Common examples of cover crops are cereal rye, hairy vetch, oilseed radish, and crimson clover. These four cover most farm needs. They stop erosion, fix free nitrogen, and break up hard soil.
I watched an Iowa corn-soybean farm seed a mix of cereal rye and hairy vetch one October. They picked a 60-pound seeding rate. The plane flew the seed right into the standing soybeans for an early start. By the time the combine left the field, those cover crop species were already two inches tall. They were ready to take off.
Cover crops fall into four main groups based on how they help your soil. Grasses like cereal rye and oats grab leftover nitrogen and grow thick roots. Legumes like hairy vetch and crimson clover pull nitrogen from the air. Brassicas like oilseed radish punch through hard pans with deep taproots. Broadleaves like buckwheat draw in bees and add mix to the field.
Cereal rye is the king of popular cover crops. More than 5 million US acres get planted each year per USDA trends. The reason is simple. Rye sprouts in cold soil and lives through harsh winters. By spring it makes huge top growth to shield the soil. Hairy vetch comes in second since it can give back 80 to 150 pounds of nitrogen per acre for your next cash crop.
Oilseed radish has taken off in the last ten years for one big reason. Its taproot can punch down 32 inches deep through plow pans. The radish dies in winter cold. It leaves a hollow tube where new roots and water can flow next spring. Crimson clover is the southern pick for both nitrogen and bee forage.
When you pick from the best cover crop types, do not try a 12-species mix your first year. Start with one or two species that match your top goal. If your worst pain is gully erosion on sloped corn ground, plant cereal rye. If you want free nitrogen ahead of tomatoes or sweet corn, plant hairy vetch. If your soil feels hard and roots can not get down, try oilseed radish.
In my own test plot, I started with just cereal rye for two full years. That kept things simple. Once I knew how the rye grew and how to kill it on time, I added hairy vetch into the mix. The phased path saved seed cash and let me learn each plant on my own soil first.
Pick your top goal first and then match the species to that goal. Most farms get strong wins from just one or two well-chosen plants. The fancy multi-species mixes can wait until you have a few seasons under your belt.
Read the full article: Cover Crops: Cut Fertilizer Costs, Boost Yields
