1. Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka
2. School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Perth, WA, Australia
3. Department of Agriculture, Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka
4. Department of Crop Science, Section of Plant Nutrition and Crop Physiology, University of Göttingen, Göttingen, Germany
5. Department of Geology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka