From Former Mined Land to Productive Soils

On April 26, 2016, I visited Keith Farms with Jeff Bowie, District Conservationist for the Natural Resources Conservation Service (NRCS), Maury County, Tennessee. Keith farm is located in Pottsville, Tennessee in Maury County. Keith Farms consist of Father, Ritchie and his son, Chad.  The Keiths are our nineteenth of Profiles of Soil Health Heroes.

A portion of the farm is formerly mined phosphate land. The location of the farm is on the Duck River. The farm was cleared of trees and shaped and disked to smooth a few years ago. This is the third year in production. The rest of the farming operation has been no-tilled for seven years. Recent rotation on the mined field has been one year of soybeans and this is the third year of corn. Approximately 335 acres are in center pivot irrigation. Just to make a point how effective Keith Farms are in keeping the soil covered, I have a picture below in the photo gallery of conventional tillage from a farm less than two miles from their farm.

Their crop rotation for the entire operation is corn, wheat or cereal rye, and soybeans. They crop approximately 3,600 acres. Four hundred of those acres are in cereal rye for grain, and 1,000 acres are in wheat for grain. 

They grow 3.9 - 5.2 group soybeans, group 3.9 for single-cropped beans. When following wheat or rye, they plant 4.9 - 5.2 group soybeans. Soybeans are planted in 15" rows, while corn is planted on 30" rows. All crops are GMO. They use grid sampling, variable application of nutrients, and yield monitoring. Application of nutrients are recommended based on former yields. They have recently reduced nitrogen application by 15%. Their average corn production under irrigation is 236 bushels per acre. The land is rolling and slopes are 4-8%. Soils are limestone from high phosphates. Their dry land corn averages 125-130 bushels per acre, where their more productive soils are over 200 bushels per acre. They have not taken soil test for soil organic matter. However, there are visual evidences that soil organic matter is increasing.

Their planter is a John Deere 1790 with no row cleaners. They use variable rate for planting and plant 28,000 - 32,000 plants per acre. The recently disturbed areas are the less productive. However, their variability is lessening each year. They use Gramoxone^TM to kill cover crops, along with low-rate insecticide. The low rate of insecticide is better for the beneficial insects. They also use low-rate Atrazine^TM.

Keith Farms are sloping and vulnerable to sheet, rill, and gully erosion. Since they have been in no-till for seven years, they have not seen visible signs of erosion. They also added cover crops seven years ago which has lessened any transition problems from tillage to no-till. They began with both wheat or rye as a cover crop for four years. For more diversity, they added multi species cover crops three years ago. Their current cover crop mixture consist of a five-way species of 15 pounds of cereal rye, 10-15 pounds of crimson clover, 15 pounds of wheat, 10-15 pounds of Austrian Winter Peas, and 2 pounds of rape, all per acre rate. 

The entire farm is 100% in cover crops or winter wheat and cereal rye for cash crops. Keith Farms want to keep evolving using cover crops. They noted the following benefits: better moisture retention, erosion control on sloping cropland, knobs and swags (low lying areas) produce more consistently, more rainfall is infiltrated, and less or non-existent ponding. Ritchie Keith said that the better job that farmers do with planting and getting a good stand, the better the cover does as far as improving soil function.

Keith Farms plant all cover crops after harvest of main crops. They use a drill or a spinner truck on all acres of cover crops. When using a spinner seeder on truck, they use 100 pounds of potash as a carrier with multi species cover crop seed mixture. They experimented on planting in the high covers, 5-6 feet tall. They began planting green prior to desiccating the cover crops. When they had some problems applying fertilizer evenly, they sprayed the remaining fields April 19-20 prior to planting. Keith Farms understand the importance of growing the covers as late as possible to achieve benefits. They were planting the day that I visited, April 26. 2016. They said patience is a must when farming using cover crops. Always plan to plant toward middle to end of April for corn. Be flexible when killing covers. They had challenges applying sulfur, zinc, and phosphate at planting. Killing cover at right time is essential and varies based on season. 

They continue to experiment by using plots. They planted some green, and others they planted after a week or so after spraying. He also has tried some turbo tilling (vertical tillage in plots). He saw no advantages in tilling. We dug some holes at planting and noticed some obvious platy structure or traffic pans at 0.5 - 3" from the vertical tillage. Keith Farms said their goal is to produce 300 bushel corn. "Covers will make that possible." It was very evident that this farm was not very productive after converting from mined lands, but has improved due to seven years of covers with last three years being multi species cover crops. Keith Farms had received technical assistance and financial assistance from NRCS. While looking at the all of the earthworm casts and biological activity on the soil surface, Ritchie Keith said that he is going to back off from any tillage and let the roots do the work. 

Keith Farms is a hilly farm that has been revitalized by clearing, shaping, and transitioned back to agriculture. There are challenges in farming lands like this. Keith Farms has done a wonderful job by reducing disturbances, no-tilling continuously for seven years, keeping the soil cover, utilizing crop residues from wheat, rye, soybean, and corn, along with multi species cover crops. They have kept roots growing almost continuously by keeping crops or cover crops growing year round. They have increased diversity with their crop rotations and multi species cover crops. Soil health has improved annually and continue to improve based on yield, and the way the soil now functions. Farmers should note the recipe that Keith Farms are doing and apply those principles on their operations.