Young Scientist
Dr. Gulshan Kumar Sharma
Scientist
ICAR-Indian Isntitute of Soil and Water Conservation, Reseacrh Centre, Kota, Rajasthan
INDIA
The heightened awareness concerning resource paucity, environmental conservancy, food safety and nutrition, has created the need for a more sustainable and resourceful agricultural production system. In this context, microalgae offer the prospective to recover nutrients from waste streams to forbid eutrophication and subsequently use the microalgal biomass as viable slow-release biofertilizers. In a current study, microalgae Chlorella minutissima was selected for sewage wastewater remediation. C. minutissima was found to be very efficient in the removal of total dissolved solids, nitrate, ammonium, phosphate, and potassium content in sewage wastewater by 93.2, 89, 48.2, 67.4, and 66.3% respectively. The algal biomass obtained after phycoremediation was tested as fertilizer on baby corn and spinach crops. The application of 100% N dose by algal biomass leads to a higher or equivalent economic yield of spinach and baby corn than the yield obtained by the supply of recommended dose of mineral fertilizer. The dehydrogenase, urease and nitrate reductase activities were analysed in spinach and baby corn grown soil. As compared to mineral fertilizer applied soil, microalga manure applied soil had higher soil microbial activity. The organic carbon, available nitrogen and phosphorus contents of algae biomass applied soil were equivalent to the soil having recommended dose of NPK applied by mineral fertilizer. The nitrate leaching was also estimated in the study. The experiment was conducted in polyvinyl chloride (PVC) pipes of dimension 100 cm in length and 30 cm in diameter. The leachates were collected from the depth of 15, 30, 45, 60, and 90 cm to quantity the nitrate leaching. Nitrate leaching was found to be significantly lower in microalgal manure applied treatment compared to mineral fertilized. The study revealed that phycoremediation coupled with manure production is a resource conservation and recycling approach to reduce eutrophication and improvement of soil health in a sustainable manner. Keywords: Phycoremediation, Wastewater, Microalgae, Fertilizer, Soil improvement, Nitrate leaching