The gray soil zone, extending into the northern regions of the Prairies, is characterized by higher moisture levels, cooler temperatures, and a shorter growing season. Climatic conditions also influence the susceptibility of crops to disease and pest infestations, requiring different combinations and levels of herbicides and pesticides. Price forecasts can vary considerably as a result of unusual weather in the major importing or exporting countries, and other changes in market conditions. Adjustments for soil zone are based on historical data from Statistics Canada. Adjustments to a 'stubble' basis were based on provincial data.
Actual yields can vary greatly due to factors such as weather, disease, pests or input use.
Natural gas is the primary raw material required for the production of ammonia, which is the foundation for virtually all forms of nitrogen fertilizer. Currently, all production capacity has returned and it is estimated that supplies of fertilizer are sufficient to meet expected demand. The forecasts were based on dealer survey estimates. It is expected that producers may switch some of their seeding to crops that require a lower percentage of nitrogen fertilizer. There are significant differences in the variable costs between provinces and soil zones.