Assessment of brewery wastewater as an alternative irrigation source: impacts on soil health and nutrient uptake by maize in Tamil Nadu, India

Abstract Background The growing demand for sustainable water management in agriculture has led to the exploration of unconventional water sources, including treated industrial wastewater. Brewery wastewater (BWW), with its inherent nutrient content, seems promising for irrigation. Nevertheless, there is limited knowledge regarding the influence of BWW on soil properties, crop nutrients and overall productivity in the Tamil Nadu context. This study delves into the intricate relationship between BWW irrigation and its impact on soil properties, plant responses and, ultimately, suitability for sustainable agricultural practices. Comparing BWW with Narugampally River water (NRW) serves as a baseline to assess potential differences in its effects. Methods Laboratory analyses were conducted on BWW and NRW to characterize their irrigation potential. A pot experiment was also carried out in a completely randomized design (CRD) with four treatments covering 100%, 75%, 50% and 25% BWW, along with an additional 100% control (NRW) treatment. The analysis of the BWW samples revealed elevated levels of TDS, BOD, COD, CO 3 − , HCO 3 ⁻, K + , NO 3 ⁻-N, SO 4 − , B + , SSP, KR and TH beyond the permissible limits of the FAO irrigation water quality standards. However, the mean values of pH, EC, TSS, Ca 2+ , Mg 2+ , Na + , Cl − and MH remained below the permissible limits according to FAO standards. In the NRW, all the studied parameters fall within the allowable limits. Results The results of the pot culture experiments revealed that the height and stem girth of the maize plants in the soils irrigated with different concentrations of BWW did not significantly differ ( P < 0.05). Furthermore, 100% BWW irrigation significantly ( P < 0.05) increased the leaf area, chlorophyll content, shoot and root biomass and uptake of NPK and other cations in maize leaves. The same treatment significantly increased the pH, EC, OC, available NPK, exchangeable Ca, Mg, Na and soil CEC compared with those of the soils irrigated with 100% NRW. Principal component analysis (PCA) was used to identify key properties contributing to variance, highlighting the positive impact of organic carbon on soil properties and plant growth. Conclusion This study provides a comprehensive assessment of the impact of BWW on soil and crop productivity in Tamil Nadu, filling a critical knowledge gap in sustainable water management for agriculture in water-scarce regions.