Organic Broadcaster

Diverse mix of livestock, crops helps this organic farm thrive

By Dave Bishop

Belted Galloways graze the wheat field at PrairiErth Farm two weeks after the wheat harvest. Photo by Dave Bishop

Belted Galloways graze the wheat field at PrairiErth Farm two weeks after the wheat harvest.

Photo by Dave Bishop

I grew up on a typical Midwestern farm in the middle of the 20th century when most farms still had a diverse mix of crops and livestock, were mostly self-sufficient and provided a comfortable lifestyle for a sizable number of Americans. Diversity was just common sense. Crops and livestock became food for all—the family, the community, and the soil that fed the crops.

I never could have imagined a landscape of industrial monocultures powered by GPS-guided, driver-less tractors passing through the ghost towns that became rural America.

In the midst of this sea of monoculture in Central Illinois, my family’s farm relies on diversity as the basis of a sustainable production system. It’s a 400-acre certified organic farm producing corn, soybeans, wheat, oats, alfalfa, vegetable crops, beef, pork, eggs and honey. The farm provides the sole income for two families, three full-time employees, and numerous part-time helpers.

Building Soil on Our Farm
In my experience here at PrairiErth Farm, providing fertility and long-term soil building is best accomplished with a combination of green and brown manures—a combination of plants and animals. Cover crops, incorporated in a vegetative state, mineralize quickly to feed the newly planted crop with little left over for long-term soil building. Brown manure, applied to the soil either as stabilized compost or spread by grazing livestock, contributes additional nutrients and adds humic materials that remain in the soil long term.

Prairie soils were built by ruminants that moved in tight formation across a densely vegetated landscape consuming part of the vegetation, trampling in (incorporating) part, and spreading most of the processed vegetation behind them. We’ve only recently “discovered” that high density grazing grows more vegetation and builds soil faster than any other system.

In natural cycles of fertility, relationships develop between plants and mycorrhizal fungi in the soil. The fungal network transports nutrients thru the soil to the plants; the plants in turn “pay” for those nutrients with carbon, which the fungi transport back to the soil. In fertilizer-dependent farming systems which feed plants with water-soluble nutrients, plants no longer need the services provided by the soil ecosystem, which eventually degrades.

Research from the University of Illinois (grist.org/article/2010-02-23-new-research-synthetic-nitrogen-destroys-soil-carbon-undermines/) shows that long-term use of synthetic nitrogen degrades soil organic carbon, making it more difficult to store N and moisture in the soil, and increases runoff and compaction, which limits root growth and degrades the ability of the soil biology to feed the crop.

Thirty-six months of transitioning might get you a USDA organic certificate, but restoring a healthy soil ecosystem may take considerably longer, especially in soils where the biology has been badly degraded and imbalanced.

Keeping Every Acre Busy
Imagine the CEO of a company saying, “This year we’re going to run the plant for 6 months, then just let it sit idle for the rest of the year.” That would be as astonishing as a farmer using his or her most expensive asset—the land—just half the year to grow one crop and then let it sit idle and unprotected the rest of the year.

Cover crops keep the engine in the soil running, building fertility and organic matter, sequestering nutrients that might otherwise end up as runoff, and manufacturing nitrogen. Chemicals secreted by certain cover crops suppress the germination of weeds and reduce various diseases and pathogens. Adding a “crop” of livestock will keep the land productive late fall through winter.

One rotation that works well on our farm is corn, soybeans, a small grain, and beef cattle; dairy would work equally well. Red clover (a different legume might work better in your area) is frost seeded into fall-planted wheat. The grazed clover field from last year’s wheat will be planted to corn. I prefer to rotary till the 18-inch tall clover no deeper than 3 or 4 inches. Last year’s corn, seeded with late summer cereal rye and grazed in late fall and winter will go to soybeans. Currently we’re tilling that, too, but looking closely at rolling the rye and no-tilling the beans—maybe next year!

Typically, our pastures are stressed from about mid-July through mid-September, making it difficult to grass-finish beef without supplemental feed. But with the wheat crop coming off in early July, the cows have a brand new pasture at just the right time. Our Belted Galloways can gain 3 pounds a day, while the tired pasture can recover. Then, after the corn is out and the rye has gotten a good start, we can move the cows there for the remainder of the fall and into winter if practical. The bean field will be fall seeded to wheat, and the cycle starts all over. No acre goes into winter naked.

As grazing resources become more challenged in late winter and early spring, we’ll concentrate feeding in a small area. The cattle still have access to pasture, except when the frost is coming out of the ground in early spring. Then we’ll feed hogs in that area through the summer. They’re great compost-makers and eliminate the need for mechanical turning. To avoid issues with the organic standards, we apply the hog-made compost in November so it falls under the raw manure rules.

