The man who literally wrote the book on soil science, Craig Weil, headed up the Conservation Cropping System field day at Moody Farms in Fremont last Wednesday. Over 90 farmers and agriculturally-related business people attended the field day at Moody Farms to compare notes, pick up tips and learn how to more efficiently use cover crops to capture nutrients and enrich their fields.
Weil began by comparing the Chesapeake Bay watershed with the Great Lakes watersheds. By the 1980s, the Chesapeake Bay waters were polluted by high levels of phosphorus and nitrogen due in large part from agricultural runoff. Algae blooms plus increased sediments in the bay ruined fisheries and breeding grounds for shellfish. Maryland got serious about doing its part to clean up the bay, Weil said. Now, Maryland has strict oversight and rules to manage agricultural runoff from fertilizer and manure.
He said that Maryland pays farmers a base price per acre as an incentive to plant cover crops and control nutrient loss. Weil added that the Chesapeake Bay is showing some encouraging signs of recovery; some fish and shellfish species and water plants are reappearing after years of absence.
Indiana farmers may find themselves in the same situation as Maryland if they are not more proactive with their nutrient management, Weil warned. Lake Erie is again experiencing a toxic algal bloom. If voluntary efforts by agriculture to contain nitrogen and phosphorus are not showing results, he said, farmers in the Great Lakes watersheds should expect more regulations governing their operations.
Farmers in the audience were challenged by Weil to re-think their planting strategies. Corn and soybeans produce income on land that is only used three or four months of the year. Why not cover your ground with plants that will add nutrients to your soil, improve the soil structure the other months of the year and save money, he questioned his listeners.
Below ground, research is accumulating more evidence for the cover crop case, Weil said. Seeding cover crops before or after harvest keeps the biology of the soil active. Studies show that more roots equals more organic matter, more channels for roots to go deeper in the soil, more capturing of nutrients and improves the ability of soil to hold and release moisture as needed to the soil, he stated.
"Another field of study we are just starting to scratch the surface of is the way plants 'talk' to each other with chemicals." Weil told his audience.
He added that simply getting rhizobium to nodulate soybean plant roots is a complicated process which scientists are just beginning to understand. There is a lot of chemical communication that takes place before nodulation occurs.
Dan DeSuttter, a longtime no-till Indiana farmer and 2015 Eisenhower Fellow, spoke about the economics of cover crops. He emphasized the importance of building soil resiliency—the ability of the soil to adapt to any conditions and revert to the original state. Aerial photographs of one of his 2015 corn fields vividly made his case, as it was deep green next to a neighbor's lighter green conventionally tilled field.
Rebuilding organic matter, facilitating soil biology and increasing diversity are DeSutter's three goals of every year.
Over last 20 years, DeSutter has seen improvement in the organic matter (OM) of his acreage, which translates into money saved. The OM in his fields has increased from 2 percent to 4 percent and for every 1 percent of OM about 1,000 pounds of nitrogen is produced. This same 1 percent of organic matter can also absorb and store up to 1 inch of rain, so soil rich in organic matter can handle either wet or dry conditions.
DeSutter proposes a return to regenerative agriculture rather than degenerative agriculture. We don't have a technology gap but rather an education gap, he said.
"Man-made solutions tend to degrade resources over time whereas natural solutions tend to improve resources over time," DeSutter stated emphatically.
He added that regenerative agriculture makes economic sense over time rather than the quick fix for quick profit mentality of the present-day farmer.
Outside at a nearby field, three groups rotated between examples of conservation tillage and seeding equipment, cover crop examples and a root pit.
Weill recommended that farmers dig a root pit to look at the soil structure and rooting channels in their fields. Field day participants could see how the Sudex roots followed previous root and earthworm channels in the soil. Air moves down through these channels, which also benefits the microorganisms and soil.
More than 10 examples of cover crops were planted in a small plot to examine. Zach Bolla spoke about each plant and detailed the positive and negative attributes of each one. Although daikon radishes are good soil conditioners and forage, the plant is not winter hardy. The radishes will decompose during the spring thaw and Bolla always alerts the neighbors of the potential for noticeable odor. He also recommended that farmers research what nutrients the field needs in order to pick the best combination of cover crops to amend the soil.
Tyson Franks and brothers Tony and Allen Dean described their efforts to find the best cover crop seeding equipment. Drilling cover crops with a bean drill or seeding from the air did not give them the stand they wanted. The Deans designed and built a self-propelled machine so they could plant in an existing corn or bean field late in the season but before harvest. After harvest, the cover crop is already well established before winter sets in and the soil active for a longer period of time.
Deans' machine also offers a variable rate seeder, so seed numbers can be increased when needed. Greater amounts of cover crop seed can be planted on hillier terrain to cut down on erosion, Tony said.
"You go back in the spring and those slopes will hold, and those hills are short on organic matter and areas with more thickly seeded cover crops add greater organic matter where it is most needed." Allen said.
Franks mentioned Allen Dean had seeded over a thousand acres for him over the last couple of years. He said that damage to the standing crop was minimal-no more than if he had to spray for spider mites or apply fertilizer.