The Effect Combination of Liquid Organic Fertilizer and Inorganic Fertilizer on Potato (Solanum tuberosum L.) var. Granola G2

The potato (Solanum tuberosum L.) is a crucial food source highly demanded in Indonesian society. The national potato crop productivity in 2018 was approximately 1,284,773 tons. Enhancing potato availability necessitates increasing productivity by expanding cultivation areas and employing improved cultivation techniques. However, excessive use of inorganic fertilizers may adversely affect soil fertility and quality. Therefore, it is imperative to enhance soil fertility by augmenting organic matter content using organic fertilizers, such as liquid organic fertilizers derived from processed sugar cane residue. Consequently, this study aimed to ascertain the optimal dosage of liquid organic fertilizer for enhancing the growth and yield of potato plants. The research was conducted from June to October 2022 in Nongkojajar Village, Tutur District, Pasuruan Regency. Various tools were utilized, including hand tractors, nameplates, bamboo pegs, gembor, tape measures, a 150 L drum, a stirrer drill, 5 L and 250 mL measuring cups, waring, and a camera. Potato seeds of the granola variety, liquid organic fertilizer, inorganic fertilizers (Urea, SP-36, and KCL), as well as soil and water samples, constituted the materials for the research. The experimental research method was employed, utilizing an environmental randomized block design (RBD) with seven treatments repeated four times. Parameters observed encompassed plant height, number of leaves, leaf area, dry weight, plant growth rate, soil chemical analysis, nutrient absorption, and harvest analysis. The results revealed that the treatment of liquid organic fertilizer at a 100% dose and the combined treatment of liquid organic fertilizer at doses of 50%, 100%, 150%, and 200% + 80% inorganic fertilizer exhibited superior productivity in potato plants compared to the control treatment without fertilizer. Additionally, these treatments demonstrated comparable potato plant productivity to that achieved with the 100% standard dose of inorganic fertilizer.