Effect of mineral fertilization (NPK) and foliar spraying with organ-ic silicon on some growth traits and yield of maize

A factorial experiment using a randomized complete block design (RCBD) was conducted in the spring of 2024 in clay loam soil at Ibn Al-Bitar Vocational Preparatory School/Al-Husainiya District, Holy Karbala, to study the effect of adding mineral fertilizers (NPK) and spraying with silicon on some growth and yield traits of maize. The experiment included two factors: mineral fertilizers (N, P, and K) at three levels: without fertilization, symbolized by M0, adding 50% of the fertilizer recommendation (150 kg N ha-1, 50 kg P ha-1, and 80 kg K ha-1) and symbolized by M1, and adding 100% of the fertilizer recommendation (300 kg N ha-1, 100 kg P ha-1, and 160 kg K ha-1) and symbolized by M2, and the second factor is foliar feeding with Organic silicon (80%) at three concentrations (0, 3 and 6 ml L-1), the results of the study showed the significant superiority of adding mineral fertilizers individually in most of the studied traits. Adding the full fertilizer recommendation 100% achieved the highest averages in the trait of number of leaves (11.884 leaf plant-1), leaf area (6220.60 cm2 plant-1), chlorophyll index (53.82 SPAD), biological yield (16.418 tons' ha-1), and grain yield (7.827 tons' ha-1). The increase in the concentration of silicon added as a spray on the vegetative group of maize led to a significant increase in the averages of the studied traits. The concentration (6 ml L-1) achieved a significant superiority in the trait of leaf area (5917.30 cm2 plant-1), chlorophyll index (52.55 SPAD), biological yield (16.418 tons' ha-1), and grain yield (7.112 tons' ha-1). The results also showed the response of maize to the two-way interaction between the two study factors. The treatment (M2Si2) was significantly superior in the number of leaves (12.013 leaf plant-1), leaf area (6303.80 cm2 plant-1), chlorophyll index (55.78 SPAD), biological yield (17.045 tons' ha-1), and grain yield (8.250 tons' ha-1) compared to the comparison treatment without fertilization.