Agricultural Non-point Source Pollution Control Research Articles

Confronting our Agricultural Nonpoint Source Control Policy Problem

AbstractFederal and state agricultural and environmental agencies have spent enormous sums since the 1990s to reduce nonpoint source (NPS) water pollution from agriculture. Yet, water quality problems are pervasive, and agriculture is a major cause. The lack of progress is often attributed to insufficient funding for pollution control practices relative to the scale of the problem. However, we attribute the lack of progress to shortcomings in agricultural NPS pollution control policy. We illustrate our argument after considering nearly four decades of federal, state, and local efforts to reduce agricultural NPS pollution to the Chesapeake Bay. Additional funding for current programs, absent fundamental program reform, is unlikely to produce reductions from agriculture needed to achieve desired water quality outcomes.

Heterogeneous public preferences for controlling agricultural non-point source pollution based on a choice experiment

The public's stated value and heterogeneous preferences are crucial for formulating policies and financing approaches to promote the control of agricultural non-point-source pollution (ANSP). This study aims to investigate urban residents' willingness to pay (WTP) for ANSP control and analyse the source of preference heterogeneity using a choice experiment method. Survey data were obtained from face-to-face interviews with 595 respondents in south Shaanxi Province, China. We found that respondents' average WTP for the attributes of ANSP control schemes were 2.34 yuan ($0.36) and 5.42 yuan ($0.83) per year per household for a 1% reduction in fertiliser and pesticide use, respectively. We also found significant impacts of WTP from individuals' socio-economic characteristics (i.e., gender, age, education, and income) and cognitive factors (i.e., policy understanding, and government trust). Thus, to improve the efficiency and universality of ANSP control policy, the public's willingness and preference heterogeneity should be thoroughly taken into policy formulation.

An Integrated Framework for Agricultural Non-Point Source Pollution Control Technology Evaluation: Application of an Improved Multiple Attribute Decision Making Method

An Integrated Framework for Agricultural Non-Point Source Pollution Control Technology Evaluation: Application of an Improved Multiple Attribute Decision Making Method

Development and Assessment of a New Framework for Agricultural Nonpoint Source Pollution Control

The transport of agricultural nonpoint source (NPS) pollutants in water pathways is affected by various factors such as precipitation, terrain, soil erosion, surface and subsurface flows, soil texture, land management, and vegetation coverage. In this study, based on the transmission mechanism of NPS pollutants, we constructed a five-factor model for predicting the path-through rate of NPS pollutants. The five indices of the hydrological processes, namely the precipitation index (α), terrain index (β), runoff index (TI), subsurface runoff index (LI), and buffer strip retention index (RI), are integrated with the pollution source data, including the rural living, livestock and farmland data, obtained from the national pollution source census. The proposed model was applied to the headwater of the Miyun Reservoir watershed for identifying the areas with high path-through rates of agricultural NPS pollutants. The results demonstrated the following. (1) The simulation accuracy of the model is acceptable in mesoscale watersheds. The total nitrogen (TN) and total phosphorus (TP) agriculture loads were determined as 705.11 t and 3.16 t in 2014, with the relative errors of the simulations being 19.62% and 24.45%, respectively. (2) From the spatial distribution of the agricultural NPS, the TN and TP resource loads were mainly distributed among the upstream of Dage and downstream of Taishitun, as well as the towns of Bakshiying and Gaoling. The major source of TN was found to be farmland, accounting for 47.6%, followed by livestock, accounting for 37.4%. However, the path-through rates of TP were different from those of TN; rural living was the main TP source (65%). (3) The path-through rates of agricultural NPS were the highest for the towns of Wudaoying, Dage, Tuchengzi, Anchungoumen, and Huodoushan, where the path-through rate of TN ranged from 0.17 to 0.26. As for TP, it was highest in Wudaoying, Kulongshan, Dage, and Tuchengzi, with values ranging from 0.012 to 0.019. (4) A comprehensive analysis of the distribution of the NPS pollution load and the path-through rate revealed the towns of Dage, Wudaoying, and Tuchengzi as the critical source areas of agricultural NPS pollutants. Therefore, these towns should be seriously considered for effective watershed management. In addition, compared with field monitoring, the export coefficient model, and the physical-based model, the proposed five-factor model, which is based on the path-through rate and the mechanism of agricultural NPS pollutant transfer, cannot only obtain the spatial distribution characteristics of the path-through rate on a field scale but also be applicable to large-scale watersheds for estimating the path-through rates of NPS pollutants.

