A Comparison of Two Modes of Dairy Farming Intensification and the Impact on Water Quality in Ohio, USA

International audience

anglais. Two different modes of dairy farming intensification in two adjacent sub-watersheds in the headwaters of the South Fork of Sugar Creek in Ohio, USA, are compared with the potential sustainability consequences in connection to landscape structure and patterns as they impact water quality. A survey was administered between 2005 and 2007 in the southern part of the Sugar Creek watershed where we interviewed 28 Amish and non-Amish farmers. We collected data at the field level on farms totaling 3422 ha to characterize intensifications in production under divergent management strategies and to assess the collective implications for the environmental impacts. In addition, water quality was monitored biweekly from 2010-2018 using nutrient concentrations at the sub-watershed outlets and in 1998 and 2017 using instream habitat and biological assessments across both sub-watersheds. The main result was that, despite contrasting farming and cropping systems (small versus large farms, animal grazing versus feed), both Amish and non-Amish dairy operations had increased the number of cows and milk per cow on their farms with similar organic nutrient production by animals per hectare farmed. Equally, surface water quality assessed through our monitoring program was similar with both systems showing decreasing nutrient enrichment and increased habitat quality. Interestingly, these equivalent intensifications and environmental impacts were realized despite contrasting demographics and land use patterns found when comparing Amish and non-Amish operations. Collectively, these results illustrate the need to include sociocultural dimensions to truly capture the trajectory of development as it pertains to the intersection of sustainability and intensification-especially since the complexity of interactions occurring can potentially mask impacts relative to sustainable water resources management.