pesticide use. The highly poisonous organic phosphorus and aminoformin pesticides accounted for 67.0% of the total insecticides. Most of them were applied to vegetables, fruit trees and cereals (rice and wheat) (ECCPDR 2005). A large amount of pesticide enters directly into or is deposited on soil or is moved by wind drift to surface waters. The average pesticide-use efficiency was only about 30% of the total pesticide applied, which was caused by the over application, inadequate spray technology and poor mixing methods (Shao and Zhao 2004). The recovery of pesticide on the target plant was only 9-16% of the total sprayed to the wide-row crops, such as cotton and oil seed rape (Tu et al. 2003). REASONS FOR UNSUITABLE APPLICATION OF FERTILIZER AND PESTICIDE The Pressure for High Levels of Food Self-Sufficiency China is a major agricultural country with 22% of the world’s population (1.3 thousand million) but only 7% of the cultivated land of the world. Food production has increased substantially during the past 50 years, and this is largely because of progress in science and technology and institutional reform. Much of the increase in grain pro￾duction was the result of greater use of synthetic N fertil￾izers, and there is a significant correlation between the annual fertilizer application and the grain production. The collectives on behalf of central government used to put pressures on farmers to increase production to meet local and national food self-sufficiency targets, and most of them responded by increasing fertilizer use. Since 1978, how￾ever, when China started to open up its economy, farmers have become more involved in off-farm activities and Fig. 4 Livestock number and milk and poultry production in China from 1996 to 2008 5 Insecticides mainly include parathion, parathion_methyl, trichlor￾fon, dichlorvos, dimethoate, omethoate, ethamidophos, isocarbophos, carbamate, pyrethroid, disosultap and chlordimeform. Fungicides mainly include copper sulphate, carbendazim, benodanil, kitazin (EBP), iprobenfos (Kitazin P), zineb, tricyclazole and jiangangmycin. Herbicides mainly include nitrofen, butachlor, 2,4-D butylate, chlor￾toluron, MCPA, glyphosate, atrazine, prometryn and trifluralin. 374 AMBIO 2012, 41:370–379 123 Royal Swedish Academy of Sciences 2012 www.kva.se/en

AMBI02012,41:370-379 375 Fig.5 Total pesticide 180 (formulation)application rate in China from 1991 to 2008 gunowe 160 140 uonesydde (sauuog 120 20) 100 pnsad 80 60 19911993 19951997199920012003200520072009 Year responded to the rising opportunity cost of their labour. 3.3 million ha in 1980 to about 28 million ha in 2008.An They applied fertilizer in a single application rather than investigation in the late 1990s of 18 provinces(city)showed using split applications which give higher nitrogen use that in all of them except Inner Mongolia,the average efficiency but need more labour. synthetic N fertilizer application rate commonly exceeded Farmers generally fail to take into account of the dif- 200 kg N ha,with the highest rate of 740 kg ha- ferences between the agronomic,economic and environ- occurring in Shandong province(Fig.6)(Ma et al.2000).In mental optimum application rate.Fertilizer trials in China addition,they commonly applied high rates of nitrogen as over many years for different crops,soil types and agro- manure (Li et al.2006).Excessive N inputs are often one of climates have provided good estimates of the agronomic the main reasons for the high incidence of pests and diseases optimum application rate (Yang and Sun 2008).The in vegetable production,and in turn,this commonly leads to average agronomic efficiency of fertilizer N in the 1990s farms using even more pesticide,resulting in high-pesticide when applied to cereals at a rate of 120-150 kg N ha-1 residues on vegetables and in the environment.Insecticide was 8.1-11.8 kg yield per kg of N in over 2700 field application rate are often 2-3 times the recommended experiments(Zhu et al.1997).Farmers,however,generally dosage (Ma et al.2000;Li et al.2006). need to apply higher rates of fertilizer to reach the optimum The excessive and unbalanced inputs of inorganic fer- agronomic efficiency,because of crop varieties developed tilizers can cause the damage to soil structure and soil in recent years commonly require more nutrients and quality.Although the ratio of N:P:K increased from higher management levels.The economic optimum N input 1:0.20:0.11in1991to1:0.28:0.21in2008,the proportion (the balance between the income from increased yield and of potassium fertilizer commonly needs to be increased. the cost of increased fertilizer used to achieve it)will be Nitrogen ratios have been too high in most of regions in less than the agronomic optimum.Finally,the environ- China since the 1970s,especially