Q: It's nearly time to seed our hay field into horse hay after having it in corn last season. Can you tell me what would be a nice mix of alfalfa and timothy? Also, do you know what rate to seed oats as a nurse crop to keep down weeds? I do prefer alfalfa in my horse hay, but not clover.
A: I like your plan of seeding an alfalfa-grass mixture under an oat nurse crop. However, there may be better grass options than timothy in that mix. What kind of soil do you have? That might influence the best grass option(s). I trust the field has adequate pH (upper 6.0's), potassium levels, and drainage to support good alfalfa production?
For the oats, if you're on sandier soil, no more than 1 bushel (bu)/acre (ac). If you're on heavier, more clayey soil, you can probably go as high as 1.5 bu/ac. If you're planning to harvest the oat for grain, use no more than 1 bu/ac no matter what the soil type.
Regarding the grass species in the field, a number of different options can work well. Timothy is often favored by horse owners, but it lacks the total season production that other grasses have. It generally provides a nice first cutting, but not much after that. This would be even more pronounced on a more droughty soil, so 2nd and 3rd cuttings would be mostly alfalfa.
Smooth bromegrass has some of the same problems with yield distribution as timothy. Orchardgrass generally has better yield distribution, drought tolerance, and total season yield than timothy or brome. Same is true for reed canarygrass. If you use orchardgrass, its probably best to request a relatively late-maturing variety for better hay quality potential and better persistence. If you use reed canarygrass, ensure its a low-alkaloid variety. For a hay mix that you'd like close to 50:50, I'd recommend 7-10 pounds (lb)/ac of alfalfa. Orchardgrass or reed canarygrass seeded as the sole grass could be seeded at 4-6 lb/ac. Bromegrass has a larger seed, so that would be seeded at 7-10 lb/ac. Timothy seeds are small, so 3-4 lb/ac is usually adequate.
If you choose to use some combination of grasses, you can decrease their rates proportionally. The ranges provide flexibility for what species you'd like more dominant, if any.
Designing hay mixtures is science-based, but there's certainly some art and personal preference involved as well! As a side note, most horses do not need the amount of protein that is usually found in alfalfa dominate hay. The excess protein exits the body via the urine and can lead to strong ammonia smells. Finally, clover, generally speaking, is more difficult to dry in hay compared to alfalfa.
By Paul Peterson, PhD, University of Minnesota