By Rory Lewandowski, Extension educator, Athens County and Buckeye Hills EERA
September and October are important months in the lifecycle of perennial cool season pasture plants because this is when those plants store carbohydrate reserves. Carbohydrate reserves are needed to allow the plant to survive the winter. Although the top growth of the plant will die, the crown and root system of the plant remain alive, continue to respire, and require “food” in the form of carbohydrates. There must be enough carbohydrates stored up to allow the plant to last through the winter and to send out new top growth in the spring.
Carbohydrates are manufactured in the plant through the process of photosynthesis. In order to produce and store up these necessary carbohydrate reserves, the plant must have green living leaf tissue. Therefore, your job as a grazing manager in the fall of the year is to make sure that pasture paddocks are not over grazed and that adequate plant leaf area is maintained. What is adequate plant leaf area? I suggest leaving a plant residue or average plant height of 4 to 5 inches in the fall of the year.
Good fall management is especially crucial on those pasture paddocks that were grazed hard during spring and/or summer rotations. I’m using the term grazed hard to mean that these paddocks were grazed low and that regrowth had to come from carbohydrate reserves in the stem base or root system. In these paddocks, plants may be in a weakened state and fall is the last opportunity to restore carbohydrate reserves.
Graziers have several management options that will allow pasture paddocks to retain leaf area and build carbohydrate reserves. The most basic option is to just follow the basic grazing principle of take half and leave half. I know of some graziers who use the fall period to rotate livestock through hay fields and give their pasture paddocks some extra rest. Another option that should be given some serious consideration is to feed some hay during this period to avoid overgrazing and provide some paddocks with a rest period heading into late fall. In many instances this may prove to be the best use of low quality hay. Young animals are being weaned at this time and once lactation is over the nutrient needs of the mother are greatly reduced.
Fall is not the time to relax grazing management. The management decisions made in the fall can impact pasture production next spring.