in eastern areas.Phos- mental optimum N input will generally be comparable or phorus ratios have changed from a deficit to small surplus less than the economic optimum because the latter fail to (with a large surplus in some vegetable areas),but potas- take account of the costs to the public at large of the sium is generally still in deficit (Shen et al.2005). environmental damage caused by NPS pollution.These Unbalanced nutrient ratios in mixed synthetic fertilizers costs (depending primarily on the extent of overuse)are can cause both biological and physicochemical damage to difficult to estimate and are not known with precision but in soils,leading to acidification,secondary salinization and the case of rice in the mid-1990s were estimated to be in reduction of microbial activity (Cao et al.2004;Ge et al. the range of 2.0-7.4 thousand million USD per year for 2009;Guo et al.2010).This damage lowers crop yields and whole China (Norse et al.2001). may lead to farmers applying even more fertilizers to try to The fast development of vegetable production has added compensate for the reduced soil productivity and thereby considerably to the overuse of fertilizer and pesticide.The intensify NPS pollution and the cycle of environmental total area planted with vegetables in China increased from degradation. Royal Swedish Academy of Sciences 2012 www.kva.se/en ②Springer

responded to the rising opportunity cost of their labour. They applied fertilizer in a single application rather than using split applications which give higher nitrogen use efficiency but need more labour. Farmers generally fail to take into account of the dif￾ferences between the agronomic, economic and environ￾mental optimum application rate. Fertilizer trials in China over many years for different crops, soil types and agro￾climates have provided good estimates of the agronomic optimum application rate (Yang and Sun 2008). The average agronomic efficiency of fertilizer N in the 1990s when applied to cereals at a rate of 120-150 kg N ha-1 was 8.1-11.8 kg yield per kg of N in over 2700 field experiments (Zhu et al. 1997). Farmers, however, generally need to apply higher rates of fertilizer to reach the optimum agronomic efficiency, because of crop varieties developed in recent years commonly require more nutrients and higher management levels. The economic optimum N input (the balance between the income from increased yield and the cost of increased fertilizer used to achieve it) will be less than the agronomic optimum. Finally, the environ￾mental optimum N input will generally be comparable or less than the economic optimum because the latter fail to take account of the costs to the public at large of the environmental damage caused by NPS pollution. These costs (depending primarily on the extent of overuse) are difficult to estimate and are not known with precision but in the case of rice in the mid-1990s were estimated to be in the range of 2.0-7.4 thousand million USD per year for whole China (Norse et al. 2001). The fast development of vegetable production has added considerably to the overuse of fertilizer and pesticide. The total area planted with vegetables in China increased from 3.3 million ha in 1980 to about 28 million ha in 2008. An investigation in the late 1990s of 18 provinces (city) showed that in all of them except Inner Mongolia, the average synthetic N fertilizer application rate commonly exceeded 200 kg N ha-1 , with the highest rate of 740 kg ha-1 occurring in Shandong province (Fig. 6) (Ma et al. 2000). In addition, they commonly applied high rates of nitrogen as manure (Li et al. 2006). Excessive N inputs are often one of the main reasons for the high incidence of pests and diseases in vegetable production, and in turn, this commonly leads to farms using even more pesticide, resulting in high-pesticide residues on vegetables and in the environment. Insecticide application rate are often 2–3 times the recommended dosage (Ma et al. 2000; Li et al. 2006). The excessive and unbalanced inputs of inorganic fer￾tilizers can cause the damage to soil structure and soil quality. Although the ratio of N:P:K increased from 1:0.20:0.11 in 1991 to 1:0.28:0.21 in 2008, the proportion of potassium fertilizer commonly needs to be increased. Nitrogen ratios have been too high in most of regions in China since the 1970s, especially in eastern areas. Phos￾phorus ratios have changed from a deficit to small surplus (with a large surplus in some vegetable areas), but potas￾sium is generally still in deficit (Shen et al. 2005). Unbalanced nutrient ratios in mixed synthetic fertilizers can cause both biological and physicochemical damage to soils, leading to acidification, secondary salinization and reduction of microbial activity (Cao et al. 2004; Ge et al. 2009; Guo et al. 2010). This damage lowers crop yields and may lead to farmers applying even more fertilizers to try to compensate for the reduced soil productivity and thereby intensify NPS pollution and the cycle of environmental degradation. Fig. 5 Total pesticide (formulation) application rate in China from 1991 to 2008 AMBIO 2012, 41:370–379 375 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123

