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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #333448

Research Project: ENHANCED MODELS AND CONSERVATION PRACTICES FOR WATERSHED RESOURCE MANAGEMENT AND ASSESSMENT

Location: Grassland Soil and Water Research Laboratory

Title: Short duration, perennial grasses in low rainfall sites in Montana: Deriving growth parameters and simulating with a process-based model

Author
item Kiniry, James
item Muscha, Jennifer - Boyle
item Petersen, Mark
item KILIAN, R - Natural Resources Conservation Service (NRCS, USDA)
item METZ, L - Natural Resources Conservation Service (NRCS, USDA)

Submitted to: American Journal of Experimental Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2017
Publication Date: 4/4/2017
Publication URL: http://handle.nal.usda.gov/10113/5700687
Citation: Kiniry, J.R., Muscha, J.M., Petersen, M.K., Kilian, R.W., Metz, L.J. 2017. Short duration, perennial grasses in low rainfall sites in Montana: Deriving growth parameters and simulating with a process-based model. Journal of Experimental Agriculture International. 15(6):1-13. doi:10.9734/JEAI/2017/32232.

Interpretive Summary: Rangeland grasses in the arid western U.S. must grow quickly, set seed, and lose their green leaves in a relatively short timeframe in order to survive and reproduce when the limited soil moisture is available. In addition, rangeland management in arid sites can benefit from computer models to optimize grazing intensity and duration and for assessing impacts of invasive species and of climate change. In this project, we derived the needed variables that describe grass growth for the ALMANAC computer model to simulate three common cool season grasses and one warm season grass in Montana. These growth variables were then used with the computer model to simulate three typical range sites near Miles City. Model variables such as the amount of plant growth per unit light intercepted and potential leaf area cover showed expected trends with the four grasses. Once the variables were used with the computer model, simulations showed reasonable agreement with published grass yields for normal years, wet years, and dry years. Thus this computer model and the growth variables such as those described herein will be valuable for assessing various management scenarios and climate variables in these types of low rainfall, western U.S. range sites.

Technical Abstract: Rangeland grasses in the arid western U.S. must grow quickly, set seed, and senesce in a relatively short timeframe in order to survive and reproduce when the limited soil moisture is available. In addition, rangeland management in arid sites can benefit from process-based simulation tools to optimize grazing intensity and duration and for assessing impacts of invasive species and of climate change. In this project, we derived the needed growth parameters for the ALMANAC model to simulate three common cool season grasses and one warm season grass in Montana. The parameters were then used with the model to simulate three typical ecological sites near Miles City. Model parameters such as radiation use efficiency and potential leaf area index showed expected trends with the four grasses. Once the parameters were used with the ALMANAC model, simulations showed reasonable agreement with published NRCS grass yields for normal years, wet years, and dry years. Thus this process-based model and parameters such as those described herein will be valuable for assessing various management scenarios and climate variables in these types of low rainfall, western U.S. range sites.