THE MANITOBA LAND CALCULATOR: A TOOL TO ESTIMATE LAND REQUIREMENTS FOR MANURE APPLICATION IN MANITOBA, CANADA

The planning of new livestock and poultry facilities or expansion of existing facilities should ensure sufficient land for manure application. Decision support tools used to establish land requirements for manure nutrients should take into consideration advances in animal genetics, performance, feeding strategies, and available feeds. This article presents a new tool for estimating land requirements for new and expanding pig, beef, dairy, and poultry operations in the province of Manitoba, Canada. The Manitoba Land Calculator (MLC) estimates land requirements for manure nitrogen (N) and phosphorus (P). It uses a mass balance approach to estimate nutrient excretion by livestock and poultry based on typical Manitoba feeding practices, weight gain, and production cycles. Crop nutrient utilization and removals can be calculated for 20 common crops grown in Manitoba using reliable long-term yields and farm-specific crop areas. Two case studies (pig and poultry) were selected from the Livestock Technical Review Public Registry on the Government of Manitoba website to illustrate the inputs and outputs associated with the MLC. The results indicated that land requirements increased by 4.6-fold and 5.7-fold for the poultry and pig operations, respectively, compared to the previous provincial methodology due to the inclusion of P in the model. Securing additional land during the planning stages will support the implementation of nutrient stewardship principles that ensure the long-term environmental sustainability of livestock operations.