Forage crop yield and nutritive value under climate change in Canada

摘要

Changes in forage yield and nutritive value under future climate conditions might affect the economic and environmental performance of dairy farms. Few studies, however, have simulated future fotage production with a farm-scale model in areas with short growing seasons and cold winters. We assessed the potential effect of future climate change on the yield and nutritive value of a mixture ot alfalfs [Aledicago sativa L.) and timothy (Phleum pratense L.), pure alfalfa, and silage maize (Zea mays L.),with an adaptation of seeding dates, maize hybrids, and the number of cuts of perennial forage crops. Using the Integrated Farm System Model (IFSM), simulations covered three contrasting climate areas in Canada for reference (1971-2000) and future (2050-2079) periods, with three climate models and under two representative concentration pathways (RCP 4.5 and 8.5). Simulations indicated that yield of perennial forage crops would increase in all areas (+3 to +65%) with little change in forage nutritive value. Yield of silage maize would increase more in colder (+63 to +83%) than in warmer (+15%) areas, while concentrations of neutral detergent fibre (NDF) and crude protein (CP) would decrease in the colder areas only.