Pengaruh POC Rumput Laut sebagai Substitusi Nutrisi AB Mix pada Tanaman Sawi (Brassica juncea L.) dengan Sistem Hidroponik

Hydroponic cultivation typically employs AB Mix nutrition, which contains all essential nutrients but comes at a relatively high price. Organic fertilizers can be used as an alternative to reduce AB Mix's nutritional requirements. This study seeks to (1) determine the impact of substituting seaweed liquid organic fertilizer for AB Mix nutrients. (2) determine the optimal composition of seaweed liquid organic fertilizer when AB Mix nutrition is substituted. A Completely Randomised Design (CRD) comprising 4 single treatments and 6 replications was used to compose the treatments. The treatments included four levels: R0 (100 percent AB Mix), R1 (75 percent AB Mix plus 25 percent seaweed liquid organic fertilizer), R2 (50 percent AB Mix plus 50 percent seaweed liquid organic fertilizer), and R3 (25 percent AB Mix plus 75 percent seaweed liquid organic fertilizer). The results demonstrated that 25% seaweed liquid organic fertilizer as a nutrient replacement for AB Mix was equivalent to the nutritional quality of AB Mix at 100%, as indicated by the leaf length, leaf width, number of leaves, leaf greenness level, number of leaf stomata, fresh weight stems and leaves, dry weight stems and leaves, fresh weight of roots, dry weight of roots, and stem diameter. The optimal ratio of nutrients from AB Mix to seaweed liquid organic fertilizer is 75% AB Mix and 25% seaweed liquid organic fertilizer.