
%0 Journal Article
%A Parfitt, R. L. 
%A Whitton, J. S. 
%A Theng, B. K. G. 
%T Surface reactivity of A horizons towards polar compounds estimated from water adsorption and water content
%J Soil Research
%D 2001/09/19
%V 39
%N 5
%P 1105-1110
%K allophane, clay mineralogy, moisture factor, smectite, topsoils.
%R https://doi.org/10.1071/SR00059
%U https://www.publish.csiro.au/paper/SR00059 
%X The measurement of the specific surface area of soils may be useful for ranking soils in their ability to sorb polar compounds such as some pesticides and pollutants. For A horizons with varied mineralogy, particularly those containing large amounts of soil organic matter, this is problematic. We have estimated the surface area of a range of topsoils from water adsorption using the BET equation. The values obtained were greater than those measured from the adsorption of para-nitrophenol. There was a good relationship between the BET water area and the CEC of the samples (r2 = 0.83). There was a better relationship between the BET surface area and the water content of air-dry topsoils (r 2 = 0.98). We suggest that the air-dry water contents of topsoils could be used as a quick method to rank soils in order of their surface reactivity towards polar molecules, and this is preferable to more complicated methods. 