Hogs create another value-added product for us to market directly to our customers; and as organic grain prices are trending lower this year, marketing our grain through pigs keeps us from becoming price-takers in a down market.

Another rotation that works well in vegetable production utilizes poultry grazing cover crops alternating with the vegetable crops. For example, after several cool season veggie plantings, a late summer seeding of Dutch white clover (5 – 7 lbs/acre plus 1 bu oats) does a great job of suppressing weeds, building soil, and adding nitrogen. In spring we’ll till narrow strips thru the clover on 5-foot centers and transplant tomatoes. Then we’ll add drip tape and mulch in between plants. Dutch white rarely gets more than 6 inches or so in height, forms a thick ground cover that tolerates the heavy traffic of summer long tomato harvests, and holds up well during prolonged wet spells. Following that, the strips can be planted to vine crops like watermelon, and then rotated out of vegetable production and grazed for several years, if desired.

Broilers make an excellent crop to rotate inside hoop houses, providing a high-value crop to address disease issues and build soil fertility in expensive real estate. Permanently installing poultry netting inside the structure keeps the birds in when the sides are rolled up, and keeps rabbits out when veggies are rotated back in.

One variation is to divide the house in half, raise a flock of broilers in one side and a cover crop in the other, then alternate. Want to take a break in August? Lay plastic and close up the house for a month. Rotating and solarizing addresses a multitude of soil issues and keeps profitability on track.

Conducting On-Farm Research
Ongoing research conducted by the University of Illinois on our farm is helping us better understand the value of cover crops and how they contribute to healthy soil ecosystems. Ashley Holmes, a graduate student at the University of Illinois at Urbana-Champaign, took second place at the Organic Research Forum poster session during the MOSES Organic Farming Conference this year with her poster about this research. Read on to learn about her research.

Dave Bishop is a certified organic farmer from Illinois.

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Cover crop benefits vary by species, mixture composition

By Ashley Holmes

Tillage radish grew well in the mixture-minus-cowpea crop in 2015 at Kinnikinnick Farm in Caledonia, Ill.

Photo by Ashley Holmes

We are conducting a 3-year field study funded by the Ceres Trust investigating the impacts of cover crop mixtures and their component species’ effects on weed suppression, soil microbial activity, soil nitrogen cycling, and primary productivity. The study takes place on two organic farms in Illinois – PrairiErth Farm in Atlanta and Kinnikinnick Farm in Caledonia. A total of 18 species are assessed, spanning three seasonally appropriate rotations (spring, summer, and fall) with 6 species each.

In spring we plant oat, spring wheat, Kodiak mustard, purple top turnip, faba bean, and field pea. In summer, we plant forage corn, Sudangrass, buckwheat, tillage radish, cowpea, and soybean. In fall, we plant cereal rye, triticale, forage kale, Austrian winter pea, hairy vetch, and yellow blossom sweetclover. Each species is planted in monoculture and each mixture treatment is composed of all possible 5-way combinations of species seeded at 20 percent monoculture seeding rates, based on common seeding rate recommendations for each crop.

Cover crop treatments are compared to a weedy control and a mechanically weeded control. Cover crops are allowed to grow for approximately 8 weeks before termination.

We have found that species and mixture performance are generally strongly influenced by yearly weather conditions, such as snow cover and temperature, and locational differences between central and northern Illinois, such as soil type and pest pressure. However, some interesting results have emerged from the data thus far in our study:

· Mustard, Sudangrass, and cereal rye were among the strongest biomass producers and weed competitors in monoculture.
· Legumes were among the least productive species and competed poorly with weeds.
· Mustard, Sudangrass, and cereal rye tended to dominate mixtures when they were present, causing other species, especially legumes, to suffer in terms of biomass production.
· Cover crop mixtures and monocultures performed equally well at scavenging nitrogen. The mechanically weeded control had up to 200 percent more nitrate present before cover crop termination than most monocultures and mixtures.
· In most cases, microbial activity was similar under both controls and cover crop treatments.
· Weeds often performed just as well as cover crops at accumulating tissue nitrogen prior to termination.

Recommendations
We recommend that farmers consider their cover cropping goals first and foremost before deciding what species to plant and what mixture composition to use. If a farmer is more concerned about weed suppression, using species like mustard or rye in mixture would make the most sense. But if nitrogen fixation is a more important goal, then either increasing the seeding rate of the legume in mixture or leaving out a more competitive species from the mix would be a couple of options to consider. Some cover crops (like faba bean) are far more expensive than others (like forage corn), so considering the financial feasibility of each species and their potential benefits is important as well.

Ashley Holmes is in the masters’ program in Crop Science at the University of Illinois at Urbana-Champaign, where she will graduate in August.

From the July | August 2016 Issue

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