[Terrapreta] charcoal in agriculture

[Richard Haard]

Experimental research at Fourth Corner Nurseries

Greetings

I just finished over the last few days organizing images and data from  
my charcoal experimental plots. I am presenting a  new set of posters  
showing root systems of the native shrub, Lonicera involucrata or  
black twinberry that I used as an experimental subject in these  
treatment plots this summer.

This will be the last of a series of piecemeal postings about my  
findings on the terrapreta reading list. In time, I will prepare a  
summary of what I have accomplished this year, the shortcomings, what  
I feel I have learned from this work about using charcoal and my plans  
for continuing this experiment for 2 or more growing seasons.

Quick background - my employer, Fourth Corner Nurseries  is a bare  
root native plant nursery. We grow more than 350 kinds of plants for  
environmental restoration and landscaping purposes. Our farm is 60  
acres in 2 fields. Shown here is our east field. Formerly, I have been  
trying charcoal as a soil additive for several years and this season I  
attempted a controlled experiment. It did not go without a hitch.

What I established this year was a series of 28 - 17 foot long  
treatment blocks that are a pair of treatment sets consisting of  
untreated soil, charcoal only, fertilizer only compost only and  
combinations of charcoal, compost, fertilizer. In each treatment block  
3 kinds of plants were installed: a native shrub, Lonicera; a native  
perennial - Aster subspicatus; and a vegetable - swiss Chard. All were  
selected for their heavy nitrogen consumers and all production was  
removed from the plots, roots and tops, then the plots replanted and  
cropped again without further fertilizer, compost or charcoal.

The most detailed measurements accomplished this year is 2 sets of  
soil chemical analysis completed at a University laboratory. Plant  
response measurements this year, for several reasons was only visual  
observation. This set of posters I am presenting today shows subtile  
but interesting and positive additive effects of compost and charcoal.  
Further analysis will be presented at a later date.

How it went. Early April while the plants were still dormant I took 2  
year old bareroot Lonicera seedlings trimmed tops and roots and  
planted in peat/perlite mix in 4X4 inch containers.   At these same  
time I planted sprigs of Aster in the same manor. After the plants had  
firmly rooted into the containers and our field soil had warmed, I  
prepared a growing bed in our normal propagation field ( Field 13, row  
8). The growing bed is about 4 feet wide and 500 feet long. I divided  
this into 17 foot beds with separate treatments in a systematic way.  
Here is charcoal 1, a fine powder that was donated by JF Waste energy  
systems. Here is charcoal 2 a lump and powder mix that Larry Williams  
and I made with a top draft earth covered mound. I am using the lump  
charcoal because I can observe microbe utilization over time as Larry  
has been studying for several years.

Here are the charcoal test beds are they appeared before rototilling.  
In this image furthest is compost only, then compost/charcoal1,then  
compost/charcoal2,then compost/charcoal 1/fertilizer and so on in a  
systematic pattern repeating again in a second duplicate set on the  
north end of the field. In discussing these tests I sometimes discuss  
each set separately, are are called south set and north set. Here are  
the plots immediately after rototilling. Note that the charcoal does  
not appear to be uniformly dispersed. After harvest with the lifter- 
shaker charcoal is better mixed in the soil. Each bed received about  
30 gallons of charcoal. Fertilizer and Compost were applied at rates  
normal for our farming practices.

We planted the plots in mid May and by late June they looked  like  
this and this and this . By the end of August the Swiss Chard had  
matured and we had our first harvest. Yields were impressive but no  
trends specific to treatments were noticed. Here you can see our plot  
method for measuring yields of swiss chard and also how the separate  
treatments, Lonicera, Aster and swiss chard have grown together making  
assessment of total production rather difficult.

In late October I conducted a survey of the Lonicera component of the  
research plots. It was the end of the growing season but before the  
frost defoliated the plants. Here is how the plots looked. My first  
look at the data that showed a subtile but encouraging trend of  
improvement from the use of charcoal 1. In this set of images notice  
that the treatments with compost when combined with charcoal tended to  
be larger. The same trend is also noticed in the compost/fertilizer/ 
charcoal combinations.  By mid November we were ready to lift all the  
plant material from the plots, examine the roots and fall replant with  
a single species crop for next year. Here we have our lifter shaker  
harvesting the plants,  Lonicera with charcoal staining roots and Rena  
picking up the plants. Later we replanted with our 4 row seeder and   
reseeding with another native shrub species, Oemleria cerasiformis,  
chosen because it too is an agressive nitrogen consumer.

Finally the posters I have prepared to compare top growth and root  
growth in each of the treatment sets. I have organized the images  
according to groups of treatments as follows: The links are to the  
larger size images for better viewing. Edit note root images  were  
created 11/15 not 10/25

First Groups 1 and 2 the  control sets that received no treatment or  
had charcoal only
Roots
Field View
Next Groups 3 and 4  fertilizer sets Edit Roots is labeled as Groups 1  
and 2
Roots
Field View
Next Group 5 South end plots compost set
Roots
Field View
Next Group 6 North end plots compost set
Roots
Field View

I think these findings will be encouraging information for John  
Flotvik and many thanks for his donation of charcoal from his  
pyrolyser and thanks again to Larry Williams , his thoughtful work and  
helping when it is most needed.

I am looking forward to another season of data from this set of test  
plots.  Comments, ideas, criticism, discussion whatever are  
appreciated as I am now preparing my season end report.

Richard Haard, Fourth Corner Nurseries, Bellingham, Washington.

copyright January 3, 2008
Permission for distribution of these materials and images is granted  
for entire text and images only so long as the author and initial  
place of publication <http://terrapreta.bioenergylists.org/>  is  
cited. Individual images may be used by permission only from author.

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