Apr 20th, 1:00 PM - 4:00 PM
Relationships Between the Timing of Snowmelt and Crop Production in Camas County , Idaho
Dr. Jennifer Pierce
Snowmelt runoff is an important source of water for many snowmelt-dominated basins of the western United States. In the last several decades, warming temperatures in the western U.S. have lead to earlier spring runoff in snowmelt-driven watersheds. While earlier spring runoff has important implications for agriculture, the relationships between the timing of snowmelt and agricultural production have received little study. In Camas County of southwestern Idaho, snowmelt provides water needed for the initial germination of barley seed and for further barley growth. The specific timing for planting spring barley is critical. Early snowmelt requires earlier planting of seeds, but cool spring temperatures inhibit seed germination. When seeds do germinate, soils are dry which prevents or slows barley growth. This study uses dry-land barley yields from the Camas Prairie in Idaho due to the county’s reliance on runoff (vs. irrigation), for agricultural use. In the mid-1960’s in Camas country, the type of barley planted was switched between winter barley (planted ~1930 -1964) and spring barley (1965-2008). Barley yields in bushels per acre show a strong correlation with the timing of peak streamflow reconstructed from snowmelt records (Kunkel and Pierce in review). After 1965 (spring barley) early snowmelt is negatively correlated with bushels per acre of barley (Spearman’s correlation r=0.5806, n=41, P<0.0001). Prior to 1965 (winter barley) early snowmelt is positively correlated with bushels per acre of barley. This study has important implications for how barley production and seed type may need to be modified in a warmer and possibly drier future.