Cow urine as an organic nutrient source for hydroponic vegetable production

Purpose: Fermented cow urine (cow bio urine) is used as an organic source of nutrients. This study aimed to determine the effect of various concentrations of cow bio urine as the organic nutrient source on the growth and yield of vegetable crops in hydroponic systems.Method: Research was conducted in a greenhouse at the University Farm from November ۲۰۲۰ to January ۲۰۲۱ with a split plot in RCBD. The main plot consisted of ۳ vegetables (bok choy, spinach, and water spinach). The subplot had ۵ concentrations prepared by mixing cow bio urine with distilled water at C۱: ۱۰%, C۲: ۲۰%, C۳: ۳۰%, C۴: ۴۰%, and C۵: ۵۰%. These solutions were used as hydroponic nutrient solutions. All the treatment combinations were maintained in ۴ replications.Results: Cow urine analysis before and after fermentation revealed an increase in nutrient content. The highest plant growth and yield were obtained in all three vegetables at the concentration of ۵۰% cow bio urine. Maximum leaf number, leaf area, foliage dry weight, root dry weight, total dry weight, and foliage fresh weight were significantly higher in the above treatment. The highest foliage fresh weight was observed in treatments with ۵۰% cow bio urine, with values of ۵۷.۰۲ g (bok choy), ۵۴.۹۷ g (spinach), and ۲۶.۲۹ g (water spinach).Conclusion: Cow bio urine could be effectively used as a hydroponic nutrient solution to grow organic vegetables. The regression showed that the optimal concentration of cow bio urine might be higher than the present levels.