Ecological sanitation [Ecosan] is aimed at safely closing the nutrient and water cycles. Nutrients from human excreta should be returned to the soil as a crop fertilizer. The products of ecological sanitation, urine and faeces, are in many ways well suited for use as fertilizers. They contain all nutrients essential for crops. In order to ensure sustained soil fertility and ample harvests, the soil in the cultivation fields needs to be replenished with nutrients and soil improving material.

This paper tracks the guidelines on the use of urine and faeces in crop production, as well as the various methods used to sanitize human excreta including its application rates.