Browsing by Author "Robson, A"

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A review of nitrogen use efficiency in sugarcane
(2015) Bell, MJ; Biggs, J; McKellar, LB; Connellan, J; Di Bella, L; Dwyer, R; Empson, M; Garside, AJ; Harvey, T; Kraak, J; Lakshmanan, P; Lamb, DW; Meier, E; Moody, P; Muster, T; Palmer, J; Robinson, N; Robson, A; Salter, B; Schroeder, B; Silburn, M; Schmidt, S; Skocaj, DM; Stacey, S; Stanley, J; Thorburn, P; Verburg, K; Walker, C; Wang, W; Wood, A
The Great Barrier Reef (GBR) is the world's largest coral reef ecosystem, providing both substantial economic benefit to Australia and significant international ecological value. The health of the GBR is under pressure from sediments, pesticides and nutrients (especially nitrogen) discharged from nearby catchments. Discharge of nitrogen is of particular concern as it stimulates outbreaks of the Crown of Thorns Starfish, a major predator of GBR corals. Recent research has shown that the amount of nitrogen fertiliser applied in excess of crop uptake is an important determinant of nitrogen discharge from catchments, so increasing the efficiency of nitrogen use in cropping systems is an important step in protecting the economic and ecological benefits provided by the GBR. Importantly, an increase in nitrogen use efficiency (NUE) also offers opportunities to improve productivity and profitability of agricultural industries, with such benefits a major incentive for industry adoption and practice change. The Australian sugarcane industry is a significant contributor to the anthropogenic loads of nitrogen entering the Great Barrier Reef lagoon, with recent estimates in the Reef Water Quality Protection Plan (2013) suggesting it contributes 18% and 56% of particulate and inorganic nitrogen loads, respectively. A focus on improving NUE in the Australian sugar industry to reduce these loads wherever possible is a logical outcome from these statistics. While the relative impact of dissolved inorganic nitrogen (DIN) and particulate nitrogen (PN) is still uncertain, recent NUE forums in the sugar industry in 2014 identified clear target reductions in DIN that would be needed in order to significantly improve water quality in line with Reef Plan (2013-18) targets. The forum also identified a clear need for a joint industry-government funded research program to improve NUE in sugarcane cropping systems. The review conducted for this report was commissioned and funded by the Australian Government Reef Programme to provide a foundation for this joint NUE research program. The review was tasked with providing an improved understanding of past and current research effort and available field trial information (both published and unpublished) relating to nitrogen management in the sugar industry. From this perspective the review was then tasked with identifying research gaps and opportunities for future research projects and field trials that would collectively contribute to improving NUE from both agronomic and production perspectives as well as delivering significant reductions in nitrogen lost to waterways and the Great Barrier Reef lagoon. It is widely recognized that in any crop, the demand for N is determined by the size of the crop and the fundamental efficiency with which that crop produces a unit of biomass or harvested product from a kg of acquired N (N use efficiency - NUE). Therefore a good understanding of yield potential at the spatial scale of the productivity unit (i.e., farm, several blocks of similar productivity, individual blocks or within-block) about which N fertilizer management decisions (rate, form, placement, timing) are made is required, along with an understanding of how that yield potential varies with seasonal conditions. Collectively, this could be called seasonal 'block' (or productivity zone) yield potential, and it will produce a crop N demand that may vary from year to year. The sugar industry is currently operating at the district level (generally comprising several thousand cropped hectares across variable soil types and landscapes), and basing N demand for all growers in the district on the best farm yield ever achieved over a 20 year time frame. It is apparent that overall NUE could be improved by basing N fertiliser inputs on the seasonal yield potential of the productivity unit.
An assessment of the potential of remote sensing based irrigation scheduling for sugarcane in Australia : Final report 2015/082
(Cotton Research and Development Corporation, 2017) Sinha, P; Lamb, DW; Robson, A
There is currently no operational method of managing irrigation in Australia’s sugar industry on the basis of systematic, direct monitoring of sugar plant physiology. Satellite remote sensing systems, having come a long way in the past 10 years now offer the potential to apply the current ground-based ‘FAO’ or ‘crop coefficient (Kc)’ approach in a way that offers a synoptic view of crop water status across fields. In particular, multi-constellation satellite remote sensing, utilising a combination of freely available Landsat and Sentinel 2 imagery, supplemented by paid-for imagery from other existing satellite systems is capable of providing the necessary spatial resolution and spectral bands and revisit frequency. The significant correlations observed between Kc and spectral vegetation indices (VIs), such as the widely used normalised difference vegetation index (NDVI) in numerous other crops bodes well for the detection and quantification of the spatial difference in evapotranspiration (ETc) in sugar which is necessary for irrigation scheduling algorithms.
Developing remote sensing as an industry wide yield forecasting, nitrogen mapping and research aid : Final report 2013/025
(Sugar Research Australia Limited, 2017) Robson, A; Rahman, M; Muir, J
The science of Earth Observation (EO) is a rapidly developing discipline that has seen an unprecedented rise in remote sensing technologies and application development, including those in agriculture. The Australian sugarcane industry has seen a steady increase in the development and adoption of remote sensing applications over the last decade, predominantly as a result of investment by SRDC and then Sugar Research Australia (SRA). SRA project (DPI025), with collaborative support from Australia's sugar mills, grower's, research institutions and extension agencies, has been at the forefront of this evolution, evaluating modern remote sensing technologies and novel analysis methodologies for improved in-season yield forecasting and Nitrogen management, both issues identified as priorities by the industry. Accurate yield forecasting at the regional level is vital for the Australian sugar industry as it supports decision making processes including harvest scheduling, product handling and forward selling. At the farm scale, accurate yield mapping provides growers with a stronger understanding of in-crop variability, both spatially and temporally, thus supporting the adoption of precision agricultural practices to maximize productivity. Currently, yield forecasting within the Australian sugarcane industry is undertaken by visual inspection or destructive sampling by either growers or mill funded productivity officers. Although relatively accurate, these methods are labour intensive and are subject to the influences of varied seasonal climatic conditions, crop age and human error. Remote sensing technologies have evolved across many cropping systems as an accurate 'tool' for measuring in-season performance and for the prediction of yield, pre- harvest. This project, built on the initial findings of DPI021, further developed regional yield prediction algorithms derived from SPOT satellite imagery for 11 growing regions: Broadwater, Harwood, Condong, Isis, Bundaberg, Maryborough, Burdekin, Herbert, Tully, South Johnstone and Mulgrave); investigated novel statistical methods for improving prediction accuracies at the block level; and investigated time-series remote sensing based models for improved forecasting accuracies earlier in the growing season.
Remote sensing-based precision agriculture tools for the sugar industry : SRDC Final report DPI021
(2013) Robson, A; Abbott, C; Bramley, R; Lamb, D
This project aimed to develop remote sensing applications that were both relevant and of commercial benefit to the Australian sugar industry and therefore adoptable. Such applications included the in season mapping of crop vigour so as to guide future management strategies, the identification of specific abiotic and biotic cropping constraints, and the conversion of GNDVI variability maps into yield at the block, farm and regional level. In order to achieve these applications the project team reviewed an array of remote sensing platforms, timing of imagery capture, software and analysis protocols; as well as distribution formats of derived imagery products, to a range of end users. The project developed strong collaborative linkages with all levels of the industry including mills, productivity services, agronomists, growers and researchers and increased its initial coverage from three individual farms in Bundaberg, Burdekin and the Herbert, coinciding with project CSE022, to include over 33,000 crops grown across 6 growing regions (Mulgrave, Herbert, Burdekin, Bundaberg, ISIS and Condong) during the 2011/2012 season.