Closing the Loop: Community-Scale Nutrient Management at Perry Farms

Perry Farms | Regenerative Alberta Living Lab

The management practice at the centre of this story is closed-loop farming: keeping nutrients and organic matter cycling within the system instead of buying fertility in and shipping waste out. What makes Perry Farms' version distinctive is that their loop doesn't stop at the property line. It runs through their community.

Harold and Chris Perry farm about 5,000 irrigated acres near Chin, Alberta, growing potatoes for Frito-Lay and McCain's. The practice started with a problem most potato producers know well: what to do with cull and reject potatoes that can't go to market. Putting them back on the field wasn't an option, because rotten potatoes carry disease and returning them to the soil risks re-inoculating fields with the same pathogens. But throwing them away wasn't satisfying either, because all the organic matter and nutrients those potatoes held would be lost. The Perrys wanted both: the disease kept out of their fields and the fertility kept in the system. That tension is where the loop begins.

A loop that runs through the community

Most closed-loop thinking stays on a single farm. The Perrys built theirs to draw on the operations around them. To meet the regulatory requirement that at least 50% of digester inputs be manure-based, they source dairy manure from neighbouring farms, currently running about 60% dairy manure. A separate arrangement with a local feedlot runs the other direction: Perry Farms supplies straw bales from four fields and receives manure back for roughly three fields in return. Neither side stockpiles, which Harold notes reduces nutrient loss at both ends.

The point isn't only to feed the digester. It's nutrient management at a community scale. Organic waste that already exists in the area, cull potatoes, dairy manure, straw, gets gathered, processed, and returned to the land as fertility, instead of every operation hauling inputs in and waste out on its own. Harold describes it as a circular economy that makes sense within their demographic, using organic waste that exists in the area anyway. One goal running underneath it is reducing the distance fertility has to travel. Keeping nutrients cycling locally cuts the miles, and the fuel, that would otherwise go into moving fertilizer in and waste away.

How the loop works

Organic waste goes into the digester, where anaerobic bacteria break it down and release biogas. The material is then pasteurized at 70 degrees Celsius, which the Perrys report achieves 99.99% pathogen destruction. That pasteurization step was central to the original decision: it meant the nutrients in cull potatoes could be returned to the land without re-inoculating fields with disease. The output on the fertility side is digestate, roughly 20,000 metric tonnes per year, which goes back onto Perry Farms fields as an organic fertilizer.

Lowering the footprint from both ends

The loop reduces the farm's overall footprint in two ways at once.

First, it turns waste into energy. A cogeneration engine runs on the biogas to produce electricity along with the heat the digester itself needs, and the biogas beyond that is upgraded to renewable natural gas. The facility originally exported electricity to the Alberta grid. In 2023, after determining RNG offered better returns, the operation added RNG production. The farm now injects approximately 70,000 GJ of RNG per year into the ATCO natural gas grid, with sales to Fortis BC and Irving Oil, while the cogeneration unit continues to supply on-site power and the heat the digester runs on. The capital investment to add RNG came in at around $5 million.

Second, it returns fertility to the farm. The digestate going back on the fields replaces nutrients the Perrys would otherwise have to buy, which cuts the amount of synthetic fertilizer the operation needs. Turning waste into energy on one side and displacing manufactured fertilizer on the other is where the footprint reduction comes from.

Within the Regenerative Alberta Living Lab, producers have been working through how to reduce dependency on synthetic fertilizers while lowering GHG emissions, with composting one approach a number of operations have been exploring. Perry Farms has taken that question in a different direction. As part of the Living Lab, data is currently being collected comparing GHG emissions from composting versus the anaerobic digester approach. Results are still being processed, but the Perry operation is giving the project a useful point of comparison at commercial scale.

In 2023, the operation brought in EverGen Infrastructure as a 67% partner and operating lead, partly for their engineering expertise and partly to free the Perrys up to focus on farming. Chris notes that one practical benefit of the partnership has been access to feedstock opportunities they weren't previously aware of.

What this shows for other producers

The Perry operation is one example of how closed-loop farming can work at commercial scale, and how far the loop can reach when neighbours are part of it. A few things stand out as potentially transferable:

The community dimension is central, not incidental. The loop works because it draws on organic waste the surrounding area already produces, which keeps fertility close to home and cuts the distance it has to travel.

The pathogen destruction step, pasteurization after anaerobic digestion, is what made it practical to return cull potato waste to the land without disease risk. That was the original problem the system was designed to solve.

The income diversification angle has become increasingly relevant. Fixed-rate RNG contracts offer a steadier revenue stream alongside commodity crop sales, which Chris describes as a useful balance to the variability that comes with potato markets.

The timeline and capital requirements are significant. The concept took shape around 2003, approvals ran to 2011, and the facility was commissioned in 2014, about 11 years from idea to operation. The Perrys were among the first to build a digester like this, and the process is faster now, so a producer looking at it today wouldn't face the same timeline. The RNG upgrade alone was a $5 million investment, and the Perrys are candid that the system isn't generating large profits on its own. The value, as they see it, is what it contributes to the whole farm: less synthetic fertilizer, energy self-sufficiency, fertility that stays close to home, and waste streams that are closed rather than open.