The Application of Slow Release NPK Fertilizer on Inceptisols to Changes of Soil Chemical Properties and Growth of Sweet Corn (Zea mays L. saccharata)

Effort to increase the efficiency of fertilizer use, reduce loss of nutrients in the soil due to leaching, evaporation and reduce residues which can be one of the causes of soil damage, slow release fertilizer is needed. This slow-release fertilizer can optimize plant growth and production as well as nutrient absorption by plants because the release of nutrients is according to the time and amount needed by the plant, while fertilization costs can be reduced because this type of fertilizer is only applied once in a growing season. The experiment was carried out to determine the effectiveness of inorganic fertilizers (NPK) which are slow release with various types of coating percentages to help provide nutrients slowly for sweet corn to grow and produce optimally and reduce environmental pollution due to excessive fertilizer application on the soil. The pot experiment was carried out using a Randomized Block Design (RBD) which consisted of four treatments with the percentage of slow release fertilizer (SRF) i.e. 0%, 3-4%, 5-6% and 7-8%. Each treatment was repeated six times. The results showed that in 60 days after application of slow release NPK fertilizer gave the best effect for improving the chemical properties of Inceptisol (N-total, P-potential, and K-potential), by releasing the entire content of 75.03%. Slow Release NPK fertilizer with 0% coating percentage gave the best effect on the chemical properties of Inceptisol and increased growth (plant height and stem diameter) of sweet corn (Zea mays L. saccharata).