|Wauchope, Robert - Don
|AHUJA, LAJPAT - USDA-FT. COLLINS, CO
|QINGLI, MA - ETS, INC., WHEATON, MD
|MALONE, ROBERT - USDA-AMES, IOWA
|LIWANG, MA - USDA - FT. COLLINS, CO
Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2003
Publication Date: 3/20/2004
Citation: Wauchope, R.D., Rojas, K.W., Ahuja, L.R., Qingli, M., Malone, R.W., Liwang, M. 2004. Documenting the science of the pesticide processes module of the usda-ars rzwqm model. Pest Management Science. 60:222-239.
Interpretive Summary: A team of ARS scientists is developing the "Root Zone Water Quality Model," or RZWQM, as a next-generation tool which can be used to predict the water pollution potential of agricultural chemicals, including fertilizer nutrients such as nitrate and phosphate, and pesticides. The model is unique in that it attempts to completely describe all aspects of an agricultural production system-weather, soil properties, crop growth, soil and plant water relations, and nutrient and chemical transport and transformations in the soil. When complete and validated for specific "scenarios" it will have the capability of predicting the effect of changes in such a scenario on pollutution potential. This paper is the first journal publication describing how pesticide transport and degradation processes are simulated in RZWQM. It describes the design of the model and cites the scientific literature on which the model is based. Thus it is almost a review of the current state of knowledge of pesticide fate and transport in agricultural environments
Technical Abstract: We describe the history, design philosophy, theory and current developmental state of the pesticide process module of the USDA-Agricultural Research Service Root Zone Water Quality Model, or RZWQM. Selected references are given to document the understanding of pesticide fate and behavior in the environment reflected in the model. Several processes which are highly significant in determining the fate of a pesticide application are integrated in this module for the first time, including application technique, root uptake, ionic dissociation, soil depth dependence of persistence, volatilization, wicking upward in soil, and aging of residues. The pesticide module requires a large number of parameters to run (as does the RZWQM model as a whole) and it is becoming clear that RZWQM will find most interest and use as part of a "scenario" in which all data requirements are supplied and the predictions of the system compared with a real (usually partial) data set. Such a scenario may then be tweaked to examine the response of the system to changes in inputs. It also has significant potential as a technology transfer or teaching tool, providing detailed understanding of a specific agronomic system and its potential impacts on the environment.