Affiliation: | (1) Soil Science Laboratory, Dept. of Plant Sciences, University of Oxford, Agricultural Science Building Parks Rd, OX1 3PF Oxford, UK;(2) Present address: Dept. of Biological Sciences, Wye College, Wye, Ashford, Kent, UK;(3) Present address: Dept. of Soil Science, Massey University, Palmerston North, New Zealand |