Previous PageTable Of ContentsNext Page

Management effects on biological cycling of phosphorus in Southern Australia

Else K. BŁnemann, Petra Marschner, Ann McNeill and M.J. McLaughlin

Soil and Land Systems, University of Adelaide, PMB 1 Glen Osmond, SA 5064, Australia. E-mail: else.bunemann@adelaide.edu.au

Abstract

Biological cycling of phosphorus (P) in soils includes various processes: the release and mineralisation of P from plant residues, microbial immobilisation, re-mineralisation and turnover, mineralisation of soil organic P, and flush effects due to abiotic stress, e.g. drying and rewetting. The influence of these processes on plant available P is largely unknown. We analysed soil samples from several long-term field experiments in order to assess the effect of crop rotation, tillage, P fertilization and residue management on soil P pools, especially available inorganic, microbial and total organic P. Radioisotopes (P-32, P-33) were then used to quantify P fluxes, specifically dynamics of microbial P and basal mineralisation of soil organic P. We will present results in relation to data previously obtained on a tropical Ferralsol from Kenya and to published data from temperate soils.

Previous PageTop Of PageNext Page