Incentive Measures for Agricultural Nonpoint Source Pollution Control of Farmers Based on Choice Modelling: A Case Study on the Water Source Region of Xin’an River Reservoir

In water governance, the government, downstream residents, and upstream farmers are closely associated stakeholders. The participation willingness of upstream farmers directly bears on the success of environmental policies. Xin’an River Reservoir Water Protection Zone is the second water source region of Hangzhou, China. Taking this region, for example, this paper surveys the willingness to accept compensation of local rice farmers, mainly using Choice Modelling (CM) methodology. This paper assesses the farmers’ willingness of minimum compensation amount to adopt various ecological compensation means and, on this basis, discusses the key factors determining their willingness to accept compensation. It helps to confirm that the farmer participation mainly depends on whether the government could provide satisfactory compensation incentives to cover farmers’ losses. Hence, at the ending of the paper, we call for the relevant departments of the government fully understanding the farmers’ willingness to accept compensation before formulating compensation policies, so that the compensation at least reaches the minimum requirements of farmers. Only in this way could the water source region achieve the optimal efficiency in environmental governance.

Can Increasing Scale Efficiency Curb Agricultural Nonpoint Source Pollution?

The Chinese government has made great efforts to improve the scale efficiency of land through various measures during recent years, hoping to realize the coordinated developing goal of promoting agricultural benefits and protecting the environment. Statistics show that China’s land scale efficiency has steadily increased, but agricultural nonpoint source (NPS) pollution has also increased, which seems contrary to the expected outcome. Can increasing scale efficiency really curb agricultural NPS pollution? This study uses provincial-level data from China, together with a panel model and spatial econometric model, to investigate the relationship between scale efficiency and agricultural NPS pollution. It is found that the increase of scale efficiency aggravates the agricultural NPS pollution, and the conclusion still holds after considering spatial effect. The results of spatial analysis shows that the agricultural NPS pollution is spatially dependent. Further decomposition of the spatial effect shows that the scale efficiency not only intensifies the local agricultural NPS pollution, but also has a spillover effect (though not statistically significant) on agricultural NPS pollution in the surrounding areas. It is worth noting that financial policy, raising wage income and upgrading industrial structure can effectively curb agricultural NPS pollution in this region and adjacent areas, which also deserves our attention in the control of agricultural NPS pollution. In addition, it is necessary to make financial and fiscal support policies specifically for the governance of agricultural NPS pollution, adjust the distorted prices of input factors such as chemicals and pesticide, and accelerate the transformation of small-sized farmers to family farms, in order to maximize the inhibitory effect of scale efficiency on relieving agricultural NPS pollution.

Impact of soil thickness on productivity and nitrate leaching from sloping cropland in the upper Yangtze River Basin

