Browsing by Author "Bramley, RGV"

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Environmentally sound phosphorus management for sugarcane soils : final report on SRDC Project no CSS3S
(1998) Bramley, RGV; Edis, RB; White, RE; Wood, AW
A field and laboratory-based survey of the behaviour of phosphorus (P) was carried out on the soils of the lower Herbert River catchment, and sediments derived from them. The aim was to explore the factors governing P sorption or desorption in Herbert soils, and in suspended sediments in associated riverine and estuarine waters, so that the extent of any problem associated with sugarcane and soil-derived inputs to streamwaters could be defined. With this information, advice on the development of best management practices for P fertilizer could be provided to the sugar industry. The results of the study of P behaviour in Herbert soils suggests that there is scope for refining the management of P fertilizer in the sugar industry based on a knowledge of particular soil properties and the behaviour of P in specific soils. Sorption of P in soils was found to be closely correlated with soil particle size, organic matter content and oxalate-extractable aluminium (Al). The results of this part of the project suggest that: • in refining P fertilizer management, both for more efficient crop production and improvec\ environmental stewardship, the utility of oxalate-extractable aluminium (Alo,) as a predictor of P fertilizer requirement should be investigated; and • clustering soils with similar physical and chemical properties is useful as a basis for identifying soils of similar potential P sorption/desorption characteristics so that, when coupled with a knowledge of the soil P content measured using normal soil testing procedures, they may' also form a basis for delivery of improved fe~tilizer advice. Further research is therefore warranted on both of these issues with a view to the developme!1t of specific guidelines for best-practice P fertilizer management.
Final report SRDC Project CSR024 Improving the environment for sugarcane growth through the amelioration of soil acidity
(2002) Wood, AW; Noble, AD; Bramley, RGV
Most soils used for growing sugarcane in wet tropical northern Queensland are highly acidic. Comparisons between new cane land and land that has been growing sugarcane for many years have demonstrated that our soils have become degraded under continuous sugarcane monoculture and that many of the changes in soil chemical properties are associated with soil acidification. Continued acidification, due to heavy applications of nitrogen fertilizer and the removal of base cations in the cane sent to the mill, will not only further acidify surface soils but will also progressively acidify the lower parts of the soil profile, making amelioration difficult and costly. Low soil pH not only reduces the availability of some nutrients to plants but also reduces soil surface charge resulting in a permanent reduction in the capacity of the soil to hold nutrients. Since many soils in the wet tropics already have a low cation exchange capacity, further reductions in cation exchange capacity (CEC) due to accelerated acidification may lead to sub-optimal levels of exchangeable calcium, magnesium and potassium, which will have a direct impact on sugarcane yields. Current industry recommendations for applying lime are based on perceived economic crop responses to calcium and are based only on the level of soil exchangeable calcium in the surface layer. Whilst this philosophy may be appropriate for soils with very low cation exchange capacities and suboptimal levels of exchangeable calcium, where frequent lime applications would be required to maintain soil calcium levels, it does not offer a sustainable management solution for highly acidic soils with adequate exchangeable calcium levels. Over 85% of cane growing soils in the Herbert River District fall into this category, having exchangeable calcium levels above the critical level and yet having an average soil pH of less than 5. This project aims to enhance the sustainability of the sugar industry by investigating and developing strategies for ameliorating soil acidity and thus making soils more amenable not only for sugarcane production but also for leguminous fallow crops which are now considered to be an important part of a sustainable sugarcane production system. Replicated experimental trials involving five rates of lime and three rates of gypsum were established on farms in the Herbert River District with contrasting soils that were highly acidic but had exchangeable calcium above the critical level. A fourth trial site was included later in the project with very low exchangeable calcium levels. Cane yields and ccs were monitored and soil samples taken from different depths in selected treatments in each trial were analysed in order to monitor changes in soil chemical properties.
Precision agriculture options for the Australian sugarcane industry
(2007) Bramley, RGV; Davis, R; Bartels, R; Schmidt, E; Bruce, R
Precision agriculture (PA) has been embraced in other Australian agricultural industries. With the increase in adoption rates of new farming system principles including controlled traffic within the sugarcane industry, many growers and harvesting contactors are turning to PA to improve their profitability and productivity. Recognising the high level of interest among members of the Australian sugarcane industry in the potential of PA, the Sugar Research and Development Corporation called for projects to review and analyse technologies that are applicable to sugarcane farming and harvesting. SRDC commissioned two studies following this call. The first was undertaken by CSIRO Sustainable Ecosystems and examined research and experience with PA in a range of cropping industries worldwide over the last 15 years including sugarcane in Australia, Mauritius, South Africa, the USA and South America. The second study was undertaken by the National Centre for Engineering in Agriculture in partnership with FSA Consulting. Their report describes how PA technologies operate, their uses, opportunities, limitations, risks and costs with respect to precision farming in the sugar industry. The report also describes how PA technologies can be integrated into a management system that will have both economic and environmental benefits for sugarcane production and harvesting. Both papers are provided in this publication. These findings were presented at an SRDC-hosted Precision Agriculture workshop on 11 May 2007. The purpose of the workshop was to identify what aspects of precision agriculture would benefit sugarcane farming and harvesting and to determine the priorities for R&D. The reviews were presented by Dr Rob Bramley (CSIRO Sustainable Ecosystems, Adelaide) and Rod Davis (FSA Consulting in partnership with NCEA, Toowoomba). Approximately 60 people attended representing growers, millers, BSES Limited, productivity service organisations, CSIRO, QDPI&F, universities, agricultural consultants, CANEGROWERS and agribusiness. The workshop sought to generate priority issues for further R&D to support the Australian sugarcane industry’s adoption of PA technologies. These priorities have been identified below.
Risk assessment of phosphorus (P) loss and guidelines for P use in lower Herbert soils Final report on SRDC Project No CLW010
(2000) Bramley, RGV; Wood, AW
In project CSS3S (Bramley et aI., 1998), a field and laboratory-based survey of the behaviour of phosphorus (P) was carried out on the soils of the lower Herbert River catchment, and sediments derived from them. The aim was to explore the factors governing P sorption or desorption in Herbert soils, and in suspended sediments in associated riverine and estuarine waters, so that the extent of any problem associated with sugarcane and soil-derived inputs to strearnwaters could be defined and advice on the development of best management practices for P fertilizer could be provided. Accordingly, an assessment of the risk of P loss from selected lower Herbert soils was made based on their P sorption characteristics and an assessment of the susceptibility of the lower Herbert soils to runoff following rainfall events. One of the recommendations made at the conclusion of CSS3S was that "spatial analysis of the assessment of P desorption risk based on digital maps of the CSR soil survey would enable more precise guidelines for better P management to be derived.". Following the recent availability of the CSR 1:5,000 soil survey in geo-referenced digital form, this report details the results of the suggested spatial analysis. Nine hundred and thirty four soils for which detailed soil property data are available in the database accompanying the 1:5,000 CSR survey of lower Herbert sugarcane soils were classified according to a range of indices of P sorption and the results mapped using either a geostatistical interpolation routine (kriging) or the mean values for each soil type identified in field survey. The results were coupled with an analysis of the susceptibility of these soils to runoff to produce maps of the potential for P loss.