Growing Cover Crops to Manage Nutrients and to Improve Soil Health Near the Mississippi River

My name is Mike Hubbs. I am the Soil Health Specialist with Tennessee Association of Conservation Districts (TACD). I have authored the series of Profiles of Soil Health Heroes. I introduce myself in this article because I live in north Knox County in a community called Halls, sometimes called Halls Crossroads. In its long history, Halls Crossroads, or as locals call it Halls, has attempted to obtain its own postal zip code. For whatever reason, it has not happened. Years ago, they tried and the post office was going to be named Halls Dale in order not to be confused with Halls, Tennessee. That fell through, and Halls still has a Knoxville zip code. 

I give you this background because our next Profiles of Heroes, number 26 is Charlie Roberts from Halls, Tennessee in Lauderdale County. Halls Crossroadsin Knox County is approximately 400 miles east of Halls, Tennessee in Lauderdale County. I say all of this because it has been a common miscommunication. Recently a delivery for Halls in Knox County comes to Halls in West Tennessee. The driver of the truck was absolutely perturbed when he realized that he had to drive an additional 400 miles east because of miscommunication from his home office. So on November 3, 2016, I made my way from Halls in North Knox County to just 14 miles east of the Mississippi River in Halls, Tennessee. I met Charlie Roberts and George Henshaw, NRCS District Conservationist for Lauderdale County at Charlie's mother's place of business, Charlene's Collectibles and lunch at " Just Divine Tea Room." I was surprised by the bustle of activity at Charlene's Collectibles with several women all over the region shopping and eating. I am not accustomed to eating at too many "Tea Rooms;" however, I must say the food was great and plentiful for a man's appetite. I can see why the crowd was there.

I have attended some Soil Health Round Table Discussions with Charlie Roberts over the last two years in Madison County on two occassions. I also traveled with him with the Tennessee's tour of Dave Brandt's in Ohio in August of 2015. I have also seen him at some field days where I presented. I knew about his enthusiasm to learn more about soil health. I also had discussed with him some of his farming experiences. Thus, I am now writing about his sucesses in improving his soil.

With drought and extreme warm weather this fall, I noted the temperature was 82 degrees on November 3, 2016 at Charlie's farm. They have not received any rain in approximately six weeks. Charlie said the last rain was 0.25 to 0.5 inch. Charlie said that he was a fourth-generation farmer. I also met his Dad, Ronnie during lunch. He said that their ancestors made their way from North Carolina to the Cumberland river and then westward to Carroll County. The Roberts made their way from Carroll County in 1920 in seven wagons and traveled for seven days to the Barr Community in Lauderdale County. Their reason for picking up and relocating was the inexpensive land prices and higher fertility of the soils adjacent to the Mississippi River. Their original track of land was the Barr Farm on the Mississippi River.  Ronnie said that Charlie runs the farming operation now. Ronnie helps out from time to time with the farming operation and also at Charlene's Collectibles. Charlie said their original farm was a historical cotton farm. Recently the farm has changed to a corn, soybean, triticale and cereal rye and oats for grain.  They only produced corn, soybeans and oats in 2015 and 2016. The last cotton produced on the farm was 2013. Charlie says they will continue to grow corn, soybeans, oats, triticale and rye in the future. The farming operation is approximately 1,300 acres.

I asked Charlie how he became a full-time farmer. He graduated at Mississippi State with a degree in Agriculture, majoring in Agronomy with emphasis in Golf and Sports Turf Grass Management. He was a golf course superintendent. When the economic crash or downswing occurred in 2009, Charlie was visiting home at Christmas of 2009. He had lived away from the farm for 13 years. He received an invitation to take over the farm. He jumped at the opportunity and began farming at the end of January of 2010. Charlie talked about the conversion from turf grass profession to farming. He said it worked well. The science is very similar. He simply went from growing grass to killing grass in his crops. He said the above ground agronomy science was easy. The mystery of soil biology, especially soil microbiology or below the ground was much more difficult. 

Charlie told me that while growing up, they were traditional cotton farmers using conventional tillage methods. His dad and Uncle Johnny began no-tilling in 1975. Johnny designed and built the first hooded sprayer in West Tennessee. Johnny applied for a patent, but the cost was too great to pursue. They successfully no-tilled soybeans into sod pastures and achieved great stands and crops despite lack of herbicides to kill the weed pressures. They tried for years but finally abandoned the concept due to inability to control weeds and resorted back to tillage. With improved crop genetics and better herbicide chemistry, his dad, Ronnie began no-tilling during the 13 years that Charlie was away from the farm. Charlie soon bought a farm of his own in 2011. He attended a meeting and learned about "Cover Crop Solutions." He tried their "Indy Mix" in the fall of 2011. The mix consisted of tillage radishes, crimson clover, and annual rye grass. He drilled 50 acres at approximately 17-18 pounds per acre for the mix. He said that was the first time in 20 years that winter cover had been planted on the farm.  

