Listen to the Land “We’re gearing for feast-or-famine weather patterns,” Steinlage says. “We’re building our soils with cover crops, diverse crop mixes and no-till. We’re erosion-proofing our soils. We had 21 inches of rain in one week the summer of 2017. The neighbors had runoff, but we did not. “In 2012, we had a big rain the day after planting. I was worried about getting back in to spray the clovers (cover crop). That’s why I now band herbicide with the planter—to give the cash crops an edge.” The cost is about $6 per acre. He uses Acuron or combines acetochlor or metolachlor and atrazine. “If we don’t disturb the soil, we don’t have weed problems,” Steinlage adds. He customized row cleaners that move residue but not soil. After 10 years of these practices, a $15-per-acre cover-crop seed investment and diverse species in the same field, his corn yields are 15 bushels per acre ahead of any other fields he farms. The result of these practices is more soil carbon, the fuel for crops and nutrient recycling. “Liquid carbon is the ‘underground currency’ that feeds soil microbes,” Steinlage says. He explains carbon is what microbes exchange for more plant-available nutrients, which they recycle from residue. (See “The Underground Economy.”) The per-acre revenue for ground planted to cereal rye cover crops, cash soybeans and buckwheat cover crops is a minimum of $660, he says. “We can easily double that; I just don’t like to promise the moon.” In 2018, he switched to non-GMO soybeans to capture an additional $60,000 in IP (identity preserved) premiums ($2 per bushel non-GMO premium) and $50,000 in lower seed costs. Steinlage tailors cover crops to the crop that will follow them. “You want all four plant families in a mix (warm-season broadleafs and grasses, and cool-season broadleafs and grasses),” Steinlage says. For continuous corn, he plants into live N-rich (nitrogen) legumes like clovers and loran steinlage vetch. On ground going to soybeans, he mixes annual ryegrass with brassicas. On a test field, Steinlage interseeds a varying “jungle mix” of 17-species combinations of tillage radish, dwarf Essex rape, vetch, buckwheat, phacelia, flax, oats, several clovers and more, depending on the field and rotation. This test field has 15-bushel higher yields than his others on some of the poorest county soils. susaN wINsor GIFTED WITH A WRENCH Known far and wide for his mechanical creativity, Steinlage has built and modified at least eight cover-crop interseeders in the past 10 years. When he could afford to build from the ground up, he mounted a Montag dry fertilizer box on a Dalton custom bar, adding customized Dawn DuoSeed row units with a seed sensor that precisely monitors cover-crop seeding rates. This feature is now standard on Dawn’s new DuoSeed Pro. Steinlage’s interseeder also has Precision Planting monitoring, seed firmers and a wide drop tube The Underground Economy increasing soil carbon is loran steinlage’s main goal. soil carbon supports the residue and nutrient recycling that improves soil aggregate structure. The space between soil aggregates drains or stores moisture as needed, and circulates oxygen and nutrients. soil microbes feed on soil carbon and produce carbon dioxide (Co 2 ), which happens to be a crops’ primary nutrient requirement, says Will brinton, solvita soil-health test inventor and founder of Woods end soil Laboratories, mount vernon, maine. and, soil is the world’s largest active carbon reservoir. Carbon, in the form of soil humus and crop residue and roots, feeds soil insects, bacteria, fungi, algae, protozoa and nematodes. These tiny soil animals release Co 2 , mineralize (release) nitrogen and release phosphorus (p) and minerals in crop-available forms. Half of soil humus—what gives healthy soil its structure and smell—is carbon, brinton says. soil microbes may produce Co 2 at rates up to 100 pounds per acre per day, the amount ST-6 required in crop photosynthesis, he adds. Crops may get more Co 2 from soil than from the air. so, soil carbon is a crops’ lifeblood. “Now that we can measure Co 2 , metabolism, we’ll find crop nutrient uptake can also be Co 2 -limited,” brinton says. more diverse crops can support more diverse soil microbes, which can boost soil structure and speed nutrient recycling. The bottom line is resilient soil in wet and dry seasons. resilience is stable yields over time and less variation within fields, says Jerry Hatfield, director, usda National Laboratory for agriculture and the environment. as rain falls in more concentrated bursts, and droughts hang on longer than before, carbon improves your “factory”—your soil. High earthworm counts correlate strongly with an active soil-carbon life cycle in 17-year swedish field plot studies, brinton says. The solvita test uses soil Co 2 respiration as a key indicator of soil health. “We need to change our farming practices to be more Co 2 -oriented,” brinton says. progressive farmer / mid-february 2019 /// listen to the land