Setting a sustainable stocking rate. Setting the proper stocking rate, defined as animals per acre per year, is a primary determinant in grazing system success. A stocking rate set too high will result in the degradation of the entire grassland ecosystem. A stocking rate that is set too low will result in wasted forage and decreased profitability. In addition, stocking rate also impacts the amount of conserved forage that will be needed. A stocking rate set too high will result in less grazing and more hay feeding. Stocking rate depends on many factors such as forage species, soil type, soil fertility level, and grazing management. In general, supplying each cow-calf unit with 2 to 3 acres of grazable pasture is a good place to start. In most cases it is better to start with a lighter stocking rate that can be gradually increased as soil fertility increases and grazing management improves.
Grazing management. Controlled grazing or rotational stocking is a management practice that allows producers to determine how closely pastures are grazed and how long they are rested between grazing events. Leaving residual leaf area and resting pastures between grazing events allows pastures to re-grow quicker and produce up to a third more forage in a given grazing season (Sollenberger, et al., 2012). Some forage species are better adapted to close and frequent grazing than other.
Soil fertility. The soil fertility can have a profound impact on both the productivity and botanical composition of pastures. When fertility is low, improved forage species like tall fescue and orchardgrass and red and white clover become less productive and weed species that are better adapted to lower fertility fill in the gaps. Fertilizer and lime applications should ALWAYS be based on a recent soil test. If funds are limited, apply lime if needed. Lime not only reduces soil acidity, but also makes nutrients in the soil more available to plants.
Hay and silage remove large quantities of nutrients. In contrast to grazing, making hay or silage removes large quantities of nutrients. These nutrients must be replaced to maintain soil fertility, and stand health and productivity. Each ton of hay that is removed from a field takes with it approximately 15 lb of phosphate and 50 lb potash. In a good year a tall fescue-clover mix may yield 4 tons per acre and remove 60 lb phosphate and 200 lb of potash.
Successful pasture management requires an integrated approach that involves the soil, plant, and animal. This means we need to select well adapted forage species and manage them in a manner that creates a healthy and vigorous sod that excludes weeds from our pastures. When we combine this with clipping and the judicial use of herbicides, we will have a winning combination! ~ Dr. Chris Teutsch. See the full article in the upcoming June issue of Cow Country News.