Controlling Surface Runoff Threats
Farmers preparing for expected strict rules limiting phosphate runoff can start with the surface of their soil.
Ivan O’Halloran, a soil fertility and nutrient association professor at the Ridgetown Campus of the University of Guelph, told the Kent Federation of Agriculture during their recent annual meeting, that controlling surface runoff can be a key to not letting phosphates get away and possibly contribute to algae blooms in the Great Lakes.
He says cover crops and residue from previous crops are options.
“Anything that we can do to control that runoff, whether it is slowing it down so the particulate matter comes out, it’s harder to control the soluble [nutrients],” O’Halloran says. “It really becomes having it move [down] through the soil as opposed to having it move over the soil.”
Ontario farmers are expecting new rules to try and reduce runoff, and O’Halloran says crop crop residues and cover crops can play a big role in helping them meet potential targets.
“The utilization of cover crops help hold the soil in place, improve infiltration, and if the cover crop grows reasonable amount it helps dry the soil a bit which means there’s a greater potential to hold on to water,” he says. “The idea of leaving soil bare is an issue.”
O’Halloran says the water that leaves through field tiles often removes less nutrient from the field than surface water. He says slowing the movement of water, with crop residues and cover crops can pay big dividends.
The timing of applying nutrients to the soil is also critical. He says if at all possible, spring is a better time for fertilizer and manure applications because it is when the plants are most able to absorb it.