How Much Forage Do You Have?
Larry D. White and Calvin Richardson
Forage production varies considerably depending on precipitation amount, season and past and present grazing management. Since production is not predictable, the current forage supply must be monitored and compared with the livestock forage requirements. For proper management of range resources, animal numbers must be balanced with current forage supply. Thus, forage supply information can be used to forecast a forage shortage or surplus and make needed stocking rate adjustments.
Forage surveys are often conducted by riding through various pastures to observe plant and animal conditions. Many ranchers have the experience to notice changes in forage quality and quantity, but more specific information can improve stocking rate decisions and help avoid over-utilization. Over-utilization can result in range resource damage and a crisis situation with fewer livestock marketing alternatives.
This forage survey procedure is easy to use, and it provides unbiased estimates of the forage supply, requires minimum sampling time and provides specific information to improve grazing management decisions. The only materials required are a range site map (aerial photograph), a plot frame, vegetation shears, paper sacks, drying oven, camera, weigh scales, notepad (data sheet), pencil and calculator (with linear regression capabilities). Included is an example photoguide and forage survey with calculations. This insert can be removed and used in the field.
Forage supply should be monitored visually throughout the year; however, more detailed information may be required before important decisions are made. Since forage production is not predictable, forage surveys should be conducted at the end of the normal forage production cycles. This allows immediate estimation of how long the accumulated forage supply will last during expected non-growth periods. Late June-early July and late October-early November surveys are recommended for range areas that normally receive spring and fall rains. For summer rainfall areas, the late October-early November survey would be conducted in September. In addition, due to increased forage disappearance during the winter (weathering), a March survey is recommended to evaluate the remaining days of grazing prior to regrowth. This can be critical if spring forage growth is late. [Next Page]
Authors: Larry D. White, Calvin Richardson