So far 2012 has been a better year climate-wise than 2011. However, the full impact of the 2011 drought on warm-season forages was not fully realized until the early spring and summer of 2012. Warm-season perennial grasses were much weaker than anticipated and did not fully hit their growth mode until late June. We are now approaching the end of warm-season forage growth. Management from this point forward will impact warm-season growth next spring and continued drought recovery. By looking back to the winter and spring of 2011-2012, we can better plan ahead for winter and spring of 2012-2013 and its impact on our warm-season forage production.
Warm-season forage stands weakened by the drought combined with the wet and warm winter of 2011-2012 produced a heavy influx of cool-season forages such as annual ryegrass, Texas wintergrass and arrowleaf clover. This influx shaded the warm-season grasses underneath, resulting in weak, slow growing stands. The same scenario could happen again for fall-winter 2012. Warm-season grasses have not fully recovered from the 2011 drought, with many stands still thin, allowing ample room for cool-season forages to take hold provided there is good moisture availability.
Knowing that we could have a possible repeat of a cool-season flush, we can manage to take advantage of the cool-season forages for the benefit of our warm-season forages. For all warm-season perennial grasses, the time from August to frost is crucial for the plants to build carbohydrate reserves for spring growth. This was limited in 2011 and management needs should provide for it in 2012. If possible, weak stands of bermudagrass and native grass should be deferred from grazing from August until after frost to give them a chance to put on leaf growth and build those carbohydrate reserves prior to frost. Leaving 6 to 10 inches of residual leaf growth on native grass and 4 to 6 inches on bermudagrass will provide benefits for the plant and help suppress cool-season grasses.
For bermudagrass, August is the time to apply late season nitrogen fertilizer for fall stockpile production. If phosphorus and potassium are called for, based on a soil test report, apply those as well. This will help the stand become more efficient in nitrogen utilization and aid in root development prior to frost. A rule of thumb is to provide 1 acre of stockpile per mature cow for 50 to 60 days of stockpile grazing. Bermudagrass that has been stockpiled will typically flush in the spring to annual ryegrass. Be prepared to come back into these pastures following bermudagrass stockpile and graze the annual ryegrass out.
In native grass that had strong cool-season forages last winter, begin looking for grazing opportunities in February. Texas wintergrass came in very strong in many range sites and is excellent early season forage. Cattle will actively seek it out early, but avoid it at seed head emergence. Use grazing management to suppress cool-season forages during late winter and early spring prior to native grass breaking winter dormancy.
The take-home message is that cool-season forages provide excellent forage for grazing or early season hay production. However, they can delay and further weaken warm-season forage stands still recovering from drought. A repeat of the cool-season flush seen during the fall-winter of 2011-2012 is possible. As a forage manager, be prepared to manage this flush to your advantage and to the advantage of your warm-season perennial forages.
Source: James Rogers