Tama County Soil and Water Conservation District
Jack Boyer Farms, Inc. (a century farm)
We raise corn, soybeans, and seed corn in a corn soybean rotation on our Century Farm (est. 1912). I have used a variety of conservation practices in our operation over the years. I am currently using No-Till, Strip-till, and Cover Crops (single and multi-species). When growing seed corn and soybeans in rotation, the declining organic matter is a concern.
My father-in-law believed that we should pull out of the seed corn rotation every few years to grow commercial corn for reducing the rate of decline. About four – five years ago, I began to hear about the potential benefits of Cover Crops and “Soil Health,” so I started to research the possible options and benefits. I started with Annual Ryegrass aerial applied to standing commercial corn. I also have been using the Haney Soil Health test to evaluate my progress.
Soil Health Practices
The first thing that I suggest when someone is considering cover crops is to ask yourself, “what are my objectives?” For my operation, it started out to be building Organic Matter with secondary objectives of erosion reduction and nutrient capture. My first experience was with Annual Ryegrass and it was not the best experience. It was a dry year and did not get a good stand. Not to be detoured by one bad experience, the next year I planted some more Annual Ryegrass, but also planted Cereal Rye and Hairy Vetch. This time both had an excellent stand in the Fall, however over winter the Cereal Rye and some Hairy Vetch was all that survived.
The practice of aerial broadcast seeding cover crops is a less than sure thing as far as getting a stand established. To have any success, I believe that you must have 0.5″-1″ of rain within 24-48 hours of seeding. So try to time the seeding when there is rain in the forecast.
In my climate, Annual Ryegrass does not have the vigor to survive the Iowa winters, therefore if that is your objective, then Cereal Rye is a much better selection. Also in this climate, unless you can seed much earlier than the first week of September, radishes do not have enough time to provide the benefits often advertised. For my farm, I will plan to use Cereal Rye as the base species and continue to experiment with additional species to supplement Cereal Rye.
After three years of cover crops, I am starting to see some significant benefits, based on the Haney Soil Test and yield.
The short growing season is the principal challenge, along with the cost of implementing cover crops into the rotation. The lack of “good” data to show the economic benefit and the idea of it being an “investment in the Future” with low crop prices makes this a difficult idea to implement for some.