Cover crops promote soil health and plant vitality
Editor's Note: This is the second part in a series on Soil Health
JUNEAU - Soil is filled with living organisms that hold particles. Without the life in the soil, it would not hold together when it rains nor would it produce healthy plants.
Justin Morris, Regional soil specialist with the federal Natural Resources Conservation Service shared ideas on soil health during the Dodge County Farmer-to-Farmer non-point workshop at Juneau recently. He listed five ideas farmers can adapt to mimic nature and create soil that sustains life.
First on the list is minimize disturbances. Limiting tillage and using fewer chemicals is just the beginning, according to Morris. Along with it needs to be the establishment of a cover. Living plants impact soil temperature, infiltration, and weed control.
Morris points out, “Nature will cover the soil with something. If it’s not a cover crop that you put there it will be weeds.”
The third step is to incorporate diversity into the system.
“You need diversity above ground in order to stabilize diversity below ground,” he said.
Among the diversified crops he suggests cool and warm season grasses, cool and warm season broadleaf plants, and deep rooted plants that go into places in the soil that the cash crop doesn’t. Diversity of plants will reach out to grab a much wider variety of minerals in the soil and bring them to where they can be utilized by the established crop.
The fourth step is to provide continuous living roots.
“Ten to 40 percent of the carbohydrates in plants created by photosynthesis are leaked out into the soil," he said. "That feeds sugars to the soil biology.”
The fifth step is the integration of livestock into the system.
“Some of the most productive soils on the planet were made with animals grazing and recharging the soil,” he said. “It speeds the nutrient cycling.”
He points to the buffalo that once grazed out west and other areas of the world where animals graze freely, building healthy grass soils as they moved around.
He further noted how the rumen in a cow helps to explode the bacteria and then, through its manure, feed the life in the soil.
“There are many methods but few principles. If we can understand the principles (of building healthy soil) we can design a system of methods that work with your own farming enterprise,” he said.
On Farm Experience
Jim Harbach, a Pennsylvania farmer who runs 2500 acres of land in the mountainous and flat valley regions of the state, and milks 1000 cows shared how his family has been feeding the life in the soil through 40 years of no-tilling and ten years of cover crops.
His farm includes a methane digester and a solids separation system that allows them to reuse bedding and capture the nutrients from the manure to distribute on their crop land.
He says that he saw many benefits to the no-till system but the greatest benefits were highly visible after he also applied a cover crop system in addition to no-till.
“Agencies think we can fix all of our problems with a conservation plan,” he said. “We need to adapt a system that creates healthy soil if we really want to solve the problem.”
He showed photos of his land and of his neighbors' land, illustrating how the established contour strips on neighboring farms did not prevent erosion. The strips with bare ground also had exposed stones where soil had washed off into the next strip and beyond.
In contrast, there was no washing on his fields were the soil had not been disturbed and a cover crop created soil that acted like a sponge to soak off rainfall without runoff.
“We inject very little of our manure because we don’t want to disturb the soil,” he said.
He helps to control the cost of establishing a cover crop by harvesting a portion of his rye cover as grain and then using it for seed for the next cover crop.
Using a special tool that rolls and crimps the tall rye ahead of the planter, he establishes the new crop into a living green field. The rye lays flat between the rows of corn, acting as a mulch to hold moisture and prevent the establishment of weeds.
He stressed the need to go deep enough with the planting depth to get below the rye roots and reach moisture.
While some farmers were concerned about how to handle compaction with a no-till system, Harbach said it is not an issue on his farm because the soil is soft and more forgiving to field traffic.
Harbach also cautioned about putting too much manure on soil and killing the living organisms.
He noted that some farmers who have not had success with no till or cover crops have had problems due to poor planter set-up, design, planting covers too heavy or not heavy enough. He said it takes some time to figure that out.
He also underlined the importance of a diversity of crops, noting that each species of cover crop serves a different purpose.
Regarding insects, he says that in nature there is only one pest for every 1700 insects. Harbach said that 22 percent of insects eat weed seeds.
Chemicals, including seed treatments, kill beneficials. Cover crops, through photosynthesis from the sun, fix carbon. The key to building organic matter and food quality and plant health is a function of soil health.
He looks at cover crops as an investment, not a cost.
“You need to manage for the biology, not for yield,” he said.
“You wouldn’t build a milking parlor and use it only half of the year. You want a return on your investment all year round," he said. "Why do you use your soil only half of the year? Cover crops pull energy from the sun and rain all year around.”