Effect of nitrogen fertilizer rates and splitting nitrogen on yield and yield components of Egyptian cotton cultivar Giza 90 under surface and drip irrigation systems in newly reclaimed lands

The current study aimed to use surface and drip irrigation systems with rates of nitrogen fertilizer and splitting of nitrogen fertilizer rates. Two field experiments were carried out at the Agricultural Research Farm at Al-Kawamel site, Faculty of Agriculture, Sohag University, Sohag Governorate, Egypt during 2019 and 2020 seasons to study effect of two irrigation systems; surface and drip irrigation, three rates of nitrogen (N) fertilizer and three splitting of N rates on yield and its components of cultivar Giza 90 cotton. In each season, separate trial was conducted for each irrigation system and the combinations between N fertilization rates and splitting N fertilizer rates. A field experiment was designed as randomized complete block with split-plot arrangement of treatment with three replications, whereas rates of nitrogen fertilizer were allocated to the main plots and the sub-main plots include splitting of nitrogen fertilizer. Results indicated that sowing Egyptian cotton crop (Giza 90) cultivar in newly reclaimed sandy soil with drip irrigation system, fertilization at a rate of 90 kg or 75 kg nitrogen per feddan with splitting to 4 doses, caused to maximized productivity through increased significantly the seed cotton yield 6.50 and 6.33 kentar/feddan, respectively. Drip irrigation system saved the amount of water required per feddan to almost a quarter (25%) compared to the surface irrigation, under conditions of the area under the study.