I asked what led him to try the three species cover crops in 2011. He knew that no-till was helping the soil, but felt that there was still a problem with the soil. Charlie knew that ripping the soil would only make it worst. He was seeing j-roots with soybeans which showed some compaction issues. He said that the salts in chemicals were making the soil hard. The soil organic matter was too low. The cation exchange capacity (CEC) was not in balance. He kept seeing soybeans reach 36-38 bushels per acre and could not yield above that barrier. He wanted to emulate nature and bring back soil life, loosen the soil, and increase soil organic matter. He was inferring that he needed to improve water infiltration. Besides improving infiltration, he wanted the roots to go deeper into the soil. In order to be a successful farmer, Charlie understood that he had to change the soil, which motivated him to add cover crops to his farming operation.

In the spring of 2012, he no-tilled soybeans into the 50 acres, of killed cover of rye grass, radishes, and crimson clover. He said that he observed soybean taproots at 10-12 inches, which was significantly deeper than prior to growing cover crops. Previously, soybean taproots stop at chisel tillage depth at about 7-8". Charlie wanted to assist the cover crops in adding more organic amendments to the soil. He began adding 2 tons per acre of chicken litter for three years, 2012 - 2014. Those fields received six tons per acre. Charlie said one farm received 8 tons per acre of chicken litter over three years. He said that was too much too soon due to the phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca) and sodium (Na) were too high.

Charlie annually soil tests for application of his nutrients. He is interested in seeing what covers up take certain nutrients. Buckwheat brings up P, where cereal rye brings up K. Charlie understands that soil test may show nutrients are optimum, but sometimes it is difficult to have nutrients available off of the soil colloids and available for plant uptake. Cover crops can uptake nutrients outside or deeper than the cash crops root zone, and make them more available. He is grid sampling and applying K, nitrogen (N) and sulfur (S) by variable rate. No P has been called for in soil test recently. In 2016, he took N biomass readings on the cover crops and the nitrogen contribution this spring, a few days before corn planting. Charlie was pleased with the contribution of nitrogen from the covers.

Charlie plants his corn on 30" rows, soybeans on 15" rows, and drills small grains for seed on 7.5" rows. Charlie enrolled in Conservation Stewardship Program (CSP) in 2013. He signed up for structures in 2011 under Environmental Quality Incentive Program (EQIP) and Tennessee Department of Agriculture funds (TDA) in 2016.

Charlie has experimented with several of options of multi species since 2011. His current core species for 2016 are daikon radishes, hairy vetch, Austrian winter peas, annual rye grass, and winter oats. He formerly has tried rape, blue lupin, Balanca clover, triticale, cereal rye, yellow sweet clover, buck wheat, and sorghum sudex grass.

Charlie farms near the Mississippi river and tributaries that drain into the river. In March of 2016, 35 acres out of a field of 50 acres flooded. His blend, in 2015, was cereal rye, triticale, and rape. During the time of the water receding and planting soybeans, he planted 20 pounds of buckwheat per acre and 5 pounds of rape per acre. He said "it worked to perfection." He said the field was very clean as far as weed pressure and that the buckwheat had loosen the soil at 2-3" depth. The buckwheat was 12-14" and flowering, while the rape was 8-10" in height. He plans to do this again if flooding drowns out his winter cover mix. He said that soybeans planted in buckwheat and rape seemed healthier. However, yields were similar from planted after winter cover. Charlie said that he was sold on buckwheat and rape to plant in late winter or early spring on flooded ground. Charlie began using cover on 50 acres. He expanded to 700 acres in cover 2012 -2015. Counting acres in triticale, cereal rye, or oats, the entire farm of 1,300 acres were in winter growing cover crops or grain crops.