376 AMBI02012,41:370-379 Fig.6 Synthetic fertilizer 1400 application rates on vegetables in 18 provinces (municipalities) 1200 -0K in China 1000 800 600 400 200 olia n Shanxi Qinghai Guizhou Jiangxi Fujian Hebei w Hainan Gansu Shanghai Shangdong Inner Guangdong Province or municipality Inadequate Agricultural Extension Services manufactures in various ways but particularly through low- energy prices >RMB 6.3 thousand million every year since The ratio of agricultural extension investment as a per- 2003 (Chanda et al.2009)and tax rebates,to keep pro- centage of total agricultural GDP in China was only 0.49% duction costs and retail prices low so that farmers can in 1999.and 80%of the funds allocated to extension ser- afford to buy and use more fertilizers on their crops.While vices were used to pay staff salaries.Local government in the past such approaches helped to increase grain pro- reforms in the 1980s required local extension agencies to duction,it has also encouraged the overuse of N fertilizer allocate staff to other duties unrelated to extension,and to (Zhang et al.2006;Ju et al.2009)and serious environ- engage in commercial activities in order to generate reve- mental damage.Therefore,the Chinese government needs nue to maintain or supplement salaries and compensate for to remove such price distortion and place more emphasis the reduced public funding for extension.However, on providing farmers with better advice on plant nutrient because one of the main commercial activities of the management,and support to research and development on extension workers was(and may continue to be)the selling breeding higher yielding varieties and small scale equip- of pesticides and inorganic fertilizers,this hampered their ment for the precision placement of fertilizers.In addition. enthusiasm to give any technological or nutrient manage- more investment is needed to improve the basic production ment advice that would reduce the overuse of fertilizers infrastructure,such as high-efficiency irrigation. and pesticides.Surveys in many parts of China have highlighted the poor support that farmers receive from Provide Greater Incentives for Recycling Organic extension services.For example,an investigation in Hubei Manure and Fujian provinces in the 1990s showed that only 15%of families received the training in fertilizer management, The addition of straw to soil is a means to immobilize N as 34%of famers received instruction from technicians on organic N in microorganisms and their remains,which is a pesticide application and 84%of farmers applied the pes- favourable option in terms of soil carbon sequestration and ticide over the recommended dose (Huang et al.2001). nutrient returning (Lu et al.2009).Rural environmental protection strategies should require the development of comprehensive straw utilization plans that maximize the POLICY SUGGESTIONS AND MITIGATION return of straw and forbide the straw burning in the fields. MEASURES TO REDUCE NON-POINT SOURCE The recycling of organic manure needs to be promoted by POLLUTION FROM AGRICULTURE introducing new incentive measures such as investment for the development of better techniques to produce commer- Correct Distortion in Fertilizer Prices cial organic fertilizers with high-quality standards.At the same time,the state should consider expanding the subsidy One of the dominant strategies that China has used for programme for the enhancement of soil organic matter by many years to boost grain production is to keep chemical the application of rice straw decomposition agents and fertilizer price low.Subsidies are provided to fertilizer commercial organic fertilizers,and possibly expand the Royal Swedish Academy of Sciences 2012 ②Springer www.kva.se/en

