Farm Income and Ground Water Quality Implications from Reducing Surface Water Sediment DELWERIES1

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Agriculture, Ecosystems & Environment, 2008

Nonpoint sources of pollution, primarily from agricultural sources, are a major cause of water quality impairment. Yet policies to address this issue remain underexplored in the literature. This article first reviews the agricultural nonpoint source (NPS) pollution policy literature and categorizes its major findings. The North American literature, in particular, rarely analyses NPS policies already in force, and pays even less attention to overcoming implementation barriers to reaching desired environmental outcomes. Second, this paper evaluates a newly adopted policy approach that addresses nonpoint sources of nutrient contaminants in the surface waters of one of the United States' most agriculturally productive and environmentally pristine areas, California's Central Coast. The article then reveals the political, budgetary and technical barriers faced by farmers, regulators, and other stakeholders. The article concludes by arguing that more analyses of implemented policies designed to address agricultural NPS pollution will better inform both local-level and federal policymakers towards the successful creation and implementation of policies that achieve environmental outcomes.

Agricultural Water Management, 2013

Since intensive farming practices are essential to produce enough food for the increasing population, farmers have been using more inorganic fertilizers, pesticides, and herbicides. Agricultural lands are currently one of the major sources of non-point source pollution. However, by changing farming practices in terms of tillage and crop rotation, the levels of contamination can be reduced and the quality of soil and water resources can be improved. Thus, there is a need to investigate the amalgamated hydrologic effects when various tillage and crop rotation practices are operated in tandem. In this study, the Soil Water Assessment Tool (SWAT) was utilized to evaluate the individual and combined impacts of various farming practices on flow, sediment, ammonia, and total phosphorus loads in the Little Miami River basin. The model was calibrated and validated using the 1990-1994 and 1980-1984 data sets, respectively. The simulated results revealed that the SWAT model provided a good simulation performance. For those tested farming scenarios, no-tillage (NT) offered more environmental benefits than moldboard plowing (MP). Flow, sediment, ammonia, and total phosphorus under NT were lower than those under MP. In terms of crop rotation, continuous soybean and corn-soybean rotation were able to reduce sediment, ammonia, and total phosphorus loads. When the combined effects of tillage and crop rotation were examined, it was found that NT with continuous soybean or corn-soybean rotation could greatly restrain the loss of sediments and nutrients to receiving waters. Since corn-soybean rotation provides higher economic revenue, a combination of NT and corn-soybean rotation can be a viable system for successful farming.

American Journal of Agricultural Economics, 2003

An integrated watershed management framework that combines economic, hydrologic and GIS modeling is developed to study cost effective land retirement in multiple watersheds to achieve off-site sediment reduction goal. This integrated framework examines two alternative standards -a uniform standard under which each watershed is required to achieve the same sediment reduction goal and a non-uniform standard under which marginal cost of sediment abatement is equal across watersheds. Furthermore, for each standard, costs of abatement under two alternative rental instruments based on marginal cost of sediment abatement ($/ton) and uniform payments per acre ($/acre) are examined. Then the cost effectiveness of the four policy options (uniform standard with $/ton and $/acre instrument, non-uniform standard with $/ton and $/acre instrument) is discussed. The integrated framework is applied to 12 agricultural watersheds in Illinois Conservation Reserve Enhancement program (CREP) region. The watersheds varied in size between 29,995 and 70,849 acres. Cropland within 900 feet of streams -129,955 acres (33.4% of all cropland in the 12 watersheds) -is considered eligible for enrollment into the CREP. Consistent with Illinois' program, a sediment reduction goal of 20% is selected for all of the simulations. Policy implications from the empirical results are quite interesting. With either a $/ton or a $/acre instrument, the non-uniform standard, which equalizes marginal cost of abatement across watersheds, outperforms the uniform standard policy. With either a uniform or non-uniform standard, a $/ton instrument outperforms a $/acre instrument. The least preferred policy option, the uniform standard with a $/acre instrument, is 2.5 times as costly as the most preferred policy option, the non-uniform standard with a $/ton instrument. These results suggest that program administrators may want to consider a program that includes a non-uniform standard and a rental payment instrument based on marginal cost of abatement in order to achieve their objectives at least cost.

1995

This study examines the trade-off between agricultural production and groundwater contamination potential for ten potential herbicide cancellations. Theoretical and empirical models are developed for estimating losses in consumer and producer benefits in the agricultural commodity market and changes in groundwater quality. Using com and soybean production in the southeastern Coastal Plain as a study area, the analysis concludes that (1) effects of herbicide cancellations on groundwater quality can be very significant; (2) a cancellation does not guarantee groundwater quality improvement; (3) effects of a multiple cancellation are different from the summation of the effects of independent cancellations; and (4) weed density has a very strong effect on losses to farmers and consumers from cancellations, but output demand and supply elasticities do not.