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4 Tips to Rejuvenate Pastures From Drought
Sometimes, even in a drought year, something positive happens. For instance, a drought situation can be an opportunity to improve grazing lands for the long haul.
Some of your pastures were due for an overhaul anyway, and drought is forcing the fixes, says Rob Kallenbach, University of Missouri grazing specialist.
Following are Kallenbach’s top four tips for making lemonade from your drought-stressed pastures.
1. ADD LEGUMES. Legumes, such as clover or alfalfa, are easier to establish when there is less competition. Some pasture grasses are showing signs of very thin stands after last summer; 2013 would be a good time to seed legumes.
The advantages of getting about a third of a pasture stand into a legume are huge, says Kallenbach. “Fescue or bromegrass alone may have about 13% protein,” he says. “With red clover in the mix, you can get that up to 18.5% protein.”
Daily gains of stocker animals have been shown to go up about 10% just by having legumes in the pasture.
Because legumes fix nitrogen (N) from the air and make it available in the soil, you need less N fertilizer for the grass plants. Legumes also are deeper rooted than most grasses; they act a little like a water pump, pulling moisture up to the grasses.
The only problem is that legumes are more difficult to establish and maintain in many pasture settings. They are easily crowded out and more susceptible to diseases and insects. A good legume stand may only last two or three years before you need to reseed.
Establishing legumes works best when the grasses have been knocked back by heavy grazing, burning, or dry weather. The timing is right this year.
You can frost-seed legumes with a late winter broadcast, letting the freeze-thaw cycle work the seed into the soil for germination. Kallenbach prefers a no-till drill for seeding legumes.
“It costs more, but the germination success rate can be about 67% with the drill vs. 32% by broadcast,” he says. Be meticulous in setting the drill, because the small legume seeds should be placed only ¼ to ½ inch deep.
Kallenbach says a good program is to seed about 4 pounds an acre of a legume every year to achieve an ongoing balance of new plants coming on. The ideal is to have about a third of the plants in a pasture be a legume. The cost to do that, with clover seed at $2 a pound or less, is cheap for the benefits.
You might want to avoid seeding legumes at the same time that you apply nitrogen fertilizer. The fertilizer will stimulate the grasses to grow rapidly, possibly crowding out the legume seedlings. Rather, seed the legume and give it 60 days to germinate before fertilizing.
2. MANAGE FERTILITY. Fertilizing a pasture is much different than fertilizing row crops. Grazing animals leave behind much of the nutrients they consume. Kallenbach estimates that 75% to 95% of the phosphorus and potassium are returned to the pasture soil in cow manure.
“The biggest issue is controlling the distribution of the manure and getting the animals to move around to all parts of a pasture,” he says. “It can be done with controlled grazing or drinking water management.”
Nitrogen is different since up to three fourths of the nitrogen is lost in a pasture when it’s grazed. It takes about 40 to 50 pounds of N to grow 1 ton of cool-season grass. If you expect a pasture to produce 3 tons of forage, that’s 150 pounds of N per acre.
Think carefully about when you apply N to pastures. Many farmers do it in the spring, which is fine if you have a need for the extra tonnage then.
“You’ll get about 80% of the extra growth in the next six weeks after applying nitrogen,” Kallenbach says. “If you have a fixed number of animals and you really can’t use the extra growth in the spring, maybe you should wait and apply the nitrogen in late summer. You will get a little less response at that time, but it may be a more economic response because you need the forage then.”
Part of the good news about a fall application of fertilizer is that pasturelands are not very leachy of fertilizer – it stays put. “Of the nitrogen that isn’t used by the plants in the fall, 97% of it is still there the next spring,” says Kallenbach.
3. RENOVATE THE WORST PASTURES. As you look at pastures, you can pick those that suffered the most in the drought and completely renovate them. If a pasture has fewer than 50% desirable plants, it’s a good candidate for renovation.
Few farmers can afford the time or the cost of a whole-farm renovation, but you could do it 10% at a time.
“At that rate, you could do the whole farm in 10 years,” Kallenbach says. “Or if only half of your pastures need a full renovation, you could be done in five years. Pick a percentage and start the process.”
Which pastures should be renovated first? Kallenbach says to start with those that have endophyte-infected tall fescue as the primary grass. Endophyte is a fungus that can negatively impact animal performance. Some newer strains of fescue are available that are endophyte-free. You’ll have to kill the old fescue and reseed.
Other criteria for selecting pastures to renovate are very thin stands and very weedy areas or fields that limit animal-carrying capacity.
4. MONITOR CONDITIONS. At a minimum, Kallenbach suggests you walk pastures and observe conditions closely three times a year: May, July, and autumn. “Look closely at what is going on out there, where your thin stands are, and which weeds you have,” he says. “Then you can start to apply some of these management techniques for better growth of the forages and the animals grazing them.”