Inadequate Agricultural Extension Services The ratio of agricultural extension investment as a per￾centage of total agricultural GDP in China was only 0.49% in 1999, and 80% of the funds allocated to extension ser￾vices were used to pay staff salaries. Local government reforms in the 1980s required local extension agencies to allocate staff to other duties unrelated to extension, and to engage in commercial activities in order to generate reve￾nue to maintain or supplement salaries and compensate for the reduced public funding for extension. However, because one of the main commercial activities of the extension workers was (and may continue to be) the selling of pesticides and inorganic fertilizers, this hampered their enthusiasm to give any technological or nutrient manage￾ment advice that would reduce the overuse of fertilizers and pesticides. Surveys in many parts of China have highlighted the poor support that farmers receive from extension services. For example, an investigation in Hubei and Fujian provinces in the 1990s showed that only 15% of families received the training in fertilizer management, 34% of famers received instruction from technicians on pesticide application and 84% of farmers applied the pes￾ticide over the recommended dose (Huang et al. 2001). POLICY SUGGESTIONS AND MITIGATION MEASURES TO REDUCE NON-POINT SOURCE POLLUTION FROM AGRICULTURE Correct Distortion in Fertilizer Prices One of the dominant strategies that China has used for many years to boost grain production is to keep chemical fertilizer price low. Subsidies are provided to fertilizer manufactures in various ways but particularly through low￾energy prices[RMB 6.3 thousand million every year since 2003 (Chanda et al. 2009) and tax rebates, to keep pro￾duction costs and retail prices low so that farmers can afford to buy and use more fertilizers on their crops. While in the past such approaches helped to increase grain pro￾duction, it has also encouraged the overuse of N fertilizer (Zhang et al. 2006; Ju et al. 2009) and serious environ￾mental damage. Therefore, the Chinese government needs to remove such price distortion and place more emphasis on providing farmers with better advice on plant nutrient management, and support to research and development on breeding higher yielding varieties and small scale equip￾ment for the precision placement of fertilizers. In addition, more investment is needed to improve the basic production infrastructure, such as high-efficiency irrigation. Provide Greater Incentives for Recycling Organic Manure The addition of straw to soil is a means to immobilize N as organic N in microorganisms and their remains, which is a favourable option in terms of soil carbon sequestration and nutrient returning (Lu et al. 2009). Rural environmental protection strategies should require the development of comprehensive straw utilization plans that maximize the return of straw and forbide the straw burning in the fields. The recycling of organic manure needs to be promoted by introducing new incentive measures such as investment for the development of better techniques to produce commer￾cial organic fertilizers with high-quality standards. At the same time, the state should consider expanding the subsidy programme for the enhancement of soil organic matter by the application of rice straw decomposition agents and commercial organic fertilizers, and possibly expand the Fig. 6 Synthetic fertilizer application rates on vegetables in 18 provinces (municipalities) in China 376 AMBIO 2012, 41:370–379 123 Royal Swedish Academy of Sciences 2012 www.kva.se/en

AMBI02012,41:370-379 377 scope of programme and increase the scale of subsidies revenue or income.This created a major incentive for them where this is the most cost-effective way of mitigating to emphasize the expansion of sales of fertilizers and GHGs and other forms of NPS pollution.Furthermore, pesticides rather than advising farmers on appropriate there needs to be clear labelling requirements for green and application rates.The recent reforms efforts have focused organic foods so that consumers can understand and accept on how to separate these two functions.Furthermore,new the need for price premiums for such products.? extension service models have been examined to find more effective ways of meeting farmers'needs for sound infor- Giving Farmers Access to Better Knowledge mation on the control of NPS pollution.It is important to on the Sound Application of Agro-Chemicals emphasize that no matter which communication model is Through Promotion of Farmers Associations used the guidance they provide must include measures to promote the sound management of agro-chemicals,manure Lack of awareness by farmers and the general public of the and crop residues in ways that are both economically viable negative consequences of overuse of fertilizer and pesti- and environmental sustainable.These measures will cides is a major challenge to appropriate use of these include the promotion and adoption of high-efficiency essential agricultural inputs.This includes the widespread fertilizer technology. lack of knowledge of the correct applications rates.Fur- thermore,the rural household contract responsibility sys- Improving the Implementation of National tem allows farmers to decide which crops they will grow Standards and Legislations on Organic Waste depending on market demand themselves (as opposed to Discharges and Pesticide Use the