You are here:
LEACHING EVALUATION OF AGRICULTURAL CHEMICALS (LEACH) HANDBOOK
Citation:
Dean, J., P. Jowise, A. Donigian, AND Jr. LEACHING EVALUATION OF AGRICULTURAL CHEMICALS (LEACH) HANDBOOK. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-84/068.
Description:
A methodology has been developed to assess potential pesticide leaching from the crop root zones in major (corn, soybean, wheat and cotton) crop growing areas of the United States. Use of the Leaching Evaluation of Agricultural Chemicals (LEACH) methodology provides an indication of the presence or absence of leaching past the rooting depth and, if such leaching is indicated, its severity. LEACH was developed through the use of long term simulation (i.e., 25 years) of annual pesticide leaching time series using the Pesticide Root Zone Model. The user must evaluate key parameters for a pesticide-site-crop-management scenario to locate pesticide leaching cumulative frequency distributions. Each scenario has a unique distribution associated with it. The distribution functions indicate the chance that the annual quantity of pesticide leached past the crop rooting depth will exceed a given value. The distributions can be used as an integral part of a framework for decisions concerning the use of the pesticide.