
TY  - JOUR
A1  - Blair, GJ 
A1  - Chinoim, N 
A1  - Lefroy, RDB 
A1  - Anderson, GC 
A1  - Crocker, GJ 
T1  - A soil sulfur test for pastures and crops
JF  - Soil Research
JO  - Soil Res.
Y1  - 1991
VL  - 29
IS  - 5
SP  - 619
EP  - 626
KW  - 
UR  - https://doi.org/10.1071/SR9910619 
N2  - Soil testing for S has generally been unsuccessful when using extractants that remove only sulfate from the soil. An assessment of a range of extractants to predict S status was undertaken on soil samples taken from 18 field trials in northern N.S.W. The extractants were water, 0.01M monocalcium phosphate (MCP) and 0.5M NaHCO3, 0.25 M KCl heated for 3 h at 100, 80, 40, or 25°C. The highest correlation between soil S test level and % maximum yield was found in the 40°C KCl extractant (r2 = 0.73). This compares with an r2 value of 0.47 for the widely used MCP extractant. A study using a soil from a pot experiment where rice was grown showed that the KCl extract removed more S from the HI reducible (ester sulfate) fraction than did MCP. This S fraction is believed to be important in supplying S to plants. A comparison of the specific radioactivity of soil extractants and rice plants confirmed that the KCl 40°C extract removes S from similar soil pools as do plants. The procedure is recommended for wider evaluation. 
ER  -

