Brewery sludge quality, agronomic importance and its short-term residual effect on soil properties

Wastewater sludge generated from agro-industrial wastewater treatment plants is accepted as a good option for land application as a soil conditioner and substitute mineral fertilizers. However, the quality of the sludge sometimes posed a threat to the surroundings. The objective of the study is to evaluate the biochemical characteristics and fertilizer potential of brewery wastewater sludge for agricultural reuse. A field experiment was conducted in a randomized block design array with three replications using brewery wastewater sludge, and nitrogen, phosphorus and sulfur (NPS) containing commercial fertilizer along with control treatments. The result showed that sludge application significantly increased average above biomass production by 5.7% and 37.2% over the NPS and control plots, respectively. Also, the sludge-amended plot produced more grain yield of maize with 26.8% greater than the control. The brewery sludge temporary residual effect analysis revealed that the addition of the sludge led significant changes in soil pH reduction and soil electrical conductivity, total phosphorus, total nitrogen and total potassium increment as compared to others and background concentration. Similarly, lead and fecal coliform concentrations in the sludge-amended soil showed 150% and 24.4% increments, respectively, over the control. In general, the preliminary sludge temporary residual effect analysis showed an encouraging outcome on soil basic properties and maize crop productivity. Conversely, future long-term study is essential to monitor the effect of soil salinity, heavy metal and pathogen contaminations on soil and crop production.