Title: Physicochemical characteristics of liquid fertilizer from fish viscera.
Abstract
A study was conducted to develop a liquid fertilizer from fish viscera and analyse its physicochemical character. Effectiveness on the growth of plants was verified by estimating the amount of nutrients in onion and garlic. Liquid fish fertilizer obtained by three methods represents an alternative process for the use of viscera; 1 M NaOH treatment as first method, natural enzyme treatment as second method and alcalase treatment as third method. The results showed alcalase treatment fertilizer contain 13.16% of protein, 79.80% of moisture, 0.20% of lipid and 1.91% of ash. Alcalase treatment fertilizer has high macronutrient such as 2.11% of nitrogen, 0.22% of phosphorus, and 0.25% of potassium. Comparing fish fertilizers with industrial fertilizer (Maxicrop) showed the latter contained less nitrogen (0.72%). Fish viscera can be applied as a fertilizer because it contains enough nutrients for plants. Onion and garlic treated with alcalase treatment fertilizer showed highest total growing ratio (92.60% for onion and 105.55% for garlic) and plant height (38.50 cm for onion and 50.13 cm for garlic). Alcalase treatment fertilizer was very effective to be used as fertilizer for growing onion and garlic as it produced higher total growing ratio and yields, compared with industrial fertilizer (Maxicrop). Solid fish silage has the potential to be developed into a dry fertilizer and could be a suitable substitute for fishmeal in producing high quality and nutrient-rich powder fish silage.