A computer model was developed using monthly inputs of rainfall to predict forage production, carrying capacity (CC) and stocking rate (SR) in arid and semiarid rangelands in northern Mexico. Using worksheets of Microsoft Excel, as from of the information available about of the relationship between the rainfall (mm) and forage production in dry matter per hectare (DM•ha-1). The model is simple and considers only the components of interest to determine carrying capacity and stocking rate, like number of hectare (ha), rainfall (mm), range condition, utilization grade (%), grazing days, water distance (km) and slope percentage (%). The effect of rainfall on forage production and carrying capacity and stocking rate was then determined. The use of the computer model enables the effect of stocking rate to be determined in good and poor rainfall in northern Mexico and to predict the periods during which cattle must be removed from pasture to another to prevent overgrazing. The model predicted a forage yield of 345 kg/DM/ha with 300 mm of rainfall in a semidesert grass-shrub in good condition, carrying capacity 23.7 ha/AU and stocking rate 96.8 AU (Animal Unit defined as a 450 kg cow). Nevertheless, when model was adjusted by slope and water distance the SR decrease up to 62 and 43 AU. As a conclusion, the model has the potential to improve decision-making regarding stocking rate and it is suggested that a flexible SR dependent on annual variation of rainfall must be a key in any improved range management strategy.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.