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Potassium Newsheet Vol 1 Issue 1 : Autumn 2002 |
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This newsheet is supported by: |
Welcome
to the first edition of the Potassium Newsheet, a quarterly email
newsletter designed to keep you informed about who is doing what
in the field of potassium nutrition in Australia and New Zealand.
The newsheet has evolved from the ideas of attendees at Potassium Workshops held in New South Wales and Western Australia. You have been entered into the recipient list because you either attended one of these workshops or because you have had contact with the Canpotex Potassium Development program. Should you not wish to receive future editions of the newsheet please click here. The newsheet is part of the wider Potassium Development program which provides agronomic information on potassium nutrition of crops and pastures through publications, workshops and a website. The program also supports research and development into the best management practices for potassium fertilizer use in Australian and New Zealand agricultural production systems. If you would like to inform others about a potassium nutrition issue or project contact the newsheet editor Jonnie White. Comments or feedback about any newsheet articles are also welcome. New P and K cotton nutrition project needs research scientist The Cotton Research and Development Corporation has recently approved funding for a project to be managed by CSIRO at the Cotton Research Unit Narrabri, to further investigate P and K nutrition of cotton. CSIRO has been trying to recruit a research scientist with experience in plant nutrition and cotton agronomy to undertake the project. The cost of P and K fertilizers to the cotton industry is about $13M annually. However, inadequate P and K nutrition are responsible for substantial losses of yield and profitability in cotton farming. Deficiencies of both nutrients have been linked with the premature senescence syndrome that has been prevalent in cotton crops across New South Wales and Queensland for many seasons. Confusion has arisen between the relative importance and the interactions of the two nutrients. The new project will investigate the relationships between P and K, provide better means of identifying deficiencies through soil and plant tissue testing and indicate how to avoid or remediate P and K deficiencies. A research scientist with experience in plant nutrition is needed to manage the 3-year project. More information on the project or the position is available by contacting Ian Rochester on 02 6799 1520 or by email. Wheat leaf disease and K nutrition interaction project in WA A project investigating the effect of K nutrition on the incidence and damage caused by wheat leaf diseases has recently been funded by the Grains Research and Development Corporation. The project, to be managed by staff from the Department of Agriculture in WA, will monitor the impact of K fertilizers on the incidence of leaf disease at sites across the medium to high rainfall cereal growing regions of WA from 2002 to 2005. In recent seasons a relationship between the application of K fertilizers and the severity rating of wheat leaf diseases has been noted in several trials. This project will attempt to quantify the impact of K fertilizer application, to identify the mechanisms involved and to define critical ranges for soil K and/or Cl which are required for disease suppression. The project will benefit from the input of plant pathologist, Kith Jayasena based at Albany with the Department of Agriculture. For more information contact the project manager, Ross Brennan, Research Agronomist with the Department of Agriculture on (08) 9892 8474 or by email. Potassium in Agriculture Website - Stage 2 launched The Potassium Development Program website at www.potash-info.com has been expanded to include information on potassium research in Australia and New Zealand. In addition to information on potassium in soils, plants and fertilizers and on potassium management in the major agricultural industries, the site now also contains information on local research results in a format useful to agronomists. The new research section contains a library of short research articles, a searchable database of abstracts from published scientific papers, information and reviews of useful publications and a feedback survey form. Stage 3 of the website development will be tailored for the needs of primary producers and will include information on conducting on-farm research, as well as nutrient budget calculators. This stage will be launched early in 2003. CSBP futurefarm find that K improves quality of export hay Production of oats for hay and grain is increasing in Western Australia, particularly for the export hay market which has stringent quality standards. Some farmers were concerned that fertilizer application was having a negative effect on hay quality. Recent trials undertaken by CSBP futurefarm studied the effect of K and N fertilization on the yield and quality of oaten hay and grain. There was no evidence from 4 site-years to suggest that quality was negatively affected by fertilizer application. It was found that N improved the yield of hay and grain, and improved the protein content of hay. It appeared that K was less important than N for hay yield but had a significant positive effect on the hay quality parameters important for the export market. Measurements of metabolisable energy (MJ/kg), digestible dry matter (%), neutral and acid detergent fibre (%) were all improved by K application in at least one site-year. For more information contact Stephen Loss, Field Research Manager with CSBP futurefarm. Palatability studies continue in New Zealand A preliminary study to investigate the impact of very high K concentrations on the palatability of pasture and funded by FertResearch in New Zealand has been expanded with further results due in April 2002. Initial studies were prompted when some graziers noticed cattle avoiding areas where pastures were testing very high in K. The preliminary studies which measured bite rate from small plot areas of differing pasture K concentration, showed that bite rate and grazing activity time decreased when pasture K concentration reached 3.7%, well above the concentration required for maximum pasture production. Very high pasture K concentrations usually occur where K has accumulated due to animal transfer (eg. in night paddocks) or where high K effluent has been applied. The studies are demonstrating the importance for graziers to monitor the nutrient concentration of pastures, and to keep in mind the transfer of nutrients within the farm. The current trials are also examining the impact of the concentration of other cations on palatability. For more information contact project manager Jeff Morton, Scientist with AgResearch on (03) 489 3809 or by email. K Questions Answers to recently posed questions on K nutrition: A grower asks: "I have recently top-dressed a paddock with muriate of potash (MOP) fertilizer and now need to burn the standing cereal stubble for disease management reasons. Will anything happen to the K in the fertilizer?" Answer: MOP is very soluble, so if you have had sufficient rain since topdressing, the K ions would now be either in solution or associated with the soil particles in an exchangeable or fixed form. Burning stubble will not affect these forms of K. MOP granules go through a heat treating and compacting process as part of granulation, before being treated with de-dusting oils. If there has been no rain since topdressing and granules are still intact on the soil surface, there may be a small "flashing" reaction as the de-dusting oils combust during stubble burning, however no fertilizer K will be lost from volatilisation. Recently published papers Recently published scientific papers examining issues of potassium nutrition: Kaya, C., Kirnak, H., and Higgs, D. (2001). An experiment to investigate the ameliorative effects of foliar potassium phosphate sprays on salt-stressed strawberry plants. Australian Journal of Agricultural Research 52, 995-1000. Li, G. D., Helyar, K. R., Conyers, M. K., Cregan, P. D., Cullis, B. R., Poile, G. J., Fisher, R. P., and Castleman, L. J. C. (2001). Potassium deficiency and its management in a long-term rotation experiment in the south-western slopes New South Wales. Australian Journal of Experimental Agriculture 41, 497-505. Pal, Y., Gilkes, R. J., and Wong, M. T. F. (2001a). Mineralogy and potassium release from some Western Australian soils and their size fractions. Australian Journal of Soil Research 39, 813-822. Pal, Y., Gilkes, R. J., and Wong, M. T. F. (2001b). Soil factors affecting the availability of potassium to plants for Western Australian soils: a glasshouse study. Australian Journal of Soil Research 39, 611-625. Wong, M. T. F., Corner, R. J., and Cook, S. E. (2001). A decision support system for mapping the site-specific potassium requirement of wheat in the field. Australian Journal of Experimental Agriculture 41, 655-661.
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New P and K cotton nutrition project needs research scientist |
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