Caring for Hay Fields
Drought, too much rain, disease, insects, weeds, even normal wear and tear can all take a toll on your hay fields. Thankfully, there are off-season practices you can use to get your forages back in shape.
Your No-Cut Window
“For alfalfa, I would recommend a no cut window to rebuild the roots and condition,” says University of Wisconsin Extension Forage Specialist Dan Undersander. “Let it fill the gas tank to help it make it through the winter.”
He says there are two options. First, take the last cut about six weeks before a killing frost so it can re-grow before cold weather. For instance, in Wisconsin that would be, historically speaking, by September 1. Or, wait to cut the alfalfa until near a killing frost, so it won’t try to re-grow and use up those reserves.
You can also determine your “no-cut” window by calculating Growing Degree Days (GDD). There are, however, a number of ways to calculate GDD, so it’s best to speak with your local Extension agent to determine the best for your region.
If you have a mixed stand of alfalfa and grass, that also factors into your decision. If your stand is over 50% alfalfa, you can go by GDD or cut six weeks before the killing frost date. However, if your stand is over 50% grass, then wait until late to cut it.
“We don’t want the grass to lay down and make a mat,” says Undersander. “Disease will grow so cut it late enough that less than six inches of regrowth will occur.”
Adding potassium is another way to help winterize alfalfa stands. “We need to replace whatever potassium was removed by haying during the season,” says Undersander. He explains that approximately 50 lbs. of potassium (K2O) is removed with every ton of hay harvested. If you bale five tons of hay an acre, then put out 250 lbs. of potassium per acre.
“You can apply it anytime after the first of September as long as the ground isn’t frozen,” he notes.
Potassium is a good winterizer for other forage crops, too. University of Georgia Extension Forage Specialist Dennis Hancock says, “Potassium fertility is very important to help with the utilization of the carbohydrate and nitrogen reserves in the plant. If the plant is healthy, with stored reserves, it will be ready to pop right back in the spring.”
Whether it is tall fescue or bermudagrass and bahiagrass, he says, “We recommend going by soil test results and applying 40 to 50% of the recommended potassium in the spring and the remaining 50 to 60% in the late summer or early fall, before mid-October. The forage has to be growing to take it up.”
He says it doesn’t hurt to give tall fescue and orchard grass up to 30 lbs. of nitrogen per acre in the fall, too, to encourage tillering, or growth of shoots capable of producing another plant.
Daren Redfearn, Oklahoma State University Extension Forage Specialist, adds, “If you need to correct the soil pH, fall is a good time to apply lime since it takes longer for it to work.”
The weather and his workload dictate when Madisonville, Tennessee, grower Doyle Cardin fertilizes his 400 to 500 acres of tall fescue hay that he uses to feed to his dairy cattle and 250 commercial beef cows.
“We spread one to two tons of manure per acre from the dairy in the fall and early spring,” says Cardin. “Occasionally we’ll spread between the first and second cuttings.”
He stores the manure in both a dry stack area and a lagoon, then hauls and applies it with a side delivery manure spreader. “It will haul manure that is almost water.”
“Where we’ve spread manure we usually just have to put out nitrogen,” he says.
For fields that are too far from the dairy to make manure applications feasible, he applies commercial fertilizer according to soil tests.
Three years of drought in Oklahoma resulted in thinning bermudagrass stands. That left room for weeds, which were encouraged by July rains this past summer.
Oklahoma specialist Redfearn says, “Scout your hay fields and pastures. You can identify any summer weeds and plan for controlling those next year. Identify the weeds and poisonous plants and make a weed control plan.”
“Thistles and dock, which are common in the lower areas, can be controlled more easily during the fall. Then there are the cool-season grassy weeds and cool-season bromes like cheatgrass.”
Before the summer grasses break dormancy, which can be as early as mid-March in his area, is a good time to control cool-season grassy weeds such as cheatgrass with a low rate of glyphosate. He also says to watch out for summer weeds like ragweed that come up the same time as bermudagrass.
“Anything cool-season is relatively easy to control in warm-season grasses. Broadleaf weeds are easy to control in grasses. But for summer grassy weeds such as johnsongrass and sandspur, there are no easy answers,” Redfearn adds.
“The reason it is not easy is because the grasses grow at the same time. One [weed] we currently fight in the Southern U.S. is Johnsongrass in a bermudagrass hay field. If it is grazed, the animals will keep the Johnsongrass grazed out. In a hay field, it is possible to use a rope wick with [glysophate] and ‘wipe’ only the Johnsongrass. The two major disadvantages are it is a tedious process with sometimes inconsistent control.”
Burn, Burn, Burn
For bermudagrass hay fields, a drip torch is one of Hancock’s favorite tools. “Burning has a lot of positive benefits. First, it increases the rate of green up in the spring. It removes the biomass and the black color warms the soil.”
“Second, the primary reason to burn is it decreases disease. Disease spores can build up in the thatch, particularly leaf spot disease. When you burn up the thatch you burn up the spores.”
“Third, burning releases a lot of nutrients that are tied up in the thatch, particularly potassium, but also nitrogen, calcium and magnesium.”
He adds, “It also burns up the winter weeds.”
The Georgia specialist says burning, which he recommends undertaking in February or early March in his area, can have its drawbacks. “There is the risk of the fire getting too hot and getting away. There is also the risk of lowering air quality.”
Rotate. Or not.
Wisconsin specialist Undersander is not a fan of trying to extend the life of alfalfa hay fields. “We recommend a short rotation of three to four years. If there are less than 55 stems per square foot, kill it and replant alfalfa in another field. The advantage to a short rotation with alfalfa is corn, wheat and canola all yield more following alfalfa than they do following themselves.”
He adds, “Corn yields 10 to 15% more. If there are four plants per square foot of alfalfa when you kill the stand, add 25 lbs. of starter fertilizer and that should be enough nitrogen.” (For more on rotating alfalfa, see “Alfalfa: Irrigation, Harvest Scheduling and Rotation Timing.”
Because of auto-toxicity with alfalfa, he says to wait at least one year before planting alfalfa in the same field. He also says that overseeding in alfalfa, either with another forage or more alfalfa, is never a good idea. However, weather permitting, Tennessee farmer Cardin overseeds the bare spots in his fescue hay fields with more fescue and possibly wheat.
For bermudagrass, Redfearn recommends patience. “I am the eternal optimist. With bermudagrass, if you can find some plants out there you are okay, even if it is a half an inch tall plant every five feet. If you can just let it go for two or three months and give it some help with fertility and weed control, it will come back.”