Ya Dig? A Look Into Soil Biodiversity and Why You Should Care

Here we are, one week out from our original sampling excursion outside our campus grocery store/Subway, and we are proud to report substantial microbial growth. The plated colonies have continued to grow in size (and grossness) over the past few days. The most growth remains on the plate that contains the highest concentration of soil sample (diluted 1000-fold), while the least amount of growth remains on the most diluted sample plate (diluted more than a million fold).

We now turn our focus on observations of biodiversity within our samples. After one week of incubation, we have witnessed the growth of many different types of bacterial and fungal colonies. These colonies vary in size, texture, and color. Some colonies have dark, discolored centers, while other remain uniform in color. Some are raised dramatically from the plate surface, and still others are as flat as pancakes. Some colony edges appear circular, while others stretch wildly across the plate. Every variance in appearance between colonies indicates a change in species, implying that our soil sample contained more types of organisms than could allow for peace of mind. The presence of a single fungal colony on our flourescent growth plate suggests a greater biodiversity among bacteria than fungi in the sample area. By applying some simple algebra, we estimated that there were 50,000 microbes per gram of soil at our sampling location.

You might be asking, "Why does soil biodiversity matter?" Well, it's really important - to say the least. Bacteria in the soil are responsible for the decomposition of organic matter. By breaking this matter down, they release nutrients into the soil that are vital for the production of the natural fertilizers that allow for agriculture. Basically, if we don't have any soil biodiversity, we have no food! You can find more information about the importance of soil microbes by clicking on the following link: http://www.fao.org/agriculture/crops/thematic-sitemap/theme/spi/soil-biodiversity/agriculture-and-soil-biodiversity/en/

Come back next week for updated pictures and more dirt on dirt!
- Austin and Anne