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United States Department of Agriculture

Agricultural Research Service

Title: Rzwqm - An ARS Model for Simulating Effects of Management on Water Quality and Crop Production

Authors
item Ahuja, Lajpat
item DeCoursey, Donn
item Farahani, Hamid
item Hanson, Jonathan
item Johnsen, Karen - COLORADO STATE UNIVERSITY
item Rojas, Kenneth
item Shaffer, Marvin

Submitted to: Agricultural Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 3, 1997
Publication Date: N/A

Interpretive Summary: The complexity of the processes in the natural environment suggests the use of computer models to help interpret, quantify, and extend experimental results. This is a quick and efficient way of evaluating the effects of alternate management practices on soil and water conservation, crop production and water quality. Models thus aid in transfer of technology to ofields outside the experimental location with a minimum of further work. In this report, we introduce the USDA-ARS Root Zone Water Quality Model (RZWQM) which was designed by a team of ARS scientists to allow study of management practices (including a wide range of tillage; irrigation, fertilizer, manures, and pesticide applications; tile drainage, and crop rotations) and their impacts on production and surface and groundwater quality. RZWQM is capable of long-term (20+ years) simulation of crop growth (i.e., corn, soybean, wheat, and potato) and movement of water, nutrients, and pesticides over and through the crop root zone of an agricultural field. During the past few years, the simulation model has undergone an extensive testing period and thus soon will be released to the general public.

Technical Abstract: The most efficient way to research and devise new agricultural management systems is through an interactive use of selective experimentation and modeling. In this report, we introduce the USDA-ARS Root Zone Water Quality Model (RZWQM). Specifically, we discuss general and distinguishing features of RZWQM along with input data requirements and present summary results from recent model evaluations and typical output. RZWQM is an integrated physical, biological, and chemical process model that simulates plant growth and movement of water, nutrients, and pesticides over and through the root zone for a representative unit area of an agricultural field. Multi-year simulations are also made possible to infer long-term impacts of management practices. The model allows for a wide spectrum of management practices, including tillage; irrigation, fertilizer, manures, and pesticide applications; tile drainage, and crop rotations. During the past few years, the simulation model has undergone an extensive testing period and has reached a crossroads in its development. The version with all the capabilities listed herein has been frozen and will soon be released.

Last Modified: 7/28/2014