| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
a USDA-ARS, Nat. Resour. Res. Cent., 2150 Centre Ave., Bldg. D, Fort Collins, CO 80526
b Cent. Great Plains Res. Stn., USDA-ARS, Akron, CO 80720
* Corresponding author (Liwang.Ma{at}ars.usda.gov).
Received for publication December 18, 2002. Agricultural system models can provide an alternative, less time-consuming and inexpensive means of determining the optimum crop N requirement under varied soil and climatic conditions. In this context, we parameterized the Root Zone Water Quality Model (RZWQM) for winter wheat (Triticum aestivum L.) production and then evaluated it along with the CERES-Wheat model to assess their potential as N management tools at Akron, Co. Both models were evaluated with data from five N treatments (0, 28, 56, 84, and 112 kg N ha–1) and three crop seasons (1987–1988, 1988–1989, and 1989–1990). Data from 1987–1988 zero-N treatment were used for model calibration, and the rest of the data were used for model validation. Genetic coefficients for winter wheat (cv. TAM 107) were developed for the CERES-Wheat model. The crop parameters required for the generic crop model of RZWQM were parameterized using information from the literature or by calibration. Both models were calibrated first for soil moisture and then for biomass and grain yield. Grain yield predictions had a root mean square error (RMSE) of 500 and 363 kg ha–1, respectively, for CERES-Wheat and RZWQM. Aboveground biomass was predicted with RMSEs of 1247 and 1441 kg ha–1, respectively. Long-term simulations of both RZWQM and CERES for winter wheat growth using historical weather data (1912–2001) showed that 56 kg ha–1 N applied as broadcast incorporated is a viable N management option in eastern Colorado, taking into account the grain yield, crop N uptake, N leaching into groundwater, and residual soil N at harvest. Model simulations also showed that the wheat–fallow cropping system is less water use efficient than a continuous wheat system under rainfed agriculture in eastern Colorado.
Abbreviations: CW, continuous wheat • ET, evapotranspiration • NOF, normalized objective function • NUE, nitrogen use efficiency • RMSE, root mean square error • W-F, winter wheat–fallow • WUE, water use efficiency
This article has been cited by other articles:
|
|
 |
|
  C. Hu, S. A. Saseendran, T. R. Green, L. Ma, X. Li, and L. R. Ahuja Evaluating Nitrogen and Water Management in a Double-Cropping System Using RZWQM Vadose Zone J., March 8, 2006; 5(1): 493 - 505. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Ma, G. Hoogenboom, L. R. Ahuja, D. C. Nielsen, and J. C. Ascough II Development and Evaluation of the RZWQM-CROPGRO Hybrid Model for Soybean Production Agron. J., July 13, 2005; 97(4): 1172 - 1182. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. S. Anapalli, D. C. Nielsen, L. Ma, L. R. Ahuja, M. F. Vigil, and A. D. Halvorson Effectiveness of RZWQM for Simulating Alternative Great Plains Cropping Systems Agron. J., July 13, 2005; 97(4): 1183 - 1193. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. C. Nielsen and M. F. Vigil Legume Green Fallow Effect on Soil Water Content at Wheat Planting and Wheat Yield Agron. J., April 27, 2005; 97(3): 684 - 689. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Crop Science | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||
