Coastal Bermudagrass, Bahiagrass, and Native Range Simulation at Diverse Sites in Texas

Abstract

Effective comparisons of natural grasslands and improved pasture require a robust model for plant growth, soil water balance, runoff, soil erosion, and climatic impacts. Our first objective was to develop plant parameters in the field that enabled the ALMANAC model to simulate growth of coastal bermudagrass [Cynodon dactylon (L.) Pers.]. Pensacola bahiagrass (Paspalum notatum Flü gge var saurae Parodi), and some common native, warm-season grasses. Parameters included leaf area, light interception, biomass growth, and nitrogen concentration. The maximum leaf area index values of coastal bermudagrass and bahiagrass were near 2.2. Those for native grasses other than switchgrass (Panicum virgatum L.) were much less. Mean values for light extinction coefficient ranged from 0.7 to 2.1. Radiation use efficiency values for four of the five measured grass species were between 1.0 and 2.0 g MJ 21 . Grass [N] values showed similar patterns of seasonal change among species. Our second objective was to use these grass parameters to simulate biomass production of coastal bermudagrass, bahiagrass, and some native grasses on representative soils in several counties in a number of regions of Texas. Counties and soils that were simulated represented a diversity of sites in Texas where improved grasses and native grasses are grown. The ALMA-NAC model reasonably simulated biomass means and SDs for native grasses, coastal bermudagrass, and bahiagrass. The model is a realistic tool to simulate effects of soil type and weather on native and improved grass productivity on such diverse sites.

History of model development at Temple, Texas

“…Subsequently, the model was extended to range simulation with multiple grass species at diverse sites (Kiniry et al, 2002). Parameters for common warm season grasses (Kiniry et al, 1999), improved grasses (Kiniry et al, 2007), and for mesquite and juniper (Kiniry & Bockholt, 1998) were developed to allow their simulation. The model has also been demonstrated as a valuable tool to assess switchgrass production for biofuels at diverse sites in the USA (Kiniry et al, 1996.…”

Plant growth simulation for landscape-scale hydrological modelling

“…Kiniry et al (1996Kiniry et al ( , 2005 and McLaughlin et al (2006) simulated Alamo switchgrass (Panicum virgatum L.) at diverse sites in the USA. In addition, ALMANAC was used to simulate range yields for a diverse set of ecological sites with two or more grass species competing, representing extremes of productivity for Texas (Kiniry et al, 2002(Kiniry et al, , 2007.…”

Switchgrass Biomass Simulation at Diverse Sites in the Northern Great Plains of the U.S.

“…The ALMANAC model has been extensively tested for semi-arid regions of the southern U.S. First, plant parameters were derived for several warm season native and improved grasses [8,12]. The model was effective at simulating biomass production for diverse range sites in Texas [9], for improved pastures and native range sites in Texas [12], and for Alamo switchgrass at several sites in Texas, one site in Louisiana, and one site in Arkansas [5,11].…”

“…The model was effective at simulating biomass production for diverse range sites in Texas [9], for improved pastures and native range sites in Texas [12], and for Alamo switchgrass at several sites in Texas, one site in Louisiana, and one site in Arkansas [5,11]. Likewise, the model has been validated with maize and sorghum under a wide range of conditions in the U.S. [6,7,10,22].…”