A limiting factor in large areas in the world is water. This problem can also be met with at sites after gravel and sand mining the soil might suffer from a lack of water, organic matter and nutrients following recultivation. This problem can be solved during revegetation by the addition of hydrogels – hydroabsorbents. One hydroabsorbent is TerraCottem, a mixture of more than twenty components as hydroabsorbent, nutritive, root growing activators, carrier material, all assisting the plant growth processes in a synergic way. Hydroabsorbents can play an important role not only in germination and growth rate but could effect soil properties including those of a biological and biochemical nature. These properties were of interest during small parcel research with a mixture of grasses + clover in different variations of application, namely, with hydroabsorbents and a control without hydrogel. During three years of research statistical differences were described between plots with hydroabsorbent application and the control in all the studied parameters: CO2 production, cellulose decomposition and chosen enzymes activities (phosphatase, dehydrogenase, protease and urease). These studied soil biological and biochemical parameters are connected with other soil properties which were influenced by hydroabsorbent application and previously described in the scientific literature.