2035 © 2021 The Authors Water Supply | 21.5 | 2021 Resource-based agricultural non-point source pollution control using biological agents Delong Kan and Pengfei Duan ABSTRACT Non-point source (NPS) pollution is a major cause of the deterioration of surface water quality. Delong Kan Pengfei Duan (corresponding author) Effectively controlling NPS pollution, especially that from rural areas, is critical in improving the Henan Key Laboratory of Ecological Security for Water Source Region of Mid-line of South-to- quality and safety of water resources. However, most of the approaches employed for NPS control North Diversion Project, Collaborative Innovation are low-efficiency or impractical owing to ignorance of the willingness of participants, as well as the Center of Water Security for Water Source Region of Mid-line of South-to-North Diversion high cost. To improve the effectiveness and efficiency, this study newly proposes a resource-based Project of Henan Province, Nanyang Normal University, approach for agricultural NPS pollution control via using biological agents. In this approach, the Nanyang, 473061, China domestic organic waste and livestock manure are economically utilized to produce organic fertilizers E-mail: [email protected] and plant protection agents to replace harmful chemical fertilizers and pesticides, respectively. The approach has been applied in the Danjiangkou catchment area in Nanyang City, and the results show that: (1) the most severe pollutants, total P and total N concentrations have been effectively reduced and their values in 2025 are predicted to be the same level as that before significant deterioration; (2) with unpowered sewage treatment and spontaneous participation of farmers, the treatment cost is significantly reduced; (3) the resource-based treatment of domestic waste and livestock manure supports the development of an efficient and sustainable agricultural economy. Key words | agriculture, biological agent, non-point source pollution, resource-based, South-North Water transfer project HIGHLIGHTS • The resource-based approach is cost-saving and efficient for agricultural NPS pollution control. • The domestic sewage is treated with micro-power or no power. • The domestic organic waste and livestock manure are economically utilized. • A spontaneous collaboration arises between villagers, enterprises, and governments. INTRODUCTION Non-point source (NPS) pollution deteriorates the surface gradually increased, and NPS pollution is becoming the pri- water quality of rivers and lakes. In contrast with point mary source of surface and groundwater pollution (Ongley source pollution, which can be easily monitored and con- et al. ; Wu et al. ). According to previous research, trolled, NPS pollution remains underestimated and poorly 30–50% of the Earth’s total surface area is under the influ- controlled (Wu et al. ). The contribution of NPS ence of NPS pollution (Xin et al. ); furthermore, pollution to the overall environmental pollution has agricultural NPS pollution, which is harmful to the aquatic environment, is considered the most prevalent form of This is an Open Access article distributed under the terms of the Creative NPS pollution (Fan et al. ; Yi et al. ). In the Clean Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited Water Act of the United States of America (USA), legislated (http://creativecommons.org/licenses/by/4.0/). in 1972, NPS pollution is defined as ‘any source of water doi: 10.2166/ws.2020.291 Downloaded from http://iwaponline.com/ws/article-pdf/21/5/2035/920290/ws021052035.pdf by guest on 28 September 2021 2036 D. Kan & P. Duan | Resource-based agricultural NPS pollution control Water Supply | 21.5 | 2021 pollution that does not meet the legal definition of ‘point In China, research on NPS pollution started in the 1980s. source’ in section 502(14) of the Clean Water Act’ (United Thereafter, studies on urban NPS pollution were conducted in States ). Agricultural NPS pollution, which is mainly Beijing, Shanghai, Hangzhou, Suzhou, Changsha, Nanjing, caused by fertilizers, pesticides, sewage sludge, and livestock and Chengdu, among other cities (Li et al. ). Simul- manure, includes nutrients such as N and P, as well as those taneously, research on rural NPS pollution was successively in pesticides, and other organic or inorganic pollutants (Li conducted in the Yuqiao Reservoir, Dianchi Lake, Taihu et al. ; Li et al. ). Agricultural NPS pollution is an Lake, Chaohu Lake, Jinjiang River Basin, and Dongjiang important cause of water quality deterioration in surface River Basin (Chen et al. ; Cai et al. ; Xue et al. ). waters (Liu et al. ). Owing to the prevalence, extensive dis- Since the 1990s, macro characteristics and statistical