Why put biosolids on land?

Biosolids contain organic matter and nutrients which improve soil fertility and the quality and structure of soil. They also contain micronutrients such as copper, zinc and iron and can reduce the need for fertilisers. As many commercial fertilisers are produced using hydrocarbons, the price of such fertilisers is rising, adding to the attractiveness of Biosolids under the right conditions. The application of biosolids returns nutrients to the land, thereby completing the nutrient cycle.

Biosolids also aid forestry and land rehabilitation at mining sites by conditioning and fertilising the soil.