Influence of irrigation, nitrogen and zinc on productivity and water use by late-sown wheat (Triticum aestivum)

A field experiment was conducted on deep sandy soil (Typic Ustochrept) at the Water Technology Centre, Indian Agricultural Research Institute, New Delhi, during winter seasons of 1999–2000 and 2000–2001 with late-sown ‘HD 2285’ wheat (Triticum aestivum L. emend. Fiori & Paol.). The treatments comprising 4 irrigation levels [I₀, no post-sowing irrigation; I₁, 1 irrigation at crown-root intiation (CRI) stage; I₂, 2 irrigations, each at CRI and flowering stages; I₃, 4 irrigation each given at CRI, jointing, flowering and dough stages] in main plots and combinations of 3 N levels (0, 50 and 100 kg N/ha) and 2 zinc levels (0 and 5 kg Zn/ha) in subplots were laid out in split-design, replicated 3 times, to find out the influence of irrigation, nitrogen, zinc and their interactions on yield and moisture use by the crop. Progressive increase in irrigations from 0 to 4 and N levels from 0 to 100 kg/ha, increased wheat yield attributes and grain yield significantly over the control treatments (I₀ and N₀). The average seasonal consumptive water use (CU) by wheat increased with every additional irrigation level to a maximum of 328.4 mm and 301.7 mm in the first and second season respectively. On an average (2 seasons), water-use efficiency (WUE) was the highest (1.38 kg grain/m³) with I₂. However, the straw yield (6, 808.5 kg/ha) and grain yield (3, 962.5 kg/ha) were highest with I₃. The average moisture use rate increased with increase in irrigation to a maximum of 2.63 mm/day. Maximum moisture extraction of 59.4 to 65.8% was from the 0–30 cm and the minimum (7.10 to 5.32%) from the 90–120 cm soil depth. The WUE increased markedly with the increase in N level.