Mineral fertilizers are expensive and last only a relatively short time. Proper handling of fertilizers has a direct impact on crop quality and profitability. Currently, straight fertilizers are divided into types, A and B, based on the fertilizer's sedimentation properties when mixed. Therefore, to solve these flaws, we developed a vitamin C-substrate organomineral fertilizer, AGH-Ringer. This study consisted of a fertilizer equivalency test, which lasted 15 weeks of soil cultivation in a farm field, using lettuce (Lactuca sativa L., ' Jeok Chi Ma') with AGH-Ringer as a test fertilizer. This fertilizer was based on powder compound-type fertilizer r-Ringer and manufactured by chelating essential minerals with a vitamin C substrate to have NPK contents in a ratio of 18.9:14:4.0. In the onsite evaluation, the superiority of AGH-Ringer was demonstrated through an effect of growth stimulation in both aerial and rhizosphere parts of the plants at suitable soil temperatures. This fertilizer also increased yield, even in inadequate low-temperature conditions. In addition, AGHRinger increased the absorption and bioavailability of minerals in lettuce leaves at harvest. The mineral absorption ability showed a uniform pattern during the entire harvest period. It has been confirmed that AGH-Ringer, manufactured with vitamin C as a substrate, is a fertilizer with excellent efficacy that increases growth and harvest simultaneously, solving the existing problems of chemical fertilizers such as sedimentation and lack of mineral absorptivity in nutrient solution systems.