Exploration of the potential of distillery sludge for sustainable agricultural application

Waste is one of the major challenges that humankind face today and by-products of different industries make it more challenging for their disposal as they can pose environmental risks. Distillery sludge from the alcohol production industry is one such waste product that presents a wide range of logistical as well as environmental challenges. This study aims at the scientific utilization of distillery sludge and its application as an agricultural amendment to improve the fertility of soil. The qualitative analysis of the distillery sludge revealed its richness in organic matter as well as essential nutrients making it a good alternative to fertilizers in agricultural fields. The presence of heavy metals was also observed; therefore, lysimeter studies were conducted with the application of sludge at different doses to soils from two different sources (agricultural and waste land soil). Sludge dose equivalent to 3 MT/acre (7.4 MT/ha) was observed to be the optimum dose for soil conditioning, whereas its repetitive application in consecutive years is not recommended. Field productivity of 26 and 24 MT/acre was observed upon application of the recommended sludge dose of 3 MT/acre and Farm Yard Manure (FYM) dose, respectively, indicating the suitability of sludge application. Furthermore, the study also confirmed that the use of distillery sludge as fertilizer did not have any adverse effects on the fruit juice quality, thereby, making it suitable for agricultural application upon regulated dosage.