A review of farm level responses to nutrient regulations in Manitoba, Canada

摘要

Since 1998, the Province of Manitoba in Canada has regulated livestock manure management by linking manure application to crop removal rates. Initial concerns over the risk of excessive nitrate leaching led to regulation based on nitrate-nitrogen build up in soils. This regulation failed to identify problems related to other nutrients, especially phosphorus and its impact on blue-green algae (cyanobacteria) in Lake Winnipeg. New regulations have been enacted to limit phosphorus accumulations in soil.Livestock producers, including hog farmers, were particularly concerned with these new regulations as most crops need less phosphorus than was being supplied in livestock manure when application was based on nitrogen needs. The actual response to the regulation has been much different than the forecasts. The implementation of a new enzyme, phytase, has reduced the level of phosphorus in hog manure (and lowered feed costs!). The increase in nitrogen and phosphorus fertilizer prices has also increased the demand for hog manure as a valuable input in most farming regions of Manitoba. As we show, most regions of the province could feasibly accept more manure. This article considers the impact of innovative responses to environmental regulation, at the firm level, including the adoption of phytase and of integrating forage and crop farming systems with hog production facilities. Regional impacts as assessed by previous researchers are then adjusted by these effects.