New research shows that human hair can act as a good fertilizer for plants, especially like lettuce. Hair actually provides nitrogen for plants as it decomposes, in a very similar manner as like ammonia (used in actual fertilizers) does. It is widely known that all plants need nitrogen to grow.
Even though our atmosphere has 75% nitrogen, plants cannot use it in its inert atmospheric form directly. That’s why we use fertilizers. Vlatcho Zheljazkov, a horticulturalist from Mississippi State University explains, “Once the degradation and mineralization of hair waste starts, it can provide sufficient nutrients to container-grown plants and ensure similar yields to those obtained with the commonly used fertilizers in horticulture“.