A scientist from Prince Edward Island has issued a challenge to Island farmers: Guess the yield of a potato field grown using only fertilizer left over from last year's crop.

Scott Anderson is science co-ordinator at Agriculture and Agri-Food Canada's research station Harrington, where his team planted a field specifically for what they are calling the "Plowdown Challenge."

While the challenge has a fun element to it, Anderson said it also has a serious goal.

Scott Anderson:
 

"We were trying to come up with something that would demonstrate to producers that you can actually grow a decent crop of potatoes with reduced fertilizer."

"We've been doing a ton of research on that for years now, but the adoption of that always seems to be an issue.... We just wanted to come up with a different way of demonstrating how reducing fertilizer, you can still get a crop."

Leftover nutrients

The field for the challenge was planted with red clover last summer, which was plowed into the soil, followed by a cover crop of barley and tillage radish last fall.

In the spring, the crew planted the Mountain Gem potato variety in the field without adding any fertilizer other than what was left in the soil from the cover crops.
 Scott Anderson:
 

"That's part of the goal here, too, is to use some of the residual nutrients in the soil from previous plow-down crops ."

"That's something that growers are actually using a lot more of these days ... and that just gives you extra credits in the bank when it comes to nitrogen, especially."

"That's something that growers are actually using a lot more of these days ... and that just gives you extra credits in the bank when it comes to nitrogen, especially."

Anderson has posted photos and videos on his social media, telling farmers about the challenge. Now, he's hoping to hear their predictions of what the yield per acre will be.

He said, so far, the guesses have been lower than what he himself expects.
 Scott Anderson:
 

"People who have guessed are farmers who've been doing this a long time. So they kind of looked at what we had here before, and what we were doing."

"The guesses we've been having are probably in the mid-200 weight per acre. But based on what I saw today, maybe, it might be a little higher than that. But we'll find out shortly."

Anderson said using less fertilizer has other benefits for the environment — and for a farm's bottom line.

Scott Anderson:
 

"You look at the price of fertilizer these days, it's crazy expensive. So if you can reduce your usage on the farm, there's many benefits."

'Surprising' results

Roger Henry worked with Anderson on the Plowdown Challenge and was keeping a close eye on the yield as the potatoes were harvested.

Roger Henry:
 

"I was quite surprised, actually. There was actually some 10-ounce potatoes [283 grams] here, which are the ones that will give you a bonus at the Cavendish Farms contract."

"I didn't expect to see too many of them, but I was surprised that the amount of 10-ounces that were coming up, pleasantly surprised. It's not going to be a bumper yield or anything like that, but this is just to demonstrate what the plow-down and a good soil can add to the crop."

Henry said he hopes the challenge helps get that message to a larger audience.

Roger Henry:
 

"It's also not just for the farmers: I think it's good for the public to learn the value of a good soil. The prosperity of an area is related to the quality of the soil, and it's important for us to nurture and maintain our soils."

Henry and Anderson said they will be taking yield predictions until the end of November. The actual yield — and a winner — will be announced in early December.