permaculture

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

-------- Original Message --------
Subject: Re: soil organic matter in tropical vs. temperate soils
Date: Fri, 31 Dec 2010 16:58:33 -0500
From: Karl North <knorth@BINGHAMTON.EDU>
To: SANET-MG@LISTS.IFAS.UFL.EDU

Greetings Jim,

What the Cuban agroecologists were showing us (you were there) was not 
less emphasis on SOM in warmer climates than, say, mine in NY, but a 
different practice and timing in its incorporation. They were building 
SOM for the next crop only (anything more would be a waste because 
burned up as you say), whereas in a temperate climate I can accumulate 
SOM levels over many years, and it makes sense to do so.

The Cubans generally did not point out to us visiting gringos their 
approach to SOM, I think because for them it is standard practice, just 
taken for granted for them in the tropics. But their practice of compost 
and other biomass incorporation contrasts so strongly with my own that 
eventually I discussed it with them.

Of course, as we saw, they count heavily on irrigation to get the most 
out of the temporary SOM boost during the crop season. If you remember, 
they also were teaching tiered polyculture, where leucaena and banana as 
full grown trees shaded understory crops to significantly lessen the 
need for irrigation, even in the dry season.

So I think you are right to say that SOM maintenance, not to mention
accumulation, gets harder as one gets farther into the tropics. What I
learned from the Cuban, Mexican and African farms where soil organic 
matter is considered important is: don't even try; build it only for the 
next crop.

When we begin to acknowledge the need for complex, labor-intensive 
farming systems,I think the Cuban agroecosystem models, adjusted for 
differences in climate and other conditions, are among those that will 
provide direction for change as industrial agriculture (80% dependent on 
oil energy), and even industrial organic, slowly starve in the post 
petroleum era.

Un abrazo, one "old white whale" to another,
Karl

--
Karl North - Northland Sheep Dairy, Freetown, New York USA 
http://karlnorth.com/
"Pueblo que canta no morira" - Cuban saying
"They only call it class warfare when we fight back" - Anon.
"My father rode a camel. I drive a car. My son flies a jet-plane. His son
will ride a camel." -Saudi saying