By Dave Wilson, King’s Research Agronomist
Spring green-up time is soon upon us. Actually by the time you read this, many of our southern customers may have lush, green growth!
Come spring time, perennial grass pastures and winter annual small grain forages managed either for pasture or harvest respond to spring nitrogen applications at green-up time. Yields are primarily a function of available nitrogen that they can take up for their growth. Small grain forages require 75 to 100 lbs of available N per acre to achieve economically acceptable yields. We can achieve 2 tons/acre (dry matter yield) from a good stand, and well fertilized or manured fields can produce up to 4 tons of dry matter forage.
Wheat, Wheat Plus (wheat & annual ryegrass), barley, rye, triticale, Triticale Plus (triticale and annual ryegrass) and annual ryegrass all can be productive for spring pastures, managed for grazing. Rye often has lower forage quality values than barley, wheat or triticale. Winter wheat can be grazed very early in the spring and still be harvested later for grain or silage.
We recommend that at least 100 lbs of N/acre be applied at spring green-up. Some of the spring N will come from available nitrogen portion of manure applications, but the nitrogen in the organic form in manure will not be readily available in early spring cool soils. Fields should be supplemented with a commercial available N source for quick availability just prior or after green-up, when the plants break dormancy and start to rapidly grow.