Editor’s note: These case studies are based on interviews from November 2008–March 2009. The case studies on the Davis and Brock farms were updated in 2018.
The case study farms were chosen by Natural Resources Conservation Service (NRCS) field staff based on the producers’ conservation tillage experiences and their willingness to contribute their time. The income sources on these farms range from substantial off-farm income to exclusively on-farm income. Some farms work very closely with university Extension and participate in university research and demonstrations. Others only use Extension publications, websites and/or enterprise budgets and do not participate in research or demonstrations.
Conservation tillage is commonly used in the interviewed producers’ communities. In some cases, estimates of local acreage in conservation tillage were 90 percent or greater. Other than herbicide-resistant weeds, the interviewed producers did not see significant barriers to the adoption and use of conservation tillage. The seven case study farms are described below.
The Davis Farm, Paul and Boogie Davis, New Kent, Virginia
Paul Davis works as an agricultural Extension agent, and along with his father, Boogie, he operates a grain and specialty crop farm in eastern Virginia. The 250-acre field crop and specialty crop farm is located in the upper portion of the Southern Coastal Plain. Most of the farm, 235 acres, is in a two-year corn and double-cropped wheat and soybean rotation, corn>wheat>soybeans. Pumpkins are grown on an additional 15 acres. The pumpkins are rotated with other crops and are not always grown on the same field.
The Davises began using a no-till system to plant corn and soybeans in the mid-1970s but continued to till before planting wheat and specialty crops. In 1999, they started a continuous no-till system that includes no-till small grains and pumpkins. The only tillage on the Davis Farm is the occasional smoothing of areas rutted during harvest. Cover crops were added in 2005. A cover crop or a small grain for harvest is grown on every acre during the winter.
The soil types are Bojac and Pamunky sandy loam or loamy sands with slopes of 2–4 percent. Soil pH is typically 6.5 or higher. They have used biosolids from wastewater treatment facilities and plan to continue to do so. However, they do not use lime-adjusted biosolids because that would increase the pH too much and would tie up micronutrients, especially manganese. They do not use animal manures. The Davises started using the Green Seeker variable rate nitrogen-fertilizer application technology to more accurately apply nitrogen fertilizer to their small grains. They have been involved with a Conservation Innovation Grant, a SARE grant, and other research and demonstration projects.
The Brock Farm, Kirk Brock and Gene Brock, Monticello, Florida
The Brock Farm is located in the southern range of the Southern Coastal Plain. The Brocks own approximately 450 acres and rent 500 acres. There are approximately 75 fields ranging in size from 1–100 acres. Most fields are 5–15 acres. The farm stopped animal operations in 2001 and all open land is currently used for field crop production. Usually four crops are grown: peanuts, corn, soybeans and cotton. However, cotton is not planted in some years. The acreage planted to each crop is more or less evenly distributed. When there is a four-crop rotation, approximately 25 percent of the fields are in each crop. When there is a three-crop rotation, approximately one third of the fields are in each crop. Rye is planted each fall on all acreage as a cover crop (Figure 18.3). Brock is experimenting with other cover crops, including crimson clover alone or in a blend with cereal rye or ryegrass, or with both.
FIGURE 18.3. Planting corn into a rolled/crimped rye cover crop on the Brock Farm. Photo courtesy Drew Demott, USDA NRCS.
The more common soils are Dothan, Fuguay and Orangeburg, with Pellam and Rains in the low spots. Slopes are typically 0–7 percent. The natural pH is 4.5–5.8, but the pH of cropland on the farm is maintained at 6.5–6.8 through liming. Organic matter ranges from 0.6–0.9 percent on most fields and from 1.5–2 percent on the old pastureland that is now used for crops.
Bottom (moldboard) plowing was abandoned in 1976 for corn, soybeans and cotton but was used for peanut production up to the early 1990s. The transition to strip-till/no-till on the Brock Farm began in 2001. The Brocks sample their soil every third year. During the interview, the Brocks cited literature references they used to plan their no-till and cover crop activities.
Triple J Farm, Dalzell, South Carolina
William, Whit and Hastings James own and operate a farm located in the Southern Coastal Plain region in South Carolina. Their farm has four major enterprises: cash crops, a peanut-buying station, a cotton gin and a granary. The cash crops are:
- corn and soybeans, planted in 30-inch rows using true no-till and supplemental irrigation
- cotton and peanuts, planted in 38-inch rows using strip-till and supplemental irrigation
- wheat, planted using conventional tillage with no irrigation
Soybeans follow wheat in a double-crop system when wheat is planted in the fall. The crop rotation is generally corn>cotton>peanuts>soybeans. Wheat is grown on a field once every 6–10 years. Disking before wheat is seen as a necessity in order to level out tractor and irrigation wheel track ruts accumulated during the previous years. Although ruts occur, the fields do not have erosion rills or gullies. Irrigation water does gather in the equipment ruts. The farm does not use cover crops, although the Jameses have considered it.
Cotton requires warmer soil for seed germination than the other crops. No-till keeps the ground cool longer into the growing season, which presents a concern for cotton-seed germination and stand establishment. So, the farm uses strip-tillage when growing cotton. Strips 11–14 inches wide are tilled in order to allow the seedbed to warm. Seed placement for cotton and peanuts is more critical than other crops, and planting into a tilled strip allows more-accurate seed placement.
