Using Annual Sorghum-Sudangrass in Cool-Season Pastures to Improve Soil Health and Better Profit
Bobby Ellison is a NRCS Soil Conservation Technician assigned to Union County Soil Conservation District Office and also the NRCS FieldOffice in Tazewell, Tennessee. Bobby provides technical and financial assistance to farmers in Union and Claiborne Counties. Mike Shoffner is District Conservationist of Tazewell Field Office which also has jurisdiction over Union County. Bobby began his career as an intermittent employee in 1996. He became a county employee with a partnership with NRCS until 2000 where he then became a full-time employee with NRCS. Bobby said during my interview with him that he always had a passion for farming. His attractiveness to the land led him to a career in natural resource conservation as well as farming.
Bobby purchased his farm with his dad in the 1980s from Bobby's grandfather. Bobby is a fourth-generation farmer from Sharps Chapel area of Union County. He said that his goal in life 'is to make things better." Bobby farms 800 acres with 150 cows with approximately 138 calves and a few bulls. Bobby has a unique grazing operation and is our 37th Profile of Soil Heath Heroes.
Bobby's stewardship value and his keen awareness of economics with beef cattle led him to a monumental decision approximately 10 years ago. Typically, like most cool season pasture farms, Bobby would run low on high quality pastures during the warmer and dryer months of July - September. He would have to feed hay up to four months out of the year. Bobby wanted to help his hilly-cherty-limestone soils to improve in both soil health and productivity. His goal was to improve his profit margin, and by improving his soil resources (soil health) was his means to an end to achieve better grazing in the summer, stock-pile cool season grasses, prevent over grazing, and feed 75% less feed.
He began no-tilling sorghum-sudangrass on 30% of acreage. Bobby is meticulous record keeper and told me that he invests $18.00 per acre. He plants 25 pounds of seed per acre ($8.00 per acre) and uses a Great Plains no-till drill ($10.00 per acre). He said feeding hay for 30 days is his goal. It costs him approximately five times more to feed hay than to let the animals harvest the forage. Bobby knew if he could cut feed costs, he could make more profits. Bobby has reduced four months of feeding hay down to 30 days on the average.
He cuts hay on a few fields with cool season grasses. Once the hay is harvested, he typically no-till drills the sorghum in late May until June 15 depending on weather conditions. Bobby harvests the first cutting of sorghum-sudangrass in haylage (forage that is baled at a higher moisture content than dry hay and stored in a sealed plastic wrap) and wrapped in plastic bag. He says the first cutting of haylage produces 35% more than the first cutting of cool season grasses. He cuts haylage a second time, if needed, and wraps in a plastic bag. The second cutting typically produces 25% more than first cutting of cool season grasses. So typically, his winter feed consists of one hay harvest of cool season grasses followed by two cuttings of sorghum-sudangrass harvested as haylage.
Bobby is old-school and believes in filling his hay barn, then cut haylage for higher protein feed with the hope of not touching his traditional hay during the winter. Once the sorghum-sudangrass reaches approximately 10" in regrowth, he quits grazing cool season grasses about end of June to first of July. He typically rotates five herds in different paddocks ranging from 18 - 20 acres. The cattle are turned in at 10" height and grazed to about 4" in height. Each sorghum-sudangrass field has been grazed about twice as of the day of my visit, October 3, 2017. The cool season grasses are all resting since July and will be grazed as stock-piled pastures beginning after the first killing frost.
I observed a field that had been grazed for about seven days and livestock will be moved later in the week after 10 days of grazing. The sorghum-sudangrass was still 8" in height. The amazing fact is that this is during four-five weeks of no rain. Other nearby farms were grazed closely in cool-season species where Bobby's cool-season grasses were rested and anywhere from 18" to 24" in height.
