Effects of Short Rotation Willow on Soil Hydrology and Salinity in the Riparian Zones of Wetlands of Prairie Pothole Region

1 Md Shayeb Shahariar, Department of Soil Science College of Agriculture and Bioresources University of Saskatchewan and Agroforestry Development Centre AAFC, University of Saskatchewan

2 Raju Soolanayakanahally, Agriculture and Agri-Food Canada

3 William Schroeder, Agroforestry Development Centre Agriculture and Agri-Food Canada, University of

4 Angela Bedard-Haughn, Department of Soil Science College of Agriculture and Bioresources University of Saskatchewan

Short rotation willow (SRW) is a land use of increasing interest in North America including in marginal lands of the Prairie Pothole Region (PPR). The PPR contains millions of small wetlands that serve the important hydrologic function of storing soil moisture and recharging groundwater. Water balances of these PPR wetlands are very sensitive to surrounding riparian land management. The potential effects of land use changes on the water balance of these wetlands are an important concern for agriculture, management of water resources and wildlife habitat in this region. Evapotranspiration by riparian vegetation is the dominant pathway of water loss in this semi-arid region. High transpiration rate of willow vegetation that are commonly present in the riparian zone of uncultivated PPR wetlands are known to lower groundwater levels and contribute to the accumulation of secondary carbonates in the soil profile (i.e., willow ring soils). However, it is not known whether fast growing, SRW, grown for agroforestry and bioenergy, would have a similar impact. The impact of SRW cultivation in the riparian zones of PPR wetlands on groundwater table fluctuations and changes in soil salinity levels at different depths along transects was compared to other land use practices (annual crop and pasture) in a field experiment at Indian Head, Saskatchewan. The results will have important implications in future environmental use of SRW as a land use practice in the marginal land of Prairie wetlands as well as in planning wetland management and conservation in this region.