Shallow soils are widely distributed in mountainous and hilly areas due to severe soil erosion. However, the impacts of soil thickness on soil productivity, water and nutrient retention in shallow cropland soils have not been well documented. This study was conducted to investigate how soil thickness affects soil productivity and nitrate leaching from sloping croplands in the upper Yangtze River Basin, China. Free-drained lysimeters on sloping cropland with soil thicknesses of 20 (ST1), 40 (ST2), 60 (ST3), 80 (ST4) and 100 (ST5) cm were used to monitor soil moisture, surface runoff and nitrate leaching. The results showed that total crop yields during an entire winter wheat-summer maize rotation year (October 2017-September 2018) for ST1 to ST5 were 2.38 ± 0.07, 3.22 ± 0.01, 6.43 ± 0.61, 8.21 ± 0.56 and 8.58 ± 0.29 Mg ha−1, respectively. The annual cumulative total nitrogen (N) loss loadings via surface runoff and leaching for ST1 to ST5 were 21.09 ± 1.54, 13.08 ± 0.79, 5.61 ± 0.36, 3.49 ± 0.27 and 1.96 ± 0.22 kg N ha−1, respectively. The annual cumulative nitrate leaching loadings for ST1 to ST5 were 18.41 ± 1.07, 11.27 ± 0.56, 4.93 ± 0.45, 3.05 ± 0.32 and 1.66 ± 0.12 kg N ha−1, respectively, which accounted for more than 84 % of the cumulative total N loss through hydrological processes. This finding indicates that leaching dominates the hydrological N loss in sloping cropland. Moreover, significant differences were observed in yield-scaled nitrate leaching losses among ST1 (7.74 ± 0.62), ST2 (3.49 ± 0.18) and ST3 (0.78 ± 0.13 kg N Mg−1) (P < 0.05), while no significant differences were found among ST3 (0.78±0.13), ST4 (0.37±0.02) and ST5 (0.19±0.01 kg N Mg−1). This finding implies that if the soil thickness is greater than 60 cm, then it may be possible to maintain crop yields and mitigate nitrate leaching losses on sloping croplands. Therefore, a soil thickness of 60 cm is recommended as a threshold soil layer for basic water and nutrient retention as well as land reclamation and restoration of degraded cropland suffering from severe soil erosion. Soil thickness is a critical index for evaluating soil functions for water and nutrient retention, crop productivity improvement and agricultural non-point source pollution control.

江苏农业面源污染治理的法律规制研究

江苏农业面源污染治理的法律规制研究

Farmers’ Willingness as Well as Its Compensation Strategy to Prevent and Control Agricultural Non-Point Source Pollution in Water Source Areas-Based on a Comparative Analysis of Pesticide and Fertilizer Inputs

This paper took the voluntary pesticide and fertilizer reduction ratios of the farmers as the substitute variables for farmers' willingness to prevent and control the agricultural non-point source pollution. Then, the paper adopted an improved double-bounded dichotomous choice (DBDC) to obtain farmers’ voluntary pesticide and fertilizer reduction ratios and the corresponding compensation attitudes of the farmers. The research found that, in contrast to fertilizers, pesticides are a stronger output-related factor for farmers, and any reduction in pesticides would cause great output fluctuations. After the influencing factors of the farmers’ compensation attitude towards pesticide and fertilizer reduction were subject to ordinal regression analysis, the main influencing factors of farmers’ compensation attitude towards fertilizer and pesticide reduction were obtained respectively, which had further proved that for farmers, compared with pesticides, the risk of fertilizer reduction is lower, and their attitudes are quite different, but as long as the compensation is sufficient, they are willing to take more stringent measures.

Resource-based agricultural non-point source pollution control using biological agents

Abstract Non-point source (NPS) pollution is a major cause of the deterioration of surface water quality. Effectively controlling NPS pollution, especially that from rural areas, is critical in improving the quality and safety of water resources. However, most of the approaches employed for NPS control are low-efficiency or impractical owing to ignorance of the willingness of participants, as well as the high cost. To improve the effectiveness and efficiency, this study newly proposes a resource-based approach for agricultural NPS pollution control via using biological agents. In this approach, the domestic organic waste and livestock manure are economically utilized to produce organic fertilizers 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.

Estimation of potential agricultural non-point source pollution for Baiyangdian Basin, China, under different environment protection policies.

To prevent and control non-point source pollution, many policies have been carried out by government in China. However, the effectiveness of these policies has rarely been evaluated. In this study, the potential and spatial distribution of agricultural non-point source pollution in the Baiyangdian Basin are reported. This investigation considers multiple parameters under various policies with county as a basic unit. The results for the potential pollution from chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen (TN) and total phosphorus (TP) are 60.89×104, 3.93×104, 87.05×104 and 15.10×104 Mg, with corresponding intensities of 190, 12, 272 and 47 kg ha-1 for the Baiyangdian Basin in 2016. The highest pollution from COD is attributed to livestock and poultry breeding, whereas TN and TP are dominantly produced by rural domestic sources, and NH3-N is mostly derived from planting. Spatially, distribution of the counties producing larger non-point source pollution presented a northeast to southwest direction, consistent with the Taihang mountain alignment in the basin. The counties with high pollution intensities are mostly in the south and east of the basin. Agricultural non-point source pollution control and prevention policies contributed in pollution reduction. Compared with 2016, the total potential pollution of COD, NH3-N, TN and TP in 2020 decrease by 45.1%, 14.7%, 37.9% and 37.4%, respectively, whereas for an assumed future time (F2), the decreases are 59%, 51.4%, 56.2% and 55.7%, respectively. Prevention measures should focus on reducing pollution from livestock and poultry breeding as well as planting.