earlier State system of set crop production targets).This has led to more diversified needs for fertilizer and pesti- Tighter controls should be imposed on the discharge of cides and posed challenges to the extension services.The organic waste from livestock and poultry farms.Legally latter are being reformed to meet these challenges but in enforceable environmental protection regulations for live- addition farmers need to better organized through the for- stock production should be established based on the con- mation of farmer technical associations that promote sideration of the potential to increase waste treatment and information exchange.In recent years,laws and regulations utilization of livestock's excrements,the livestock carrying have been introduced to promote farmers associations and capacity of the land,the waste storage and disposal help farmers to have better access to technical assistance requirements,and the need for ecological buffer zones. and market information. Especially in the provinces and regions that are most at high-risk from NPS.the protected area should be estab- Other Measures to Provide Better Agricultural lished to control random discharges of manure." Extension Services The registration and application of pesticides needs to be managed more rigorously,together with measures to Reforms to the agricultural extension system in the last eliminate highly toxic and stable pesticides,and to develop decade have helped to correct conflict of interest issues in new pesticides which are environmentally safe.The central the roles of some public extension services workers.Earlier strategy for pesticide use should be based on the precau- reforms in 1980s created a situation in which extension tionary principle and on integrated control systems,which workers were not only responsible for teaching farmers requires (a)the establishment of a plant disease and insect how to adopt agricultural new technologies,including pest forecasting system,(b)the adoption of integrated pest appropriate use of agricultural chemicals,but they also had techniques that use biological agents and biological pesti- the tasks of selling these chemicals in order to generate cides together with knowledge of population dynamics, (c)expansion of basic research on pest control and applied 6The Ministry of Agriculture implemented the subsidy programme research on methods of application.Finally,farmers need to enhance soil organic matter in 287 counties of 21 provinces (municipalities)in 2009,covering an area of 1.03 million ha.The state give 300 CNY (Chinese Yuan)ha-(1 USD is equal to about 6.4 CNY)subsidy to the farmers for application of 30 kg ha-rice straw decomposition agent in the South region and for application of 1500 kg ha commercial organic fertilizer in the northern region. 7 In China,there was 23.27 million ha of farmland certified to s Taihu Lake Water Pollution Prevention Regulations of Jiangsu produce innoxious food(green food)with the rational use of synthetic Province was implemented in 2008.The most closely protected areas fertilizers and organic manure in 2006,accounting for 19.1%of the include the body of Taihu Lake;a 5-km wide band of land around the total arable land(121.7 million ha).There was only 3.3 million ha of lake;and I km of land bordering the river for 10 km upstream of the farmland certified to produce organic food without synthetic fertil- lake.In this area,the construction of new centralized livestock and izers and pesticides. poultry farms is prohibited. Royal Swedish Academy of Sciences 2012 www.kva.se/en ②Springer

scope of programme and increase the scale of subsidies6 where this is the most cost-effective way of mitigating GHGs and other forms of NPS pollution. Furthermore, there needs to be clear labelling requirements for green and organic foods so that consumers can understand and accept the need for price premiums for such products.7 Giving Farmers Access to Better Knowledge on the Sound Application of Agro-Chemicals Through Promotion of Farmers Associations Lack of awareness by farmers and the general public of the negative consequences of overuse of fertilizer and pesti￾cides is a major challenge to appropriate use of these essential agricultural inputs. This includes the widespread lack of knowledge of the correct applications rates. Fur￾thermore, the rural household contract responsibility sys￾tem allows farmers to decide which crops they will grow depending on market demand themselves (as opposed to the earlier State system of set crop production targets). This has led to more diversified needs for fertilizer and pesti￾cides and posed challenges to the extension services. The latter are being reformed to meet these challenges but in addition farmers need to better organized through the for￾mation