Gibson County, Tennessee
Even though he’s new to the business, Adam Joyner operates eight different farms with a total acreage of approximately 700 acres (420 in winter cover crops and 200 in winter wheat) in Gibson County, Tennessee. He began farming in 2012 and started experimenting with cover crops – both turnips and radishes – almost immediately after in 2013. He uses no-till exclusively with his corn, wheat, and soybean rotation.
Adam’s corn is planted on 30″ rows, while his soybeans are on 15″ row spacing. He takes intensive soil test samples in 2.5 acres grids on three-intervals, and Adam phosphate (P), Potash (K), and lime by variable rate according to the results. He previously was applying 70 units of nitrogen (N) in the form of Urea at planting for corn with a second application of 120 units (granular). Since going to cover crops, he has increased to 90-100 units of N at planting to compensate for the increased carbon from the cover crops. The second N application is side dressed at approximately the V-5 growth stage, with 60-70 units of N. He sees the need to improve N-efficiency and plans to purchase a knife applicator for side dressing of N in the future.
His third year farming, Adam began using five species of cover crops as part of an on-farm demonstration project sponsored by the Gibson County Soil Conservation District. His multi-species mix consists of 25 lbs. cereal rye, 10 lbs. of Bob Oats, 8 lbs. crimson clover, 8 lbs. hairy vetch, and 1.5 lbs. Daikon radishes, all on a per acre basis.
His fields’ organic matter content hasn’t changed much in the last three years – the fields are recovering from former abuse and degradation, Adam says – but other physical differences are quite obvious.
For instance, on August 14, 2017, there was substantially more residue between corn rows of cover crops compared to the no-till. Significant soil loss was evident in the no-till field without covers and the soil was much harder to penetrate with the shovel compared to the field with covers. The soil structure of the covered field was changing to a granular structure, and had numerous earthworm casts and more biological activity present on the soil surface.
In 2017, Adam purchased a 30-foot I & J roller and crimper. He terminates his covers with Gramoxone and rolls his covers green and plants corn green (when the covers averaged 36 – 50 inches in height). He found that delaying rolling by more than 24 hours after spraying made rolling and planting into the covers more difficult. Adam says the covers have suppressed the weeds well, and saves about $16 per acre on herbicide application. When the season is wet, he said that he will need to use more residual weed control.
For soybeans, Adam waits to spray, roll, and crimp until the cover begins to produce seed and their height averages 60 – 72 inches. About 14 days later, he’ll plant.
Adam drills 100% of his cover crops after harvest. He drilled September 15 – 25 after corn, and approximately mid-October after soybeans. Adam has noticed noticed less run-off from using the covers, and in the second and third years of using, clearer water coming off the fields during intense storms. His no-till field still has more observable run-off and water is muddier.
When asked, Adam says he’s still learning, and recommends that farmers ease into it using covers. “Begin with about 10% (of your acreage) in covers,” he said, and “kill the cover at knee high in order to learn to handle residue.” Adam also stresses the need to talk to others who have tried it before, and to be open to tweaking the management of individual fields on an as needed basis.