Trifolium pratense
A low-growing crop that is great to interseed with taller crops. It helps to create loamy topsoil, add nitrogen to the soil, and suppress weeds. Also has medicinal uses. Overwinters up to zone 4, winter kills in colder regions. Plant in spring or fall with a seeding rate of 0.25 lb per 1000 sq ft or 5-7 lbs/acre broadcast.
This clover seed comes pre-inoculated with the rhizobial bacteria that it needs to efficiently fix nitrogen, so it will perform well even in soils where legumes haven't been grown recently. Because the inoculant has approximately a one-year shelf life, it's best to plant this seed in the year you purchase it. If you don't use it all in the year of purchase, it just might need some additional fresh inoculant to perform its best in future years.