Acidification of volcanic ash soils under oil palm in Papua New Guinea: effects of fertiliser type and placement
Nelson, Paul N., Berthelsen, Suzanne, Webb, Michael J., and Banabas, Murom (2010) Acidification of volcanic ash soils under oil palm in Papua New Guinea: effects of fertiliser type and placement. In: Proceedings of the 19th World Congress of Soil Science, pp. 8-11. From: 19th World Congress of Soil Science, 1-6 August 2010, Brisbane, QLD, Australia.
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Soil acidification is a widespread degradation problem, but little information is available for oil palm production systems. The aim of this work was to determine the effect of fertiliser type and placement on acidification of volcanic ash soils under oil palm in Papua New Guinea. A field trial, which had various combinations of N (114-120 kg N/(ha.year)) and K (329 kg K/(ha.year)) fertilisers applied over 13 years, was examined. Over that period, pHwater of the 0-0.2m layer declined by 0.38 units in the control treatment and 0.52-0.96 units in the fertilised treatments. Application of fertiliser and plant residues are not uniform in oil palm plantations, so the effect of placement was measured in another trial, which had been operating for 6 years. In the 0-0.05 m layer, the decrease in pHwater due to fertiliser addition (ammonium chloride plus kieserite) was least (0.52 units) when fertiliser was applied in the weeded circle and greatest (1.03 units) when it was applied in the frond pile. Soil pH buffer capacity was different between zones and fertiliser treatments, but the difference in acidification effect of fertiliser between zones was attributed primarily to differences in the water balance and N cycling rather than pH buffer capacity.
|Item Type:||Conference Item (Refereed Research Paper - E1)|
|Keywords:||exchangeable cations; net acid addition rate; pH buffer capacity; nitrogen fertiliser; potassium fertiliser|
|Date Deposited:||24 Aug 2010 23:58|
|FoR Codes:||07 AGRICULTURAL AND VETERINARY SCIENCES > 0703 Crop and Pasture Production > 070306 Crop and Pasture Nutrition @ 50%
05 ENVIRONMENTAL SCIENCES > 0503 Soil Sciences > 050304 Soil Chemistry (excl Carbon Sequestration Science) @ 50%
|SEO Codes:||82 PLANT PRODUCTION AND PLANT PRIMARY PRODUCTS > 8203 Industrial Crops > 820399 Industrial Crops not elsewhere classified @ 50%
96 ENVIRONMENT > 9609 Land and Water Management > 960904 Farmland, Arable Cropland and Permanent Cropland Land Management @ 50%