Climate change impact on hay yields will leave farmers short of feed

Scientific paper reporting analysis of hay yields from Park Grass long term experiment in Hertfordshire, suggesting that spring hay yields in southern England have already been reduced by more than a third due to changes to our climate and further declines are forecast as global heating accelerates.

Addy, J., Ellis, R., Maclaren, C., Macdonald, A., Semenov, M., Mead, A. (2022). A heteroskedastic model of Park Grass spring hay yields in response to weather suggests continuing yield decline with climate change in future decades. Journal of the Royal Society. 19, 193https://doi.org/10.1098/rsif.2022.0361

Abstract

UK grasslands perform important environmental and economic functions, but their future productivity under climate change is uncertain. Spring hay yields from 1902 to 2016 at one site (the Park Grass Long Term Experiment) in southern England under four different fertilizer regimes were modelled in response to weather (seasonal temperature and rainfall). The modelling approach applied comprised: (1) a Bayesian model comparison to model parametrically the heteroskedasticity in a gamma likelihood function; (2) a Bayesian varying intercept multiple regression model with an autoregressive lag one process (to incorporate the effect of productivity in the previous year) of the response of hay yield to weather from 1902 to 2016. The model confirmed that warmer and drier years, specifically, autumn, winter and spring, in the twentieth and twenty-first centuries reduced yield. The model was applied to forecast future spring hay yields at Park Grass under different climate change scenarios (HadGEM2 and GISS RCP 4.5 and 8.5). This application indicated that yields are forecast to decline further between 2020 and 2080, by as much as 48–50%. These projections are specific to Park Grass, but implied a severe reduction in grassland productivity in southern England with climate change during the twenty-first century.

Disclaimer

Please ensure that you have proof-read your content. Pages are not edited further once submitted and will go live immediately.