The Roles of Countrywomen in Controlling Non-point Source Pollution

The main causes of non-point source pollution in Taihu Lake are the improper ways of crop production, animal husbandry, and daily runoff. The paper discusses the relationship between countrywomen and non-point source pollution control by 731 questionnaires in Weidu village and 466 questionnaires in Dapu Town. The roles of countrywomen have changed in families and they have close relationship with non-point source pollution. Furthermore, we discuss the possibility and methods of organizing countrywomen in non-point source pollution control.

Modeling the effects of constructed wetland on nonpoint source pollution control and reservoir water quality improvement

This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The experimental field-scale wetland systems （four sets, 0.88 ha each） have been in operation since 2002, where water depth was maintained at 30-50 cm and hydraulic loading rate was at 6.3-18.8 cm/day. The wetland system was found to be adequate for treating polluted stream water with stable removal efficiency even during the winter. The integrated modeling system （modified-BASINS） was applied to the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The calibrated integrated modeling system estimated that constructing wetlands on 0.5% （about 114 ha） of the watershed area at the mouth of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%-1.0% of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir at the polder area where land use planning is relatively less complicated.

CROP-LIVESTOCK INTEGRATION FOR SUSTAINABLEAGRICULTURE IN CHINA:THE HISTORY OF STATE POLICY GOALS,REFORM OPPORTUNITIES AND INSTITUTIONAL CONSTRAINTS

This paper examines the historical evolution of crop-livestock integration in China with a specific focus on its role in mitigating non-point source pollution.Extensive examination of existing literature has unearthed the roots of croplivestock integration dating back to the Western Zhou Dynasty(1046 to 771BCE), ultimately culminating in a multifaceted and intricately interwoven system of rural development policies seen in contemporary China. This paper identifies and characterizes four distinct stages in the historical trajectory of crop-livestock integration: the era of self-sufficient subsistence production in traditional times(1046 BCE to 1948);the period where crop-livestock integration emerged as a pivotal strategy for augmenting grain and meat production under collectivist policies(1949-1977);the phase marked by the industrialization and expansion of the livestock sector during the early years of economic reforms(1978-2011);and the present era in which crop-livestock integration is harnessed as a mechanism for pollution control and ecological preservation in contemporary China(2012 to present). This paper illuminates the diverse contributions of crop-livestock integration in different epochs of rural development within China, which contributes to a nuanced and more theoretically grounded comprehension of circular agriculture. This understanding has the potential to be leveraged to promote sustainable rural development in broader contexts.

Field test of best management practice pollutant removal efficiencies in Shenzhen,China

This paper presents a study on the use of best management practices(BMPs)for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen,China.A BMP treatment train design,including a pond,a wetland,and a buffer strip placed in series was implemented at the reservoir location.A separate grass swale was also constructed at the site.Low impact development(LID)BMPs,namely a planter box and bioboxes,were used at the parking lot of the reservoir’s Administration Building.Samples were collected during storm events and were analyzed for total suspended solids(TSS),biochemical oxygen demand(BOD5),ammonia nitrogen(NH3-N),and total phosphorus(TP).The removal efficiencies of both BMP systems were evaluated using the Efficiency Ratio(ER)method based on the event mean concentration(EMC)data.In summary,the pond/wetland treatment train removed 70%–90%of TSS,20%–50%of BOD5,and 30%–70%of TP and NH3-N.The swale removed 50%–90%of TSS,30%–55%of BOD5,–10%–35%of NH3-N,and 25%–70%of TP.For the planter box and biobox,the ranges of removal rates were 70%–90%,20%–50%,and 30%–70%for TSS,BOD5,and ammonia and phosphorus,respectively.