Farmer Says Farmers Cannot Afford not to Build Their Soil Health
I am Mike Hubbs, Tennessee Association of Conservation Districts Soil Health Specialist. I have been visiting and talking to many farmers all across Tennessee that are practicing conservation practices that improve soil health. I call the series, Profiles of Soil Health Heroes. Bill Legg is our 28th of the Profiles of Soil Health Heroes. He is from near Lawrenceburg, Tennessee. I had the privilege to visit Bill on January 11, 2017 along with Mike Tatum, District Conservationist, NRCS, Lawrenceburg, and Tucker Newton, Lawrence County Soil Conservation District Office Director. January 11 was a pleasant day for January. It had rained earlier and was cloudy but a mild 66 degrees. Bill's soils range from 4-6% sloping silt loam soils to bottom land soils with slopes 0-2%.
Bill had grown up farming and had grown grain crops for many years and in his words, "just broke even." He changed his operation to grazing operation and some forestry. He did not grow annual crops for 15 years. He became interested in rotational grazing in 1996. He began to see the importance of Bio-Diversity. In 2009, he began to read more on the soil food web and soil biology. He also attended a session on the food web. This was part of a Missouri Grazing Field Day that featured soil health changes.
In 2011, he began farming crops again. He is farming on the halves with another farmer, who does the planting and harvesting for him. Bill supplies the land and seed. Bill began using cover crops in the fall of 2011. He wanted to incorporate his livestock enterprise with his crop fields. He now farms 140 acres for grain crops. Bill grows corn and soybeans in rotation and actively grazes his cover crops with his livestock. Bill drills soybeans and cover crops. He plants his corn in 30" rows. He said that his dad talked about growing cover crops back when his dad plowed with mules. They would plant cereal rye and vetch. As Bill researched soil health improving practices, he remembered his father's history with cover crops.
Bill uses composite soil sampling to determine his crop nutrient needs. He maintains his pH by liming as called for by soil test. Bill recently applied 1,000 pounds of lime per acre. He applies phosphorus (P) and potassium (K) annually by soil test analysis. His soil test results are testing medium in P and K. He applies 200 pounds on nitrogen (N) annually to his corn crop. He breaks up his N application with a starter and applies the remaining as corn is growing.
He has used many different combinations of cover crops since 2011. By mixing up his cover crops on annual basis, he sees advantages in his bio-diversity. His current cover crop mix for the fall of 2016 was 10 pounds of triticale per acre, 10 pounds of Bob Oats, 20 pounds of annual rye grass, 5 pounds of rape, and 5 pounds of Crimson Clover. His mixture is heavy in grasses to supply carbon to feed the soil biology and for grazing. When examining the soil under the cover crops, we examined that the previous crop residue has disappeared except for recent corn residue. This is an indicator of healthy soil biology. Since Bill is in his fifth year of cover crops, we witnessed the activity of soil biology on the soil surface. Grasses is a good supplier of soil carbon. With Bill's mature system, soil carbon is in more demand to feed the biology. With the increased biology, Bill is experiencing more nutrient cycling and better soil aggregation. Aggregation is the accumulation of soil particles into aggregates providing more air space in the soil. Well aggregated soil has better soil structure. The arrangement of aggregates is soil structure. When soils are healthy, structure take form of roundish granules or cube like blocks. Good soil structure results in good air and water movement, meaning better water infiltration. Bill notices good water infiltration and drainage in his soils. Bill also uses legumes in the mix. This supplies nitrogen to the soil and plants. It also lowers the carbon to nitrogen ratio in his mix making it easy for soil microbes consume carbon (decomposition) and synthesize or release nitrogen. Brassicas (rape, radishes, turnips, etc.) are added to provide a different root type, add diversity, and loosen the soil as well as uptake deeper nutrients that may be below the root zone. Rape also provides good early growth for fall grazing.
When visiting with Bill, I asked him the benefits of his five years of cover crops. He stressed the need for farmers to cease from tilling. No-till protects the benefits from the covers, crop rotations, and the grazing of cattle on his croplands. Bill stressed that his system is building equity. His first benefit is the building of soil organic matter or soil carbon. His soil organic matter is 4% on his crop fields. As earlier discussed, the previous residues have decomposed showing that his soil microbes are being fed. The manure added by grazing cover crops add a low carbon to nitrogen ratio organic material that is quickly decomposed by microorganisms. The carbon being broken down releases nutrients into the soil. Also, nitrogen is added by growing legumes. Bill also said by keeping roots growing year-round. Nutrients are kept in the field, and not running off, thus, improving water quality. Bill says that he provides much more forage by grazing his cover crops. This reduces the need to purchase or the harvest hay. Cattle harvests the cover crops for forage. By using good grazing practices, Bill turns his cattle loose into the cover crops when they reach 10-12 inches and grazes down to four inches. This simulates growth and the plant produces carbon through photosynthesis. Bill said that once he grazes his cover crops that he reduces his hay from five rolls per day to 1 roll every five days. He grazes 50 cow-calf pairs or 100 total head on the 140 acres. Bill says that he is sequestering carbon, that is by increasing soil carbon, he is taking carbon dioxide from the atmosphere and storing it into the soil. He said it is important for farmers to explain the benefits of no-till and cover crops to urban neighbors. Bill also has noticed weed suppression from allelopathic properties of oats, rye, and rape. He said there is less weed pressure when you do not till, when the cover smothers the weeds, and the natural herbicide effects from allelopathy.
As we examined the soil on January 11. The first thing I noticed was excellent cover for such a drought year. The water holding capacity of the soil along with residue from the system preserved enough water to germinate and grow the cover up to 6". When my shovel penetrated the surface, my shovel easily went down to 7" with no restrictive layers. As shown by the adjacent picture, soil structure was sub angular blocky indicating excellent pore spaces for water and air movement. The soil had a strong sweet earthy smell to it, indicating good soil biology health. There was good activity on soil surface showing residue decomposition and many holes caused by insects and earthworms. Each shovel full of soil had five or greater number of earthworms. The soil looked almost like it had been in permanent sod. The soil was very healthy.
As previously mentioned, Bill drills his cover crops, grazes them when they reach approximately 10-12 inches in height. He terminates his cover crops at about 12 inches in height due to late grazing for corn. He terminates in mid-April at approximately 24" when planting soybeans. Bill says that in addition to planting cover crops to his cropland, he plants rye grass, at 25 pounds per acre, into his pastures.
I asked Bill what he would say to future readers of this article. He said that farmers who are not doing this cannot afford not to do it. These practices build the soil's ability to produce crops. He said time is a major factor. We need time for the soil organic matter to increase. We need time for soil biology to build and for fungi numbers to increase in crop fields. He said in addition to all of his benefits, he receives a year of grazing from his cover crops, so he encourages others to consider adding cattle to their cropping enterprise.
Bill is very active with working with NRCS and his Soil Conservation District. He has had an Environmental Quality Incentive Program (EQIP) contract for three years. He really appreciates the financial assistance and technical assistance from NRCS and the local Soil Conservation District. He said the benefits of soil health are worth it by themselves, and would plant cover crops even if he did not receive financial assistance. His message is clear, farmers cannot afford not to plant cover crops. He also said that when doing something important such as improving the soil, farmers need to be patient. Bill said he saw stark changes in the soil three years after planting cover crops and grazing them. Bill's change in management and consistent use of cover crops have made a difference in his soils and his profits.