"If somebody posed the question - would I farm without cover crops - I would say no," says Kirk Brock, who grows peanuts, corn and soybeans on 1,000 acres in Northern Florida. Cereal rye has been Brock's go-to cover crop, but he is now experimenting with mixes that include ryegrass, clover and blue lupine.

His biggest challenge with cover crops is timing: finishing harvest and getting the cover crop planted early enough that it will grow before winter. But it pays off. The main benefits he sees are improved soil retention - his area is hilly - as well as better weed control and water infiltration.