Leaving Cover Crops Growing Later in Spring is Key to Quicker Soil Changes
Our 25th Profiles of Soil Health Heroes are Justin and Javen Fann. The Fann Brothers farm in Warren and Cannon Counties, Tennessee. They are third generation farmers. Their soils are mostly Dixson soils and lays gently on approximately 0-4% slopes. I visited the farm with the brothers, Javen's son, J. Daxton Fann, Trent Hancock, an employee, and Matt Feno, District Conservationist, NRCS, McMinnville, Tennessee.
As I am writing this article, Tennessee is suffering a drought in most locations of Tennessee. As Matt and I drove up to the farm, I saw green fields of cover crops growing exceptionally. I was pleasantly surprised. Their cover crops growing so well is a testimony to their following soil health principles. They left last year's covers undisturbed (no tillage), the soil is continuously covered, and they planted a cover crop for continuous growing plants with continuous growing roots after cash crop harvest. The cover crop is acting as a solar panel and is intercepting sun light energy and converting sun light to carbon in the green plants. Carbon is then increased in the soil from the biomass and roots. The diversity in the covers and crop rotations are up taking nutrients at different times, and the diversity above ground is improving the environment for soil biology and the soil is improving very quickly.
The Fann Brothers farm approximately 1,800 acres. They grow corn, wheat, and soybeans. Their dad taught them to always be stewards of the land. He began early on planting on the contour, and building terraces where applicable. In the 1980s, they began to plant crops using a no-till planter. Justin told me that even when they tilled, their dad was particular when and where he tilled. He was raised farming with mules and knew tillage could degrade the land. The family knew no-till was the key to preserving the land. They kept experimenting until they were pleased with the results. Most of their crops have been no-tilled since the late 1980s. Justin stated that no-till is their only planting method. Tilling the land is not an option. They are truly focused on conserving and improving their most treasured natural resource on the farm, their soil.
With their high standards for conserving the soil, it did not surprise me hear that they keep their soil fertility as high as possible. Their pH is close to 7. Their phosphorus is medium to optimum. Justin stated that they have to add significantly amounts of potassium each year. They have been practicing random collected soil samples. In 2016, they converted to grid sampling and variable rate for application of nutrients and seeding rates. They traditionally planted higher populations of corn on bottom-lands and less on uplands ranging from 28,000 to 32,000 plants per acre. Their variable rate seeding could range from 20,000 to 34,000 based on production. With soybeans, they reverse the order and plant lower populations of about 90,000 on bottom-lands to up to 130,000 plants per acre for soybeans on uplands. Their corn is planted in 30" rows, where their soybeans are planted on 15" rows. All of their crops are GMOs.
Over the years, they use to bale their wheat and plant double cropped soybeans in the wheat stubble. They noticed their soil was hard, and had substantial runoff. They have a natural drainage area that floods when they receive intense rainfall. They jokingly call this "Fann Lake." In about 2000, to improve the infiltration, they quit baling the straw and left it on the soil in their no-till system. They still experienced hard soils that would not infiltrate as well as they expected. They have grown about 1,100 acres to 1,500 acres in wheat for grain or cover. They also tried a monoculture cover crop of Austrian Winter Peas about ten years ago. They did not elaborate, but called it a "train wreck."
With their main desire to soften their soil (reduce the bulk density) and to improve infiltration, Matt Feno, NRCS convinced them to try multi species cover crops in 2015. Their results were amazing. Matt recommended a seeding rate of 54 pounds per acre of cereal rye, triticale, crimson clover, hairy vetch, canola, Daikon radishes, and Austrian Winter Peas. The Fann Brothers changed it to 64 pounds per acre to assure them of better cover. They drilled the cover crops and applied diammonium phosphate (DAP) on the covers. Last spring in early May, they sampled and estimated the covers to be 25,000 pounds of biomass (wet weight). All of the NRCS employees that were assisting, were quite nervous about the high amounts of biomass. The Fann Brothers were not very concerned. They planted their typical precision planted corn at approximately 32,000 plants per acre with excellent stands. They planted the majority by pushing the cover over with planter. They did use a ten feet roller/crimper on the remaining acres. They like the roller, but need a bigger roller. Justin stated that they really did not have any problems planting. He did say that they removed their row cleaners at planting due to cover wrapping around the row cleaners.