Application of systematic strategy for agricultural non-point source pollution control in Yangtze River basin, China

Non-point pollution is becoming one of the main causes of the degradation of rural environment in China. A systematic strategy encompassing source reduction, process retention, nutrient reuse, and water restoration for controlling agricultural non-point source pollution was applied to a 1.5 km2 intensive rice-wheat rotation area at Yaoqiao county, Zhenjiang city, Jiangsu Province, in the downstream reach of the Yangtze River, China, from 2016 to 2018. The results showed that the use of organic and controlled-release fertilizers reduced the total nitrogen (TN) and total phosphorus (TP) input for rice and wheat by 20 % and 27 %, respectively, without any yield loss. The N and P concentration in the ecological ditches declined by 8%–50.4% for TN and 12%–69.7% for TP in comparison with that in the control ditches, and then further declined after the purification of eco-ponds. The removal efficiency was positive related with the N and P centration of inflow. TN concentration in the drainage water finally flow into the Shangshe River was lower than 2 mg/L during three out of 19 times. The river water quality was distinctly improved, wherein the TN, NH4+-N, TP, and chemical oxygen demand (CODCr) concentrations were lower by 28.9 %, 30.4 %, 21.9 %, and 35.5 %, respectively following implementation of ecological water restoration technologies. The water quality improvement was mainly attributed to reduced pollutant load from agricultural fields and the aquatic plant uptake. This study found that the systematic “4R” approach is a promising method for decreasing the N and P loads from agricultural fields and improving the downstream water eutrophication problem, and can be extended to other agricultural intensive regions.

Identification and prevention of agricultural non-point source pollution risk based on the minimum cumulative resistance model

