HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Saseendran, S. A. Articles by Halvorson, A. D. Search for Related Content PubMed Articles by Saseendran, S. A. Articles by Halvorson, A. D. Agricola Articles by Saseendran, S. A. Articles by Halvorson, A. D. Related Collections Nitrogen Wheat Crop Models Nutrient Management

Modeling Nitrogen Management Effects on Winter Wheat Production Using RZWQM and CERES-Wheat

^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

View larger version (17K): [in a new window]   Fig. 1. Daily precipitation recorded at Akron during winter wheat crop seasons of 1987–1988, 1988–1989, and 1989–1990.

View larger version (36K): [in a new window]   Fig. 2. Comparison of field-measured and CERES-Wheat– and RZWQM-predicted soil water content with time in different soil layers. Error bars represent one standard deviation from mean of measured values.

View larger version (43K): [in a new window]   Fig. 3. Measured and CERES-Wheat– and RZWQM-predicted winter wheat grain yields during three crop seasons of 1987–1998, 1988–1989, and 1989–1990 under different N treatments (0 kg N ha–1 experiment of 1987–1988 was used for calibration of the models). Error bars represent one standard deviation of measured grain yield from mean.

View larger version (30K): [in a new window]   Fig. 4. Measured and CERES-Wheat– and RZWQM-predicted winter wheat biomass during three crop seasons of 1987–1998, 1988–1989, and 1989–1990 under different N treatments (0 kg N ha–1 experiment of 1987–1988 was used for calibration of the models). Error bars represent one standard deviation of measured biomass from mean.

View larger version (23K): [in a new window]   Fig. 5. Cumulative probability function plots of winter wheat grain yields simulated by RZWQM and CERES-Wheat models under different N treatments.

View larger version (21K): [in a new window]   Fig. 6. Cumulative probability function plots of winter wheat whole plant N uptake simulated by RZWQM and CERES-wheat models under different N treatments.

View larger version (22K): [in a new window]   Fig. 7. Cumulative probability function plots of residual soil N at harvest of winter wheat simulated by RZWQM and CERES-Wheat models under different N treatments.

View larger version (17K): [in a new window]   Fig. 8. Cumulative probability function plots of winter wheat N uptake simulated by RZWQM and CERES-Wheat for 56 kg N ha–1 treatment, applied using three methods, namely (i) broadcast, (ii) broadcast incorporated, and (iii) injected.

View larger version (19K): [in a new window]   Fig. 9. Cumulative probability function plots of winter wheat grain yields simulated by RZWQM and CERES-Wheat for 56 kg N ha–1 applied using three methods, namely (i) broadcast, (ii) broadcast incorporated, and (iii) injected.

View larger version (17K): [in a new window]   Fig. 10. Cumulative probability function plots of winter wheat N uptakes simulated by RZWQM and CERES-Wheat for 56 kg N ha–1 applied as broadcast incorporated in a single application and split application of 50% at planting followed by 25% each at 14-d intervals.

View larger version (17K): [in a new window]   Fig. 11. Cumulative probability function plots of winter wheat grain yields simulated by RZWQM and CERES-Wheat for 56 kg N ha–1 applied as broadcast incorporated in a single application and split applications of 50% at planting followed by 25% each at 14-d intervals.

View larger version (20K): [in a new window]   Fig. 12. Cumulative probability function plots of winter wheat grain yields under continuous wheat (CW) and wheat–fallow (W-F) rotations simulated by RZWQM and CERES-Wheat for 56 kg N ha–1 applied as broadcast incorporated in split applications of 50% at planting followed by 25% each at 14-d intervals.

View larger version (29K): [in a new window]   Fig. 13. (a) Water use efficiency (WUE) response on grain yield, and (b) N use efficiency (NUE) of continuous wheat (CW) and wheat–fallow (W-F) crop rotations. Water use efficiency is defined as the grain yield per unit of water used in meeting the seasonal evapotranspiration requirement of the crop or fallow, and NUE = (plant N uptake under a particular N treatment – plant N uptake of the 0 kg N/ha treatment)/amount of N applied.