Nightsoil is also allowed to ferment longer in the tank before application. As chemical fertilizers provide an inexpensive and convenient nutrient source, nightsoil use is on the wane, and flush toilets are becoming more common. If the trend toward nightsoil overapplication in small areas and sewage dumping continues, serious environmental damage is unavoidable, and dependence on external sources of phosphorus will increase. Use of nightsoil conserves nutrients within the farm and household. It also helps in sustaining soil nutrient resources .
Nutrient cycling is increased by returning manures to soils .
Using human manure as a fertilizer resource also eliminates wastes . Use of nightsoil builds soil fertility over the long term . Pictures of nightsoil use . Related Publications .