Farmer Began Farming by No-tilling and Planting Cover Crops to Improve Soil Health
Adam Joyner is our 36th Profiles of Soil Health Heroes. Adam is a full-time farmer operating in Gibson County, Tennessee. His farming operation is made up of eight different farms with a total acreage of approximately 700 acres. He said that all acres except 80 acres are either in winter cover crops (420 acres) or winter wheat (200 acres). Adam has his degree in Wildlife Management and began farming in 2012. He started farming by taking over a field that had been previously vertical tilled in 2012. His cover crop experience began in 2013, growing both turnips and/or radishes. The brassicas winter-killed, and Adam planted no-till into the cover. Adam never tilled or has not had cover crops in his management other than the field he took over for in 2012. Adam's farming operation consists of corn-wheat and soybean rotation. He farms predominantly Memphis Silt Loam, Providence Silt Loam, and Loring Silt Loam soil types. His slopes are gently sloping to sloping with slopes ranging 2 - 6%. These soils are from loess parent material and are highly erosive. His corn is planted on 30" row spacing while his soybeans are on 15" row spacing. Wheat is drilled. He uses a fluted coulter with a floating roll cleaner, double disk opener on his Kinze planter, and one rubber closing wheel and one spike closing wheel. Adam is considering dropping the spike closing wheel in 2018 and operate with two rubber closing wheels. He said the spike closing wheel had wrapping issues with the cover crop residue.
Adam takes intensive soil test samples on 2.5 acres grids. Samples are pulled on three-year intervals. Adam applies phosphate (P), Potash (K), and lime according to soil test and by variable rate. 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.
On August 14, 2017, Dustin Graham, NRCS District Conservationist, Trenton, Tennessee and myself (Mike Hubbs, Author) visited Adam and two of his fields. Adam divided a farm into two fields. One has been in covers since 2014. The other portion has been no-tilled without covers since 2014. Adam began using five species cover crops in his third-year farming. He became part of an on-farm demonstration project sponsored by the Gibson County Soil Conservation District. He also participated with NRCS in the Environmental Quality Incentive Program (EQIP). Since sampling began in 2014, the Haney Tests and Phospholipid and Fatty Acid Analysis (PLFA) show no differences between three years no-till and three years no-till with cover crops. The Soil test in 2015 showed soil organic matter (SOM) in both fields to be at 1.8%.
Looking closely at the fields on August 14, 2017, visual differences were obvious. 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 while covers protected the field from soil loss in the cover crop field. When I dug into the cover crop field, the shovel easily penetrated the top 4". The no-till without cover field was much harder to penetrate with the shovel. The soil structure of the cover crop field was changing to granular structure. Visually, the soil surface of the cover crop field had numerous amounts of earthworm casts and more biological activity present on the soil surface compared to no-till field without covers. Furthermore, the no-till without covers also had platy structure. The three years of cover crops are showing significant physical differences. Since both sections of the field were tilled prior to Adam taking over in 2013, the fields are recovering from former abuse and degradation. The soils were dysfunctional. However, they are recovering slowly but surely. Based on other fields using this management, we expect to see Haney test and PLFA differences in the future. Providing carbon and protecting the soil from tillage will increase soil carbon. Increasing soil carbon will improve the soil capacity to function (soil health).
In 2014, Adam began using five species cover crops that consisted 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. He also used Micronoc in 2016 as an innoculant on all of his seed which stimulates root development and provides a balanced microbial population to the soil. He plans to use Micronoc only on his legume seed for the 2017 cover crop season. In 2017, Adam purchased a thirty foot I & J Roller and Crimper. He sprayed covers and began rolling covers green and planting green for corn. He said if you delay rolling more than 24 hours after spraying covers the covers becomes harder to roll and plant into the covers. He terminated the covers with GramoxoneTM . He said the covers averaged 36 - 50 inches in height prior to planting corn. He obtained the roller to manage the higher growing cover crops. He also wanted to put the cover down to completely cover the soil. Covered soil functions better than bare soil. Also, he felt like he was having some shade issues planting in standing cover, especially in corn. The better coverage of soil suppresses weeds better. Laying the cover on the soil affords soil biology closer contact to cover thus increasing decomposition of cover. Lastly, once cover reaches 60 inches or higher in height, it is more apt to lodge making planting more difficult. Rolling and crimping helps manage taller and thicker biomass when planting.
For soybeans, he waited until cover matured and produced seed. He said that he should have killed at boot to early bloom stage to manage the cover easier when planting. He said the height was 60 - 72 inches. He killed the cover, rolled, crimped, and planted 14 days later. He used GramoxoneTM and crop oil concentrate on some fields, Round-upTM plus crop oil concentrate on other fields, and Round-up plus DicambaTM on another field. He said due to the wetness, he wished he had added a residual to the mix for long-term broad-leaf control.
Adam drills 100% of his cover crops after harvest. He drilled September 15 - 25 after corn, and approximately mid-October after soybeans. I asked Adam the benefits that he is noticing. In the first year he noticed less run-off. Adam said in the second and third years, he saw clearer water during intense storms. His no-till field still has more observable run-off and water is muddier. The soil in the cover crops seems spongier compared to the no-till field. He said there is definitely less weeds using covers. This field had a history of mare's tail. He said that he saved some on residual herbicides. Adam estimated savings of about $16.00 per acre. When the season is wet, he said that he will need to use more residual weed control.
I asked Adam his advice to others. Adam said that he still learning. He recommends that farmers should ease into it using covers. Begin with about 10% in covers. Kill the cover at knee high in order to learn to handle residue. Need to discover what it takes to get a good stand of crop into the residue of the covers. Adam also stressed the need to talk to others who have tried it and bounce off ideas. He said ultimately the farmer will have to tweak it to their individual fields, soils, and their particular operation.
Adam basically began farming no-tilling. He acknowledged the need to add cover crops to his farming operation. He is following the four principles of improving soil health: 1. keep the soil covered, using previous crop residue and cover crops; 2. reduce disturbance of the soil and cover, cease tilling and use exclusively no-till; 3. take advantage of energy and sunlight and capture radiation by keeping plants present and growing continuously, which increases carbon by photosynthesis and feeds soil biology while improving soil functions; and 4. add diversity by growing multi species cover crops and following a diverse crop rotation system. Diverse plants provide diverse quality and increased quantity of soil biology. The fields show remarkable observable changes. By Adam retaining a no-till field without cover crops, provides a baseline that will further our ability to compare and measure the differences between fields using cover crops and fields in no-till without cover crops. Adam is making a difference in his soil health as well as his bottom line.