Slake Test Demonstrates Cover Crop’s “Sponge” Qualities…and Bio-health

Ray Makenzie of Marcellus, Michigan, found himself with a thousand acres of highly erodible land when he switched from raising outdoor hogs to a confinement system in 1996. He went to no-till and foresees cover crops next year because of a farm demonstration he just attended.

“I am really excited about cover crops and have to get on this for next year,” he said. “I worry about where the land is leading to with our current practices. At the rate we are going, we are not going to leave the next generation with much healthy dirt.”

(Read the whole article by clicking here…No-Till Farmer magazine)

Hans Kok, a partner in the Indiana-based Conservation Cropping System Initiative, spoke on the benefits of cover crops and demonstrated one aspect with the “Slake Test.” ,Side by side soil samples were submerged in water. One sample was tilled soil while the other had not been tilled for several years. The tilled soil crumbled away and disintegrated in the soaking, leaving a murky sediment at the bottom of the beaker.

A second demonstration simulated a 2-inch rainfall over a one-hour period using spray bottles to soak no-till versus tilled soil samples. The tilled sample had runoff containing a high percentage of soil in the collection vessel while the no-tilled soil held together, absorbing the rain like a sponge and leaving only trace amounts of soil runoff in collection containers. Ironically, the soil samples for both demonstrations were taken from fields that were only forty feet apart, so soil type differences were negligent.

A new cooperative effort through the conservation districts in Van Buren, Berrien and Cass counties offered growers the opportunity to aerial seed annual rye grass into standing corn or soybeans at a cost of $32.50 per acre in 2013. Additional farmers who were not members of the cooperative joined the effort, resulting in a total of 1,600 acres seeded on Aug. 28 in the three counties, according to Colleen Forestieri, conservation technician for the Van Buren Conservation District. “Our goal next year is to triple that number to 3,000 acres,” she said.