Agricultural non-point source pollution (AGNPS) risk prevention and control is more conducive to reducing costs than post-treatment. Therefore, how to effectively identify risks is a key problem to be solved. The study area is located in the NANTUO small watershed of the Three Gorges Reservoir Area in China, on the side of the Yangtze River, where agriculture is developed with many kinds of plantings. There is a water level fluctuation zone (WLFZ) with seasonal elevation difference up to 30 m due to the water level regulation of the Three Gorges reservoir, which is a hot area of AGNPS research. On the basis of daily water level observation in NANTUO small watershed, based on the theory of “source” and “sink”, this study explored the land use change in different seasons with the help of high-resolution remote sensing image (According to the change of water level, it can be divided into two periods: non-submergence period (low water level period from the beginning of June to the end of September) and submergence period (high water level period at other time)). With the help of “source” identification (Types of land use that produce pollutants) and resistance surface calculation index system (Minimum cumulative resistance model, MCR model), the risk level and risk transmission path (The easiest path for pollutants to move to water) of AGNPS in WLFZ were analyzed. Combined with the idea of ecological corridor construction and pollution control, the risk change of regional AGNPS under the optimization of land use mode (The cultivated land types within 50 m and 100 m (Landscape optimization zone) around the water area are adjusted to forest land respectively in two scenarios (Q1 and Q2)) was analyzed as well. Based on our results, 1) the difference in the water areas between the non-submergence and submergence periods was 3.79 km2, and the areas of grassland, farmland, and forest land in the non-submergence period increased by 0.62, 0.85, and 0.35 km2, respectively. The “source” land in this region was mainly sloping farmland with slope above 6°. 2) The calculation results of the minimum cumulative resistance base surface for each source land showed the characteristics of “high values in the west and dispersedly distributed, low values in the east and continuously distributed”. 3) The distribution of the resistance surface during the non-submergence and submergence periods was basically the same; the high-risk zones were widely distributed throughout the region, while the low-risk zones were mainly distributed in the eastern mountains. 4) The number of risk transmission paths followed the order of a4 (farmland with slopes between 6° and 15°) > a5 (farmland with slopes between 2° and 6°) > a1 (rural settlements) > a3 (farmland with slopes between 15° and 25°) > a6 (farmland with slopes ≤ 2°) > a2 (farmland with slopes above 25°), and about 90% of the risk transmission paths were distributed in the lower levels (i.e., level 1, level 2, level 3). The proportion of risk transmission paths in the lower levels during the submergence period was higher than that during the non-submergence period. 5) The proportions of high risk, relatively high risk, medium risk, low risk, and no risk in the study area varied respectively following the rules of 72.79%→70.07%→66.56%, 16.85%→18.16%→18.3%, 6.24%→7.21%→9.3%, 2.25%→2.36%→3.32%, and 1.87%→2.2%→2.52% under the intact status of non-submergence period (Q0), Q1 scenario, and Q2 scenario. 6)The maximum values of pollution transmission path resistance of “source” land under the intact status of non-submergence period (Q0), Q1 scenario, and Q2 scenario followed the order of Q0 < Q1 < Q2. The results showed that the seasonal regulation of water level by artificial water conservancy project has a negative impact on AGNPS, and the MCR model was effective in the study of AGNPS risk and transmission path identification in small area. The results indicated that the wider the landscape optimization belt was, the stronger the barrier effects on pollutants would be and the more difficult it was for the pollutants to reach the water. The increase in the width of the landscape optimization belt could significantly reduce the proportion of low-level transmission paths, which indicated that the construction of ecological corridor had a good positive effect on the water environment protection.

Application performance and nutrient stoichiometric variation of ecological ditch systems in treating non-point source pollutants from paddy fields

Nutrient emissions from paddy fields are one of the main sources of agricultural non-point source (NPS) pollution. Based on the “4R” (Reduce-Retain-Reuse-Restore) strategical system of agricultural NPS pollution control, ecological ditches are effective control measures under the “Retain” system. In this study, the nutrient removal efficiency and stoichiometric variations in three different ecological ditch systems were studied in order to better understand the long-term performance of ecological ditches, and to determine which type of ecological ditch system (Eh, concrete ecological ditch with holes on the wall; Ec, concrete ecological ditch; and Es, soil ecological ditch) is optimal for the removal of agricultural NPS pollutants. The results indicated that the converted ecological ditch (Eh type) significantly reduced nutrient levels in two-year rice season runoff compared to a traditional concrete ditch. The average removal efficiencies of total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in the converted ecological ditch were 20.8 %, 37.0 %, and 44.4 %, respectively. All ecological ditch types had considerable capacity to remove nutrients in simulated rice season runoff. There were no significant differences in the efficiency of nutrient removal between Eh (TOC 24.1 %, TN 42.8 %, and TP 52.6 %) and Es (TOC 20.3 %, TN 35.7 %, and TP 47.9 %). However, the results indicated that Eh systems could provide a relatively stable environment for plants with increased capacity to maintain biological homeostasis. Of the three ditch types, Ec (TOC 12.9 %, TN 23.3 %, and TP 32.6 %) had a relatively low removal efficiency. Redundancy analysis (RDA) indicated that leaf P content, sediment C:N ratio and root N content were more closely related to water variables, and nutrient stoichiometric characteristics of water, plants, and sediment systems were significantly related to the nutrient removal capacity of ecological ditches (99.5 % of the total variation). It is anticipated that this study will promote further development of the “4R” strategical system, and encourage additional improvements to ecological ditches so they can become more effective in reducing agricultural NPS pollution in the field.

Effect of plant hedgerows on agricultural non-point source pollution: a meta-analysis.

