Drought stress is usually the major limitation to forage yields. When drought has compromised tonnage of corn grain, silage producers may still retain part of its feeding value.
Although grazing the plants is an alternative, mechanical harvesting maximizes the tonnage obtained. Preserving drought-stressed corn plants as hay is usually not recommended because plants retain moisture and are difficult to dry.
Preserving high-moisture corn plants as baleage (50 to 60 percent moisture) can also offer difficulties as stalks can puncture the plastic wrap with air infiltration of the forage mass. Aeration will lead to heating (and even spontaneous combustion), mold growth and mycotoxin production, and reduced palatability and overall feeding value of the stored forage.
Because of these considerations, if producers are going to go through the trouble and expense of harvesting corn plants, it is worth doing so as silage by following traditional best management practices.
Of the water uptake by plants, approximately only 1 percent is retained for metabolic processes. The rest is used to move minerals from the roots to the stem and during evaporative cooling. During dry periods and water losses through transpiration, plants respond by closing their pores (stomata). This mechanism saves water, but also shuts off evaporative cooling, which when combined with environmental heat, results in higher foliage temperatures; this further impairs plant metabolism. Slowing down of enzymatic processes allows the plant to save energy and nutrients to be used in regrowth once soil moisture conditions improve.
Continue reading this article published in Progressive Dairyman.
