Finesse Field Fertility - 9

By Susan Winsor
Progressive Farmer Contributing Editor

Bryan Jorgensen figures the early settlers were optimists to give his South Dakota hometown the name of Ideal. Native gumbo clays, 20 to 23 inches of annual rainfall and cold, wet springs aren't exactly ideal cropping conditions. Farming closer to the edge of profitability means Jorgensen Land and Cattle has to produce more with less than those who enjoy better soils and climates.

These economic realities coupled with erosion prompted the family to park the chisel plow in the 1980s and adopt a long-term strategy to return to a native prairie ecosystem. It's this change in philosophy that is keeping their 11,000 acres of cropland productive and profitable.

A prairie system uses no-till, cover crops and grazing livestock to efficiently recycle roots, crop residues and organic matter into carbon and nitrogen that feed crops.

"The prairie ecosystem is the best way to convert the sun's energy to carbon efficiently, as native prairie plants have for billions of years," said Jorgensen, whose diversified farm involves five other family members.

"We have several lifetimes' worth of phosphorus [P] in our soil system (Bray2 soil test reading), but it's not readily available," he said, citing one example. "An active soil biological system releases nutrients in the soil that are normally tied up or unavailable for plant use."

DIVERSITY DOES IT

Like a football team with a deep bench of strengths, Jorgensen counts on extended crop rotations of five to seven crops to diversify soil microbes as a hedge against pests and disease, even-out labor demands and reduce trips across the field.

A variety of plant families carry out his game plan. Warm-season grasses, cool-season broadleafs, warm-season broadleafs and legumes all play a starring role, depending on the job that needs to be done. For example, one common rotation is oats, winter wheat, milo, soybeans and peas or alfalfa. Another rotation might include spring wheat, winter wheat, corn, forage sorghum, oats or peas, and winter wheat.

Cover crops are standouts in the strategy, too. They further mimic the prairie's plant and microbe diversity.

Jorgensen seeds cover crops into standing silage corn and forage sorghum to launch the new cover crop immediately after silage harvest. He'll seed approximately 20 pounds per acre of oats, rapeseed, peas, turnips and radish seed, and let cattle graze on them during the winter. The following spring, he plants corn into the cover-crop residue. Side-by-side trials have shown he can justify spending $20 to $40 per acre growing a crop that isn't harvested except by cattle grazing.

He finds cover crops help recycle excess nutrients and improve soil structure to manage precipitation extremes. Covers also reduce commercial fertilizer and pesticide needs by increasing soil health and efficiency, and crowding out weeds.

"Crops following cover crops generally get only one spray for weeds versus two or three on non-cover crop acres," Jorgensen said. "We see more beneficial insects from the diverse rotations, and we see little to no disease carried into the next crop."

NO-TILL NEEDED

"Carbon is the framework and fuel of every living thing," Jorgensen said. He believes most weeds, diseases, insects and fertility problems result from ecosystem imbalances.

"A conventional corn/soybean rotation is unsustainable without tremendous amounts of technology and capital," he said. "It's carbon-negative and mines the soil rather than renewing it. Tillage mobilizes nutrients before they're needed, creating a leaky system. In undisturbed natural systems, livestock and soil microbes recycle nutrients and residues.

"No-till and crop diversity build soil structure to handle weather extremes," he added. "This minimizes equipment needs, fuel and labor expense, and broadens planting and harvesting windows."

The Jorgensen acreage is managed with just nine full-time employees, one 40-foot air seeder, two combines, one large sprayer, a 24-row planter and a lot of GPS technology. Diesel use is just 1.7 gallons per acre per year (wheat, corn and soybean average).

Efficiencies are helping Jorgensen weather the current commodity price squeeze by lowering cost of production. North Dakota State University agronomist Dave Franzen has documented that continuous no-till requires 50 fewer pounds per acre N in a prairie system.

Soil biologist Jill Clapperton, the principal scientist at Rhizoterra in Reardan, Washington, credits the recycling nature of the system for these savings. "After five or six years of continuous no-till, soil microbes' predator/prey cycle concentrates N into a plant-available form as they eat," she explained. "When the cycle reaches full efficiency, it recycles N more efficiently, and you require less commercial N."

Jorgensen has been able to reduce N rates and P application rates on his ground by 70% under the prairie system. He does depend on in-furrow starter. "I prefer a liquid, low-salt, high-orthophosphate 7-25-5 starter, along with additional micronutrients and enzyme catalysts," he said.

He uses 4 gallons per acre of SummitGold 7-25-5 in-furrow starter on corn, milo and wheat to promote early seedling growth and enhanced biological activity. In addition, he applies 0.5 gallons per acre of SummitGold InFuze. It contains enzyme catalysts, live biology, micronutrients and plant-growth regulators.

Farm crop yields have doubled and sometimes tripled since the family abandoned the wheat-fallow system in 1991. Dryland corn now averages 135 bushels per acre compared to 65 bpa before the switch. Soybean yields are averaging 40 bpa contrasted with 15 bpa in 1991. Winter wheat yields are up to a 65 bpa average versus 35 bpa.

"Some would credit yield gains to improved crop genetics," Jorgensen said. "But the milo genetics that we use haven't changed since the 1980s. Improved soil health has doubled our milo yields from 55 bushels to 130 bushels per acre. Our soil water-holding capacity's improved to where we get three alfalfa cuttings without irrigation." The farm is realizing dryland alfalfa yields of 3.5 tons per year.

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Editor's note:

This is the ninth in DTN/The Progressive Farmer's series on Finesse Field Fertility, helping farmers fine-tune how to feed their crops and get the most value from every input and practice. Next in the series: Bryan Jorgensen shares the soil measurements he uses to gauge how closely his crop soils resemble native-prairie soil levels.

(ES/CZ)

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