Pasture and Forage Minute: Improving Alfalfa Production, Alternative Forages in a Drought
Evaluating Alfalfa Stands
Were you expecting more from last year’s alfalfa yields? Did your plants get enough time to winterize in the fall? Did this year’s open winter cause concern about winter kill? Evaluating your alfalfa stand in the spring is key to planning management and setting expectations for this year.
A hay square is a quick and easy way to begin evaluation. While we call it a hay square, square or circle shapes work equally well. A 17x17-inch square or 19 inch in diameter circle are the size we need.
Next, we need to determine what to count. There are two options when evaluating your stand: 1) by the number of plants per square foot (typically recommended for new stands, like plantings last fall) and 2) by the number of stems for established stands. Stem count more accurately predicts yield compared to plant number. However, either method will provide information for making management decisions.
Pick four to five random areas in your field to sample. Then count the plants or stems that would be harvested — typically anything over six inches — to determine your count. Then divide those numbers by two to get stems or plants per square foot. For established stands, having four to five healthy plants per square foot or 55 stems per square foot would warrant a productive and healthy stand. Stem counts below 55 see a significant decrease in dry matter production.
For stands planted last fall, you will see more plants per square foot compared to stems. Remember, a good rule of thumb is, for every pound of seed planted, expect three to five plants. New plantings that contain fewer than 12 plants per square foot may need to be reseeded.
Spring Cereals in Alfalfa
Have you noticed any winter injury to your alfalfa fields or maybe you have some older stands that are thin?
Maximizing tonnage from every inch of rain your alfalfa hay fields receive this year may be necessary. 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 the first cutting as possible, before summer heat sets in.
One way to boost first cutting hay yield from thin or winter-damaged alfalfa stands is to drill cereals like oats, spring triticale or spring barley into those stands. Depending on the thickness of the alfalfa stand, drill 30 to 60 pounds per acre directly into your existing stand as soon as possible. These cereals will use spring moisture very efficiently to add tonnage to your first cutting.
Where the alfalfa is thick, you may not get much, but in thin spots these cereals should fill in rapidly. These spring cereals will have rapid growth in late May and early June, so cutting your hay a little later than usual will help you get the most yield benefit from this addition.
Besides the small grains, annual or Italian ryegrass is another option to increase hay yield. For these, a seeding rate of 5 to 12 pounds per acre is adequate.
Getting the most out of each inch of moisture could be especially important this year.
Pasture Alternative Forages
Drought conditions have caused significant delays in pasture green-up and dormancy break. As a result, livestock producers may be seeking alternative forages and adjusting stocking rates to compensate for decreased forage production. The Drought Mitigation Center provides free drought management educational resources.
For example, when forage plants are under drought stress, managers may extend the rest period between grazing cycles. Using rotational grazing along with longer rest periods will allow more plant growth readiness when rains finally come. Overgrazed pastures will also recovery slower during drought if animals continually graze off regrowth.
So, if pasture forage production is limited, what are alternative forage options? In general, annual forages are more water use efficient than perennial grasses. Thus, wheat and rye fields may be greening while grass pastures are still looking brown. With lower soil temperatures, seeded cool-season annuals like oats will provide quicker forage growth. However, drought water use efficiency favors warm-season annual forage grass such as foxtail millet, sudangrass and sorghum-sedan grasses as soils warm.
If alfalfa fields are lacking height for haying, then grazing the alfalfa may be a way to extend pasture rest. Note that drought impacted alfalfa is less likely to cause bloat problems with grazing cattle.
Grazing wheat or rye may also extend pasture rest. If grain harvest is still a goal, then cattle should be removed from grazing the wheat prior to the hollow stem growth stage, since immature wheat heads may be eaten off. However, this forage option may be gone within the next two weeks. Grazing rainfed or dryland corn could be an option later if our dry conditions continue into the summer months.