LAB #4 - Community Gardens and The Dirt We Play In....

We journeyed not too far off the beaten path to Macon Community Gardens for this lab. Here is the link and the picture from their website:

COMMUNITY GARDENS

http://www.maconroots.org/

This organization, founded by Mark Vandenhook (by the way we met him the day we went there), is a great organization encouraging middle Georgians to grow fresh food, and have a sustainable food source for the community. I must say that when we went, the garden seemed a little "thirsty." Some of the produce growing had wilting leaves, and some areas needed some upkeep. Having said that, it was still nice to see that a garden was growing in an urban area.

Speaking of urban areas, we discussed early on in the semester about URBAN SOILS. Urban soils can sometimes contain contaminents (i.e., lead) that may make it a problem to safely grow food in that type of soil. Plants growing in soil will automatically pick up any contaminents and absorb it into their system - - - and so when we eat that produce, we, in turn, eat whatever contaminent the plant has. NOT GOOD! A way to get around that problem, is to grow your garden in a "raised bed" in a box above ground. This way, you can put fresh soil in the box for the plants to grow in. MACON ROOTS Garden did just that. Their gardens are in raised boxes - above ground. There were a variety of fruits, herbs & vegetables growing: Peas, watermelon, eggplant, chili peppers, rosemary (herb), Spearmint (herb), and others.

DIRT
We also learned some cool things about dirt. Dirt is made up of SAND, CLAY, and SILT. We received a handy dandy SOIL TEXTURE DIAGRAM, that illustrated how dirt is mostly made up of clay. The diagram then illustrates throughout the flow chart, several varations combining the three components. We wet a sampling of dirt and used a flow chart called DICHOTOMOUS KEY CHART in order to identify what type of dirt we retrieved.

1. We wet the dirt until it became like a moldy putty ball
2. We tried to make a "ribbon" out of the dirt - a thin strip of the "putty" that could sustain on its own. If it did, there were several more steps to determine what type of dirt we had.
3. The sample we had did not have to go far down the CHART because we could not even make a RIBBON out of it. We determined (after saturating it a bit more with water, that it was a LOAMY SAND.
 Here is an example of someone making the "RIBBON".....
The longer and thinner you can make the RIBBON, the higher percentage of clay you have in the dirt. We could not even get this far with our dirt.

Here is a picture of what we had - except our dirt was much darker than the dirt in this picture.

II. PROBING
We also took samples by using a Soil probe called a SPLIT SPOON CORER.


Our Corer was very similar to this one. You push it directly down into the ground, and when you pull it back up, the dirt is captured in the center section of the corer. This is really cool. You can see the different layers of dirt, and can sometimes see the different colors, and tell the different types of soil present in the soil you just sampled. We mostly saw organic dirt in our sampling, but did find at the deepest part some much brighter red clay dirt.

We did not have one on-site with us, but Dr. Rood told us about the MUNSELL SOIL COLOR CHART. A handy chart that helps identify the type of color soil you have, by placing it right behind the page of colors, and matching it up. Here is a pic of a chart:
   
The second picture of the person using the color chart is not a picture from our lab day, but I just wanted to show how the chart is used to identify the color of soils.

III. SIEVES
We also used SIEVES to identify dirt.

This is a picture of different sized Sieves. Each sieve has a different size strainer in which dirt filters through.The ones we used were stacked, so that the dirt goes in the top sieve, the top is placed over it and you shake. The larger "clay" dirt clumps will stay at the top, and the thinner dirt particles will make their way down through additional sieves, until only the thinnest SAND particles can be seen in the bottom sieve. It was interesting to see. It was also funny - well maybe not so much - when one of the students mistakenly dropped the sieves when we were almost done shaking it. So we had to start over. It was ok, no dirt particles were injured during the fall!

I'm not much of a dirt person, but this was a fun lab, and I did learn alot about dirt. Perhaps I will never look at dirt in the same way again.....I will be immediately trying to identify whether it is Clay, Silt, Sand, or any combination of the three! :)