The soaring cost of phosphorus and potassium are significantly destabilizing agriculture in recent times. In this connection a recent Ph.D. dissertation at University of Agriculture Sciences, Bangalore, on the use of human urine (Anthropogenic Liquid Waste, ALW) is particularly interesting and pioneering. Billed as India's first Ph.D. on Ecological Sanitation ('Ecosan'), it also makes a connection with the composting toilet movement that provides a solution to environmentally-friendly handling of human excreta.
Arghyam Trust funded a study undertaken by a doctoral student - Sridevi.G at the GKVK, College of agriculture (Department of Soil Science & Agricultural Chemistry) under the guidance of Prof Sreenivasamurthy of the Dept. of Soil Sciences. Maize, banana and radish were fertilized using human urine (Anthropogenic Liquid Waste, ALW), and compared with plants fertilized using chemical fertilizer to provide an equivalent amount of nutrient. It was found that anthropogenic liquid waste performed well in comparison to chemical fertilizer, consistently showing better results in all parameters like grain and stover yields in maize and yield in banana. Sensory parameters in a blind test also showed good results.
It was found that applying anthropogenic liquid waste in 6 split irrigations provided the best results. Cost : Benefit ratio for the farmer of using ALW was calculated and found to be better primarily since the input cost of chemical fertilizer is avoided. For root crops, biosand filtered ALW was found to be a suitable approach to get rid of pathogens. Gypsum was used to mitigate the possible negative effects of sodium in the urine on soil quality.