Dirt vs Soil: The Soil Food Web

We got our soil test results back this week and John and I talked a bit in class today about how we might use these tests to better understand what is happening in the soil of our different growing areas. We also talked at length about the limitations of such standard soil tests, which measure the chemical make-up of soil but don't take soil biology into consideration. In this 15 minute video, soil biologist Dr. Elaine Ingham gives a nice, succinct  overview of the role soil biology plays in the health of plants and how agricultural practices affect the life within the soil:

And for more in-depth information about the soil food web, check out the National Resources Conservation Service's "Soil Biology Primer". Here's the soil food web diagram from the primer that we looked at in class:

Second Week Pictures!

This is the first time I've ever tried to add pictures to blogger, we'll see how it goes. I'm sure, if you are so inclined, that you can click on the images to see them bigger. I know that they're mine and all, but I still swear bigger is better.

Tuesday, April 9: Germination experiment

We started a little experiment this week!

Amy designed an experiment that would show us all the things she's been telling us about the best way to plant and germinate seeds indoors for transplanting. Each cross-section of the trays are planted with the same variety of yellow tomato, the Golden Ray. Two of each tray have a soil-less planting mix (A) and the other two have the compost soil mix (B) that we've been using for all the soil blocking. Each of the three separate trays will be placed in locations that receive varying amounts of light.

This is posted on the bulletin board so we remember how we set up the experiment!

This will allow us to see the effects of both soil quality and light on the germination of seeds of the same plant variety. We'll be able to observe the results over the coming weeks. Cool, huh?

April 1 and 2: Soil samples

On our first work days, one of the things we did was gather soil samples from four different areas around Harvest of Joy.

 These included the area near the hoophouse that was a garden before a field, a field with good soils that has been under cultivation ~3 years, a sandy area planted last year with poor results, and a new area to be planted this year down by the river.

Soil was gathered from different spots in each location and aggregated to give us a representative sample of the soil in the field. These will be sent off to the MSU Soil and Plant Nutrient Laboratory for soil testing, which will give us a detailed break down of the type of soil and nutrients present. (http://www.psm.msu.edu/SPNL/)

We also did a little experiment of our own right there on the porch!

Adding about 16 oz of soil and a full jar of water, we were able to see the layers of soil-- from clay to silt-- and their different colors. They told us a lot about the soil composition and looked beautiful too!

Perlite & Vermiculite

On Tuesday this week we talked a bit about perlite and vermiculite in seed starting mixes but I wasn't entirely sure what these materials were made of. So . . . 

Perlite, according to Wikipedia: "Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. It is an industrial mineral and a commercial product useful for its light weight after processing." http://en.wikipedia.org/wiki/Perlite

And Vermiculite: "Vermiculite is a hydrous, silicate mineral that is classified as a phyllosilicate and that expands greatly when heated. Exfoliation occurs when the mineral is heated sufficiently, and the effect is routinely produced in commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite.^[1]Large commercial vermiculite mines currently exist in Russia, South Africa, China, and Brazil." http://en.wikipedia.org/wiki/Vermiculite

Also on Tuesday we started some experiments with different seed-starting conditions so that you can get a visual sense of what a healthy (and unhealthy) transplant looks like. We used two different planting mediums Metro Mix 300 from Sun Gro horticulture and Seed Starter 101 from Morgan Composting.

Metro Mix ingredients: "Vermiculite, bark, Canadian Sphagnum peat moss, coarse perlite, bark ash, starter nutrient charge (with Gypsum) and slow release nitrogen and dolomitic limestone." (I think I told you that this was a nutrient-less mix, but as I look at the ingredients, I see that I was wrong in this. It does have that "starter" nutrient charge.) http://sungro.com/products_displayProduct.php?product_id=104&brand_id=17

Morgan's Seed Starter 101 "contains products like worm castings, meat and Bone Meal, Feather Meal, and paramagnetic rock." http://www.dairydoo.com/Morgan_Composting/For_Greenhouses.html

We planted four tomato plants in each of three 4-chambered plastic pots with two chambers filled with Seed Starter 101 and the other two with Metro Mix 300. We put one pot under a grow light, one in a sunny (well it will be if the sun ever comes out) window, and the other in a shady area of the porch. We'll water them and see what happens!