Modeling weather and stocking rate effects on forage and steer production in northern mixed-grass prairie

Autor: Justin D. Derner, Liwang Ma, Quanxiao Fang, P.N.S. Bartling, Justin L. Reeves, Zhiming Qi, L. R. Ahuja, Allan A. Andales
Rok vydání: 2014
Předmět:
Zdroj: Agricultural Systems. 129:103-114
ISSN: 0308-521X
DOI: 10.1016/j.agsy.2014.05.011
Popis: Stocking rate (SR) is the primary management factor that influences livestock gains, plant community changes and forage production, as well as economic returns for livestock producers. More effective stocking decision making by ranchers in the semi-arid northern mixed-grass prairie requires clearly understanding forage production and yearling steer weight gain (SWG) responses to SR and high weather variability. The objectives of this study were to: (1) test the Great Plains Framework for Agricultural Resource Management-Range (GPFARM-Range) model for predicting forage production and SWG under three experimental SR treatments and long-term weather conditions on semiarid northern mixed-grass prairie in southeast Wyoming, USA; and (2) quantify the threshold responses of forage production and SWG to SR and the yearly weather variability across years using long-term simulations with SR higher than those experimentally evaluated. We improved upon the GPFARM-Range model to simulate peak standing crop (PSC) and SWG for three experimental SR treatments (low, moderate and high; 0.20, 0.33 and 0.44 steer ha � 1 , respectively) from 1982 to 2012 at Cheyenne, Wyoming, USA. The improved model accurately predicted the effects of SR on PSC and SWG across years (root mean square errors from 355 to 387 kg ha � 1 for PSC and from 12.8 to 14.2 kg head � 1 for SWG). We ran the model with long-term
Databáze: OpenAIRE
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