Farm level and regional impacts of forage based manure management in Manitoba:

 La Broquerie Project Phase I (completed 2007)


Team:

Project Leader:  Derek Brewin, Dept. Agric. Economics
Collaboraters:  Suren Kulshreshtha, Kim Ominski, Mario Tenuta
Students:  Mathew Wiens, Jonathon Bouw, Collin Gyles and Oteng Mondongo
Acknowledgements:  Mr. Allan Florizone, Debbie Jacobs of Statistics Canada

Funding:

Manitoba Rural Adaptation Council

Goal:

At least as early as 2001 (Petkau and May, 2001), researchers began studying an emerging strategy for beef and hog farms in Manitoba. Farmers had begun to use more forage land for hog manure disposal. It had long been known that the productivity of forage land could be improved through the application of nutrients. Prior to the expansion of the hog sector in Manitoba (MB), the more common method of doing this was through the use of commercial fertilizers. The expansion in the Manitoba hog sector, starting in the 1980s, created more opportunities to improve productivity through the application of hog manure. This manure was often available at no cost to the forage producer.

The production basis for this study was a pilot site near La Broquerie, MB which now has three years of data on forage responses to manure application (see Ominski et al., 2008). Based on these production effects, farm level economic impacts of applying hog manure to forage production are assessed. This study also looks at regional impacts of changing manure management practices using an input-output model of the Manitoba economy. Input-output models track the impact of changes in one sector on all the sectors in an economy.

Objectives:

The La Broquerie Project

As the practice of forage based manure management became more common, researchers began to be concerned with the information available on the advantages and/or disadvantages of this practice in terms of environmental sustainability. There were apprehensions about methane and nitrous oxide production, the soil nutrient profile and the potential persistence and transmission of bacteria from the manure to the forage and to the cattle. These concerns, in relation to the productivity of the pasture and the animal, required additional exploration. To address this need, a team led by the University of Manitoba, along with numerous government and industry partners, was established using a research site in the RM of La Broquerie in Southeast Manitoba (SE20-5-8E). This site was selected as it was deemed environmentally sensitive – located in an RM with high animal density and it had forages that had not recently received manure nutrients.

Design:

In order to examine the impact of manure application, forage and animal productivity, greenhouse gas production, as well as nutrient movement and pathogen flow, the site contained six replicated paddocks:

  • rotationally grazed only (no manure);
  • harvested only (no manure);
  • fertilized with an early summer application of hog manure and rotationally grazed;
  • fertilized with an early summer application of manure and harvested;
  • manure application divided between spring and fall application of hog manure and rotationally grazed; and
  • manure application divided between spring and fall application of manure and harvested.

With three years of data analyzed, the University of Manitoba research team published a major report (Ominski et al., 2008) and several journal articles based on that data (for example Holley et al., 2008 and Undi et al., 2008). Production impacts from the La Broquerie project, which are relevant to the current economic analysis, are reported in a subsequent section of this report. In general, significant yield advantages were identified, nitrogen balances appeared sustainable and no evidence of pathogen transmission between hog manure and grazing cattle was found. There was evidence of phosphorus build up in some systems which lend some support to some of the phosphorus based regulation options being discussed in Manitoba.

Learn more about the La Broquerie Project

Download Full Report here (pdf)