Northern cold-climate farms are small and often established on less fertile soils that require significant management to maintain soil carbon and productivity.

Farms in the northern cold-climate regions of Canada are small (under 100 acres) and thus not amenable to large-scale farming protocols. They are established either on less fertile soils that require significant management to maintain soil carbon and related functions, or on soils perceived as fertile mainly due to nutrients freed by rapidly mineralizing organic carbon that is easily lost. They are in direct contact with the natural ecosystem and are spread across a large geographical area, from Labrador to Yukon.

While farmers already implement innovative approaches relevant to 4R Nutrient Stewardship (regenerative and organic practices, re-use of local organic waste, strip-cropping and intercropping, crop rotation, biochar), there are no objectively verifiable, locally calibrated tools to evaluate their impact on the long-term sustainability of soil fertility and health. Establishing carbon-friendly practices requires a thorough understanding of management impacts on soil fertility and health, a verifiable approach to quantify carbon and its long-term stability, and rapid dissemination of knowledge.

The Labrador component (led by Dr. Joinal Abedin) examined the effect of biochar applied alone or with fishmeal and chemical fertilizers, the effect of different biochar application rates, the micronutrient-supplying capacity of biochar, and the response of soil nematode communities to biochar amendments, with the Labrador field research at Nature's Best farm.

A parallel effort assessed the nutrient stoichiometry of fish hatchery waste. Most nitrogen in recirculating aquaculture system (RAS) waste is found as ammonium; the waste's low pH likely does not favour ammonia volatilization, making it readily available to plants, while phosphorus and other nutrients become available during growth via mineralization. Plant cultivation assays were used to assess how RAS-based mixes change soil fertility and nutrient-use efficiency.

Results showed that the management of converted podzolic soils in circumboreal regions must account for the initial status of the soil. Good initial responses to fertilization can be misleading and do not guarantee that the soil can sustain productivity over the longer term; distinct organic fertilizers behaved distinctly even on soils of arguably equivalent fertility. Sustaining long-term fertility requires long-term, comprehensive agronomic experiments, and the type of fertilizer and carbon-rich supplement must be tailored to the age of the land after clearing.