Losses of nitrogen fertiliser under oil palm in Papua New Guinea: 1. Water balance, and nitrogen in soil solution and runoff
Murom Banabas A B D , Max A. Turner B , David R. Scotter B and Paul N. Nelson CA Papua New Guinea Oil Palm Research Association, PO Box 28, Popondetta, Papua New Guinea.
B Institute of Natural Resources, Massey University, Palmerston North, New Zealand.
C School of Earth and Environmental Sciences, James Cook University, Cairns, Qld 4870, Australia.
D Corresponding author. Email: murom.banabas@pnp.pngopra.org.pg
Australian Journal of Soil Research 46(4) 332-339 https://doi.org/10.1071/SR07171
Submitted: 1 November 2007 Accepted: 28 April 2008 Published: 23 June 2008
Abstract
Nitrogen (N) fertiliser is an important and expensive input to oil palm in Papua New Guinea. Of about 3000 mm/year of rainfall, about 1300 mm is lost as evaporation. This leaves an excess of >1000 mm/year lost as surface runoff and/or deep drainage, and with it the potential for N loss. Approximately 11% of rainfall reached the ground as stem flow. Throughfall was generally lowest near the trunk and highest where canopies overlapped, but random spatial variability was large. The difference between the measured rainfall and stem flow plus throughfall was 6%, indicating relatively little interception.
Surface runoff from the volcanic ash soils was 6% of rainfall at one site, but only 1.4% at the other. Less than 2% of the applied N was lost in the surface runoff after an ammonium chloride application. Calculations of N leaching losses made using suction cup data and the water balance indicated that significant losses occur, but the estimates were not reliable due to the huge spatial variability in the suction cup and throughfall data. Therefore, another technique is needed to study N leaching in oil palm plantations.
Additional keywords: evaporation, evapotranspiration, leaching, interception, infiltrability.
Acknowledgments
The European Union funded the work (Stabex 4.22). Dr Michael Webb provided useful discussion. Competent and dedicated technical support was provided by Papua New Guinea Oil Palm Research Association staff in the field, and by Massey University Institute of Natural Resources staff in the laboratory. Two anonymous referees provided useful criticism.
Banabas M,
Scotter DR, Turner MA
(2008) Losses of nitrogen fertiliser under oil palm in Papua New Guinea: 2. Nitrogen transformations and leaching, and a residence time model. Australian Journal of Soil Research 46, 340–347.
Nelson PN,
Banabas M,
Scotter DR, Webb MJ
(2006) Using soil water depletion to measure spatial distribution of root activity in oil palm (Elaeis guineensis Jacq.) plantations. Plant and Soil 286, 109–121.
| Crossref | GoogleScholarGoogle Scholar |
Ng SK,
Thamboo S, de Souza P
(1968) Nutrient contents of oil palms in Malaya. II. Nutrients in vegetative tissues. Malaysian Agricultural Journal 46, 332–391.