Addressing water scarcity and waste: innovative irrigation for wheat using dairy effluent and the alternate wetting-drying practice

Dairy wastewater, a nutrient-rich resource, presents a viable strategy to boost agricultural productivity in regions facing severe water scarcity. The comprehensive study at Bangladesh Agricultural University evaluated the effects of conventional irrigation (CI) and water-saving alternate wetting and drying (AWD) practices using varying ratios of dairy wastewater and freshwater on wheat cultivation through a meticulously designed lysimeter experiment. The investigation encompassed six distinct treatments with three replications each, analyzing growth performance, yield components, water productivity, and soil microbiological properties. Results demonstrated that conventional irrigation with pure wastewater (CIW) produced the highest grain yield (4.76 t/ha) and straw yield (5.75 t/ha), along with superior growth parameters, including plant height and spike density. In contrast, alternate wetting and drying with wastewater (AWDW) achieved remarkable water savings of up to 49.78% compared to CIW and recorded the highest water productivity (1.08 kg/m3). Microbiological analysis revealed no Salmonella, and E. coli were detected in post-harvest soil samples under the tested conditions, though significantly higher total viable counts were observed in AWDW treatments, indicating enhanced microbial activity. These findings demonstrate that dairy farm wastewater irrigation significantly improves wheat yields and water use efficiency, offering a sustainable agricultural solution for water-scarce regions like Bangladesh.