models persion, and uncertain transport paths of NPS pollutants, the (black-box or empirical models) of pesticide and fertilizer pol- mechanism of agricultural NPS pollution is not well-known; lution have played an important role in agricultural NPS however, it does involve a long latent period, which is signifi- pollution research (Stephenson et al. ). Currently, the com- cantly harmful (Zeng ). Agricultural NPS pollution is bination of the NPS pollution model with 3S (GIS, GPS, and considered as a world–wide environmental issue (Yang et al. RS) technology (Emili & Greene ; Yaghi & Salim ) ), and it hinders the sustainable rural development in and the water quality models of watersheds have become China (Liu et al. ). Therefore, the development of an effec- new research hotspots in water quality management (Zhang tive approach for controlling NPS pollution is crucial. et al. ). However, research on NPS pollution in China is Research on NPS pollution was first conducted in the still limited, mainly concentrated on the assessment of NPS 1960s in several developed countries, such as the USA, pollution loads, simulation of pollutant transport, and data Britain, and Japan, and global research interest expanded management with GIS. The deficiencies regarding public from the 1970s. In the 1980s, research on agricultural policy and administration with low participation of house- NPS pollution underwent a period of vigorous development. holds are the most challenging (Wu & Ge ; Zhang et al. By the 1990s, new pollutants had become the focus of ). There is still much work to fill the gap between research research (Tong et al. ; Adu & Kumarasamy ). And and its applications in this field. then numerical researches on NPS were presented, includ- Owing to the unique context of NPS pollution in China, ing the pollution source identification, modeling and the theories and experience from developed countries estimation, control and management and so on (Xiang cannot be simply transplanted (Ongley et al. ). Agricultural et al. ; Yang et al. ). By using ArcHydro (ArcGIS NPS pollution control should utilize various sustainable pre- extension model) and a long-term hydrological and NPS vention, treatment, and control technologies, and be pollution model, Wilson & Weng () evaluated the informed by the natural conditions and pollution character- impact of urban land-use change on lake water quality in istics of the concerned catchment (Yang et al. ; Wu & Calumet, Chicago. Burow et al. () analyzed 5101 Ge ; Yi et al. ; Zhou et al. ). However, owing to samples collected via the National Water Quality Assess- the high-cost and low reward for farmers in China, the agricul- ment program of the US Geological Survey in 51 research tural NPS control is low-efficiently pushed forward only by the areas from 1991 to 2003, and found that the nitrate concen- government. Besides, the agricultural harvest heavily relying tration was highest in shallow groundwater in the on fertilizers and pesticides (Wu & Ge )alsohindersthe agricultural subsoil. Currently, numerical NPS pollution NPS pollution control. Therefore, this study proposes a practi- models are available, and detailed reviews can be found cal approach for agricultural NPS pollution control using the in studies conducted by Yang et al. () and Adu & biological agents for waste utilization. In this resource-based Kumarasamy (). Among these models, the Soil and approach, the domestic sewage disposal is conducted with Water Assessment Tool (SWAT), agricultural non-point micro-power or without power, and the domestic organic source pollution model AnnAGNPS, and areal non-point waste, sewage sludge, and livestock manure are economically source watershed environment response simulation utilized to produce biological agents to replace the harmful (ANSWER) have been commonly applied (Liu et al. ). chemical fertilizers and pesticides that contribute significantly Downloaded from http://iwaponline.com/ws/article-pdf/21/5/2035/920290/ws021052035.pdf by guest on 28 September 2021 2037 D. Kan & P. Duan | Resource-based agricultural NPS pollution control Water Supply | 21.5 | 2021 to NPS pollution. Therefore, the best contribution of this addition to pollutants from farmland. Livestock manure, research is advancing the NPS pollution control towards which is released into rivers, also contributes to NPS pol- beingmorelow-cost,efficient and environment-friendly: (1) lution. The NPS pollutants converge into lakes or the treatment of domestic waste and livestock manure is reservoirs through different pathways, such as streamflow, turned into the production of biological agents; (2) the pro- overland flow, and groundwater flow. NPS pollution is a duced biological agents reduce