The root zone around plants, known as the rhizosphere, is an area of intense activity in the soil. It’s a lot like the snack stand at the state fair on a hot day. Everyone is crowding around trying to get to the cold drinks, funnel cakes and hot dogs. Snacks are being sold as quickly as the workers can make them. In return, the snack stand is bringing in a lot of cash.
While the snack stand exchanges food for money, plant roots feed nearby microbes in exchange for plant nutrients. The roots put sugars down into the soil, creating an area of crowded, busy bacterial feeding in the rhizosphere, and exchange that microbial food for nutrients the plant needs but would otherwise have a hard time accessing.
We tend to think that plants photosynthesize entirely for their own metabolism, but in truth plants spend a good portion of their energy feeding soil life.
Plants fix sugars through photosynthesis, and while 55 to 75 percent of those sugars support plant growth, reproduction and defense from pests, the rest goes into the soil through the roots to feed the soil biology. This isn’t a waste of energy by the plants.
Those organisms living in the rhizosphere, primarily bacteria, not only make nutrients available to the plants — they also provide a protective layer against pests and diseases. It’s a win-win for the plants and the bacteria living in the rhizosphere. Continue Reading →