Processing kills disease-causing organisms such as bacteria and viruses, and reduces odors. A variety of chemical, physical, and biological processes are used to process raw solids. Despite their name, not all biosolids are solid. After all this processing, biosolids are ready to go to work. Good soil tilth means that soils are easy to dig in and work up, easy for seedlings to emerge from, and easy for plant roots to move through.
Healthy soil means healthy plants.
For instance, biosolids increase the number and size of air spaces in the soil and enhance its ability to hold together. This provides a better balance of water and air in the soil for plant growth. Better still, biosolids contain plant nutrients, such as nitrogen, phosphorus, and sulfur, in organic and inorganic forms. The inorganic forms are immediately available to plants. Nutrients in the organic form are released slowly as the biosolids decompose in the soil.