The Migrant Worker Solidarity Network and the Canadian Centre for Policy Alternatives, Manitoba have released Migrant Voices: Stories of Seasonal Agricultural Workers in Manitoba. 

Migrant Voices is based on interviews conducted with migrant farm workers in Manitoba during the summer of 2011. From the report:

Each year approximately 400 Mexican men, migrant labourers under the Seasonal Agricultural Workers Program (SAWP), work on farms in Manitoba. These labourers perform physically strenuous work on vegetable farms and in greenhouses, jobs that most Canadians prefer not to do. Workers spend up to eight months in Canada, returning year after year for the agricultural
season. They live and work under precarious conditions that often foreclose the possibility of accessing the human rights protections provided in the Canadian Charter of Rights and Freedoms. Workers regularly toil twelve hours per day, six to seven days a week, and they live socially isolated from Canadian society. This report highlights the stories of these labourers
and invites readers to bear witness to the aspirations and transborder lives of these Mexican men working on Manitoban soil.

You can download a copy of the report here.