Forage Seed Response to Copper Fertilization
In June 2013, we applied foliar EDTA chelated copper to established timothy (3 locations) and hybrid bromegrass (1 location) on replicated mini-plots. This was repeated in June of 2014 and June 2015, but we added 2 other liquid Cu foliar treatments; dropped one unresponsive site and added another potentially responsive hybrid bromegrass site. At harvest we evaluated treatment effects on seed yield in all three years and on straw yield in 2014 and 2015.
At Site 1 in 2013 (a field with a history of copper fertilizer application) seed yield of timothy did not increase when copper was applied, and showed a weak tendency to decline slightly. At two other sites in 2013, copper fertilization increased seed yield of timothy by 20 and 29% (Site 3 and Site 2 respectively). At Site 4, copper fertilizer increased seed yield of hybrid bromegrass by 30%. The three sites where copper did increase yield all had no known history of copper application.