Abstract

Farm-made liquid fertilizers are used in organic agriculture, however crop growth promotion and mineral nutrion levels in liquid fertilizers can vary drastically depending on manufacturing methods. Therefore, laboratory research was conducted during 2018 at Sunchon National University, Korea to determine certain manufacturing methods to produce the best fermented liquid fertilizers for red pepper and tomato seedlings. All extracts had acidic pH levels except for fish II and bone + fish meal I extracts. During storage, bone + fish I-V and tomato I-IV experienced almost no change in pH whereas all other extracts experienced a reduction in pH. Although extraction EC values varied during storage, most EC values were not high and could therefore be used for extracts. Overall, extracts used in this study were far more effective growth promotors of red pepper plants than tomato plants and shoot fresh weight with increase at a greater rate than plant height in response to fertilizers. Most extracts produced using onion, fish, and bone + fish meal had red pepper shoot fresh weight growth promotion levels of 59 to 128%. The most effective growth promoting extracts were onion extracts IV and V which produced 182 and 202% higher shoot fresh weight of red pepper, respectively. In all extracts, there was greater variation in micro-element than macro-elemnet levels. Macro and micro-element levels were higher in fish and sesame oil cake extracts than in onion, tomato, red pepper leaf, and bone + fish extracts. Generally, macro-elements such N, P, K, Ca, Mg, and Na in fish extracts were higher than in bone + fish, tomato, onion, red pepper leaf, and sesame oil cake extracts. Micro-elements such as Zn, Fe, Mn, and Mo in fish extracts were also higher than in bone + fish, tomato, onion, red pepper leaf, and sesame oil cake extracts. Despite having greater levels of either micro or macro-nutrients, some extracts had far lower levels of growth promotion. Crop growth promotion in extracts varied depending on materials, material combination, and material amounts. Thus, farm-made liquid fertilizers, though effective, need to use a standardized manufacturing method in order to produce the most effective and consistant growth promoting liquid fertilizers.