IButton fever

For the last few weeks we have been trying to understand how to use iButtons for our experiment. We got pretty frustrated because someone forgot to include a manual with the equipment (I'm looking at you, Maxum Integrated). IButtons remotely record the temperature, allowing us to gather multiple data points over a period of time. We were  eventually able to set them up to record the temperature once every hour, on the hour.

Susanna showing off her hard work.

We then planted the iButtons in a randomly selected trays of each experimental group. Each iButton was double bagged of course to prevent water damage.

Me, getting ready to plant an iButton.

Digging the hole.

A well planted iButton.

We also placed three iButtons on the bare roof to measure background roof temperature. Through these temperature measurements, we expect to see lower temperatures in the green roof soil compared to the bare roof temperature.

One of three hot roof iButtons.

After 2000 hours (that's all the storage the iButtons have) we will collect them and finally be able to see some data. After a few days, we downloaded the measurements from one of the bare roof iButtons to see if they were working. We were so excited to see beautiful oscillating data between night and day temperatures.

Corn harvest and root washing

Last week, we harvested the MIP corn. We had to do so carefully as to preserve the stalk and root tissues while also separating them for individual analysis.

Dr. Chaudhary demonstrating the harvest method.

We used clippers to cut the stalk at the very base and put it in a paper bag for later. We then put the conetainer, containing the roots, into plastic bag and into the freezer. We put them in the freezer to stop all biological activity, especially decomposition. 

We want to weigh and record the root tissue mass, but we first must wash all of the soil off of the roots (The roots are very dirty). We do this very carefully.

Gaze in wonder at my clean roots

We then collect some of the tissue to be made into slides and save the rest for weighing. 

MIP update and Why Corn?

A lot has happened over the last month, including significant growth of our corn seedlings for our mychorrizal infection potential experiment.

Our MIP corn has grown significantly larger since last post.

As you can see, the corn looks pretty sad though (excuse the anthropomorphism). The stalks and leaves are streaked with a very vibrant purple.

Isn't that purple almost fuchsia?

The purple is because the soils that we are testing [apparently] have very little phosphorus. While not much is known about phosphorus in the life cycle, plants do need small amounts to grow healthily.

Question: why are we using corn in our experiment? 

Through this MIP, we hope to quantify how much arbuscular fungi is present in the different soil types. We can only find out by seeing how many symbiotic relationships the fungi form with the plant roots in the soil. Corn is perfect for this because it is a great host for these mycorrhizal relationships. Corn roots are so happy for the fungi that if there is any fungus in the sample, the corn roots with make relationships with it.
This comes back to why the corn is purple. In the relationship between fungus and plant root, the plant gives up carbohydrates and sugars in exchange for nutrients such as phosphorous.

MIP hypothesis

Two [technically three] possibilities come to mind.

1. There is no phosphorus in the soil samples
2. There is no fungus to help the corn get the phosphorus
3. There is no phosphorus and there is no fungus

We shall conclude the MIP experiment soon and maybe find out what's really going on around here.

Also, say goodbye to the corn, because we are harvesting the MIP tomorrow. A.k.a., cutting the corn stalks at their bases and separating the roots from the soil. 

Green roof sucess

We were able to set up the green roof yesterday. It is not in its ideal location, but man is it great to see it outside :) It took a lot of work but we were able to pull it off (with no cursing!). A good attitude is half of the battle.
                               

Our green roof, finally set up.

Me, watering empty trays again.

Our roof garden with the city view.

Summary of :Erika Orberndorfer, Green Roofs as Urban Ecosystems

This bullet point list will be expanded on in the future.

Green roofs are beneficial in many ways

• increase fire resistance
• increase sound insulation
• increase longevity of the roof itself
• keep buildings cooler
• reduce rain water run-off
• habitat for insects and birds

Stresses on the plants include

• moisture stress
• drought
• high temperatures
• light intensity
• high wind speeds

The plants used have adaptations

• low, mat forming growth
• succulent leaves
• tough twiggy growth

Green roof soil

• mineral based
• light expanded clay granules
• crushed brick

Main benefits

• storm water management
• energy conservation
• urban habitat

Erica Orberndorfer, Lundholm, J. et al. Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services. BioScience, Vol. 57, No. 10 (November 2007), pp. 823-833.

Mychorrizal Infection Potential

One aspect of our experiment involves adding inoculum to the roof garden soils to stimulate fungal growth. The inoculum we are using is soil collected from a prairie. This soil contains fungal spores and hyphae that may not be present in the roof garden soils of our main experiment.
At the end of our main experiment, to see if adding the inoculum changed the amount of mychorrizal relationships, we must have a base line measure of the fungal growth of the uninoculated soils.
We are using corn in our MIP experiment.
The first step of the MIP procedure was germinating the corn seeds. We used certified organic corn seeds because we don't want there to be any anti-fungal herbicide on the corn. We used deionized water in the germinating stage to avoid adding any extraneous contaminants to the developing plants.

 Corn kernels half immersed in water.

 After two days , the seed coats began to split and the first root, called the radical, began to emerge.

Root radicals emerging from the seeds.

We chose the seeds with the most developed radicals for our MIP experiment and planted them in our conetainers. 

Planting germinated corn kernels.

At the end of our MIP experiment, we will study the roots under a microscope and score the amount of mychorrizal relationships between the fungus and the corn roots.

Mychorrizal Infection Potential setup after one week.

Bicarbonate extractable soil phosphorus

The procedure for extracting phosphate looks more difficult than that for nitrates :(

OH NO!! Someone took these super helpful videos off of youtube! I can't find any replacements either. Uber sad face!