I asked Charlie which methods had he used in planting his cover crops since 2011. He has used a spinner truck to broadcast his seed, an airplane for aerial seeding, and a no-till drill. He drills as much as possible, and that is his method of choice when timing is right. He rates airplane as second method of choice, and spinner truck last in preference. He plants and calibrates on pounds per acre and mixes his seeds. If broadcasting, Charlie prefers straight downward direction with airplane over the circular pattern of a spinner truck. Based on his experience, he said the weight of seed and size of multi species will give scattered stands when using a spinner truck. Charlie says that he does more research on preparing for cover crops than he does on cash crops. As farmers read this article, it is much more than simply signing up for financial assistance and planting covers. The commitment must be there in order to truly change your soils. Covers provide many benefits. Growing the right combinations for your objectives are important. Planting dates as well as termination dates need to be part of the strategy as well as planting method and timing with the cash crops harvest or planting inter seeding in cash crop prior to harvest.

Charlie said that the benefits of cover crops surprised him somewhat. He began with the objective that loosening up his soils would be the number one benefit. Covers have loosened his soil, but he ranks that fourth in importance on his list of benefits. His benefits are in his order of preferences: (1) Weed suppression. There are much less weed suppression since using covers from 2011 until present. (2) Nutrient cycling, the covers up take other nutrients that otherwise would be unavailable. (3) Reduced nitrogen due to legumes and more nitrogen from increased soil organic matter. (4) Reduced bulk densities or loosening the soil (as earlier discussed). (5) Other benefits from increased soil organic matter such as higher CEC, and water infiltration. Charlie said that West Tennessee Farmers do not have a run-off problem but an infiltration problem. No-till with multi species cover crops will heal soil structure and increase water infiltration. Soil biology breaks down roots and residue and aggregates soils which results in more crumbly and sub-blocky structure. 

Charlie noted that as the soils began to loosen and infiltrate better, his dad, Ronnie was sold on using covers. There are no longer any run-off, erosion and the need to fill in gullies after harvest. This results in savings both in money and time. George Henshaw, NRCS District Conservationist also chimed in. George said that prior to 2014, the office handled almost exclusively soil erosion prevention practices such as grade stabilization structures, and water and sediment control structures. Now, his staff is seeing more cover crops. This is the first year that the Lauderdale County Soil Conservation District (SCD) is utilizing Tennessee Department of Agriculture (TDA) funds for cover crops. Charlie says that is a good investment. "It is cheaper to grow cover crops than to repair and shape gullies." 

I asked Charlie if he was experiencing any savings with reduced fungicides or herbicides since going to cover crops. He said no yet, but he was saving on preemergent herbicides and using some more post emergent herbicides. Cover crops due to smothering and allelopathy were reducing early weed pressures.  

As earlier reported in earlier Profiles of Heroes, Tennessee experiences some problems in 2016 with rape and canola. There were problems terminating the rape and canola. Charlie had planted as much as 10 pounds per acre of rape in 2015. He plans on using rape in the future. He has his recipe to terminate the rape. However, he did not plant any rape in 2016, due to several plants volunteering from seed. In the future, when he resumes planting rape, he plans to plant 2-4 pounds per acre. He plans to buy true rape seed with no GMO qualities. He said some of the seed planted in 2016 had crossed with glyphosate-resistant rape. Charlie said that when rolling rape, the key is get the leaf on the ground to provide allelopathy. Rape is a natural soil fumigant.

All of the pictures taken on my visit, November 3, 2016, were of recent aerial seeding in October. There had been no rain for at least six weeks. You could see some germination under the residue, which is a benefit from last year's residue. I also asked Charlie to send me pictures of last spring prior to and at planting which are seen below. There are also pictures of 2016 crops growing in residues. As we dug and looked at the soil, I was amazed at the amount of moisture found in soil. we saw rye grass and crimson clover germinating. Charlie said that he also adds four pounds of sugar per acre to jump start microbes in the spring. We noticed a lot of biological activity in the soil, with earthworm holes, earthworms, earthworm casts, and insects working on the residue. The soil was truly alive.

We dug in the soil and saw crumbly and blocky soil structure. There was no longer any platy structure. Platy structure is normally the case in no-till fields in West Tennessee. Below left, is a field that has been vertical tilled. Some count this as conservation tillage. Like all tillage, it destroys soil aggregates. Note the strong platy structure. It takes roots and multi species and no tillage or little disturbance to aggregate soil and form crumbly structure. This results in good infiltration. Charlie returned to the farm in 2010. He researched and learned from others on how to add multi species cover crops to his farming system as well as following no-till for the last 13 or so years. The soils are changing very quickly. Charlie is benefiting from better soils with better profits. Charlie is an example that we can improve our soil health and emulate nature with multi species to add diversity, reduce soil disturbances, keep roots growing and keep the soil covered. All of these components are essential to building soil health.