Assessing future drought risks and wheat yield losses in England

Abstract Droughts pose a major risk to agricultural production. By comparing the outputs from an ecophysiological crop model (Sirius) with four drought severity indicators (DSI), comparative assessment of impacts on wheat yield losses has been evaluated under current (baseline) and two future climate scenarios. The rationale was better understand relative merits limitations each approach perspective quantifying productivity. Modelled were regressed against highest correlated variant for DSI. A cumulative distribution function loss scenario (baseline, near far future) calculated as best fitting DSI (SPEI-5July) equivalent Sirius model. Comparative analysis between approaches highlighted large differences in estimated attributed drought, both terms magnitude direction change, baseline scenario. For baseline, average year (0.25 t ha−1 1.4 approaches, respectively). However, dry year, substantial (0.7 2.7 ha−1). approach, increased up 1.25 2.8 (for years, In contrast, modelling showed reduction loss, down 1.0 ha−1, marginal 2.6 ha−1. comparison risks adopting response particularly estimating related losses, where changing calendars CO2 fertilisation are not incorporated. challenge lies integrating knowledge DSIs onset, extent responses water use relations respect soil moisture conditions.