An economic analysis of low-input agriculture as a groundwater protection strategy

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Virginia Tech


The unique characteristics of agricultural contamination of groundwater requires an innovative solution, such as the voluntary use of low-input agriculture (LIA) practices. This study was conducted to identify potential barriers to LIA adoption, analyze the effectiveness of agriculture and natural resource policies designed to remove the barriers to LIA adoption, and to determine the effectiveness of LIA practices in reducing the amount of chemicals released into the environment.

A survey of Richmond County, Virginia farming operations and attitudes identified current practices, potential LIA practices for the Northern Neck region of Virginia, and perceived barriers to LIA adoption. A 15 year nonlinear mathematical programming model was used to determine optimal farming practices, among 34 low-input and conventional practices, under various agronomic and policy scenarios. Two non-point simulation models, CREAMS and GLEAMS, were used to estimate the nitrogen and chemical loadings of runoff, groundwater, and sediment; and the soil erosion from each of these scenarios.

The model shows that yields, labor requirements, and variable costs, individually have a weak influence on the adoption of low-chemical and organic production activities. The price of the organic nitrogen source, poultry litter, was strongly related to the use of LIA practices. The most cost effective policy for reducing Aatrex (atrazine) contributions to groundwater was a one-third reduction in surface application of Aatrex. However, there were many tradeoffs between chemical, nitrogen, and soil contributions to runoff, percolation, and sediment. The only policies which reduced all of these factors were land retirement policies. The tax level required to promote the use of a LIA practice was too high to be politically feasible, and the use of green-manure crops would require a 100 percent annual subsidy of those crops. A proposed base flexibility program caused more intensive use of conventional chemicals because of the limited number of eligible crops.

Low-input agriculture has promised reductions in chemical contamination of groundwater and runoff. This study’s results showed that although that is indeed the case, there are tradeoffs between reduced chemical contamination and nitrogen and soil losses which should be considered when examining the cost effectiveness of using LIA practices as a groundwater protection strategy.