Georgia farmer Randy Dowdy says just one weak nutrient can limit yield
Even after post-mortem browning, Randy Dowdy’s soybean stand was tall enough for a child to slip into and disappear. In the fields of Brooks County, Georgia, in the belly of the Deep South, full-season soybeans are typically 2' to 3' high after desiccation. Dowdy’s stand was 4' tall and whispered at extraordinary yields, with three gravid stalks carrying pods from top to bottom. He was about to fire a shot heard round the soybean world, a 171 bu. per acre volley aimed at the heart of nutrient management.
During a three-year span, Dowdy has dug up the nutrient secrets of his soil, focusing on high baseline soil fertility, early production and aggressive management. Dowdy shattered soybean records in 2016 after a 171.8 bu. per acre yield on 15" rows with a UniSouth Genetics 74A74 variety in the Georgia Soybean Production Contest, passing the 160.6 bu. mark set by Missouri’s Kip Cullers in 2010. Post-harvest yield monitor analyses also revealed Pioneer variety P47T36R grown in a separate field and harvested several days later might have produced even higher yields for Dowdy.
Prior to big soybean numbers, Dowdy’s name was synonymous with massive corn yields and a 503 bu. per acre benchmark. Possessed by the insatiable drive of a crop gumshoe, he doesn’t hide his management numbers, maintains a website (www.grow bigcorn.com) and is eager to trade growing techniques. With favorable weather blanketing his fields in 2016, Dowdy’s corn output is again exceptional, with four separate AgriGold varieties each significantly surpassing the 450 bu. per acre mark in the NCGA National Corn Yield Contest.
Dowdy is a disciple of the Law of the Minimum: One weak nutrient to rule them all. Yield is limited by the least available nutrient, he says, akin to the weakest muscle of a bodybuilder. “The Law of the Minimum applies to all areas of my farm,” Dowdy explains. “Herbicides, timing, disease, water, plant stand and every other endless variable.”
Layering data from multiple seasons, Dowdy is in a constant building process. In 2014, his first year in the soybean contest, he hit 116 bu. per acre and 90 bu. across an overall 60-acre field. In 2015, he reached 140 bu. per acre and 103 bu. over an 80-acre field. And in 2016? A maturity group IV soybean yielded 171.8 bu. per acre on a three-acre block and a 140 bu. field average across 70 acres.
Dowdy farms 2,000 acres of sandy loam on rolling terrain and his growing region is highly susceptible to root knot nematode. In the fall, Dowdy applies a soil fumigant gas (Telone II) 15" deep with a subsoiler to fight the pathogens. Two weeks after application (at a hefty $100 per acre cost) the nematodes are eradicated and he follows with a cover crop to crank up microbial activity.
His planting population ranges from 140,000 to 160,000 and results in stands of 110,000 to 150,000. At 110,000, the stands are heavy with copious amounts of lateral branching. However, the key is attaining lateral branching at high populations, he says, which the 150,000 stands lack: “We’re trying to strike a balance and it’s just one more thing to learn.”
Prior to planting, Dowdy puts tremendous stock in seed treatments and used Renwood Farms’ RenPro Plus on the contest field. “More plants came up, and more importantly, there was a uniform stand at emergence,” he says. “It’s a no-brainer. I don’t mind paying premium costs on treatments if they consistently show bushels.”
Bushels, indeed. The field had multiple spots with yields ranging between 227 bu. to 250 bu. per acre. Yet, only 100' away, yields dropped to 100 bu. per acre, a discrepancy driving Dowdy to uncover variability sources. In an effort to track fertility, he tissue samples weekly and soil samples those same locations multiple times in the year. When he rings the yield bell, as he did in 2016, the nutrient content numbers tell the tale.
Dowdy’s nutrition starts with preseason poultry litter. Up front, he adds muriate of potash, and later fertigates with in-season potash, nitrogen and sulfur. Dowdy also applies a mix of foliar products from Brandt and Genesis Ag to match nutrient needs based on historical data and tissue samples.
Dan Poston covers the southeastern U.S. as an agronomy research manager for DuPont Pioneer and helps Dowdy design experiments and analyze data. Dowdy’s soybean success begins with high baseline soil fertility, a high concentration of nutrients in the soil profile in ratios balanced enough to facilitate uptake of macronutrients. Coupled with high baseline fertility, Dowdy implements a proactive plan to supplement both macro- and micronutrients during the growing season to address periods of peak demand. “Peak demand must be anticipated and nutrients applied well in advance of the soybean plant actually needing the large nutrient load,” Poston stresses.
Overall, meeting plant nutritional needs and early production, combined with aggressive insect and weed management, make for a strong soybean recipe on Dowdy’s operation.
“Randy is willing to make applications on time and spend on inputs as needed, just to learn what drives yield,” Poston explains.
Dowdy runs center pivot irrigation and also has some drip tape. During grain fill, he makes sure soybeans get 3" of water per week.
Soil moisture probes and ion sensors are placed at multiple locations on Dowdy’s farm, measuring water and ion availability. As nutrients move through the profile, the salt index registers on the soil moisture probes. Rising ion levels reflect salt movement in the profile, an indication of fertilizer movement. “We can see what’s going on in the root zone,” he says.
Weeds are a persistent battle. Dowdy planted triticale as a cover to fight Palmer and believes the density of the cover adversely affected final stand counts. Despite Valor, Reflex, Dual and Roundup, he still chases escapes and has to hand weed. “Resistant pigweed is forcing us to make changes, which might mean switching to Liberty or dicamba beans,” he says.
Overall in 2016, Dowdy’s soybean crop cost $7.95 per bushel, including $250 per acre land rent, aerial applications, drying and handling, fertilizer, fungicides, fuel, ground rig applications, harvesting, hauling, herbicides, insecticides, irrigation, planting expense, revenue protection, seed and seed treatments. “We spent too much money but sold the beans at an average of $10.50. We’re in the black.”
Dowdy insists his success is a collaborative effort of coworkers, mentors and industry professionals. “All these people put sweat equity into my fields, and provided intellectual property and resources,” he says. Ultimately, he attributes success to Providence: “I’m responsible to be the author of my crop production, but make no mistake, God is the finisher and I’m so thankful.”
As the consummate student of the crop, Dowdy is trying to learn what he’s done right and wrong each season. “I’m not afraid to try anything, but in the end, it has to make money,” he says.
Tips to Drive Yields
Randy Dowdy’s critical factors to producing more bushels include:
- Soil baseline fertility
- In-season supplementation for periods of peak nutrient demand
- Aggressive weed and pest control
- Timely and frequent irrigations to keep nutrients in solution, meet water demand and possibly cool plants (still in debate as to value)