Scientific Publications

 

  • Widdowson, J.P.; Blakemore, L.C. (1976). Fertility of Soils of Tonga, Interim Report 2. 1. Glasshouse Studies. 2. Soil Analyses. 61 p.
  • Lee, R.; Widdowson, J.P. (1977). The potassium status of some representative soils from the Kingdom of Tonga. Tropical Agriculture 54: 251–263.
  • Widdowson, J.P. (1977). Proceedings of the Kingdom of Tonga Soil and Land Use Seminar, Nuku’alofa, Tonga, June 14–18, 1976. 109 p.
  • McGaveston, D.A.; Widdowson, J.P. (1978). Comparison of six extractants for determining available phosphorus in soils from the Kingdom of Tonga. Tropical Agriculture 55: 141–148.
  • Hart, P.B.S.; Widdowson, J.P. (1979). Effect of mycorrhizal fungi on the growth of Pinus caribaea in Tonga. (Abstract) In: 49th ANZAAS Congress, Abstracts. Auckland, Australian and New Zealand Association for the Advancement of Science. P. 384.
  • Claridge, G.C.C.; Percival, H.J. (1980). Clay for brickmaking: A study of the suitability of the soils of the Pacific Islands. New Zealand Journal of Science 23: 335–342.
  • Cowie, J.D. (1980). Soils from andesitic tephra and their variability, Tongatapu, Kingdom of Tonga. Australian Journal of Soil Research 48: 273–284.
  • Claridge, G.G.C. (1981). Mineralogy of the soils of the Kingdom of Tonga. (Abstract). In: ‘Soils with Variable Charge’ Conference, Massey University, Palmerston North, New Zealand, 11–18 February 1981, Programme and Abstracts. Pp. 176–177.
  • Hart, P.B.S.; Meyrick, K.F. (1981). Ectomycorrhizae increase zinc intake in pines. (Abstract). In: ‘Soils with Variable Charge’ Conference, Massey University, Palmerston North, New Zealand, 11-18 February 1981, Programme and Abstracts. P. 81.
  • Hart, P.B.S.; Widdowson, J.P. (1981). The response of caribbean pine, green panic, and siratro to fertiliser on soils of the ‘Eua uplands, Tonga. New Zealand Journal of Experimental Agriculture 9: 255–262.
  • Hart, P.B.S.; Widdowson, J.P.; Fa’anunu, H.O. (1981). Fertility evaluation of some soils in Vava’u, Tonga. NZ Soil Bureau Scientific Report 47. 30 p.
  • Widdowson, J.P.; Hart, P.B.S. (1981). The effects of mycorrhiza on the growth of Pinus caribaea seedlings in Tongan soils: preliminary investigations. NZ Soil Bureau Scientific Report 48. 21 p.
  • Childs, C.W.; Wilson, A.D. (1983). Iron oxide minerals in soils of the Ha’apai Group, Kingdom of Tonga. Australian Journal of Soil Research 21: 489–503.
  • Speir, T.W. (1984). Urease, phosphatase and sulphatase activities of Cook Island and Tongan soils. New Zealand Journal of Science 27: 73–79.
  • Wilson, A.D.; Giltrap, D.J. (1985). Effectiveness of “Soil Taxonomy” for prediction of soil chemical properties on Mollisols under a shifting cultivation system in the Ha’apai Group, Kingdom of Tonga. South Pacific Journal of Natural Science 7: 45–57.
  • Wales, J.F.; Thomas, R.F.; Northey, R.D. (1986). Engineering characteristics of and effect of lime on some soils from the Kingdom of Tonga. NZ Soil Bureau Laboratory Report EP 13.
  • Widdowson, J.P.; Watts, H.M. (1989). Crop responses to fertiliser on some major soils in Tonga. In: Haynes, R.J.; Naidu, R. eds Agricultural development in the Pacific Islands in the 90s : proceedings of an international conference and workshop held in Suva, Fiji, 31 March to 1 April 1989. Pp. 64–80. 
  • Lee, R.; Searle, P.L.; Leslie, D.M.; Widdowson, J.P. (1989). The distribution of the major soil groups of the southern Cook Islands, Tonga, Niue and Fiji according to soil taxonomy, their chemical properties and fertility status. In: Haynes, F.J.; Naidu, R. eds Agricultural development in the Pacific Islands in the 90s : proceedings of an international conference and workshop held in Suva, Fiji, 31 March to 1 April 1989. Pp. 219–242. 
  • Manu, V.T.; Powell, H.K.P.; Banks, L.; Sheat, A.; Widdowson, J.P. (1990). Accession of SO4 2- – sulphur from Tongan rainfall. Australian Journal of Soil Research 28: 727–736. 
  • Trangmar, B.B. (compiler) (1992). Proceedings of the Soil Fertility and Land Evaluation Workshop, Nuku’alofa, Kingdom of Tonga, 3–7 February 1992. DSIR Land Resources, Lower Hutt. 239 p.

 


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