ARS | Publication request: Maize Yield Potential: Critical Processes and Simulation Modeling in a High-Yielding Environment

Submitted to: Agricultural Systems
Publication Acceptance Date: November 4, 2003
Publication Date: October 20, 2004
Citation: Kiniry, J.R., Bean, B., Xie, Y., Chen, P. 2004. Maize Yield Potential: Critical Processes And Simulation Modeling In A High-Yielding Environment. Agricultural Systems. 82(1):45-56.

Interpretive Summary: When studying potential corn yields, it is important to accurately describe growth and grain yield production in high-yielding, irrigated conditions. In this study we measured maize leaf area, the light interception by the leaves, and the grain weight:total plant weight ratio(HI)in irrigated plots near Dumas, TX. The amount of plant material produced per unit intercepted light was determined with measurements of the fraction of light intercepted and biomass harvests. The plant productivity values in 1999 and 2000 were similar to expected values in such environmental conditions. The mean values describing light interception were similar to the expected value reported in the literature for this row spacing. The mean HI measured in 2000 was similar to values in the literature. Application of these values to crop modeling with the ALMANAC model for 14 fields near Dumas in 1999 and for 5 yr. of grain yields reported for four counties in this region of TX showed realistic predictions. Consistency in plant values in this study as compared with values reported in the literature will help predict maize growth and grain yields in similar high-yielding, irrigated conditions.

Technical Abstract: Accurate parameters describing processes of maize (Zea mays L.) growth and grain yield production in high-yielding, irrigated conditions provide a system for studying grain yield potential in different environments. In this study we measured maize leaf area index (LAI), the light extinction coefficient (k) for Beer=s law, and the harvest index (HI) in irrigated plots near Dumas, TX. The radiation use efficiency (RUE) was determined with sequential measurements of the fraction of light intercepted and biomass harvests. The RUE was 3.98 g of aboveground biomass per MJ of intercepted PAR in 1999 and 3.41 in 2000 for three sampling dates prior to silking. These values are 106 and 93% of the expected RUE values at the measured vapor pressure deficits, using a previously published response function. The mean k value was -0.46 in 1999 and -0.47 in 2000, similar to the expected value of -0.43 reported in the literature for this row spacing. The mean HI measured in 2000 was 0.52, similar to values of 0.53 and 0.54 in the literature. Application of these parameters to maize simulation with the ALMANAC model for 14 fields near Dumas in 1999 and for 5 yr. of grain yields reported for four counties in this region of TX showed realistic simulations. Consistency in values of RUE, k, and HI in this study as compared with values reported in the literature will aid modelers simulating maize growth and grain yields in similar high-yielding, irrigated conditions.