THE EFFECT OF APPLYING LIQUID ORGANIC FERTILIZER (LOF) DERIVED FROM VEGETABLE WASTE ON THE GROWTH AND YIELD OF GREEN MUSTARD GREENS (Brassica Juncea L.)

This study aimed to determine the effect of liquid organic fertilizer (LOF) derived from vegetable waste on the growth and yield of mustard greens (Brassica juncea L.), to identify the optimal LOF concentration for the best growth and yield, and to assess the nutrient content of the LOF through laboratory analysis. The research was conducted in an open field in Soroma’asi Hamlet, Hilimbuasi Village, Lolofitu Moi District, West Nias Regency, using a non-factorial Randomized Block Design (RBD) with six treatments and four replications. The treatments consisted of P0 (0 mL/L), P1 (50 mL/L), P2 (100 mL/L), P3 (200 mL/L), P4 (300 mL/L), and P5 (400 mL/L) of the fertilizer in water. Each plot contained 10 plants, with five plants selected as samples. Observed parameters included plant height, number of leaves, fresh weight per sample, and fresh weight per plot. Data were analyzed using ANOVA, followed by DMRT at the 5% significance level where applicable. The results indicate that the vegetable waste-based LOF had a significant effect on plant height (at 1–4 weeks after planting/WAP), the number of leaves (at 2–4 WAP), as well as the fresh weight per sample and per plot. The P3 treatment (200 mL/L) yielded the highest values: a plant height of 31.33 cm, 13.65 leaves at 4 WAP, a fresh weight of 141.00 g per sample, and 711.75 g per plot. Laboratory analysis revealed a nutrient content of 0.12% N, 10.29 ppm total P₂O₅, 0.01% K₂O, and 0.15% organic carbon. Consequently, a concentration of 200 mL/L is the most effective treatment under the conditions of this study.