Application of inorganic fertilizer NK (18-32) on growth and yield of sweet corn on clay soil

Abstract

To determine the effectiveness and efficiency of the application of inorganic compound fertilizer NK (18-32) on sweet corn, an experiment was conducted at the experimental garden in Malang, East Java, Indonesia, starting from March to June 2020. The study was arranged in a single-factor RBD with ten treatments and three replications. The treatments were a combination of doses of NK compound fertilizer, a single fertilizer as a comparison, and a control (without fertilizer). Besides control, all treatments were given P fertilizer at a dose of 100 kg/ha. The result showed that doses of 500-750 kg/ha of NK compound fertilizer significantly increased the growth and yield of the sweet corn plant. Each 10 kg dose increase of NK fertilizer will increase the total dry weight of the plant by 1.3055 g and give a yield of 12.57–13.64 tons/ha of fresh cobs. This result is equivalent to the yield of standard N-K single fertilizer (350 kg/ha Urea + 75 kg/ha). The dose of NK compound fertilizer of 125-250 kg/ha was proven to be able to substitute 100% KCl fertilizer (75 kg/ha). The RAE value of 750 kg/ha of NK fertilizer was 105.99 % higher than the standard/comparative single fertilizer. The combination of 125 kg/ha NK fertilizer + 250 kg/ha Urea and 250 kg/ha NK fertilizer + 100 kg/ha Urea, respectively, resulted in a RAE 3.91% and 1.00% higher than the standard fertilizer. Fertilization can improve the quality of sweet corn, namely the level of sweetness increases. NK (18-32) fertilizer doses of 500-750 kg/ha significantly increased the sweetness level of seed corn from 11.17% (without fertilizer) to 15.25-15.25%.