Evaluation of irrigation scheduling on water use efficiency, nutrient availability and uptake of nutrients by aggregatum onion (Allium cepa var. aggregatum)

Field experiment was conducted at Agricultural Research Station, Bhavanisagar. The treatment structure comprised of five irrigation regimes with six levels of boron. The trials were laid out in split plot design and replicated thrice. The water use efficiency of treatments indicated that the highest water use efficiency was noted with 1.20 IW/CPE ratio (19.60 kg/ha.mm) and the lowest was noted with 1.80 IW/CPE ratio (16.86 kg/ha.mm). With regard to nutrient availability the irrigation regimes failed to exert their influence on phosphorus and potassium, while the nitrogen and boron availability was significantly influenced. Among the irrigation regimes, irrigating the crop at 1.80 IW/CPE ratio registered the highest nutrient availability. With regard to boron levels, the NPK availability was slightly increased by the addition of varied levels of boron and the values were higher than control plots. Irrigation levels and increasing levels of boron significantly influenced the nutrient content and uptake which could be ascribed to the increased yield.