When he wants to find out what will work on a given field, South Dakota farmer Rick Bieber tries to take his cues from the natural world.
“To believe that through research and invention humanity can create something better than nature is an illusion,” Bieber said.
Bieber appears to be doing something right. In 33 years of no-tilling and 25 years of cover cropping, he has increased his soil organic matter from 1.2% to 3.5%.
Bieber spoke at the Pennsylvania No-Till Alliance field day July 21 at the Roger Rohrer farm.
One way Bieber tries to mimic nature is by having plants at various life stages in the same field.
For example, he interseeds cover crops into his corn. After the grain is harvested, the small cover crops that have been slowly growing under the canopy are ready to take off.
Farmers typically focus on one crop at a time, but in the woods or the open prairie, plants young and old grow side by side.
In a farm field, intercropping increases the chance of having living plants on the soil at all times, a key soil health goal.
Bieber also believes the practice aids soil fertility.
“We want the youngsters coming along. They have the energy. They’re the ones that pump the carbon into our soils,” he said.
Bieber even visited one farm that is experimenting with planting corn and cover crops on the same day. The move has cut yields by 15% but has also increased silage protein content by a full point.
Protein is a more expensive feed component than energy, so that planting strategy could save on purchases from the mill, Bieber said.
Though he is primarily a wheat farmer, Bieber makes some planting decisions by observing the ecosystem surrounding his field.
For one thing, he wants his sunflower crop to bloom at the same time as the local wild sunflowers.
In another case, Bieber let a field go without herbicide, and wild buckwheat took over. So he planted a crop of buckwheat there. It turned a healthy profit.
“We’re following the plants that are there as indicators of what should be there,” Bieber said.
Increasing crop diversity is another soil health principle. One of the simplest ways Pennsylvania farmers are achieving this goal is by double-cropping soybeans after wheat, Bieber said.
Looking Out for the Microbes
Bieber also recommended that farmers plant a multispecies cover crop mix for grazing.
Not only does this practice increase the diversity of plants on the soil, but it also reduces equipment needs by having the livestock harvest their own feed.
Bieber’s cows fatten up nicely for winter by grazing his cover crop after wheat, and he is a big believer in using cattle to restore beneficial microbes to the soil.
“Everything that they have in their gut the soil needs in its gut,” he said.
Cattle are useful in part, he thinks, because they provide a warm, moist habitat for microbes when the environment outside is frozen or parched.
When Bieber takes on a new tract of beat-up land, he finds he does not need heavy manure coverage to rehabilitate the field. The microbes spread prolifically from just the sparse cow patties dropped by grazing stock, he said.
To Bieber, farming with nature also means protecting the beneficial microbes that are already in the soil.
The most familiar strategy for that is to have plant material covering the soil year-round. The plants, or their residue, absorb the force of raindrops, protecting the microbes’ habitat.
“It looks like a bomb going off, the destruction going on there on the micro level,” Bieber said as he played a slow-motion close-up of a raindrop striking soil. “You’ve got to remember, these little guys here are invisible, and they have a home built down there in that soil.”
Farmers can also protect earthworms — which provide nutrient-rich castings as well as channels for roots to grow in — by staying off the soil during dry periods.
During droughts, earthworms cocoon themselves in mucus to rest until the rains return. Vibration from equipment can rupture this protective coating, causing the worms to dry out and die, Bieber said.
To cut vibrations, Bieber has stripped his planters down to the essentials and put tracks on his equipment tires.
“All these little things help,” he said.
Bieber is also excited about the potential for diverse cover crop mixes to replace ag chemicals.
Pesticides harm beneficial microbes, and synthetic nitrogen disturbs the natural carbon-to-nitrogen ratio caused by organisms cycling nutrients, he said.
Some research suggests that growing a mix of many types of plants — eight, 16 or 20-plus species in the same field — could allow a farm to give up fungicides, insecticides and even synthetic fertilizer, Bieber said.
On fields where Bieber has stopped applying nitrogen, he said yields dropped significantly for a few years before rebounding to 10% higher than when he used fertilizer.