by Robin Stanback

Soil is the bank from which grasses draw nutrients, and nurturing that resource should be of paramount importance to horsemen whose animals rely upon pasture grasses for their nutrition.

Generally speaking, late fall is the best time to assess and treat pasture foundations by applying fertilizer, nitrogen, phosphorus, potash, and agricultural limestone. This year, all generalities have gone out the window.

A late-summer drought, the worst since 1897, has changed the rules in some horse-raising regions. Farmers throughout many areas of Kentucky are struggling with the question of what they can do to preserve their grass and top soils.

A good stand of grass provides feed for the animals that graze upon it, starves out encroaching weeds, and protects the soils beneath it from erosion. When grass stands are continually compromised by droughts or overgrazing, organizing a recovery plan can be challenging.

Kentucky grasses have been compromised by two straight years of drought. Last year, most areas of the state saw extremely dry conditions throughout the summer. Roger Allman of the Farm Clinic, an independent research firm in West Lafayette, Indiana, described the 2007 growing season as being hit by a "triple whammy" of a late killing frost at Easter, drought, and extreme heat in August.

A. J. Powell Jr., Ph.D., the extension turfgrass specialist for the University of Kentucky, said many farms in the Bluegrass area suffered from last year's drought. "The grasses had a chance to recover somewhat this year," he said.

"We had an El Niño effect last winter and early this spring that provided us with more rain than we usually have during those times. Certainly, June and July of this year provided us with more rain than we have had during those same months in many years. However, that all dried up in August [and September]. Pastures that were starting to recover have been hurt again."

Second-driest period

The University of Kentucky's Agricultural Weather Center released a report this month that showed Kentucky received 2.62 inches of rain in August and September, the second-lowest amount of rainfall for those months in 114 years of record-keeping. By comparison, the same two months of last year were the ninth-driest on record.

Compounding the problem for horse farms today is that many people depend upon fall rain showers and cooler weather to germinate grass seed and encourage existing grass growth before the winter months. This year, most grass seed that has been planted has yet to germinate. "Fall is when you need to reseed pastures if you are using cool-season grasses like bluegrass, orchard grass, and tall fescue, said Steve Higgins, Ph.D., an agriculture research specialist at the University of Kentucky. "The very best time to plant seeds is usually from August 15 to early October. The earlier in that time frame, the better." His advice is based on the fact that Kentucky farmers can typically expect late summer and early fall showers to help germinate the seeds. This year has been far from typical.

The seeds that have been planted are not all lost. Debbie Prewitt has been helping Woodford Feed Co. clients decide planting and fertilizing strategies for more than 30 years.

"Seeds that are in the ground still have a good chance of germinating if we get rain. They have a whole lot better chance in the ground than they do in the bag," she said. "You just may not get the full benefit of your planting this year."

Powell said the region usually has one or two soaking rains by October.

Ike effects

"Adding to the problem is that we had those windstorms associated with Hurricane Ike in September. That really dried out the topsoils," he said. "Still, I would recommend trying to get some seed into the ground now even though it is past the stage where you would get the maximum benefit from the seed. Orchard grass and timothy would be good because they are faster growing than bluegrass and have a better chance of getting established before the frosts.

"I'm not too crazy about rye even though it will germinate quicker and in drier conditions than other seeds. It has endophyte issues like some fescues, and that is a problem for farms with broodmares. Still, it could be useful in areas where the horses are not grazing."

"Two endophyte-free grasses, a fescue and a green-tag pasture rye, are acceptable grasses for horse pastures," Allman said. "Bluegrass requires 21 days of good conditions to germinate. Planting it now would be a wasted effort, but, even though we are at the very, very end of our growing window for seeding, you might be able to get some germination from orchard grass, timothy, and the endophyte-free fescue and rye."

Allman believes many of the bare spots in pastures will come back with a bit of rain and cool weather.

Powell maintains that it is essential to get grass seed growing in the fall because it is harder to establish the cool-season grasses that do so well in Central Kentucky in the spring. "There is less competition for grass seedlings in the fall. In the spring, the established grass and the weeds will crowd out the seedlings. If you don't establish a good cover with grass, you will get it with weeds," he said.

The immediate challenge for farms that have planted grass seed is to determine when to treat and fertilize paddocks. Soil tests can determine pH levels and indicate what might be needed to augment the ground to obtain optimum grass growth. While an organic-matter test can be performed to gauge the level of available nitrogen, most people believe that is unnecessary.

