My information was taken from "Knott's Handbook for Vegetable Growers",
by Lorenz and Maynard, second edition, 1980. Their tables showing
nutrient availability as a function of pH are on pp 86-87 in that
edition and reference "Changing Patterns in Fertilizer Use", Soil
Science Society of America, Madison WI, (1968), L.B. Nelson, ed. and
also "Relationships between pH values of organic soils and availability
of 12 plant nutrients", R.E. Lucas and J.F. Davis, Soil Science
92:177-182 (1961).

I should have said that organic soils are *slightly* better at providing
calcium than mineral soils.

The statement was actually peripheral to the question about tangerines.




Sandy wrote:
On Fri, 21 May 2004 06:54:54 -0400, dps
posted:


Calcium availability is dependent on soil pH, with low pH decreasing the
availability,


Other way around, surely?


although organic soils are better at providing calcium
than mineral soils.


Nope. Although again, it depends...