Australian research found that basic cation saturated ratio(BCSR) doesn’t work and is an inefficient use of fertiliser. Queensland University’s school of land and food sciences carried out the review in 2007 because of the use of “balanced” Ca, Mg, and K ratios, as prescribed by the BCSR concept by some soil-testing laboratories rather than the sufficiency level concept.

It concluded the BCSR concept was not suitable for the interpretation of soil analytical data. Full report: