Slow-release fertilizer brings 'dramatic' reduction in greenhouse gas emissions

New research on P.E.I. has convinced some Island potato farmers to switch over to what are known as enhanced efficiency fertilizers, that slowly release nitrogen when plants need it over the course of the season. 

The trials also showed a reduction in greenhouse gas emissions where the fertilizers were used, down as much 60 per cent in some fields. 

The studies were done over the last three years as part of the Living Labs initiative, a partnership between the federal and provincial governments, P.E.I. growers, private industry and watershed groups. 

Potato researcher Steve Watts of Genesis Crop Systems, described the enhanced efficiency fertilizers as giving crops three square meals a day, instead of every meal at breakfast.

"Traditionally on P.E.I., most farmers have put a lot of their fertilizer ingredients on at the time of planting," Watts said. 

"At that time, there's not even a plant to use those nutrients. So they're kind of in limbo until, in the case of potatoes, maybe 20, to 30, or even 40 days after planting."

"What we wanted to do is try to stretch out the availability of the nutrition," Watts said. 

"We're still applying it at, or close to planting time, but we're planning on it being more available later on in the season, when the plant really needs that extra shot for growth."

Slow release

Watts said there are several different fertilizers that offer enhanced efficiency, with a variety of coatings that help them slowly release the nitrogen into the soil.

He said the research showed that fields produced the same amount of potatoes using the slow release fertilizer, as with traditional ones.

"Obviously, yield is important to us, and we identified through the study that we can actually use this new type of nitrogen, and we maintain, or in some cases even improve our crop yields and our crop value," Watts said.

Watts said there is the added benefit of controlling the amount of nitrogen released, losing less into the soil, streams and waterways. 

"For example, if it was to rain, heavy rain in the next few days, we wouldn't have to worry about those products leaching downward into the soil," Watts said.

"It just helps maintain the integrity of the product, until a time when the crop's going to be ready to use it."

We were happy with the results in those research plots, so this year we're going to put it on 100 per cent of our acres—Blaine MacPherson, Howmac Farms

Watts provides research support to a group of Island farmers that collectively plant about 10 per cent of the potato acres on P.E.I., including Blaine MacPherson of Howmac Farms.

"We did some plots on our farms over the past few years, and we were happy with the results in those research plots, so this year we're going to put it on 100 per cent of our acres," MacPherson said. 

"It's a big change from many years ago, where we would put it all on in the planter, as soon as we planted. And then whatever happened, happened. Now we're doing it in a more controlled fashion."

'Dramatic' reduction

The director of the Centre for Sustainable Soil Management at Dalhousie University, David Burton, was also involved in the Living Labs research. 

"We found that they could, for the same amount of of money they were spending on their nitrogen program previously, they could use less of this enhanced product, which is a bit more expensive, to maintain their yields, but dramatically reduce nitrous oxide emissions," Burton said.

Burton said researchers collected the gases being emitted from the soil in weekly sampling, and tested them at his laboratory to measure the nitrous oxide, methane and carbon dioxide being emitted from the soil.

He said there were some 'very significant' reductions. 

"As much as 60 per cent reduction in nitrous oxide emissions, which is a very important global warming gas," Burton said. 

"Agriculture is one of the primary sources of nitrous oxide."

Burton said the new enhanced efficiency fertilizers are also 'very significant' when it comes to the federal government's goal of reducing green house gas emissions from fertilizer use by 30 per cent. 

"That seemed like a very big number. But these new emerging technologies make that very much achievable," Burton said.

"I think it's very, very realistic that we could achieve, or even exceed those numbers, using technologies like these enhanced efficiency fertilizer products."