Science proves that farmers who focus their mindset on feeding and caring for their soil biology “livestock” will reap the rewards of improved crops and added farm profitability. Science also has proven that Grandpa’s tillage has taken a detrimental toll on the soil — a loss of 50% organic matter since intensive tillage began.
Fortunately, farmers can rebuild soil structure over time. If you take a shovel and dig into managing your soil structure's details, you can learn to build resilient and less variable soils field by field, like you manage crops. Resilient soils guard against severe crop yield swings as weather extremes occur, boosting profits and farm resiliency.
Your spade can help evaluate and compare soil structure in your best and worst field areas. Dig and photograph a spade-full of soil in areas with historic ponding, compaction or other low-yielding areas on your maps. Then find a neighboring no-till field with cover crops and compare soil structure. Talk to that neighbor to learn from their journey.
Soil health journey
Arlington, S.D., farmer Jesse Hall used a spade to watch his soil overcome longtime issues. “In 2013-14, we switched to a permanent three-way rotation, bringing oats back in. A lot of our wet spots went away. If you bring in a small grain and start cover-cropping, you’ll build soil structure much faster, and the addition of livestock accelerates the process.” Hall says.
Hall saw water infiltration rates increase dramatically, and his three-crop rotation helped diversify herbicide use to reduce waterhemp. “It’s a true systems approach that also increased our profitability. Since we added oats, it increased our soybean yields by 3 to 5 bushels and corn by 10 to12 bushels per acre on average.”
His take-home message for other farmers? “You’ve got to give stuff time and go slowly with no-till.”
Selby, S.D., farmer Doug Sieck witnessed impressive soil structure improvement with no-till, overcoming his skepticism. “We need to challenge ourselves and quit saying it won’t work here and start saying how can I make it work here. We started no-till because there was an economic advantage to doing it — we could make more money. Then we learned another benefit, how well water soaks into the soil. It was soaking in due to aggregate stability; the soil looked like cottage cheese once we did things right.” Sieck says.
Find a soil health mentor
These farmer soil health journeys are just a few of the hundreds of soil health mentors that get excited over green fields of cover crops following harvest and before planting. They understand that increasing organic matter (carbon) leads to fewer input costs and more consistent yields.
Some producers appreciate the feed cost savings, pasture-resting and recycled manure fertility of bringing cattle back to the land with cover crop grazing. Other farmers and ranchers enjoy the renewed ability to make added rotational crops pay dividends, along with corn and soybean yields that increase in consistency each year as the soil improves, decreasing their need for crop insurance.
Whatever your goal, find a mentor who already has firsthand experience. Tom Schumacher, South Dakota State University soil scientist, and Kent Vlieger, Natural Resources Conservation Service soil health specialist in South Dakota, recommend starting with mentors in your county —from farmers and ranchers to NRCS district conservationists, ag researchers and SDSU Extension.
Science of soil structure
Without healthy soil structure (pore spaces), you’re just farming dirt that lacks the right mix of solids, liquids and gases. Billions of biological organisms (the livestock in your soil) play a major role in structure development to stabilize pore space to optimize crop productivity. They cycle and recycle the sun’s energy through food webs, as roots and plant residue provide the energy captured through photosynthesis. The value of these biological organisms is estimated at $1.5 trillion per year worldwide.
Larger biological organisms, like plant roots and earthworms, directly displace soil to create connected pore arrangements like larger macropores to allow drainage and air movement. But these are not inherently stable.
Biological organisms produce many soil-stabilizing substances — primarily various organic matter forms (carbon) — including glomalin produced by mycorrhizae and many other compounds. These adhesive organic substances form bridges between the inorganic (mineral) soil texture components (clay, silt and sand particles) to resist the tendency of pore collapse over time by external forces. Yet there’s a continual need to replace these compounds to maintain soil structure since they degrade or are used as food by other biological organisms.
Soil health improvements
To keep a steady supply of adhesive organic compounds in the soil, experienced farmers keep live roots, whether cash crop or cover crop, in the ground throughout the year. The plants can then photosynthesize, fix carbon from the atmosphere and then feed the microbes — an essential part of this symbiotic plant-soil relationship.
Human activity, from tillage to bare soil and erosion, has turned soil to dirt and reduced water infiltration. Large pores, and the disruption of pore continuity created by tillage, collapse relatively quickly while disrupting biological activity that stabilizes soil structure.
When crops are harvested and soil is exposed to rain and wind damage, soil biology has no food for winter, further reducing soil structure and stabilization. Cover crops resolve this challenge by providing living roots before winter, which can resume growth in early spring with the right species like cereal rye.
To enhance soil structure, productivity, resilience and farm longevity, talk to soil health mentors to devise your precision plan for individual fields, and start small. Matching the five principles of soil health to your farm can drive success to help build a more resilient and stable soil structure.Source: USDA Natural Resources Conservation Service, South Dakota, is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.