Climate change impacts on phenology and yields of five broadacre crops at four climatologically distinct locations in Australia

Abstract

Shifts in rainfall and rising temperatures due to climate change poses a formidable challenge to the sustainability of broadacre crop yields in Western and SouthEastern Australia. Output from18 Global Climate Models (GCMs) for the Special Report on Emission Scenarios (SRES) A2 scenario was statistically downscaled to four contrasting locations. For the first time in these regions, bias corrected statistically downscaled climate data were employed to drive the Agricultural Production Systems Simulator (APSIM) crop model that integrates the effects of soil, crop phenotype, and management options for a quantitative comparison of crop yields and phenology under an historical and a plausible projected climate. The dynamic APSIM simulation model explore the implications of climate change across multiple locations and multiple time periods (1961-2010, 2030, 2060 and 2090) for multiple key crops (wheat, barley, lupin, canola, field pea) grown in three different types of soil. On average, the ensemble of downscaled GCM projections show a decrease in rainfall in the future at the four locations considered, with increased variability at two locations. At all locations and for five crops, future changes in both crop biomass and grain yield are strongly associated with changes in rainfall (P = 0.05 to P = 0.001). The overall rainfall amount is critical in determining yields but, equally, higher future temperatures can contribute to reducing crop productivity primarily due to advanced crop phenology. For example, for wheat cropping at Hamilton (a higher rainfall site), there is a significant advancement in median flowering date for 2030, 2060, and 2090 of 10, 18, and 29 days respectively with a significant 0.50% grain yield changes for each percentage change in rainfall compared to significant 0.90% grain yield changes in Cunderdin (a lower rainfall sites). At all sites except Hamilton, the change in crop grain yield is significantly correlated (P=0.001) with the percentage change in the future rainfall and the impact increased progressively from higher rainfall to lower rainfall sites. However, the magnitude of the change in crop phenology and yield were not significantly different between soil types. These results help to define regions of concern and their relative importance in the coming years. In this future climate the negative consequences for crop yields and advancement of phenology relative to baseline are not uniform across crops and locations. Of the crops studied-wheat, barley, lupin, canola and field pea-field pea is the most sensitive to the projected future climate changes, and the ensemble median changes in field pea yield range from a decrease of 12% to a decrease of 45%, depending on location. These results highlight the importance of research and policy to support strategies for adapting to climate change, such as advances in agronomy, soil moisture conservation, seasonal climate forecasting and breeding new crop varieties.

Simulated Canola Yield Responses to Climate Change and Adaptation in Canada

“…Overall, negative impacts on canola seed yield were simulated by the CSM-CROPGROCanola model. Our results agree well with a recent study (Anwar et al, 2015) that reports canola yield would decrease by about 15 to 30% in the middle of the 21st century and by 30 to 50% at the end of this century at four locations in Australia.…”

“…Hastened crop development in a shortened growing period could result in a reduction in canola yield under the projected climate change if other factors such as water availability and fertilizer applications are not improved (Anwar et al, 2015;Gan et al, 2007). A seed yield reduction of 42, 21, and 24% was simulated with a fertilizer application of 100 kg N ha -1 for the near future and of 37, 27, and 23% for the distant future, under RCP4.5, compared to the baseline climate for Brandon, West Nipissing, and Normandin, respectively (Fig.…”

Farmers' Perceptions of and Adaptations to Changing Climate in the Melamchi Valley of Nepal

“…Such climatic and phenological changes are common in the Himalayas (Ranjitkar et al 2013;Hart et al 2014). Changes in the phenology of crops as a result of climate change can contribute to reducing crop productivity because of earlier anthesis and grain maturity at warmer temperatures, thus shortening the duration of growth and reducing grain yields (Craufurd and Wheeler 2009;Anwar et al 2015). About 62% of household survey respondents and participants in the CRiSTAL exercise reported new crop pests due to increasing temperatures, resulting in crop yield decline and increased production costs (Deka et al 2010).…”

Traditional farm expansion versus joint venture remote partnerships

“…However, an important assumption was made that these yield relativities would continue to apply in the same way under future climate. There is some evidence, for example, that in the study region canola may be more adversely affected than wheat under future climate (Anwar et al 2015).…”