Fall is prime time to invest in pastures to protect them before and throughout the winter to ensure good grazing in the spring. Most cool-season horse pastures should be fertilized with nitrogen in the late fall to boost root reserves and extend the grazing season. Other fertilizers can also be added in the fall, based on soil test results.
Nitrogen applied in the spring or summer significantly boosts grass growth, but many farms are unable to utilize this additional growth and ultimately mow it down instead. Rather than wasting good grass, consider applying nitrogen to cool-season pastures in October or early November. Fall nitrogen will not greatly increase grass growth, but it will boost grasses’ root reserves, allowing plants to remain greener longer into winter, survive winter better, and green up sooner in the spring. This effectively prolongs the grazing season. Additionally, a strong spring pasture will have better cover, which reduces annual weeds.
For best results, apply 40 to 50 pounds of actual nitrogen per acre to pastures once or twice throughout the fall. Applications can be anytime between September and the first hard freeze (overnight temp of less than 24°F). See the full article here or subscribe to the Bluegrass Equine Digest.