Mike Rankin, Hay and Forage Grower Managing Editor
(Previously published in Hay & Forage Grower: March 28, 2023)
Although 
the days of growing oats for horses have morphed into grandfather tales on most farms, the cereal grain remains a valuable and often-used species in the forage toolbox. Whenever fast forage to graze or harvest is needed, or a companion crop for an alfalfa seeding is desired, more often than not the conversation turns to oats.
The utility of oats as a forage crop can be capitalized upon not just in the fall as a late-season annual but also in the spring if winter annuals didn’t get planted last fall, if they winterkilled, or if perennials suffered winter injury. The beauty of oats is that they can be planted and harvested earlier than most other forage alternatives.
The planting window for spring oats varies by location but generally adheres to the mantra of “whenever the soil is dry enough to seed into.” Planting dates in March and April are typical for a large part of the U.S., although some Southern areas may already have oats in the ground now.
With good growing conditions, forage production from spring-planted oats often ranges between 2 and 2.5 tons of dry matter per acre. Based on this amount, nitrogen (N) fertilizer should be applied at a rate of about 60 pounds of actual N per acre following establishment.
Spring-planted oats do not produce many tillers. Therefore, a higher seeding rate and slightly shallower planting depth can result in quicker establishment and greater growth. If oats are being used as a companion crop for alfalfa and/or grasses, back the planting rate off a notch or two so they don’t compete too heavily with the perennial crop.
Oat growth typically improves when seed is drill-planted at a rate of 80-100 pounds per acre. In areas with lower precipitation, it is more common for seed to be planted at 40-60 pounds per acre. Seeding depth can be up to 1.5 inches, but planting at 0.5-0.75 inches accelerates emergence, establishment, and forage production potential. Oat seed is more seedbed-forgiving than many other crops.
It’s generally not recommended to plant bin-run feed oats because they often are not tested, may contain weed seeds and other foreign material, and have unknown seed germination. Also, seed laws require that seed being sold for planting purposes have a tag with a recent test result for germination, weed seed content, and foreign material.
Maturity drives quality and yield
There are several oat varieties that have been specifically bred for forage production. Dry matter yields for these varieties can be up to 25% higher than standard grain varieties, but they often mature about a week later. Maturity needs to be considered if you’re planting another crop after the oats are harvested.
When spring temperatures begin rising, oats can mature rapidly, and quality will decline. This is the big difference between spring-planted and fall-planted oats. The former finishes in warm weather while the latter under cool conditions.
Where oats are being used as a companion crop, harvest in the boot stage to open the canopy and remove competition with the perennial seedlings.
Spring-planted oats won’t meet the “rocket fuel” quality of fall-planted oats, but their forage nutrient value is still very good if harvested at or before early heading.
Before grazing, oats should be a minimum of 6 inches tall. Each acre of spring-planted oats can provide between 35 and 60 days of grazing when stocked at one mature cow [or 5-6 mature ewes] per acre.