of farmer technical associations that promote information exchange. In recent years, laws and regulations have been introduced to promote farmers associations and help farmers to have better access to technical assistance and market information. Other Measures to Provide Better Agricultural Extension Services Reforms to the agricultural extension system in the last decade have helped to correct conflict of interest issues in the roles of some public extension services workers. Earlier reforms in 1980s created a situation in which extension workers were not only responsible for teaching farmers how to adopt agricultural new technologies, including appropriate use of agricultural chemicals, but they also had the tasks of selling these chemicals in order to generate revenue or income. This created a major incentive for them to emphasize the expansion of sales of fertilizers and pesticides rather than advising farmers on appropriate application rates. The recent reforms efforts have focused on how to separate these two functions. Furthermore, new extension service models have been examined to find more effective ways of meeting farmers’ needs for sound infor￾mation on the control of NPS pollution. It is important to emphasize that no matter which communication model is used the guidance they provide must include measures to promote the sound management of agro-chemicals, manure and crop residues in ways that are both economically viable and environmental sustainable. These measures will include the promotion and adoption of high-efficiency fertilizer technology. Improving the Implementation of National Standards and Legislations on Organic Waste Discharges and Pesticide Use Tighter controls should be imposed on the discharge of organic waste from livestock and poultry farms. Legally enforceable environmental protection regulations for live￾stock production should be established based on the con￾sideration of the potential to increase waste treatment and utilization of livestock’s excrements, the livestock carrying capacity of the land, the waste storage and disposal requirements, and the need for ecological buffer zones. Especially in the provinces and regions that are most at high-risk from NPS, the protected area should be estab￾lished to control random discharges of manure.8 The registration and application of pesticides needs to be managed more rigorously, together with measures to eliminate highly toxic and stable pesticides, and to develop new pesticides which are environmentally safe. The central strategy for pesticide use should be based on the precau￾tionary principle and on integrated control systems, which requires (a) the establishment of a plant disease and insect pest forecasting system, (b) the adoption of integrated pest techniques that use biological agents and biological pesti￾cides together with knowledge of population dynamics, (c) expansion of basic research on pest control and applied 6 research on methods of application. Finally, farmers need The Ministry of Agriculture implemented the subsidy programme to enhance soil organic matter in 287 counties of 21 provinces (municipalities) in 2009, covering an area of 1.03 million ha. The state give 300 CNY (Chinese Yuan) ha-1 (1 USD is equal to about 6.4 CNY) subsidy to the farmers for application of 30 kg ha-1 rice straw decomposition agent in the South region and for application of 1500 kg ha-1 commercial organic fertilizer in the northern region. 7 In China, there was 23.27 million ha of farmland certified to produce innoxious food (green food) with the rational use of synthetic fertilizers and organic manure in 2006, accounting for 19.1% of the total arable land (121.7 million ha). There was only 3.3 million ha of farmland certified to produce organic food without synthetic fertil￾izers and pesticides. 8 Taihu Lake Water Pollution Prevention Regulations of Jiangsu Province was implemented in 2008. The most closely protected areas include the body of Taihu Lake; a 5-km wide band of land around the lake; and 1 km of land bordering the river for 10 km upstream of the lake. In this area, the construction of new centralized livestock and poultry farms is prohibited. AMBIO 2012, 41:370–379 377 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123

