l water productivity enabled the investigation of the relationship between water and carbon dioxide fluxes of these particular cropping systems.In terms of evapotranspiration, the results showed that the largest amount of water lost to the atmosphere was through the production of rice; the cumulative total over the growing season was 783 mm. According to the Food and Agriculture Organisation, the approximate values of seasonal water use of rice generally ranges from 400 Ã¢Â“ 700 mm (Brouwer & Heibloem, 1986). Winter wheat production accounted for the least amount of water lost; the cumulative total over the growing season was 389 mm and was typical of seasonal water use of irrigated maize grown in Australia (Sadras & McDonald, 2012).As a C4 plant, maize was found to account for the greatest amount of total carbon accumulation, or gross primary productivity, over the course of the growing season; the cumulative total of gross primary production was 1952 g C/m2/year and were higher the range of values reported globally (789 g C/m2/year Ã¢Â“ 1796 g C/m2/year; Suyker & Verma, 2012; Yan et al., 2009b). Due to decreased incoming solar radiation and air temperature, and thus, decreased biomass production, winter wheat accounted for the least amount of total carbon capture; the cumulative total of gross primary production was 1367 g C/m2/year and is within the reported range of 778 g C/m2/year and 1716 g C/m2/year (Dufranne et al., 2011; Gilmanov et al., 2003).The results of the geostatistical regression modelling showed that net radiation, air temperature, wind speed and rainfall all had an impact on evapotranspiration rates of the two summer crops, maize and rice.
|Qualification||Doctor of Philosophy|
|Award date||01 Sep 2013|
|Place of Publication||Australia|
|Publication status||Published - 2013|