Accuracy and Performance of Three Water Quality Models for Simulating Nitrate Nitrogen Losses under Corn

• Published in: Journal of environmental quality 2006-07, Vol.35 (4), p.1227-1236
• Main Authors: Jabro, J.D, Jabro, A.D, Fox, R.H
• Format: Article
• Language: English
• Subjects: Accuracy; Agricultural chemicals; Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; Biotechnology; Carbon cycle; Contamination; Corn; Drinking water; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Environmental impact; Environmental Monitoring; Environmentalists; equations; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; groundwater; groundwater contamination; Health hazards; hydrologic models; Industrial applications and implications. Economical aspects; Leaching; LEACHM model; Lysimeters; model validation; Models, Chemical; Moisture content; NCSWAP model; Nitrate content; nitrate nitrogen; nitrates; Nitrates - analysis; Nitrogen; Nitrogen - analysis; Nitrogen - chemistry; Pollution; Pollution, environment geology; prediction; Quality Control; Reproducibility of Results; Silt loam; silt loam soils; Simulation; simulation models; soil analysis; soil nutrient dynamics; Soil water; SOILN model; Statistical analysis; Studies; Time Factors; Water flow; Water Pollution, Chemical - analysis; Water quality; Water Supply - analysis; Zea mays; Zea mays - metabolism
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2005.0413

Simulation models can be used to predict N dynamics in a soil-water-plant system. The simulation accuracy and performance of three models: LEACHM (Leaching Estimation And CHemistry Model), NCSWAP (Nitrogen and Carbon cycling in Soil, Water And Plant), and SOILN to predict NO3-N leaching were evaluated and compared to field data from a 5-yr experiment conducted on a Hagerstown silt loam (fine, mixed, mesic Typic Hapludalf). Nitrate N losses past 1.2 m from N-fertilized and manured corn (Zea mays L.) were measured with zero-tension pan lysimeters for 5 yr. The models were calibrated using 1989-1990 data and validated using 1988-1989, 1990-1991, 1991-1992, and 1992-1993 NO3-N leaching data. Statistical analyses indicated that LEACHM, NCSWAP, and SOILN models were able to provide accurate simulations of annual NO3-N leaching losses below the 1.2-m depth for 8, 9, and 7 of 10 cases, respectively, in the validation years. The inaccuracy in the models' annual simulations for the control and manure treatments seems to be related to inadequate description of processes of N and C transformations in the models' code. The overall performance and accuracy of the SOILN model were worse than those of LEACHM and NCSWAP. The root mean square error (RMSE) and modeling efficiency (ME) were 10.7 and 0.9, 9.5 and 0.93, and 20.7 and 0.63 for LEACHM, NCSWAP, and SOILN, respectively. Overall, the three models have the potential to predict NO3-N losses below 1.2-m depth from fertilizer and manure nitrogen applied to corn without recalibration of models from year to year.