Recent drought years have stressed hay production in Nebraska. As this season begins, dry soil the growing season may add to that stress.
Even if you receive average rainfall from now on through the growing season, your hay tonnage could be down 10%, 20%, says Bruce Anderson, University of Nebraska-Lincoln forage specialist.
"Maximizing tonnage from every inch of rain your alfalfa hay fields receive this year may be necessary," he says. "Unfortunately, alfalfa uses quite a bit of water for each ton of hay, especially as temperatures rise. So it is critical to get as much tonnage out of first cutting as possible, before summer heat sets in.
One way to boost first cutting hay yield from older, thinner alfalfa stands is to drill oats right now into those alfalfa stands. Try to get the seed about one inch deep. Oats will use spring moisture very efficiently to add tonnage to your first cutting.
Drill one to two bushels of oats per acre directly into your existing alfalfa stand as soon as possible, Anderson says. "Where alfalfa is thick, you may not get much but in thin spots the oats should fill in rapidly. Cut the hay a little later than usual to get the most yield benefit from this oat addition."
Getting the most out of each inch of moisture will be especially important this year. Using oats is one way to do it.
Anderson also suggests considering pre-irrigation on alfalfa stands. "With low soil moisture levels in many areas, now might be a good time to start," he says.
While it seems silly to irrigate alfalfa before first cutting, but look at your soil moisture profile. "If it's dry, you may need to irrigate. In fact, early spring often is the best time to irrigate alfalfa. After all, it's about the only time you can actually build a reserve water source for summer use."
The biggest advantage of reserve water comes after each mid-summer cutting. Alfalfa can develop roots more than eight feet deep. But it will only do this when surface moisture does not meet crop needs and moisture is available all the way down to those depths.
If you have deep roots and deep reserve moisture, though, it will make your summer irrigating much easier by providing extra moisture when plants use as much as half an inch per day. Unfortunately, typical shallow watering during summer encourages only shallow rooting.
Shallow summer watering causes other problems, he warns. Alfalfa roots need oxygen in the soil if plants are to regrow rapidly. Watering right after cutting suffocates roots, slowing regrowth. Immediate watering also stimulates shallow rooted or sprouting weeds, especially at a time when alfalfa plants are not very competitive, he says.
Both problems are reduced when reserve water is available for use by deep alfalfa roots. Then the top several inches of soil can remain dry for a couple days until alfalfa regrowth is well underway.