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Article
Simulating Dryland Water Availability and Spring Wheat Production in the Northern Great Plains
Agronomy Journal
  • Zhiming Qi, United States Department of Agriculture
  • Patricia N. S. Bartling, United States Department of Agriculture
  • Jalai D. Jabro, United States Department of Agriculture
  • Andrew W. Lenssen, Iowa State University
  • William M. Iversen, United States Department of Agriculture
  • Lajpat R. Ahuja, United States Department of Agriculture
  • Liwang Ma, United States Department of Agriculture
  • Brett L. Allen, United States Department of Agriculture
  • Robert G. Evans, United States Department of Agriculture
Document Type
Article
Publication Date
12-7-2012
DOI
10.2134/agronj2012.0203
Abstract

Agricultural system models are useful tools to synthesize field experimental data and to extrapolate results to longer periods of weather and to other cropping systems. The objectives of this study were: (i) to quantify the effects of crop management practices and tillage on soil water and spring wheat (Triticum aestivum L.) production in a continuous spring wheat system using the RZWQM2 model (coupled with CERES-Wheat) under a dryland condition, and (ii) to extend the RZWQM2 model results to longer term weather conditions and propose alternate cropping systems and management practices. Measured soil water content, yield, and total aboveground biomass under different tillage and plant management practices were used to calibrate and evaluate the RZWQM2 model. The model showed no impacts of tillage but late planting greatly reduced grain yield and biomass, in agreement with observed differences among treatments. The hydrologic analysis under long-term climate variability showed a large water deficit (32.3 cm) for spring wheat. Fallowing the cropland every other year conserved 4.2 cm of water for the following wheat year, of which only 1.7 cm water was taken up by wheat, resulting in a yield increase of 249 kg ha−1 (13.7%); however, the annualized mean yield decreased 782 kg ha−1(43.1%) due to 1 yr of fallow. Other long-term simulations showed that optimal planting dates ranged from 1 March to 10 April and the seeding rates with optimum economic return were 3.71 and 3.95 × 106 seeds ha−1 for conventional and ecological management treatments, respectively.

Comments

This article is from Agronomy Journal 105 (2012): 37–50, doi:10.2134/agronj2012.0203.

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
Date Available
2014-02-03
File Format
application/pdf
Citation Information
Zhiming Qi, Patricia N. S. Bartling, Jalai D. Jabro, Andrew W. Lenssen, et al.. "Simulating Dryland Water Availability and Spring Wheat Production in the Northern Great Plains" Agronomy Journal Vol. 105 Iss. 16 (2012) p. 37 - 50
Available at: http://works.bepress.com/andrew_lenssen/24/