Adapting wheat sowing dates to projected climate change in the Australian subtropics: analysis of crop water use and yield

Abstract

Abstract. Projected increases in atmospheric carbon dioxide concentration ([CO2]) and air temperature associated with future climate change are expected to affect crop development, crop yield, and, consequently, global food supplies. They are also likely to change agricultural production practices, especially those related to agricultural water management and sowing date. The magnitude of these changes and their implications to local production systems are mostly unknown. The objectives of this study were to: (i) simulate the effect of projected climate change on spring wheat (Triticum aestivum L. cv. Lang) yield and water use for the subtropical environment of the Darling Downs, Queensland, Australia; and (ii) investigate the impact of changing sowing date, as an adaptation strategy to future climate change scenarios, on wheat yield and water use. The multimodel climate projections from the IPCC Coupled Model Intercomparison Project (CMIP3) for the period 2030-2070 were used in this study. Climate scenarios included combinations of four changes in air temperature (08C, 18C, 28C, and 38C), three [CO 2 ] levels (380 ppm, 500 ppm, and 600 ppm), and three changes in rainfall (-30%, 0%, and +20%), which were superimposed on observed station data. Crop management scenarios included a combination of six sowing dates (1 May, 10 May, 20 May, 1 June, 10 June, and 20 June) and three irrigation regimes (no irrigation (NI), deficit irrigation (DI), and full irrigation (FI)). Simulations were performed with the model DSSAT 4.5, using 50 years of daily weather data. We found that: (1) grain yield and water-use efficiency (yield/evapotranspiration) increased linearly with [CO 2 ]; (2) increases in [CO 2 ] had minimal impact on evapotranspiration; (3) yield increased with increasing temperature for the irrigated scenarios (DI and FI), but decreased for the NI scenario; (4) yield increased with earlier sowing dates; and (5) changes in rainfall had a small impact on yield for DI and FI, but a high impact for the NI scenario.

Modelling cropping periods of grain crops at the global scale

“…A common modelling approach for adaptation assessments is to perform sensitivity analysis of crop productivity under different management scenarios and to identify which return the highest yield (Barbottin, Bail, and Jeuffroy, 2006;Bassu et al, 2009;Cammarano et al, 2012;Semenov et al, 2014;Zimmermann et al, 2017;Ruiz-Ramos et al, 2018). Management scenarios include sometimes more than one practice (e.g.…”

“…Management scenarios include sometimes more than one practice (e.g. sowing dates, cultivars and irrigation) so that packages of combined management practices and their interaction can be assessed to identify the best adaptation strategy (Cammarano et al, 2012;Rötter et al, 2013;Ruiz-Ramos et al, 2018). This approach however hampers the implementation of 1.3 Scientific investigation of agricultural systems under climate change adaptation of cropping systems in the context of Earth Systems (McDermid, Mearns, and Ruane, 2017) or Integrated Assessment modelling (van Vuuren et al, 2009).…”

Vulnerability of Maize Farming Systems to Climate Change: Farmers’ Opinions Differ about the Relevance of Adaptation Strategies

“…Consequently, farmers must adapt their farming systems to reduce their farms' vulnerability to climate change [9]. Farmers have access to many adaptation strategies [10], such as changing varieties or crop species, changing sowing density and modifying the schedule of cropping operations [7,[11][12][13][14][15]. However, adaptation decisions can fail, either by not achieving the objectives, or worse, by increasing vulnerability [16].…”

Assessment of future climate change impact on rainfed wheat yield in the semi-arid Eastern High Plain of Algeria using a crop model

“…It is therefore possible to assess the impact of future CC on crop production by associating climate models with crop-climate models (Xiao et al 2018). Many such studies have been carried out worldwide (Admassu et al 2012;Gharibdousti et al 2019;Hernandez-Ochoa et al 2018;Cammarano et al 2012;Ahmad et al 2019).…”