Abstract
The objective of this study was to determine if a re-calibrated version of the computer model NCSWAP (version 36) could accurately predict corn growth and soil N dynamics in conventionally tilled (CT) and no-till (NT) corn supplied with legume green manure or ammonium nitrate as N sources. We also attempted to ascertain the reasons for limitations in the model's ability to simulate corn growth and soil N dynamics found by our colleagues in a previous study and to propose potential improvements. The model was calibrated to accurately simulate total available N (N in plant above-ground biomass plus soil nitrate in the 0 to 45 cm profile) for a control and a fertilizer CT treatment in the 1992 growing season. To do so, input values defining the quantities of active soil organic N had to be reduced to 19% of the values proposed by the model developers and a solute transport factor defining the mobile vs. immobile fractions of soil nitrate adjusted from 0.8 to 0.2. The discrepancies between the proposed values and the lower values employed in this study might be due to the uncertainties in quantitatively describing soil N mineralization processes and the way they are handled in the model, as well as the lack of a component simulating macroporous-influenced water flow and solute transport in the model. With the current version, until one knows how to predict what these values are, the model needs to be re-calibrated for each experimental site and condition and thus is of limited value as a general model.
With no further adjustment of input values, model validation success was mixed. The model accurately predicted total available N for treatments in the second year of the experiment that had the same N source and tillage as the treatments used for the calibration year but with the different weather and growing conditions. However, total available N was underpredicted where legume green manure was the N source and overpredicted with no-till cultivation. The model was accurate in simulating seasonal corn growth for nearly all the treatments, judged by nonsignificant mean difference (MD) values and highly significant correlation coefficients (r). Prediction of seasonal soil nitrate concentration was less accurate compared to total available N and corn growth variables. Potential improvements in the model's simulation of a no-till system as well as for predicting corn harvest yield and seasonal soil nitrate concentration where N deficiency occurs were discussed.
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References
Addiscott T M and Whitmore A P 1987 Computer simulation of changes in soil mineral nitrogen and crop nitrogen during autumn, winter and spring. J. Agric. Sci., Camb. 109, 141–157.
Bonde T A and Rosswall T 1987 Seasonal variation of potentially mineralizable nitrogen in four cropping systems. Soil Sci. Soc. Am. J. 51, 1508–1514.
Clay D E, Clapp C E, Molina J A E and Linden D R 1985a Nitrogentillage-residue management. I. Simulating soil and plant behavior by the model NCSWAP. Plant and Soil 84, 67–77.
Clay D E, Clapp C E, Molina J A E and Linden D R 1985b Nitrogentillage-residue management. II. Calibration of potential rate of nitrification, by model simulation. Soil Sci. Soc. Am. J. 49, 322–325.
Clay D E, Clapp C E, Linden D R and Molina J A E 1989 Nitrogentillage-residue management. 3. Observed and simulated interactions among soil depth, nitrogen mineralization and corn yield. Soil Sci. 147, 319–325.
Dendooven L, Verstraeten L and Vlassak K 1990 The N-mineralization potential: an undefinable parameter. In Fertilization and the Environment. Eds. Merckx et al. Leuven University Press, Louvain, Belgium.
DeWilligen P 1991 Nitrogen turnover in the soil-crop system; comparison of fourteen simulation models. In Nitrogen Turnover in the Soil-Crop System. Eds. Groot et al. pp 141–149. Kluwer Academic Publishers, Boston.
Dou Z and Fox R 1994 The contribution of nitrogen from legume cover crops double-cropped with winter wheat to tilled and non-tilled maize. Eur. J. Agron. 3, 93–100.
Dou Z, Fox R H and Toth J D 1994 Tillage effect on seasonal nitrogen availability in corn supplied with legume green manures. Plant and Soil 162, 203–210.
Hadas A, Molina J A E, Feigenbaum S and Clapp C E 1987 Simulation of nitrogen-15 immobilization by the model NCSOIL. Soil Sci. Soc. Am. J. 5, 102–106.
Hillel D 1980 Infiltration and surface runoff. In Applications of Soil Physics. pp 5–49. Academic Press, New York, USA.
Jabro J D 1988 Spatial variability of field-saturated hydraulic conductivity and simulation of water flow from a percolation test hole in layered soil. Ph.D. Thesis. Dept. of Agronomy, Penn State University. University Park, PA, USA.
Juma N G, Paul E A and Mary B 1984 Kinetic analysis of net nitrogen mineralization in soil. Soil Sci. Soc. Am. J. 48, 753–757.
Lengnick L L and Fox R H 1994a Simulation by NCSWAP of seasonal nitrogen dynamics in a corn crop: I. Soil nitrate. Agron. J. 86, 167–175.
Lengnick L L and Fox R H 1994b Simulation by NCSWAP of seasonal nitrogen dynamics in a corn crop: II. Corn growth and yield. Agron. J. 86, 176–182.
Linden D R 1979 A model to predict soil water storage as affected by tillage practice. PhD diss. Univ. of Minnesota, St. Paul, USA (Diss. Abstr. 80–11844).
Loague K and Green R E 1991 Statistical and graphical methods for evaluating solute transport models: Overview and application. J. Contam. Hydrol. 7, 51–73.
Marstorp H and Kirchmann H 1991 Carbon and nitrogen mineralization and crop uptake of nitrogen from six green manure legumes decomposing in soil. Acta Agric. Scand. 41, 243–252.
Molina J A E, Clapp C E and Larson W E 1980 Potentially mineralizable nitrogen in soil: The simple exponential model does not apply for the first 12 weeks of incubation. Soil Sci. Soc. Am. J. 44, 442–443.
Molina J A E, Clapp C E, Shaffer M J, Chichester F W and Larson W E 1983 NCSOIL, a model of nitrogen and carbon transformations in soil: Description, calibration, and behavior. Soil Sci. Soc. Am. J. 47, 85–91.
Molina J A E and Richards K 1984 Simulation model of the nitrogen and carbon cycles in the soil-water-plant system, NCSWAP; guide for the preparation of input data files and execution of NCSWAP. Soil Series 116. Dept. Soil Sci., Univ. of Minnesota, St. Paul, USA.
Sierra J 1990 Analysis of soil nitrogen mineralization as estimated by exponential models. Soil Biol. Biochem. 22, 1151–1153.
Stanford G and Smith S J 1972 Nitrogen mineralization potentials of soils. Soil Sci. Soc. Am. Proc. 36, 465–472.
Stevenson R E and Pennypacker S P 1991 and 1992 Meteorological summary for the agricultural research center at Rock Springs. Dept. of Plant Pathology, Pennsylvania State Univ., University Park, PA, USA.
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Dou, Z., Fox, R.H. Using NCSWAP to simulate seasonal nitrogen dynamics in soil and corn. Plant Soil 177, 235–247 (1995). https://doi.org/10.1007/BF00010130
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DOI: https://doi.org/10.1007/BF00010130