Eutrophication has been a critical environmental issue due to soil nitrogen (N) and phosphorus (P) loss in runoff from agricultural lands. Plant hedgerow is an important measure to prevent soil erosion and reduce agricultural non-point source pollution (NPSP). In the present study, we searched 3683 research papers on plant hedgerows published from 1980 to March 2020. After screening, we used 53 effective papers on plant hedgerows for the meta-analysis by using Stata 15.1. The results showed that plant hedgerows significantly increased soil organic matter (SOM) (standardized mean difference (SMD) = 1.46; 95% confidence interval (CI) = 1.12-1.80 > 0), total N (TN) (SMD = 1.33; 95% CI 0.98-1.68 > 0), total P (SMD= 0.73; 95% CI 0.26-1.20 > 0), alkali N (SMD = 0.86; 95% CI 0.52-1.21 > 0), available P (SMD = 1.28; 95% CI 0.75-1.81 > 0) and readily available potassium (K) (SMD = 1.20; 95% CI 0.75-1.65 > 0) concentrations but exhibited no significant effects on soil total K concentration (SMD = 0.17; 95% CI - 0.13-0.47 < 0). Plant hedgerows showed a greater effect on SOM increase than soil N, P, and K, and soil TN increase than the available state, but the opposite trend was observed for P and K. This meta-analysis can clarify the influence of plant hedgerows on soil nutrients and provide ideas for the prevention and control of agricultural NPSP.

Research on Scientific Strategy and Technology of Agricultural Non-point Source Pollution Control

In order to explore expansion of agricultural non-point source pollution in China is mainly related to excessive use of chemical fertilizers and pesticides, backward fertilization methods, low utilization of organic waste in the aquaculture industry, insufficient promotion of advanced agricultural technologies, and relatively weak public environmental awareness. This article focuses on the research directions of agricultural and rural pollution control and environmental protection, efficient recycling of fertilizer resources, and environmental control of production areas, and carries out related technical and environmental engineering constructions. In this paper, in the process of fully grasping the growth of crops, we will increase the technical research on environmental engineering This article studies the use of effective environmental regulation engineering technology to develop the agricultural.

An Evolutionary Game Model for the Multi-agent Co-Governance of Agricultural Non-Point Source Pollution Control under Intensive Management Pattern in China.

This paper focuses on the sustainable development dilemma of agricultural production in China under the pattern of intensive management, which is seriously challenged by agricultural non-point source pollution. The key to effectively break through the dilemma is to promote the co-governance of agricultural non-point source pollution control by stakeholders including local governments, new agricultural operators and traditional farmers. Accordingly, this paper discusses the interactive decision-making relationships between new agricultural operators and traditional farmers under the guidance of local governments, by constructing a trilateral evolutionary game model, as well as analyzing evolutionary cooperative stability strategies and realizing the simulation of evolution processes in different scenarios by MATLAB. The results show that new agricultural operators play a leading role in agricultural non-point source pollution control, whose strategies have effects such as technology spillover. The rewards from the superior government will support local governments in taking proactive action in the co-governance of agricultural non-point source pollution control, and then local governments can offer technical support and subsidies to new agricultural operators and traditional farmers for reducing their costs. Furthermore, this paper also finds that there are green synergy effects among the groups, where the variations of parameters and strategies by one group would affect the two others. Additionally, agricultural land operation rights transfers would cause traditional farmers to take more time to cooperate in the co-governance of agricultural non-point source pollution control. In order to promote the multi-agent co-governance of agricultural non-point source pollution control under intensive management pattern, this paper suggests that it should be necessary to reduce their costs and improve incentives, as well as to increase the common interests among groups and enhance their green synergy effects.

'Get a Fish' vs. 'Get a Fishing Skill': Farmers' Preferred Compensation Methods to Control Agricultural Nonpoint Source Pollution.

