Phosphorus is crucial for plant growth—with it, plants can acquire, transfer, and store the energy that helps them flourish in full health. Without it, plants flounder: they're stunted, discolored, and produce low yields. For this reason, farmers and gardeners often apply phosphate fertilizers (P-fertilizer) to increase the amount of phosphorous in their soil. However, a recent study finds that excessive P-fertilizer may actually hurt the plants it is trying to help by altering the composition and function of the microbes in the soil.