Using vertical tilling to conserve the soil

Monday, October 7, 2013

A Lucan-area farmer has cobbled together his own equipment to vertical till to keep residue on the surface and hold the soil in place

by DON STONEMAN


Lucan-area cash cropper and beef farmer Eric Devlaeminck likes vertical tilling as a soil conservation method. He couldn't justify a major purchase for his relatively modest 500-acre operation, so he cobbled together his own equipment.

Devlaeminck unhooks the grain cart from the coulters on his 15-foot-wide Great Plains drill, replacing it with a second-hand Aerway tiller acquired at a good price from a local equipment dealer. The Aerway tines fracture the soil eight inches deep but are set at "a very slight angle" of 2.5 degrees to minimize the horizontal soil disturbance. Devlaeminck uses this unit in the fall to vertically till all of the corn ground and the soybean fields that were not immediately planted to wheat.

Devlaeminck farms on Hwy 4 between Exeter and Lucan. This year, he grew 175 acres of soybeans, 155 of corn, 100 of wheat and 20 acres each of rutabagas, sunflowers and oats with the remainder producing a hay crop. He feeds about 30 head of cattle in the winter, supplementing their rations with cull rutabagas he and a neighbour provide. The cattle keep frost from setting into the bank barn and provide manure for the fields.

The sunflowers yield between 80 and 100 bushels an acre (28 pounds a bushel after cleaning).

Another aspect to Devlaeminck's soil conservation efforts is planting Tillage Radish. He plants eight pounds of radish seed per acre from the drill box of the Great Plains drill into wheat stubble in mid-August. (The seed is small, but a little too big to be planted from the grass seed box.) The plants pop out of the ground a few days later.

The Tillage Radish seed costs about $2.50 a pound. "It is a very small seed," Devlaeminck says. He says it took three years to figure out the right seeding rate – he tried 15 pounds per acre, but that was too expensive – and how to get it into the ground. Devlaeminck describes Tillage Radish as "very responsive" to hooking onto nutrients. If you spread manure on top of the Tillage Radish, "it soaks it up fast." He says the radish draws nutrients to the surface with its deep taproot.

Kate Monk, stewardship and conservation lands supervisor with the Ausable Bayfield Conservation Authority says the fields where Devlaeminck farms are flat and soils "tend to drift" in the winter when no crops are growing. Devlaeminck has planted windbreaks and his tillage practices keep residue on the surface and hold the soil in place, Monk says.

The radish crop is killed off when temperatures fall to -8 C. In the spring, Devlaeminck says, there are a series of holes in the field where the radishes were, and the field is a good place to no-till.

Devlaeminck plants about 80 acres of Tillage Radish in the fall into wheat and oat stubble. His equipment is all in 15-foot widths. He has a separate planter for 15-inch soybeans and 30-inch corn rows. The sunflowers are also planted in 30-inch rows and Devlaeminck markets the crop himself as birdseed to customers and also some are wholesaled.

Anne Verhallen, the Ontario agriculture ministry's soil management specialist for horticultural crops, says Tillage Radish is a brand of seed sold out of Pennsylvania. They are all "Diakoms" she says. The Tillage Radish is closely related to oilseed radish, with the major difference being that it has large root and flowers a bit later. Cover crop seed suppliers are listed at http://www.omafra.gov.on.ca/english/crops/resource/covercrp.htm BF

Caution on radish crops for saving nitrogen
Laura Van Eerd, a researcher at the University of Guelph's Ridgetown campus, warns that radish crops aren't as good at scavenging nitrogen in Ontario and Michigan as they are further into the Midwest. She says farmers would be ill-advised to assume they can substitute an oilseed crop for 30 pounds of N to feed growth of the next year's crop.

"If growers are looking to lower their nitrogen amounts, we aren't sure we would recommend oilseed radish, based on our research."

The reasons aren't entirely clear, but Van Eerd surmises that radish works better in drier climates where there isn't as much moisture and less of a freeze-thaw effect over the winter. In Ontario and also in Michigan, some of the N is leached in the winter and some may be nitrified and lost as greenhouse gas. "I would recommend a legume like red clover or alfalfa" for fixing nitrogen, Van Eerd says. BF