
%0 Journal Article
%A Burkitt, L. L. 
%A Moody, P. W. 
%A Gourley, C. J. P. 
%A Hannah, M. C. 
%T A simple phosphorus buffering index for Australian soils
%J Soil Research
%D 2002/05/03
%V 40
%N 3
%P 497-513
%K phosphorus sorption capacity, single-point phosphorus sorption index, phosphorus retention index, soil properties, Colwell phosphorus, Olsen phosphorus.
%R https://doi.org/10.1071/SR01050
%U https://www.publish.csiro.au/paper/SR01050 
%X Soil phosphorus (P) buffering capacity (PBC) is an important soil property that influences the amount of P fertiliser available for plant uptake. However, current methods of determining PBC are time-consuming and uneconomic in most commercial soil testing programs. The current study examined simpler methods of measuring the PBC of a wide range of Australian soils. Phosphorus sorption and extractable P data from 290 soils (initial data set) were collated to define the range of PBC values of Australian agricultural soils. Independently, detailed chemical and physical analyses were undertaken on a second set of 90 agricultural soils (principal data set), which were selected to represent the range of soil properties measured on the initial data set. Relationships between PBCO&amp;S (Ozanne and Shaw 1968) values (P sorbed between solution P concentrations of 0.25 and 0.35 mg P&sol;L) and 11 different single-point P sorption indices and selected soil properties were examined for the principal data set. Whilst relationships between PBCO&amp;S values and selected soil properties such as oxalate-extractable iron and aluminium, and clay content, were generally poor, strong relationships existed between all of the single-point P sorption indices and PBCO&amp;S. Results suggest that PBCO&amp;S values were most closely related to the P buffering indices (PBI&plus;ColP and PBI&plus;OlsP) when a single addition of 1000 mg P&sol;kg was added to soil and either the Colwell or 4.59 Olsen extractable P were added to the amount of P sorbed: PBI&plus;ColP = (Ps &plus; Colwell P)&sol;c0.41 PBI&plus;OlsP = (Ps &plus; 4.59 Olsen P)&sol;c0.41 where Ps is the amount of P sorbed (mg P&sol;kg) from a single addition of 1000 mg P&sol;kg, and c is the resulting solution P concentration (mg P&sol;L). This index provides a simple and accurate method for estimating PBC, a fundamental soil property that influences the P fertiliser requirements of different soil types. phosphorus sorption capacity, single-point phosphorus sorption index, phosphorus retention index, soil properties, Colwell phosphorus, Olsen phosphorus. 
