Crop Nutrient Balances for Eastern Canada - Ontario, Quebec, and the Atlantic Provinces
Updated to the 2011 crop year!
The crop nutrient balance--the comparison of nutrients applied in relation those removed by crops--is an important indicator of the sustainability performance of crop production. Deficits in the nutrient balance can limit crop yields and deplete soil fertility, and surpluses can cause economic waste and increase the risk of harm to water and air.
Plants require at least 14 elements as essential mineral nutrients. Each of the 14 is equally crucial to the plant's survival, but some are more likely to become deficient than others. Supplies of the three primary nutrients--nitrogen (N), phosphorus (P) and potassium (K)--need the closest attention to ensure adequate quantities for crop growth. The articles below chart the trends in the supply and removal of these three important nutrients in three major regions within Eastern Canada.
The chemical nature of each nutrient, and the nutrient status of the soil influence the interpretation of nutrient balances. Nitrogen is considered a mobile nutrient, and is susceptible to several pathways of loss, including leaching as nitrate, denitrification to nitrogen gases, and volatilization as ammonia. However, soils hold reserves of nitrogen in organic matter. Phosphorus and potassium are considered immobile nutrients, held in the soil by sorption and precipitation reactions. Surpluses build up soil test levels for these two nutrients, while nutrient deficits can reduce their soil test levels.
The balances presented below are estimates. Manure is estimated based on Statistics Canada inventory of cattle, hogs, and poultry and coefficients for excretion and recoverability. Fertilizer nutrients are calculated from industry data on shipments to agricultural markets. Legume fixation of nitrogen is assumed proportional to the nitrogen removed by the major legume crops, mainly forage legumes and soybeans. Crop removal of nutrients is estimated by applying coefficients to crop production data from Statistics Canada.
Further detail on the assumptions and data sources is provided at the link below and in a 2011 article in the Canadian Journal of Soil Science.
Assumptions and Data Sources
In general in Eastern Canada, crop removals are increasing owing to yield increases in the major crops, and historical nutrient surpluses are declining. Nutrient balances have seen dramatic changes over the past five years (2007-2011) in response to price changes for fertilizers and crops. Visit the links below for details on each nutrient in each region.
