Response of Liquid Organic Fertilizer (Goat Urine) Application on the Growth and Production of Lettuce (Lactuca sativa L.) in Hydroponic Systems

Abstract

Lettuce (Lactuca sativa L.) is one of the most widely consumed leafy vegetables in fresh form. This crop is rich in nutrients including dietary fiber, provitamin A (carotenoids), potassium, and calcium, and offers various health benefits. The use of liquid organic fertilizer (LOF) derived from goat urine has attracted growing interest due to its relatively high nitrogen and potassium content compared to solid animal manure, as well as its ability to support vegetative growth. This study aimed to evaluate the response of lettuce growth and production to the application of goat urine-based liquid organic fertilizer in a hydroponic wick system. The experiment was conducted in Sijunjung Regency, West Sumatra, Indonesia, at an altitude of 1,000-1,250 m asl, using a Completely Randomized Design (CRD) with three treatment levels (P1: 6 ml/L, P2: 8 ml/L, P3: 10 ml/L) and six replications. Parameters measured included plant height, number of leaves, leaf length, leaf width, and yield. Analysis of variance (ANOVA) showed no significant difference among treatments for vegetative parameters (plant height, leaf number, leaf length, and leaf width), likely due to sub-optimal fertilizer concentration. However, production yield showed a highly significant difference (P<0.01), with the best result recorded in treatment P2 (8 ml/L), which produced an average of 1.66 oz/plant. These results indicate that goat urine LOF at 8 ml/L is the most effective dose for improving lettuce yield in hydroponic cultivation, although higher concentrations may be needed to significantly improve vegetative growth.