Effect of Liquid and Single Compound NPK Fertilizer on Soil and Plant Nitrogen Content and Yield of Sweet Corn (Zea mays L. Saccharata) in Inceptisols of Jatinangor

The main problem in Inceptisols soil is its low fertility level. One of the efforts to overcome this problem is by providing additional nutrients that can be absorbed by the soil through compound NPK fertilization, which supplies available nutrients to optimize soil fertility, thereby improving the quality and quantity of sweet corn plants. This research aims to determine the effect of liquid compound NPK fertilizer and single fertilizer on total soil N content, plant N content, and yields of sweet corn crops; and to obtain a combination of compound NPK inorganic fertilizer and single fertilizer that provides the highest yield of sweet corn on Inceptisols soil from Jatinangor. The experiment was carried out in the experimental garden of the soil chemistry and plant nutrition laboratory, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, from July 2023 to December 2023. The research design used was a Completely Randomized Block Design (CRBD) consisting of nine treatments and three replications, namely: A (control); B (1 dose NPK fertilizer standard); C (¾ NPK compound + ¾ NPK standard); D (1 NPK compound + ¾ NPK standard); E (1½ NPK compound + ¾ NPK standard); F (½ NPK compound + 1 NPK standard); G (¾ NPK compound + 1 NPK standard); H (1 NPK compound + 1 NPK standard), and I (1½ NPK Compound + 1 NPK standard). The data collected were initial soil yield before treatment, soil N-total content, N-plant content, cob diameter, cob length, husked cob weight, peeled cob weight, and cob weight per plot. Data analysis was carried out using variance analysis and continued with the 5% level Duncan’s Mutiple Range Test (DMRT). Data analysis using SPSS software. The research results show that the application of liquid and single compound NPK fertilizer had a significant effect on increasing soil N-total, N-plant content, and yields of sweet corn on Inceptisols soil from Jatinangor; and the combination dose of 1 NPK compound (8 L ha-1) + 1 dose of NPK standard (Urea 300 kg ha-1, TSP 100 kg ha-1, and KCl 50 kg ha-1) provides the best sweet corn crop results on Inceptisols soil from Jatinangor.