383-2 Sulfur In Australian Agriculture and New Fertilizer Technologies.



Wednesday, October 19, 2011: 8:55 AM
Henry Gonzalez Convention Center, Room 214B, Concourse Level

Michael McLaughlin1, Robert Norton2, Babasola Ajiboye3, Sam Stacey3 and Fien Degryse3, (1)University of Adelaide/CSIRO Land and Water, Glen Osmond, Australia
(2)IPNI, Horsham, Australia
(3)Soil Science, University of Adelaide, Urrbrae, Australia
World demand for sulfur (S) fertilizers is predicted to increase from 50Mt to 60Mt in the next 5 years, and in Australia growth is likely to occur in many cropping areas. Historically much of the S applied in Australian agriculture was derived from single superphosphate, but with a decline in areas of pastures grown in rotations with crops, and a general decline in the amounts of superphosphate used on pastures, incidences of S deficiency are now more common. At a national scale Australia has a positive S balance (inputs-exports in food) but regional differences in farm-scale S balances indicate several areas with negative farm-gate S balances. In cropping areas, new products that incorporate both sulfate and elemental S are becoming more popular, as there are several benefits that may accrue for combining both elemental and sulfate-S into a phosphatic fertilizer, apart from the nutritional role of S for crop uptake. Changes in solution chemistry around the granule due to dissolution of these combined N:P:S products may affect P and micronutrient chemistry in the dissolution zone, and oxidation of the elemental S may subsequently affect release of nutrients from fertilizer reaction products in and around the granule. The contribution of the sulfate-S and elemental-S components in these products can also be evaluated using dual isotope labelling/dilution methods. It is likely the use of S-enhanced products will increase in Australian cropping industries, but it will be difficult to see single superphosphate being replaced as the dominant pasture fertilizer in Australian agriculture.
See more from this Division: S08 Nutrient Management & Soil & Plant Analysis
See more from this Session: Symposium--Can Sulfur Still Be Ignored? Crop Responses, New Management Strategies, and Improved Methods for Assessing Sulfur Needs