Assessment of Blended Fertilizer (NPK, S, Mg, ZnB) Rates on Grain Yield, Nutrient Uptake, and Economic Profitability of Maize (Zea mays L.) in Kwadaso Semi-deciduous Zone of Ghana

Abstract

In Ghana, maize is a major cereal crop that grows and consumes a lot. However, its output is limited by low soil fertility and inappropriate fertilizer application. This study aimed to investigate the influence of NPKSMgZnB fertilizer rates on grain yield, nutrient uptake, and maize economic feasibility. A field experiment was carried out in Kwadaso during the 2022 farming season. The treatments consisted of three blended fertilizer rates (NPK 14:18:18+6S+1B, NPK 20:20:10+4S+2MgO+0.6B+0.5Zn, and NPK 15:20:10+9S+5MgO+0.6B+0.5Zn). Treatments were set up in an RCBD design with four replications. The blended fertilizer rate exhibited a significant (p < 0.005) effect on plant height, cob weight, grain yield, and biomass output. However, it had no substantial effect on phonological features, spad meters, or 1000-grain weights. The yield was higher for the NPK20:20:10+4.3S+2.1MgO+0.6 B+0.5Zn applied at 150-90-45+18S+9MgO+2.7B+2.25Zn (mean: 4.09 t ha-1) and NPK 15:20:10+9S+5MgO+0.6B+0.5Zn  at 150-90-90+3S+5B (mean: 4.23 t ha-1) produced the largest grain yield respectively, which was composed entirely of primary, secondary and micronutrients. The zero-control treatment produced the lowest yield (mean:1.83 t ha-1).  The higher nutrient uptake of N and P was recorded from the maximum rate of NPKSMgZnB and Mg respectively. The results of the study, application NPK 150-90-45+18S+9MgO+2.7B+2.25Zn (T21) and 15:20:10+9S+5MgO+0.6B+0.5Zn at 100-60-30+27S+15MgO+1.8B+1.5Zn (T14) increases yield and yield component of maize and give the highest return from unit investment which can be recommended for the study area.