Mar 032012

Gardening has officially begin at the family farmstead out here.  We’ve got seeds started, beds prepped, and a couple of new experiments in the works.  I’ve been reading a lot about hugelkultur, and finally got all of my ducks in a row to build a bed.  Now that I have the equipment to do it pretty quickly, I expect to be building many more of these beds throughout the year for various purposes (we have  a LOT of semi-rotten wood around here).  If you’re unfamiliar with hugelkultur, the basic notion is that you bury a large amount of wood under some soil in a mound (“hugel” means “mound” or “hill” in German) and plant stuff on top of it.  For the first year or two, the wood is just starting the rotting process and the fertility of the bed is average… but the magic happens after that and keeps happening for decades hence.  As the wood becomes thoroughly rotten, it simultaneously becomes a fantastic water sponge and refuge for soil life.  A well-made hugelkultur bed can grow tomatoes through three months of drought without a drop of irrigation, and without causing the tomatoes to split from uneven watering.  If you want to read more about it, check out these links:

The other big experiment to commence soon is the creation and use of biochar.  I have found a design for a simple, cheap, and very clean-burning biochar retort klin on the web, and I’m going to adapt it so that I can try making some of this stuff to see for myself if it’s as amazing in the garden as so many people claim.  The basic idea behind biochar is that carbonaceous materials can be pyrolized (burned with insufficient oxygen for complete combustion) into black charcoal, which is a very stable substance known to last centuries incorporated into soil.  The charcoal has a couple of major effects on the soil — first, if it is used in high enough proportion it can improve the texture of a clay soil by playing the role of the missing silt particles.  The second effect is far more important and dramatic though.  Black charcoal, when pulverized into a gritty powder, has a tremendous amount of surface area.  This allows it to capture and hold soil nutrients,  provide living quarters for soil microbes, and  give ready access to these things to questing plant root hairs.  Soil with biochar added is reportedly capable of stopping vast amounts of nutrient leaching that otherwise occurs in typical soil.

The idea for this technique originated in the Amazon rain forest, which is known for having terrible soil due to the constant drenching rain.  Native peoples long ago added huge quantities of charcoal to the soil, probably by practicing “slash and char” farming.  This would entail cutting down biomass in the rain forest, then burning it incompletely so as to render it primarily into charcoal.  This then entered the soil and made an enduring change that allows the soil to prevent nutrient loss through leaching.  The soils modified this way are still some of the most fertile in the world a millennium later.  I’ll be trying this in parallel with and in combination with the hugelkultur techniques to see what kind of growing results I can achieve.  I’ll keep you posted…

Here’s a good article about biochar.

This is the design I’ll be adapting to use in my own system.

If anyone would like to be involved in building the rocket biochar retort, shoot me an email and I’ll let you know when I’ll be doing the various parts of the build.

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