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Title: SIMULATING THE FATE OF WATER IN FIELD SOIL-CROP ENVIRONMENT FOR EVALUATING MANAGEMENT EFFECTS ON WATER QUALITY AND CROP PRODUCTION

Author
item CAMEIRA, M. - TECH UNIV OF LISBON PORT
item FERNANDO, R. - TECH UNIV OF LISBON
item Ahuja, Lajpat
item PEREIRA, L. - TECH UNIV OF LISBON

Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2005
Publication Date: 12/10/2005
Citation: Cameira, M.R., Fernando, R.M., Ahuja, L.R., Pereira, L. 2005. Simulating the fate of water in field soil-crop environment for evaluating management effects on water quality and crop production. Journal of Hydrology. 315: 1-24. December, 2005.

Interpretive Summary: This paper presents a systematic simulation procedure for assessing the fate of water and nitrogen in the soil-crop environment at the field scale. This procedure is based upon the evaluation of the hydrologic and crop development sub-models within the Root Zone Water Quality Model (RZWQM). Evaluation is performed at two distinct levels. At the first level the model capability to fit the measured data is analyzed (calibration). At the second level the model's capability to extrapolate and predict the system behavior for conditions different than those used when fitting the model (validation). In a subsequent paper the same type of evaluation is presented for the nitrogen transformation and transport model. The RZWQM model is a one-dimension dual porosity model. It integrates the physical, biological and chemical process occurring in the root zone, allowing the simulation of a wide spectrum of agricultural management practices. During the first level a change in the ETc formulation was introduced, based upon the definition of the effective leaf area. The calculation of the root extraction term in the Richards equation was emphasized since it determines in great extent the goodness of soil water simulations. After refinement, the evaluation process led to the determination of main important crop, soil, and nutrient parameters for the region allowing its further application.

Technical Abstract: This paper presents a systematic simulation procedure for assessing the fate of water and nitrogen in the soil-crop environment at the field scale. This procedure is based upon the evaluation of the hydrologic and crop development sub-models within the Root Zone Water Quality Model (RZWQM). Evaluation is performed at two distinct levels. At the first level the model capability to fit the measured data is analyzed (calibration). At the second level the model's capability to extrapolate and predict the system behavior for conditions different than those used when fitting the model (validation). In a subsequent paper the same type of evaluation is presented for the nitrogen transformation and transport model. The RZWQM model is a one-dimension dual porosity model. It integrates the physical, biological and chemical process occurring in the root zone, allowing the simulation of a wide spectrum of agricultural management practices. During the first level a change in the ETc formulation was introduced, based upon the definition of the effective leaf area. The calculation of the root extraction term in the Richards equation was emphasized since it determines in great extent the goodness of soil water simulations. After refinement, the evaluation process led to the determination of main important crop, soil, and nutrient parameters for the region allowing its further application.