Jesse Castleman
Seeing the Positive Effects from Cover Crops in Dyer, County
Jesse and Danny Castleman farm in Dyer County and reside in Newbern, Tennessee. They farm predominantly hill-lands in the Newbern area. Their soils are mostly Grenada and Loring Silt Loam. Since these soils have fragipans, they tend to be wet when rainfall is plentiful and drought prone when dry. Jesse took over the farming operation from his dad, approximately two years ago. Jesse is our 33rd Profile of Soil Health Heroes. I visited the farming operation on June 7, 2017 along with Adam Willis, NRCS Soil Conservationist, Dyersburg, Josh Richardson, District Conservationist, NRCS for Obion and Lake Counties, Ryan Blackwood, NRCS Soil Conservationist, Dyersburg, Danny Castleman, Josh Phillips, NRCS District Conservationist, Dyersburg, Jesse Castleman, and Landowner, R.C. Owens.
Jesse produces grain crops with a corn and soybean rotation. He and his father began cover crops in 2014, predominantly for erosion control. Most of their fields are 2-5% slopes. The soils are from loess (wind-blown silt). They are highly erosive when left bare and tilled. Jesse and Danny learned a few years ago that no-till was the method to farm due to erosion potential on their soils. As earlier noted, the soils are drought prone when conditions are dry, so additions of SOM are essential for these soils to remain productive. Growing cover crops have added much more active soil organic matter or carbon to their soils. Historically, we have lost over 50% of our soil organic matter (SOM) or carbon. Carbon (C) makes up approximately 58% of SOM; and therefore, the terms will be used interchangeable. Keeping a plant growing is the best way to build or increase SOM. Green plants produce sugars or carbon as a result of photosynthesis. Farmers miss opportunities when they only grow one crop per year for 110 days or less. However, cover crops not only add diversity to a corn and soybean rotation, but also provide more efficiency of intercepting energy flow from the sun. Jesse is doing this by planting multi species cover crops annually. Also, multi species cover crops mimic nature with many species growing during the season instead of just a monoculture crop. The sheer amount of biomass grown in the cash crops and cover crops add significant carbon to the system which in turns feeds the soil biology in terms of quantity and quality due to the diversity. The soil biology provides better soil aggregation and nutrient cycling; thus, the soil health improves.
current Acting State Conservationist, Jamie Carpenter is following Kevin's lead and promoting soil health. It helps that Jamie's normal job is Assistant State Conservationist for Programs. Having Programs focusing on soil health is huge for promoting and providing financial assistance. Tennessee Department of Agriculture is another major partner that is also supporting soil health in working with District Supervisors and financial support. Again, the team approach has been instrumental to Coffee County's support as well as the entire state of Tennessee.
Coffee County, like Tennessee, has embraced soil health in 2013. Adam Daugherty, NRCS District Conservationist, Coffee County convinced the Soil Conservation Board that this was the direction they needed to go. Coffee County was already a leader in no-till. They were doing a good job in natural resource conservation. The systems approach of mimicking nature, a deciduous forest was the missing piece. Bringing in cover crops were important, but understanding the function of soils and mimicking a forest was the key. The Soil Conservation Board not only supported the aggressive approach but many of them also jumped in and applied many soil health improving practices.
Traditionally, farmers have grown cover crops to around knee-high and waist high, killed the cover approximately two weeks before planting of corn or soybeans and plant in a crispy or dead cover. The weaknesses of this system are it limits the growth in the spring especially in corn. Some farmers in counties as south as Coffee County begin thinking about planting corn in March. As we know, cover crops are fairly short in March and just beginning to kick in another gear in the end of March, especially species such as Austrian winter pea, hairy vetch, and crimson clover. In fact, we dug these plants up on April 25 and found many nodules on the roots of each species of legumes. Nodules when they are pink indicate they are producing nitrogen. To kill legumes early, would be to lose a major benefit from the legumes in the mix. Farmers in Coffee County have learned to wait to plant corn to middle to third week of April. I know there are exceptions, but many farms that we visited had planted only about 7 to 10 days earlier. It was very wet on the April 25th, about 8 inches of rain had fallen a few days prior to our visit. Corn was germinating why we were there with a few acres of corn was still to be planted. Another weakness of planting crispy is once you terminate the cover, there is not an active root growing. This year we are bombarded by rain and cool weather. Having a root growing right up to planting is great way to drain uptake the excess moisture. Once the cover is terminated, the residue will hold the moisture in to the soil. Warm weather will eventually alleviate this problem.
the termination.
Since Coffee County has farmers in the fourth season of cover crops, it was great to see the benefits after four years. Some of the observations were on a steep red-clay field that had been in covers for approximately three years. They had been killing the covers early about knee-high to preserve the moisture going into summer. Now after some of accumulation of soil carbon, they were letting the cover grow higher. The field was functioning at a higher-level due to the three years of no-till and cover crops.
Soil structure in all the fields we looked at are granular at surface with some sub-angular soil structure as we dig deeper into the soil. This is why Coffee County is seeing 6-8" or greater per hour of water infiltration. We have seen by comparing some bare spots or some monoculture-legumes as cover crops that we can lose this soil aggregation quickly and water infiltration will go back to 2-4" per hour. We need diversity and cover continuously to keep soils aggregating. Active carbon that is recently dead residues and cover crops are the key to aggregating soils and for nutrient cycling. Total carbon or soil organic matter is important to keep climbing, but it is much more important to see diverse high-quality carbon being produced annually and being consumed by soil biology providing policing of soil disease, cycling of nutrients, and aggregating soil. If we continue to keep the soil covered, keep an active root growing, reduce disturbances, and maintain diverse covers we will continue to see our soil health or functions improving.