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Sorghum grain P concentration and removal at a long-term N x P experiment in southern Queensland


Lester, DW and Birch, CJ and Dowling, CW, Sorghum grain P concentration and removal at a long-term N x P experiment in southern Queensland, Proceedings of the 1st Australian Summer Grains Conference, 21-24 June 2010, Gold Coast, Australia, pp. 1-7. (2010) [Non Refereed Conference Paper]

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The northern grains region has few studies reporting nitrogen (N) and phosphorus (P) fertiliser effects on grain P concentration and P removal. From a long-term experiment on the Darling Downs, Queensland, N and P fertiliser independently influenced both grain P concentration and P removal. Generally increasing N fertiliser rate decreased grain P concentration if grain yield increased with N supply, whilst grain P concentration increased with P fertiliser. Five years experimental results indicate seasonal grain P concentration differed significantly making estimating grain P removal from a single value subjective; however a value of 3400 mg P/kg grain at 13.5 % moisture is proposed similar to other sub-tropical areas, but greater than reported from tropical production zones.
N fertiliser supply increasing grain yield had the largest influence on grain P removal. Where grain yield was not N limited, P export was 20.9, 17.1 and 19.7 kg P/ha highlighting the potential for significant nutrient removal in high production environments. This supports recently reported negative P balances for grain production, and suggests further management investigation for sustainable grain production practices.

Item Details

Item Type:Non Refereed Conference Paper
Keywords:grain sorghum, phosphorus long term trials, plant nutrition, fertiliser
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Crop and pasture production
Research Field:Crop and pasture nutrition
Objective Division:Plant Production and Plant Primary Products
Objective Group:Grains and seeds
Objective Field:Sorghum
UTAS Author:Birch, CJ (Associate Professor Colin Birch)
ID Code:94136
Year Published:2010
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2014-09-01
Last Modified:2014-09-01

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