2.1.2. Soil carbon emissions
In accordance with Dalal et al. (2010) we assume that the manure contains 28% moisture and 27.8% carbon and that 15% of the available carbon will be sequestered in the soil and be available to the following year's cotton crop (Sanderman et al., 2010).
The urea applied to the irrigated crop consists of 20% carbon from the manufacturing process. We assume that all the bicarbonate is released into the Go 6976 (IPCC National Greenhouse Gas Inventories, 2006 and Brock et?al., 2012) with the hydrolysis of the urea with or soon after application, and the CO2 emissions is calculated by applying the conversion factor of CO2–C to CO2 of 3.667.
2.2. Indirect farm emissions
2.2.1. Transport emissions
Direct Scope 1 transport emissions are from fuel consumed off-farm to deliver inputs (including diesel) to the farm. As it is the farmer's responsibility to deliver the raw cotton to the gin (where it is contract ginned), this fuel usage is regarded as part of direct on-farm use. The indirect Scope 3 emissions related to the manufacturing of the diesel, are based on total fuel usage, including transport and on-farm use for production and irrigation, and we apply the NIR guidelines (Australian Government, 2011) where an emission factor of 5.3 kg CO2e per GJ is applied to the energy content of diesel of 0.0386 GJ/L times total diesel usage.