Homestead mailing list

[Clansgian AT wmconnect.com]

> >What's the rule of thumb for amount of lime needed to raise ph one point?

A better question would be:  How much lime is needed to raise the sil pH one 
point for how long??

Someone's suggestion of 5 lbs for 100 sq feet ought to be about right.  But 
agricultural lime is an iffy thing.  Ideally it is composed almost entirely 
of 
calcium carbonate and magnesium carbonate.  But in our fuel squandering 
society, it is easier to heat the rock than pulverize the rock so a lot of 
agricultural lime is half or even mostly calcium oxide and magnesium oxide.  
The latter 
two will certainly raise the pH in a hurry, but they do not persist in the 
soil.

Wood ashes work great too but the main pH adjusting components are posassium 
oxide and if the wood has a lot of beech, ash, maple, or such there will be 
lots of calcium oxide.  Like agricultural lime the pH adjusting affect can be 
a 
flash in the pan.

Better, says I, is quarry dust, crusher run chet, or limestone sand (or 
such).  It buffers out the pH over a long period of time.  It's cheap but you 
need 
to apply a lot more than 5 lbs per 100 sq ft.  Ten time that at least.  But 
then again, you might not have to appy any more for 20 years.   </HTML>