By David Barker
Dry July-August weather in Ohio has raised several questions about how pastures should be managed during drought.
Although the experts don’t all agree if this period of dry weather meets the definition of a drought, there is no doubt that pasture growth has slowed to zero in many areas of Ohio.
How should we be grazing our pastures in mid-summer?
1) Avoid over-grazing. Unfortunately, without rain or irrigation, pastures will not grow, and close grazing will exaggerate this effect. Leaf removal results in death of roots – potentially devastating during a drought. Grazing below 2 to 3 inches will accelerate drought effects on pastures, and slow recovery when rain does come.
Grazing any surplus pasture remaining from spring will clean these areas without undesirable effects so long as grazing does not get lower than 2 to 3 inches.
2) Watch for endophyte poisoning on tall fescue and perennial ryegrass. Drought can result in a double whammy in respect to endophyte: ergovaline (the toxic alkaloid) levels are elevated, and livestock graze nearer the base of plants where endophyte and alkaloids are the most concentrated.
3) De-stock pastures. Livestock pressure on pastures can be reduced by selling unproductive livestock, feeding silage/hay/grain, and finally in extreme cases you should consider selling productive livestock.
In many cases, making the hard decisions early can be the best decision in the long-run.
4) Be ready with nitrogen. Pastures and livestock can make compensatory growth upon relief of drought. Strategic use of N early in the recovery from drought can re-gain some of your losses.
Don’t make applications too early, since volatilization losses could be high without rain to ensure incorporation of N.
5) Start planning for next year. The best drought strategy is to plan in advance – it’s not “if” is gets dry, but “when” it gets dry.
Spring-planted crops such as brassica, grazing corn, and sorghum-sudan grass (use brown mid-rib varieties) can fill the summer slump.
Warm-season grass stands (big-bluestem and switchgrass) are not high quality, but will be more than adequate to keep livestock maintained during summer.
Use drought tolerant pasture mixes – species including alfalfa, chicory, red clover, orchardgrass and tall fescue have good drought tolerance and can help during dry summers.
Surplus spring growth can reduce tiller density and summer growth potential – there is evidence that closer spring grazing can benefit summer production.
Early calving could get your calves weaned and off your property before the drought hits – dry cows on a maintenance diet have a much lower feed requirement.
Learn feed budgeting. Using a feed budgeting and monitoring system can identify feed deficits up to three weeks earlier than without such a system. This advance notice can give you critical time to think and plan your options before the effects of a drought actually hit.
(Dr. David Barker is an assistant professor in the department of horticulture and crop science at Ohio State. Questions or comments can be sent in care of Farm and Dairy, P.O. Box 38, Salem OH 44460.)