Yep, there’s more to say about earthworms! There’s always more to say about earthworms because they do more than most people realize!
Today I want to share with you an article I read recently about the building up of soil health. I know that not everyone who reads my blog is a farmer, or maybe doesn’t even have any connection to the land. But, I think there is value in all people understanding the complexities of life in any arena. It just helps for more productive conversations to take place on every level so that in the end, humanity can be better served.
So, with that in mind, I hope you will enjoy the following article. I found it fascinating – of course!
Build Up Your No-Till Soils and Earthworms Will Come
By Clair Urbain posted on December 8, 2014 | Posted in Soil Health
Reducing tillage, adopting controlled traffic, seeding cover crops and improving drainage can help no-tillers build populations of these nutrient-laden subterranean creatures.
It’s kind of a “chicken or the egg” question: Which comes first, soil health or earthworms?
It’s probably not that simple. The answers typically include moving less soil, avoiding compaction, increasing microbial diversity and keeping living roots in the soil all year.
“If you want earthworms and quality soils in the Midwest, your management plan will work around conservation tillage, controlled traffic, cover crops and drainage,” Frank Gibbs, a soil scientist and owner of Wetland & Soil Consulting Services in Rawson, Ohio, told attendees at the National No-Tillage Conference.
Limit Soil Disturbance
Now retired after a 36-year career with the NRCS, Gibbs has worked mostly in the tight, clay soils in northwest Ohio, where he also happens to be a fifth-generation farmer.
“On our farm, when we used to work the ground, it would flood after a heavy rain. The swale would fill with water and everything would drown out and just lay there for days,” he says. “As soon as we went to no-till, that water didn’t pond there for days. It moved into the ground.”
Gibbs says that getting water to infiltrate soils takes more than intensive tiling. It’s building up the soil structure so the water can filter through it, and less tillage equals greater infiltration.
“We want to have a nice granular soil structure on the surface and in high clay soils, we want to have a nice blocky structure in the subsoil. We want to avoid plates and prism-type soil structures. That way, we can get the good air and water movement through the soil.”
Increase Microbial Diversity
Increasing living organisms in no-tilled soils will consume crop residue, turning it into organic matter.
Some farmers are concerned that increasing field residue increases planting and harvesting headaches. But Gibbs counters that it serves as forage for both in-field microbes and the earthworms no-tillers want to attract.
“There are more than 3,000 different species of earthworms and they’re divided into three categories. Some live on top in the residue, like you’d have in the forest; the red-and-gray worms that make the horizontal holes near the surface, and the great big lumbricus terrestris, or night crawlers that make the big vertical holes throughout the soil profile,” he says.
Gibbs recalls visiting one farm during an Ohio no-till field day where a farmer used a seven-way mix of cover crops — two types of brassica, two legumes, two grasses and some buckwheat — seeded into wheat stubble right after harvest.
The farmer cut some of this cover-crop mix, dried it and weighed it before planting corn. It produced an average of 13,000 pounds of dry matter. That’s 6.5 tons on the soil surface at planting.
But by September, the residue was gone, Gibbs says. The no-tiller had a huge, healthy population of night crawlers that were even trying to pull corn leaves down into their wormholes. Effective drainage is also key for earthworm health and growth. “If you have heavy ponding in fields, you’re not going to have night crawlers. They’ll drown or move out,” he says. “Once they’re gone, it takes a long time to get them back.”
Living Roots, Year-Round
Soils with poor soil structure can benefit from cover crops, which effectively extend the growing season and provide a great food source for earthworms and night crawlers, says Gibbs.
“Oilseed radishes have caught on and many farmers report they open up heavy clay soils. Cereal rye is also being used and it’s becoming kind of a starter system for building soil structure and drainage,” Gibbs says. “These covers break up compaction on the soil surface, which gets water to move down into the soil.”
Gibbs says radishes seeded in late summer or early fall in the Midwest will be decaying by mid-March.
“When they decay they exude saccharides, and the red worms just love them,” he says. “They feed around the radishes, building up soil tilth, and the soil looks like it’s been shot with buckshot from all the worm holes.
“The same is true in a field where cereal rye is flown on after corn. The worm activity produces a beautiful structure for a heavy clay soil. We’ve seen the same thing in one field that has been in wheat after 20 years of no-till where they seeded cereal rye. Dig in it and you find great soil structure and plenty of earthworms. It’s like getting a new field,” he says.
Seeding cover crops is also important because healthy soils will promote soil microbes that are hard at work digesting residue and building soil tilth.
A field with healthy microbial activity will consume nearly all of the dead vegetation by early fall, so cover crops are needed to feed the microbes and earthworms so they can continue building the soil and adding organic matter, Gibbs says.
Use Controlled Traffic
Soil compaction is another deterrent to healthy earthworm populations. Gibbs reports that 70% of compaction in fields occurs with the first pass.
One way to combat this problem and give earthworms a chance — especially in heavy, wet soils — is adopting controlled traffic to keep equipment running on the same path every year.
What are the consequences with compacted soils?
He once recalled a friend going up in an ultra-light aircraft and photographing a soybean field after a heavy rainstorm. He could see how the soybeans emerged differently based on where wheel traffic had been.
“You could see the ground was chiseled diagonally and which direction the field cultivator ran,” Gibbs says. “You could also see the floater pass from fertilizer application and the split duals from planting. We showed it to the farmer, and he couldn’t believe it. It looked like almost the whole farm was driven over.
“Once you get the soil in shape, use controlled traffic, improve drainage and use cover crops, the worms will appear. If you build the soil, they will come.”
I hope you found the article as informative and interesting as I did! It amazes me how much there is to think about regarding soil health when you start “digging beneath the surface” – literally!
Have a great day!