Effects of a wheat rotation on cotton production in a changing climate: a simulation study

There is mounting evidence that climate change could be threatening the viability of cotton production in regions of Australia. This study aims to evaluate the effectiveness of a cotton-wheat rotation system in dealing with climate change for the period centred on 2030 by linking the outputs of the CSIRO Conformal Cubic Atmospheric Model with the Agricultural Production System sIMulator (APSIM) through a stochastic weather generator, LARS-WG. For irrigated cotton, we considered 3 crop sequences and 9 production areas spanning the current industry. For rain-fed cotton, we considered 2 crop sequences with 3 cotton row configurations and 4 production areas. Simulation results show that (1) for irrigated cotton, cotton 3 yr in and 1 yr out would perform the best in terms of cotton lint yield; (2) crop yields would decrease in a changing climate across crop sequences at most of the locations with wheat yield decreasing more than cotton; (3) for rain-fed cotton, continuous cotton would perform better at Emerald, Dalby and/or Narrabri under solid and single skip row configurations, while a cotton-wheat sequence would out-perform continuous cotton in terms of cotton lint yields under double skip at Emerald, Moree and Narrabri; and (4) wheat yield would decrease across locations. To maintain current production levels, better performing crop sequence needs to be combined with other adaptation options