Optimum times

Normally, experts agree that late October and early November are optimum times for putting nitrogen on paddocks, but only if the grass seed has germinated and precipitation is sufficient. Nitrogen, in the form of ammonium nitrate or urea applied in late fall, promotes root growth more than top growth. It also encourages tillering, the production of new side shoots that help the existing cool-season grasses to thicken up, protecting the soils beneath them.

"Ammonium nitrate for fall fertilization is preferable to urea because urea is more likely to be lost to [evaporation]," said Garry D. Lacefield, Ph.D., professor of agronomy extension at UK. "It can be used, but you will need to apply more of it to account for the loss."

Any type of nitrogen used this year is going to cost more than it ever has before. What may have cost $20 per acre last year will cost approximately 50% more this year. "Right now it is especially important for farms to plan when they are going to fertilize their pastures," Prewitt said. "If you are planning on using nitrogen and you want to get the biggest benefit from it, wait until the soil temperatures have cooled a bit. They are pretty warm right now [in mid-October]. If nitrogen is applied under these conditions, it will promote top growth more than root growth."

Allman said it is especially important this year to fertilize pastures, even with the higher cost. "The pastures need the help to recover well," he said. "Even if the weather is not good, the fertilizer will still help. Maybe we won't get the entire benefit we would like, but we will still get some."

Potash and lime

Potash and lime also are added to pastures in the fall, Prewitt said. "If there is one thing I cannot stress enough, it is the need for farms to test their soils. These tests are inexpensive; the fertilizer is not. If ever there was a time to spoon-feed your pastures, this may be it," she said. "Look at what you absolutely need and do not use more than you have to. Nitrogen prices have risen, but nothing like potash. Two years ago potash was $154 a ton. Today it is considerably higher."

Potash (potassium chloride) performs three vital functions in a pasture. It encourages root development and disease resistance in plants, and it facilitates the chemical reactions in the plant. Prices have risen above $600 a ton in the last year for this fertilizer, which is mined in Canada (60%), Russia (30%), and the United States (10%). Commodities experts suspect that demand will continue to outstrip supply, so the price is not likely to come down any time soon.

Lime is another valuable asset to a pasture's health. A good pasture will have a pH level between 6.4 and 7. A level that is higher or lower than that range indicates that some essential nutrients in the soil will remain locked there and unavailable to the plants.

The good news here is that, if any bargain can be found in pasture management this year, it is lime. "Some quarries have actually lowered the price of lime this year," Prewitt said.

Most experts agree the best time to add fertilizer to a pasture is in the late fall when soil temperatures are cooler and ideally right before a good soaking rain. Cool-season grasses will continue to grow through the winter when soil temperatures are above 45 degrees. In a normal fall, applying fertilizers to a field at the optimum time is fairly easy to accomplish. This year, it could be a bit more difficult as the competition to get the trucks to the farms at the best time might be more intense. Bob Mack Cleveland, president of Woodford Feed, suggested that farm managers should arrange to have soil tests analyzed and have orders in place with their fertilizer providers as early as possible. "Because of the drought, we are already behind our normal fertilizing schedule. Everyone wants to wait for the first good rainfall," he said.

Rainfall is essential to getting the fertilizers and lime into the soils. It is especially important if the nitrogen is being supplied by urea because that has a greater chance of evaporation.

Off plant leaves

Another advantage to the rain is that it gets the fertilizers off the plant leaves. "If the fertilizer is spread correctly, there is a very small chance of a horse being badly affected by it," Cleveland said. "There are people who suggest that horses be kept off a freshly fertilized pasture for three days after a good rain, but a lot of farm operators do not have that option. I think it is up to the farm to make that choice."

When the rain does come, many pastures will have problems with mud. "Pastures that do not have a good stand of grass could have real problems with erosion," Powell said. Taking the time now while it is dry to protect vulnerable areas such as those around waterers and gates will protect those areas and keep them from being heavily damaged by hoof traffic.

Pasture rotation is another effective way to protect stressed grasses. Electric fencing can be used to partition off sections of larger paddocks so that some areas get a break. Some experts prefer a sacrifice pen or a dry lot to having large areas of grass eaten too short or trampled.

"If you want maximum recovery and yield from a pasture, it will need a certain amount of rest," Powell said. "If it is at all possible to allow a pasture some relief from grazing and hoof traffic, it should be done. If the grass can have a chance to get four to six inches of growth on it before the winter comes, it will hold up better."

Robin Stanback is a freelance writer based in Versailles, Kentucky