A cross-linked, water absorbent polymer is mixed with desirable additives and coated to prevent water absorption to create a blend that is added to water injection systems for turf and soil maintenance. The coating is rinsed off the water absorbent polymer resulting in expansion of the polymer into a gel-like substance. The water absorbent polymer has the ability to retain water and nutrients in the soil preventing nutrient runoff and reducing watering frequency. Injection of the water absorbent polymer directly into soil reduces waste and reduces hazard caused by slippery material left on soil surfaces. The method and system for mixing and injection into soil is disclosed.