The cash crops are grown on approximately 1,800 acres, most of which are rented annually. When the James brothers want to install irrigation, they sign a 10-year lease for the cropland. Annual land rentals are very stable in this area. A renter is fairly sure they will be able to rent the same land for several years, so the James brothers are more inclined to improve soil health on rented land, because they are likely to see the benefits in future years. The common soil types are Norfolk and Orangeburg loamy sands. Soil pH is typically 5.5 or higher, and organic matter ranges from 0.5–1.5 percent on most fields.
The farm often uses NRCS and Clemson University Cooperative Extension Service (CES) for assistance. Triple J Farm also participates in CES research. The farm is currently providing peanut production records to CES.
The Rawlins Farm, Rebecca, Georgia
Bob Rawlins farms approximately 450 irrigated and dryland acres in the central Southern Coastal Plain region of Georgia. The farm also has a cow-calf operation with approximately 200 cows. Additionally, Rawlins has a tree planting business that takes up a considerable amount of his time during the winter months.
Some fields with steep slopes were terraced when conventional tillage was used, and the terraces are still there. Some of the cover crop acreage close to the pastures is grazed to provide winter forage. The irrigated acreage is approximately evenly split between silage corn, peanuts and cotton. Watermelons are double-cropped with silage corn for a three-year watermelon>silage corn>peanut>cotton rotation. Rawlins uses herbicide-resistant varieties of cotton and corn, and Bt corn. Bt corn includes a gene that produces a protein that kills the European corn borer. The crop rotation takes disease potential into account by keeping peanuts and watermelons separated by corn or cotton. It is recommended that there be three to four years between peanut crops to help minimize disease pressure and pest pressure, especially nematode pressure [5]. However, the typical two-year rotation on the dryland fields is cotton>peanuts.
Most of the cropland on the Rawlins farm is Tifton loamy sand on slopes of 2–10 percent. Rawlins has been reading No-Till Farmer magazine for a long time.
The Dargan Farm, Darlington, South Carolina
This farm is located in Darlington County, which has land in both the Southern Coastal Plain and Atlantic Coast Flatwoods. The farm has two enterprises: turf grown on approximately 300 acres and cash crops grown on approximately 1,700 acres. Cash crops include wheat, soybeans, corn and cotton. Approximately 60 percent of the cash crop acreage is rented. Tobacco had been a major crop on this farm for many years, but they stopped production two years ago. This change in operation has allowed the Dargan Farm to implement continuous no-till on a greater amount of acreage. This farm has broadcast-planted rye cover crops for a number of years.
Edwin Dargan and his son work closely with the scientists at the Coastal Plains Research Station operated by the Agricultural Research Service (ARS), specialists at CES and consultants with Southern States Cooperative. The Dargan Farm has implemented newer technologies such as variable-rate irrigation and variable-rate nutrient application.
The Winslow Farm, Scotland Neck, North Carolina
The Winslow Farm, operated by Jack and Herb Winslow, is located in the upper portion of the Southern Coastal Plain, has always produced row crops and previously had a 2,000-sow operation. Currently, 2,200 acres are in row crops and the farm has maintained 400 acres of sod production since 1996. In 1986, Jack Winslow received the national Conservationist of the Year award from the National Association of Conservation Districts (NACD). At one time this farm had the largest subsurface irrigation system in the United States. For the remainder of the chapter, all comments about the Winslow farm were made by Herb Winslow.
The farm had been in no-till for about 20 years. Then, in 2006 the Winslow Farm became certified organic. Initially they attempted to use no-till in the organic system but experienced challenges for which technology was not yet available. The challenges were primarily weeds, but they also included residue accumulation that could limit the effectiveness of planting and harvesting equipment, and excessively cool soil temperatures at planting. The farm has returned to conventional tillage to maintain their organic certification. Now the farm is experiencing the downsides of conventional tillage, especially a degradation of soil biota that is addressed by applying compost extract.
The organic corn and soybeans go to Braswell Milling for organic chicken feed. The organic wheat goes to a Charlotte bakery. The manure from Braswell Milling’s organic chicken operation (layers) is used on the Winslow Farm as a fertilizer. The Winslow Farm conducts test plots for organic corn demonstrations and continually samples soil and plant tissue for liming and nutrient needs. The Winslow brothers designed and built their own compost extraction process.
The Harris Farm, Littleton, North Carolina
The Harris Farm includes cropland in the Southern Piedmont and in the upper portion of the Southern Coastal Plain. Tom Harris's comments were in consideration of both regions. This farm has 75–80 Black Angus brood cows. The primary rotation has wheat double-cropped with soybeans for a three-year rotation of wheat>soybeans>corn>peanuts. However, Harris often deviates from this rotation as commodity prices and feed needs of the farm change. At times, pastures are rotated with crops in a sod-based rotation system.
Harris began conservation tillage in 1993 using strip-tillage. He subsoils, strip-tills a 6-inch wide strip and plants in the strip. He relies heavily on cover crops, compost, manure, crop residues and sod rotations. This has allowed him to achieve high yields of quality products using little commercial fertilizer.