Evaluating Compost, Nitrogen and PK Fertilizer Effects on Maize Crop Productivity: Toward Economically Efficient Nitrogen Management

Abstract

The effects of nitrogen (N) fertilizer (0, 45, 90, and 135 kg N/fad), phosphorus-potassium (PK) application (0 vs. recommended rate: 31 kg P₂O₅ + 24 kg K₂O/fad), and wheat and maize composts on maize growth, yield, nutrient dynamics, and nitrogen economy were examined in a two-year field study. With increases of 4.3–12.9% and 8.0–9.2% over seasons, respectively, maize compost considerably increased grain yield (15.8 ard/fad) above wheat compost (15.2 ard/fad) and control, according to results from a split-plot design with four replicates. While the effects of phosphorus (P) differed by season, both composts increased the percentages of nitrogen (N) and potassium (K) in leaves and grains. While ear characteristics, yield components, and nutrient content in leaves and grains were increased by increasing N rates up to 135 kg/fad, nitrogen utilization efficiency (NUE: 25.11 to 16.41 kg grains/kg N) and recovery (29.24% to 23.76%) were decreased. While effects on ear morphology and P content were mixed, PK fertilization greatly increased yield, crude protein, and N and K in grains. At 45 kg N/fad, recovery and N efficiency were at their best. Combining compost with moderate N and PK inputs increased sustainability and productivity, indicating that balanced fertilization (45 kg N/fad + PK) and maize compost are good ways to maximize maize production and control nutrients.