The Impact of Nitrogen Fertilization, and Sodium Bicarbonate Application on the Growth and Productivity of Cotton under Modern Cultivation Techniques

• Sahar Fawzi Khalifa1*, Jasim Mohammed Aziz2

  Author

This study was conducted to evaluate the efficiency of dissolved oxygen through the addition of sodium bicarbonate to drip irrigation water on nitrogen uptake and productivity of cotton (Gossypium hirsutum L.), cultivar Livzara.

The experiment was carried out during the 2025 growing season at a site affiliated with the College of Agriculture, Tikrit University, Iraq. The study was arranged according to a Randomized Complete Block Design (RCBD). Two factors were investigated. The first factor consisted of five concentrations of sodium bicarbonate (0, 9, 13, 17, and 21 mg L⁻¹), applied perpendicular to the experimental units. The second factor included two nitrogen fertilization levels using urea (46% N) at rates of 60 and 120 kg N ha⁻¹.

The results indicated that a concentration of 21 mg/L NaHCO₃ achieved the maximum plant height of 122.3 cm, while concentrations of 17 and 21 mg/L were significantly superior in leaf area and leaf area index (LAI), reaching 6656.1 cm² and 4.7, respectively. Notably, the interaction between 17 mg/L NaHCO₃ and 60 kg/ha N yielded the highest leaf area of 6821.8 cm², suggesting that enhanced root zone aeration optimizes nutrient utilization and reduces the necessity for excessive nitrogen application.

 Leaf nitrogen concentration peaked at 48.4 g/kg with the 21 mg/L NaHCO₃ treatment, while the highest interaction value of 50.7 g/kg was observed under the combination of 21 mg/L NaHCO₃ and 120 kg/ha N.

 Furthermore, higher bicarbonate levels (17 and 21 mg/L) significantly accelerated phenological development, reducing the time to 50% flowering to approximately 65 days and 50% boll formation to 85.8 days.

• pdf