Bobby said prior to his sorghum-sudangrass system, he would buy feed and creep feed calves. They would gain about 3.5 pounds a day on mother's milk and calf feed. With current prices for beef, Bobby is no longer feeding grain. The calves are gaining 2.5 pounds of beef per day per calf by 100% grazing and mother's milk. The profit is much better.
I asked what if he has plenty of winter hay and haylage. Bobby responded that when barns are filled and sorghum-sudangrass is not used for haylage, he will graze after three weeks after planting. Again, his strategy changes due to weather and feed needs. He prefers that the livestock do the harvesting over harvesting for hay and haylage.
In addition to planting a summer annual, if moisture conditions are present, he will plant Marshall rye grass in most of his summer annual fields in late October to early November. Keep in mind, all annual species are no-tilled in existing fescue, clover, and other grasses such as orchard grass. No termination is done to existing cool season grasses.
So to summarize his annual grazing, he grazes cool season pastures in March - June, sorghum-sudangrass in June or July until October or November, followed by stock-piled cool-season grasses for November and December, and finally Marshall rye grass fields through end of December and January. Hay is fed normally for month of February. Cool season grasses of rye grass and fescue fill out late winter early spring grazing. If rye grass is left until May and reseeds itself, Bobby saves on that expense, usually 25 pounds of rye grass per acre. If there is a drought such as in 2016, then hay or haylege is fed in fall while resting cool season grasses for stock-piled pastures. He keeps one centralized area as a sacrifice area where the animals come to receive minerals.
On my visit on October 3, 2017 with Bobby Ellison and Mike Shoffner, we saw fresh manure piles where the animals had grazed for seven days anywhere from 4 - 18 feet apart. I saw old manure piles decomposed after 20 to 25 days. Animals were grazing almost in strips on their own without any electrical fencing to subdivide the paddocks. The field was uniformed grazed across the 18 acres. Bobby said that 32 cows, 12 calves and 2 bulls were grazing the 18 acres for 10 days.
As I dug and examined the soil in the fields, we could see excellent soil structure with many soil aggregates. Bobby stated that he rarely sees overland runoff. The constant or continuous root growth from well-rested pastures is the key to increasing soil carbon. This result of continued root growth is excellent carbon production from photosynthesis and increased soil carbon (soil organic matter) and better soil health. Urine, slobber, and manure are always present from the rotating herds adding to active carbon additions along with nutrients. In higher moisture levels, earthworms are plentiful.
Bobby soil tests every two years. he has not fertilized since 2016. He has focused on keeping his pH managed by adding lime by soil test results. His fields are all above 6.0. They were in high 4s when he purchased the farm. He said Union County averages 5.2 to 5.4 in pH. Bobby plans to add nitrogen to all fields in 2018 based on economics.
Bobby says the larger paddocks work for him instead of using electric fencing to subdivide into smaller paddocks. He has water in all fields from wells, and pipelines to frost-free tanks strategically placed where fields are adjacent to one another for centralized watering. I asked Bobby if other farmers are following his rotational grazing system with sorghum-sudangrass as the impetus of the system. Four from Union county and four from Claiborne County are mimicking the system.
The key components to improving livestock enterprise profits are cut feed costs, manage for efficient harvest of forages, cycle nutrients and reduce inputs, and build or improve soil health. Active soil carbon (soil organic matter) is the key to upstarting soil biology and cycling carbon. Grazing management that provides rest to forage species results in better opportunities for green plants to produce sugars (carbon) through photosynthesis. When forages are given the opportunity to recover, root growth is improved thus feeding soil biology and cycling carbon from plant carbon to soil carbon. By following the principles of soil health in a grazing system such as 1. reducing disturbances (over grazing); 2. managing for diversity (many cool season grasses, forbs, clovers, and summer annual grasses); 3. prescribed grazing to control livestock to keep roots and plants growing; and 4. maintaining good cover and height of approximately four inches at a minimum, soil functions are improved. Bobby has changed his soils and his bottom line in the last 10 years. Other farmers are taking note to improve soil health and their profits.