With the results of using a ten-foot roller, Justin and Javen had been in the market for a forty-footer roller/crimper. Most commercial available rollers are 10, 15, and 30 feet wide. They have had some problems in getting a custom-built roller at 40 feet wide. They were going to call a former USDA-ARS engineer that held the patents for many roller/crimper designs. He is going to share the designs with them. The Fann brothers are very engineer-minded. They have a machine shop, and plan to build a custom designed twenty-foot roller/crimper. If that meets their expectations, they will build a second twenty-footer. Once you spend time with the Fann brothers, you come away knowing that they will research their objective and figure a way to achieve their goals. Planting in heavy cover crops is only one example.
With sporadic rains, they made excellent yields in corn, full season soybeans, and double cropped soybeans. Justin remarked that the heavy cover provided moisture savings throughout the growing season. Their crops produced good yields with only 6.5 inches of rainfall. Justin said that their corn leaves did not roll up once, that is to show drought stress. He said corn around them that was no-tilled without covers had severe rolling up of the leaves from drought stress. They also did some temperature studies at 1.5 inches deep in the soil and the soil with multi species cover was always at least 10 degrees cooler than no-till soil only in crop residue.
After corn harvest in 2016, Justin and Javen no-till drilled 50 pounds per acre with seven species of cereal rye, triticale, black oats, Daikon radishes, Austrian winter peas, Ethiopian cabbage, and hairy vetch. They bulk blended the seed and mixed them in a fertilizer mixer. They drilled after corn the last week of August to early September. Some fields have also experienced corn regrowth, so despite the drought, there is substantial biomass already present. Some radishes reseeded from last year and are showing large tubers already.
The fields after soybeans were planted later up to middle October. They mixed the seed as described above and put all seed in drill-seed box and calibrated for 50 pounds per acre. They drilled eight species of cereal rye, regular oats, triticale, Daikon radishes, hairy vetch, crimson clover, Austrian winter peas, and Ethiopian cabbage.
The brothers also use a water shed blend. In areas with drainage areas, they plant cereal rye and wheat at 3 bushels per acre in late October. They plant a total of 400 acres in diverse species, and 300 acres of wheat.
Walking around the farm and digging holes to look at the soil showed some interesting findings. It was October 27 with little rain the last couple of months. The Fann brothers remarked that the one-year heavy diverse cover crop made a difference not only in yields and temperature differences as discussed above, but you could feel that the soil in cover crops after last year's cover was much softer and had much more feel of moisture compared to acres of fields with first year covers that were just planted. We also dug and found heavy platy structure at surface of fields in wheat and fields just planted to first year covers in 2016. The fields planted in multi species in 2015 and 2016 had much less platy structure in surface and it broke to granular and blocky structure very easily. There were much more earth worms in fields that were planted in multi species in 2015 and 2016 compared to fields in wheat only and fields planted in multi species only in 2016. The brothers were sold on multi species prior to me coming to their farm. But after digging and seeing the increased moisture savings, darker surface softer soil, and better blocky structure only in one year, we were all amazed. The key to getting quick results in soil health is grow cover crops to bloom stage for legumes and early head stage for grasses. Many farmers want to kill them too early. The Fann Brothers planted corn last May 3 in green cover crops. They followed up shortly with Round-upTM. Another factor is the diversity. Farmers need grass to change soil structure. So all mixes need grass to change soil structure such as cereal rye in the mix. Legumes and brassicas are excellent for loosening tight soil and up taking different nutrients, but grass is key to build soil carbon or soil organic matter in the soil.
As earlier discussed, The Fann Brothers are building their own roller/crimper. They plan to let all multi species grow to bloom or early head stage for grasses and terminate by rolling. They expect to kill the majority of cover crops by rolling and crimping. They will only use a little Round-UpTM for clean-up termination of cover crops. The pictures in this article show a neighbor's field that is planted to wheat two weeks prior to Fann Brother's wheat. The neighbor's field was tilled multiple times. The Fann's field planted to wheat after years of no-till and crop rotations is germinating quicker than neighbor's field even though it was planted two weeks later. This is a result of moisture savings and better infiltration from no-till compared to tillage. Oh by the way, Lake Fann that was discussed earlier disappeared this last year even when the rains were intense. Cover crops increase water infiltration and reduce run-off, which is a major goal that the Fann Brothers desired.
Again, one year after heavy multi species cover crop grown to near maturity produced a softer soil, a soil with less platy structure, darker due to more moisture, and had lower temperatures in the summer. The soil was much easier to dig in and had many more earth worms per digging compared to wheat fields or fields planted to multi species in only 2016. Justin and Javen had remarkable soil changes in one year. They plan to follow up with fertilizing the covers in the spring with DAP. They plan to keep the covers growing to early May. I expect to see even greater evidences of changing soil health next year. Better soil health means better crop yields and better profits.