Ecological compensation is an important means for controlling agricultural nonpoint source pollution, and compensation methods comprise an essential part of the compensation policy for mitigating this form of pollution. Farmers’ choice of compensation methods affects their response to compensation policies as well as the effects of pollution control and ecological compensation efficiency. This study divides ecological compensation methods into two distinct philosophies—the “get a fish” method (GFM) and “get a fishing skill” method (GFSM)—based on policy objectives, to determine farmers’ choice between the two methods and the factors influencing this choice. Furthermore, by analyzing survey data of 632 farmers in the Ankang and Hanzhong cities in China and using the multivariate probit model, the study determines farmers’ preferred option among four specific compensation modes of GFM and GFSM. The three main results are as follows. (1) The probability of farmers choosing GFM is 82%, while that of choosing GFSM is 51%. Therefore, GFM should receive more attention in compensation policies relating to agricultural nonpoint source pollution control. (2) Of the four compensation modes, the study finds a substitution effect between farmers’ choice of capital and technology compensations, capital and project compensations, material and project compensations, while there is a complementary relationship between the choice of material and technology compensations. Therefore, when constructing the compensation policy basket, attention should be given to achieving an organic combination of different compensation methods. (3) Highly educated, young, and male farmers with lower part-time employment, large cultivated land, and a high level of eco-friendly technology adoption and policy understanding are more likely to choose GFSM. Hence, the government should prioritize promoting GFSM for farmers with these characteristics, thereby creating a demonstration effect to encourage transition from GFM to GFSM.

Construction of an integrated technology system for control agricultural non-point source pollution in the Three Gorges Reservoir Areas

Agricultural non-point source pollution (NPSP) is becoming a severe threat and seriously restricting the sustainable development of agricultural economy and rural environment in the Three Gorges Reservoir Areas (TGRA). However, limited studies have focused on agricultural NPSP management in TGRA, especially for integrated technology systems with TGRA characteristics. An integrated slopping land/paddy field/hydro-fluctuation belt eco-system (SPHES) was constructed using best management practices in this study. Evaluation results of the SPHES at the comprehensive test demonstration zone showed that ecological engineering interception technologies on slopping land can reduce 80–90 % of sediment, 20–30 % of nitrogen (N), and 25–35 % of phosphorus (P), respectively. The utility of interception and absorption technology under ridge cropping pattern in paddy fields can effectively control inorganic N in sewage and P in external sewage within one week. Biological sequestration technologies of N and P in hydro-fluctuation belt can intercept 30–50 % of total N, 65–95 % of total P, and 75–90 % of sediments. In summary, the comprehensive removal rate of pollutants in agricultural NPSP exceeded 89 % using this eco-system. The work presented here provides the construction of this integrated eco-system for agricultural NPSP controlling, thereby applying to all small watersheds in the TGRA to control and manage agricultural NPSP. This integrated technology system has broad prospects for promotion and application in similar ecological areas.

Agricultural nonpoint source pollution in urban agricultural areas: An assessment system and mitigation methods

With rapid urbanization, the negative external effects of urban agriculture have been gradually highlighted. A quantitative description of environmental loss is the precondition of environmental pollution control. Meanwhile, the scenario analysis settings based on model simulation and different control schemes have guiding significance for mitigating the current status of agricultural non-point source pollution (ANSP). In this study, we choose the Jinjiang River basin as the study area, and the denitrification decomposition (DNDC) model was used to simulate the nitrogen cycle in the paddy ecosystem and the revised universal soil loss equation (RUSLE) model was used with a nitrogen pollution load to construct the framework of risk assessment in agricultural nonpoint source pollution in ANSP. In addition, the best management practice (BMP) of agricultural nonpoint source pollution control was discussed. Our results are as follows: (1) The average annual soil erosion is 3161 t/km2, which equates to moderate erosion. The average value of the nitrogen pollution load is 0.33 t/hm2, and the total nitrogen loss load in the catchment is 1.66 × 105 t/a. High-level risks are distributed on both sides of the river system. (2) Based on the scenario simulation of continuous cropping using traditional management practices (TMPs), the average loss of nitrogen leaching in 2030 is 67.74% higher than in 2017. (3) A comprehensive BMP with regional differences is proposed. Under the premise of guaranteeing the amount of nitrogen absorbed by crops, this scheme can reduce the nitrogen loss by about 40.72% in 2030. The current status of ANSP cannot be underestimated. Reasonable and differentiated measures to improve agricultural management can effectively alleviate the risks of nitrogen leaching from farmland.