Nutritional quality of onion as influenced by irrigation scheduling and nitrogen fertigation

Abstract

Onion (Allium cepa L.) is an important vegetable cash crop grown throughout the world. India has largest area under onion cultivation and second largest producer after China in the world. But the productivity per unit area is quite low as compared to other developed countries may be due to improper irrigation scheduling and inadequate supply of nutrients. This study investigated the influence of different levels of drip irrigation and nitrogen fertigation on nutritional quality of onion (Allium cepa L.) at Research Farm of CCS Haryana Agricultural University, Hisar in Rabi season of 2016-17 and 2017-18. The experiment comprised of sixteen treatment combinations involving four irrigation levels (drip irrigation at 60, 80, 100 and 120% CPE) and four nitrogen levels (75, 100, 125 and 150 kg/ha of nitrogen through fertigation) were laid out in split plot design with three replications. The nutrients content of onion were significantly influenced by different levels of drip irrigation and nitrogen fertigation. Nutritional quality of onion was significantly increased with the increasing levels of drip irrigation up to 100% CPE and nitrogen fertigation up to 125 kg/ha and then decreased with the further increasing levels of both irrigation and nitrogen fertigation in both years. The maximum nitrogen, phosphorus, potassium and sulfur content in onion bulb (2.42 and 2.51% N, 0.59 and 0.75% P, 2.63 and 2.70% K and 2.14 and 2.15% S, respectively) and leaf (1.37 and 1.37% N, 0.34 and 0.46% P, 2.02 and 1.73% K and 1.99 and 1.97% S, respectively) were recorded with the irrigation at 100% CPE in combination with 125 kg/ha nitrogen application through drip as compared to all other treatment combinations, while the minimum content of nitrogen, phosphorus, potassium and sulfur in onion bulb and leaf were recorded in treatment where the irrigation applied at 60% CPE in combination with 75 kg/ha nitrogen fertigation during both years of study.