Current understanding of soil biology and health actually rejects this old notion of competition for nutrients. Plants, bacteria, mycelia, insects, etc. all live and thrive symbiotically in nature. Soil is a living organism, and not just a whole lot of dirt and minerals. In fact, without the bacteria, the minerals are largely unavailable to the plants, and without the plants, the bacteria don't get the carbohydrates that they need.

It becomes a bit of a philosophical question: What is a weed?