The expected impact of climate change on nitrogen losses from wet tropical sugarcane production in the Great Barrier Reef region

Abstract

Abstract. The Great Barrier Reef is under threat from diffuse agricultural pollutants and potential climate change. Nitrogen loads are examined using the nitrogen surplus of simulated sugarcane production systems in the Tully-Murray catchment, comparing current management practice regimes with best management practice regimes under present day and future climate scenarios -nominally 2030 and 2070. These future scenarios are represented by increased carbon dioxide, increased temperature and increased rainfall variability. Simulation results suggest that the impact of potential climate change on diffuse agricultural nitrogen loads from sugarcane production in the Tully-Murray catchment to the Great Barrier Reef is likely to be small and negligible in comparison to the impacts of management practice change. Partial gross margin analysis suggests climate change will not noticeably alter the profitability of sugarcane production and, hence, is unlikely to be a driver of change for this land use in the Tully-Murray catchment. Improvements in water quality from sugarcane production are more likely to come from identification and adoption of best management practices.

Implications of climate change for the sugarcane industry

“…In addition, the question of how climate change influences sugarcane disease patterns has not yet been fully explored, and few studies examine how climate change impacts the sugarcane industry when accounting for other threat factors (e.g., biodiversity loss, land‐use change, freshwater use, pollution) . Some studies argue that the impacts of climate change on ecosystems such as the Great Barrier Reef in Australia need to be assessed in conjunction with the impacts of nitrogen losses from sugarcane production to fully understand the interactions between agricultural pollutants and climate change . Additional impacts on the industry are likely to arise from socioeconomic factors, such as changes in labor costs (given the labor‐intensive nature of production), socioeconomic and political factors (e.g., competition for land resources, R&D initiatives, industry support, and development), and future demand patterns for sugarcane.…”

Using the Soil and Water Assessment Tool to Estimate Dissolved Inorganic Nitrogen Water Pollution Abatement Cost Functions in Central Portugal

“…The adoption of BAPs may involve considerable costs due to increases in production costs or decreases in yields (e.g., Roebeling et al, 2007;Webster et al, 2009). Hence, water pollution abatement costs may be substantial and may differ between agricultural land use categories because they are conditional on (i) the local biophysical and agro-ecological conditions and (ii) the range of available BAPs for water quality improvement.…”

Crop Models

“…Examples are as follows: Benchmarking sugarcane yields in Mauritius (Cheeroo-Nayamuth et al 2000) and Australia (Muchow et al 1997) r Developing a decision support system for optimal design for water storage for sugarcane irrigation (Lisson et al 2003) r Estimating nitrogen losses (nitrate leaching, nitrous oxide emissions) from irrigated and rainfed sugarcane cropping systems used in Australia Thorburn, van Antwerpen, et al 2001;Stewart et al 2006;Webster et al 2009;Thorburn et al 2010) r Estimating the effects of residue retention on water and N dynamics and yield for several locations in Australia and South Africa (Thorburn, Biggs, et al 2001; r Investigating the feasibility of reducing N fertilizer rates through fertigation (Thorburn et al 2003) r Assessing the economic effect of water stress on sugar production in Australia to evaluate the merits of breeding for drought resistance and improved water-use efficiency (Inman-Bamber 2007) r Optimizing timing of limited irrigation water in Australia (Inman-Bamber et al 1999) r Developing a generic approach to drying off sugarcane r Supporting tactical irrigation management for sugarcane farmers in Australia with a webbased tool that uses data derived from APSIM simulations ) Examples are as follows: Benchmarking sugarcane yields in Mauritius (Cheeroo-Nayamuth et al 2000) and Australia (Muchow et al 1997) r Developing a decision support system for optimal design for water storage for sugarcane irrigation (Lisson et al 2003) r Estimating nitrogen losses (nitrate leaching, nitrous oxide emissions) from irrigated and rainfed sugarcane cropping systems used in Australia Thorburn, van Antwerpen, et al 2001;Stewart et al 2006;Webster et al 2009;Thorburn et al 2010) r Estimating the effects of residue retention on water and N dynamics and yield for several locations in Australia and South Africa (Thorburn, Biggs, et al 2001; r Investigating the feasibility of reducing N fertilizer rates through fertigation (Thorburn et al 2003) r Assessing the economic effect of water stress on sugar production in Australia to evaluate the merits of breeding for drought resistance and improved water-use efficiency (Inman-Bamber 2007) r Optimizing timing of limited irrigation water in Australia (Inman-Bamber et al 1999) r Developing a generic approach to drying off sugarcane r Supporting tactical irrigation management for sugarcane farmers in Australia with a webbased tool that uses data d...…”