When Rain Wrecks Your Pasture Plan!
By : Christine Gelley, OSU Extension Agriculture and Natural Resources Educator, Noble County, Ohio
Mud, nutrient leaching, and erosion are a few of the ailments pastures across our region are experiencing in 2018. It can be a challenge to be thankful for rain in years like this. You’ve likely witnessed it wash away freshly planted seed, topsoil, and nutrients while trudging through swamps that should be access roads, watching seed heads develop on valuable hay, and cutting fallen limbs off damaged fence.
Nature has taunted many this season. In Southeast Ohio, opportunities to make hay have been few and far between due to soggy soil conditions and high humidity. The longer harvest is delayed, the poorer nutritive value becomes. Most producers have probably harvested first cutting hay that will barely meet requirements for animal maintenance. Looking beyond the frustration to solutions, there are things we can do to relieve the pressure that heavy rainfall inflicts on hayfields and grazed pastures.
One of the best ways to manage mud in grazing situations is to keep animals moving and give pastures rest. Split large paddocks into smaller paddocks and rotate animals frequently. Fence out areas that are extremely wet. Both practices reduce damage from hoof traffic.
Rotating animals among smaller paddocks will also make manure distribution more uniform and help prevent erosion. Adjust rotation lengths and stocking densities to keep forage vegetative. If seed heads develop during the rest period, make plans to come back and clip them when the ground is dry. Clipping will re-stimulate the plants and lower your risk for fescue toxicity issues later on.
If you must take equipment into the pasture, opt for smaller loads and use extreme caution on slopes. Use light implements that have tires with substantial surface area. If you get stuck, get help early. The harder you try to get unstuck alone, the harder it will be for someone to help you.
Having a good stand of legumes (20 percent or more) in the pasture can help replace leached nitrogen and reduce the need for a nitrogen application. Stands that are primarily grasses will be drastically improved with split applications of nitrogen.
Nitrogen is removed from pastures through volatilization, harvest, and leaching. Hay fields will have a more crucial need for nitrogen than grazed pastures, because the forage is removed from the site, rather than replaced by nitrogen in urine and manure.
An application between first and second cutting can be beneficial if volatilization risks can be reduced. A third application could also be useful if there is intent to stockpile the forage for late fall or winter grazing. The amount needed depends on yield goals, actual forage removal, spring fertilization, soil pH, and grass species.
Grazed pastures may need additional fertilizer part way through the growing season as well, but no more than one third of the pasture should be fertilized at a time to lower risks of nitrate toxicity for grazing animals.
If your pasture goes from soggy to flooded, keep in mind that water flow patterns can flush soil, weed seeds, manure, and microbes into the pasture and cause concerns for animal health.
If deposited silt levels are too high, animals may accidently consume substantial amounts while grazing, which can cause digestive issues.
Weed seeds can be swept into the pasture and establish themselves in the damaged areas, crowding out the desirable forages during flood recovery. Detrimental weeds taking over damaged areas will reduce intake of high quality forages and may pose risks if poisonous plants become established. In times of pasture stress, animals are more likely to consume poisonous plants in an effort to find enough to eat.
Microbes and parasites are also easily transported into grazing pastures if water flows through an area of manure or sewage storage. It would be best to wait a week or two to return animals to pastures that have been flooded with tainted water. This will help maintain good herd health.
Once the water has drained from the pasture and the soil, investigate if there are any management decisions you could make now to reduce damage if a duplicate flooding event occurred. Consider reseeding heavily damaged areas. Choose varieties that will withstand the conditions of your operation.
Consider planting an annual forage to compensate in such areas as an emergency crop while you plan for the long term. Planting an annual forage will reduce further erosion, provide competition for weeds, and supply feed for animals more quickly than perennials. Annual ryegrass offers excellent tolerance to poorly drained soils, wheat has good tolerance, while oats, rye, and sorghum-sudangrass offer fair tolerance.
Don’t forget to eliminate standing water whenever possible to prevent mosquito development and reduce the risk of disease transmission for both animals and people.
For more information about the topics covered in this article, consult the following fact sheets from OSU Extension: