permaculture

["Lawrence F. London, Jr." <venaurafarm@bellsouth.net>]

-------- Original Message --------
Subject: Re: [SANET-MG] What controls soil pH?
Date: Sat, 1 Jan 2011 14:11:18 -0500
From: Joel Gruver <jgruv@HOTMAIL.COM>
To: SANET-MG@LISTS.IFAS.UFL.EDU

Hello folks,

it is widely recognized that some N fertilizers are acidifying and that 
lime can be used to raise the pH of acid soils but the ecology of soil 
acidity seems to be poorly understood by most agriculturalists.

Only in places
like Australia and Brazil where the soils tend to quite acidic but 
liming is often not
cost effective does there seem to be a more ecological approach to 
managing soil acidity.

The following article by 2 Australian authors (first link is for a PDF 
and second is for a *.doc of the same document) provides a good 
discussion of how the C and N cycles affect soil acidification.

http://www.potafos.org/ppiweb/brazil.nsf/87cb8a98bf72572b8525693e0053ea70/d5fbc829a2f54298832569f8004695c5/$FILE/Encarte98.pdf

http://www.ipni.net/ppiweb/pbrazil.nsf/926048f0196c9d4285256983005c64de/2d05b6e18d421a4383256c950065fce2/$FILE/Anais%20Greg%20Fenton.doc

In a nutshell, cropping systems accelerate soil acidification primarily 
through "opening" C and N cycles that are much more closed in natural 
ecosystems. Soil acidity can be managed without lime or with less lime 
using strategies derived from an understanding of how acidity is 
produced and consumed by C and N transformation processes.

Joel

Joel Gruver
School of Agriculture
Western Illinois University
jgruv@hotmail.com