New Zealand Journal of Agricultural Research abstracts

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Potassium-supplying power of selected Pallic soils of New Zealand 1. Pot trial study

A. Surapaneni*
R. W. Tillman
J. H. Kirkman
P. E. H. Gregg

Institute of Natural Resources
Massey University
Private Bag 11 222
Palmerston North, New Zealand

A. H. C. Roberts^†

AgResearch
Ruakura Agricultural Centre
Private Bag 3123
Hamilton, New Zealand
*Present address: Institute of Sustainable Irrigated Agriculture, NRE Tatura, Private Bag 1, Ferguson Road, Tatura, Victoria 3616, Australia.
^†Present address: Ravensdown Fertiliser Co-operative, P.O. Box 608, Pukekohe, New Zealand.

Abstract  Examination of the non-exchangeable K (K_nex) supplying power of selected Pallic soils of the North and South islands, New Zealand, revealed a wide variation in the measured reserve K (K_c) values. A glasshouse pot trial showed that the supply of K_nex to ryegrass grown on 13 North Island Pallic soils ranged from 0 to 409 mg kg^–1 and from 33 to 353 mg kg^–1 on 6 South Island Pallic soils. There were lower levels of K_nex supply in developed soils that had been used for agriculture compared with corresponding undeveloped soils for the South Island soils. The results have implications for the fertiliser models that are used in New Zealand to assist prediction of the fertiliser K requirements of pastures.

Keywords  potassium; non-exchangeable K; reserve K; K_nex uptake; Pallic soils; pot trial; ryegrass

A00011 Received 29 February 2000; accepted 21 March 2002
New Zealand Journal of Agricultural Research, 2002, Vol. 45: 113–122
0028–8233/02/4502–0113 $7.00/0 © The Royal Society of New Zealand 2002

PDF file of entire paper: Print-quality (240K)

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