378 AMBI02012,41:370-379 more training and supervision on the safe use of Huang,J.K.,F.B.Qiao.L.X.Zhang,and S.Rozelle.2001.Farm pesticides.9 Pesticides,rice production,and human health.EEPSEA Research Report.ISSN 1608-5434.No.2001-RR3. Ju,X.T.,G.X.Xing,X.P.Chen,S.L.Zhang,L.J.Zhang,X.J.Liu,Z.L. Acknowledgment Financial support was provided by the National Natural Science Foundation of China (40871123).the Chinese Cui,B.Yin,et al.2009.Reducing environmental risk by Academy of Sciences (KZCX2-YW-407.KSCX2-YW-N-038).the improving N management in intensive Chinese agricultural Beijing and Vancouver Secretariats of the China Council for Inter- systems.Proceedings of the National Academy of Sciences of the national Cooperation on Environment and Development (CCICED) United States of America 106(9):3041-3046. Li,J.,H.D.Zhang.J.H.Gon,Y.He,and D.Norse.2006. and the Canadian International Development Agency (CIDA). 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more training and supervision on the safe use of pesticides.9 Acknowledgment Financial support was provided by the National Natural Science Foundation of China (40871123), the Chinese Academy of Sciences (KZCX2-YW-407, KSCX2-YW-N-038), the Beijing and Vancouver Secretariats of the China Council for Inter￾national Cooperation on Environment and Development (CCICED) and the Canadian International Development Agency (CIDA). REFERENCES Cai, Q.Y., C.H. Mo, Q.R. Wu, A. Katsoyiannisc, and Q.Y. Zeng. 2008. The status of soil contamination by semi-volatile organic chemicals (SVOCs) in China: A review. The Science of the Total Environment 389: 209–224. Cao, Z.H., J.F. Huang, C.S. Zhang, and A.F. Li. 2004. Soil quality evolution after land use change from paddy soil to vegetable land. Environmental Geochemistry and Health 26: 97–103. Chanda, B., R. Katie, and L. Bao. 2009. China-Peoples Republic of Fertilizer. GAIN (Global Agricultural Information Network) Report Number: CH9082. Conway, G. 1994. 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AMBI02012,41:370-379 379 Thesis.Beijing:Chinese Agriculture Academy of Sciences (in Linxiu Zhang is a research professor at Center for Chinese Agri- Chinese). cultural Policy.Institute of Geographical Sciences and Natural Xing.G.X.,and Z.L.Zhu.2002.Regional nitrogen budgets for China Resources Research.Her research is mainly concerned with the policy and its major watersheds.Biogeochemistry 57:405-427. for sustainable agricultural development. Yang,L.Z.,and B.Sun.2008.Cycling,balance and management of Address:Center for Chinese Agricultural Policy,Institute of Geo- nutrients in agroecosystems in China.Beijing:Science Press of graphical Sciences and Natural Resources Research,Chinese Acad- China (in Chinese). emy of Sciences,Beijing 100101,People's Republic of China. Yu,T.,W.Meng,O.Edwin,Z.Li,and J.Chen.2010.Long-term e-mail:lxzhang.ccap@igsnmr.ac.cn variations and causal factors in nitrogen and phosphorus transport in the Yellow River,China.Estuarine,Coastal and Linzhang Yang is a research professor at State Key Laboratory of Shelf Science 86:345-351. Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Yuan,X.Y.2000.Primary appraisal of pollution for lakes of China. Academy of Sciences.His research is mainly focused on agriculture Volcanology and Mineral Resources 21:128-136.(in Chinese). ecological management and water quality restoration. Zhang,F.S.1999.Some consideration to the improvement of nutrient Address:State Key Laboratory of Soil and Sustainable Agriculture, resources utilization efficiency.In:Soil science towards 21st Institute of Soil Science,Chinese Academy of Sciences,No.71 East century.Proceedings of 9th National Congress of Soil Science Beijing Road,Nanjing 210008,People's Republic of China. Society of China.Nanjing.China:Soil Science Society of China e-mail:Izyang@issas.ac.cn (in Chinese). Zhang L.X.,J.K.Huang,F.B.Qiao,and S.Rozelle.2006.Economic Fusuo Zhang is a professor at College of Resources and Environ- evaluation and analysis of fertilizer overuse by China's farmers. mental Sciences,China Agricultural University.His research is In:Policy for reducing Non-point pollution from crop production mainly concerned with plant nutrition and soil resource management in China,ed.Z.L.Zhu,D.Norse,and B.Sun,233-258.Beijing: Address:College of Resources and Environmental Sciences,China China Environmental Science Press. Agricultural University,Beijing 100094,People's Republic of China. Zhang,W.,Z.Tian,N.Zhang,and Z.Li.1996.Nitrate pollution of e-mail:zhangfs@cau.edu.cn groundwater in Northern China.Agriculture,Ecosystems Environment 59:223-231. David Norse is a professor at Department of Geography,University Zhang,Z.H.,and L.R.Li.2004.Groundwater resources of China. College London.His research interests include policy making for Beijing:SinoMaps Press. sustainable agriculture and environment protection. Zhu,Z.L.,and D.L.Chen.2002.Nitrogen fertilizer use in China- Address:Department of Geography,University College London,4 Contributions to food production,impacts on the environment Taviton Street,London WCIH OBT,UK. strategies.Nutrient Cycling Agroecosystems 63:117-127. e-mail:jarvisnors@aol.com Zhu,Z.L..Q.X.Wen,and J.R.Freney.1997.Nitrogen in soils of China.Dordrecht:Kluwer. Zhaoliang Zhu (is a research professor at