Cotton and Climate Change
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Cotton is an annual crop grown in regions that experience climate variability driven by El Nino/La Nina cycles. Consequently cotton growers have already developed highly efficient and flexible farming systems that can meet the challenges of climate change
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Greenhouse Gas Emissions (GHG) from the Australian cotton industry are small, representing:
- Less than one third of one per cent of Australian agriculture’s GHG emissions (ranging from 0.16-0.29%)
- Approximately 0.15% of the nation’s total emissions in 2010/2011
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Main sources of Greenhouse Gas Emissions that can be associated with cotton growing include:
- Nitrogen from fertilizer and organic nitrogen sources
- Carbon dioxide from soils (biological decomposition of crop and pasture residues which is increased by tillage and additional moisture and nutrient present in irrigated systems)
- Carbon dioxide from fuel and fertiliser (during planting, cultivation, harvesting, chemicals, pumping, fertilisers)
- Despite being a very small contributor to agriculture’s greenhouse gas emissions, the Australian cotton industry has invested in climate change research to understand further opportunities for cotton farms to reduce or capture emissions
- Australia has led the world in accurately measuring in-field greenhouse emissions in irrigated cotton systems. Results from this research, jointly funded by the Cotton Research & Development Corporation (CRDC) and the Australian Greenhouse Office, indicate the average level of Nitrous Oxide (the primary greenhouse gas in Australian cotton cropping) is 0.5% of applied Nitrogen. This figure is well below the IPCC default figure of 1.25%
- Cotton industry research has shown that practices for optimising energy efficiency and reducing emissions in cotton production are also those that deliver maximum yield, fuel and fertiliser savings and environmental benefits such as improved soil health
- These activities have been the subject of continued cotton R&D efforts, and are captured by the industry’s Best Management Practices program (which include components on Energy and Input Efficiency, Water Management and Soil Health)
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Practical examples of cotton production practices to minimise emissions and manage soil carbon include:
- Improved water use efficiency which reduces pumping and waterlogging
- A move to use of round modules which has led to energy reduction in harvest and handling through removal of some operations and machinery
- Placing nitrogen at depth in cooler times in wet soils to maximise nitrogen efficiency (and thus minimise losses to the atmosphere)
- Assessing and optimising nitrogen fertiliser use and use of alternative sources such as legume rotations
- Using lower emissions machinery and assessing and improving existing machinery and irrigation pumping performance
- Alternative fuel sources
- Improvements in soil management through stubble retention, reduced tillage and reduction in spraying operations