Agronomic Performance of Soybean and Sorghum Irrigated with Slaughterhouse-Treated Effluent

The slaughterhouse-treated effluent, enriched with nitrogen, phosphorus, and organic matter, presents a promising alternative for water and nutrient reuse in irrigated crop systems. This study assessed the chemical composition of the effluent, nutrient dynamics in the soil, and agronomic performance of soybean (Glycine max (L.) Merr) and sorghum (Sorghum bicolor (L.) Moench) under fertigation. A randomized block design was used, with five treatments (tap water—control—and four effluent levels: 25%, 50%, 75%, and 100%) applied to two crop species, with four replications. The effluent exhibited elevated concentrations of ammoniacal nitrogen (43.9 ± 18.7 mg L−1), and potassium (13.1 ± 3.8 mg L−1), confirming its potential as a nutrient source. No significant differences were observed in soybean plant height across treatments, whereas early-stage sorghum growth showed only slight variation. Irrigation with treated effluent successfully replaced 100% of tap water in both soybean and sorghum, with no significant differences in productivity across concentrations. These results demonstrate the agronomic feasibility of using treated effluent as a substitute for tap water and synthetic fertilizers. Moreover, they highlight its potential as a sustainable input for fertigation, contributing to resource efficiency and promoting more integrated and environmentally conscious agricultural practices.