State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese AUTHOR BIOGRAPHIES Academy of Sciences.His research is mainly focused on nitrogen cycling in agroecosystem and its management. Bo Sun is a research professor at State Key Laboratory of Soil and Address:State Key Laboratory of Soil and Sustainable Agriculture, Sustainable Agriculture,Institute of Soil Science,Chinese Academy Institute of Soil Science,Chinese Academy of Sciences,No.71 East of Sciences.His research interests include the management of nutrient Beijing Road,Nanjing 210008,People's Republic of China. cycling in agroecosystem and soil quality conservation. e-mail:zlzhu@issas.ac.cn Address:State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science,Chinese Academy of Sciences,No.71 East Beijing Road,Nanjing 210008,People's Republic of China. e-mail:bsun@issas.ac.cn Royal Swedish Academy of Sciences 2012 www.kva.se/en Springer

Thesis. Beijing: Chinese Agriculture Academy of Sciences (in Chinese). Xing, G.X., and Z.L. Zhu. 2002. Regional nitrogen budgets for China and its major watersheds. Biogeochemistry 57: 405–427. Yang, L.Z., and B. Sun. 2008. Cycling, balance and management of nutrients in agroecosystems in China. Beijing: Science Press of China (in Chinese). Yu, T., W. Meng, O. Edwin, Z. Li, and J. Chen. 2010. Long-term variations and causal factors in nitrogen and phosphorus transport in the Yellow River, China. Estuarine, Coastal and Shelf Science 86: 345–351. Yuan, X.Y. 2000. Primary appraisal of pollution for lakes of China. Volcanology and Mineral Resources 21: 128–136. (in Chinese). Zhang, F.S. 1999. Some consideration to the improvement of nutrient resources utilization efficiency. In: Soil science towards 21st century. Proceedings of 9th National Congress of Soil Science Society of China. Nanjing, China: Soil Science Society of China (in Chinese). Zhang L.X., J.K. Huang, F.B. Qiao, and S. Rozelle. 2006. Economic evaluation and analysis of fertilizer overuse by China’s farmers. In: Policy for reducing Non-point pollution from crop production in China, ed. Z.L. Zhu, D. Norse, and B. Sun, 233–258. Beijing: China Environmental Science Press. Zhang, W., Z. Tian, N. Zhang, and Z. Li. 1996. Nitrate pollution of groundwater in Northern China. Agriculture, Ecosystems & Environment 59: 223–231. Zhang, Z.H., and L.R. Li. 2004. Groundwater resources of China. Beijing: SinoMaps Press. Zhu, Z.L., and D.L. Chen. 2002. Nitrogen fertilizer use in China— Contributions to food production, impacts on the environment strategies. Nutrient Cycling Agroecosystems 63: 117–127. Zhu, Z.L., Q.X. Wen, and J.R. Freney. 1997. Nitrogen in soils of China. Dordrecht: Kluwer. AUTHOR BIOGRAPHIES Bo Sun is a research professor at State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences. His research interests include the management of nutrient cycling in agroecosystem and soil quality conservation. Address: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008, People’s Republic of China. e-mail: bsun@issas.ac.cn Linxiu Zhang is a research professor at Center for Chinese Agri￾cultural Policy, Institute of Geographical Sciences and Natural Resources Research. Her research is mainly concerned with the policy for sustainable agricultural development. Address: Center for Chinese Agricultural Policy, Institute of Geo￾graphical Sciences and Natural Resources Research, Chinese Acad￾emy of Sciences, Beijing 100101, People’s Republic of China. e-mail: lxzhang.ccap@igsnrr.ac.cn Linzhang Yang is a research professor at State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences. His research is mainly focused on agriculture ecological management and water quality restoration. Address: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008, People’s Republic of China. e-mail: lzyang@issas.ac.cn Fusuo Zhang is a professor at College of Resources and Environ￾mental Sciences, China Agricultural University. His research is mainly concerned with plant nutrition and soil resource management. Address: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094, People’s Republic of China. e-mail: zhangfs@cau.edu.cn David Norse is a professor at Department of Geography, University College London. His research interests include policy making for sustainable agriculture and environment protection. Address: Department of Geography, University College London, 4 Taviton Street, London WC1H 0BT, UK. e-mail: jarvisnors@aol.com Zhaoliang Zhu (&) is a research professor at State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences. His research is mainly focused on nitrogen cycling in agroecosystem and its management. Address: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008, People’s Republic of China. e-mail: zlzhu@issas.ac.cn AMBIO 2012, 41:370–379 379 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123