Around the roots of plants, there is a tiny world called the rhizosphere. While it may be small, it is not insignificant. In fact, the rhizosphere plays an important role in cycling carbon and nitrogen between bacteria, protozoa, nematodes, and the plant roots themselves. The easiest way to see the rhizosphere is by collecting water that drips out the bottom of a flower pot. You don’t need anything more than about 100x magnification to see all the players (except the bacteria).
How does this little ecosystem work? Let’s start with the bacteria. Plants will release precious organic carbon (glucose or some sort of sugar) from their roots to feed the bacteria. As a result, the increase in bacteria population is controlled by microorganisms such as amoeba and nematodes (grazers). The consumption of bacteria increases the amount of nitrogen (in the form of nitrates and nitrites) in the soil. Since plants are able to utilize this form of nitrogen to grow, it is in their best interest to feed the bacteria.
Tiny But Important
What is the significance of learning about the rhizosphere? First, in order to work towards more sustainable agricultural practices, it is important to understand rhizosphere is disruption. Second, plants are also able to distinguish between beneficial versus harmful microorganisms, potentially helping us reduce pesticide use. And finally, just to throw in an added layer of complexity, fungus also play a role in the rhizosphere. The more we understand this micro-ecosystem, the better chance we have of finding ways to grow crops with less pesticides, insecticides, and fungicides.