Effect of pulse irrigation (Drip) through different irrigation levels on soil moisture distribution pattern and yield parameters of white onion (Allium cepa L)

Abstract

The field experiment was conducted during rabi seasons from 12th November, 2014 to 26th April, 2015 and 23rd November, 2015 to 4th May 2016, on sandy clay loam soil at Instructional Farm of Department of Irrigation and Drainage Engineering, College of Agricultural Engineering and Technology, Dr. BSKKV, Dapoli, India (latitude 170 45’ N and longitude 730 10’ E and altitude of 250 m). The experiment was arranged in twelve treatment combinations with strip plot design as horizontal factor (main treatment) one continuous irrigation (P1), two pulses (P2), three pulses (P3) and four pulses (P4), while vertical factor (sub treatment) as irrigation levels viz. I1 (0.80 ETC), I2 (1.0 ETC) and I3 (1.20 ETC) treatments. The soil moisture content at 2hr after irrigation in I2P4 treatment combination contours attained semicircular shape. The field capacity moisture (26.0 %) was discerned at 2hr after irrigation in I2P4 treatment combination at 30 cm distance from the emitter across the lateral at 15 cm depth, which might have provided favorable soil-water-air plant relationship during critical growth stages of onion between two emitters at 30 cm distance across the lateral. It was contemplated that average soil moisture content across 30 cm distance from the emitter at 2hr before and after 2hr irrigation at 15 cm and 30 cm depth in the treatment combination I2P4 provided favorable soil-water-air plant relationship in the entire root zone. The interaction effect revealed that highest mean polar diameter (63.88 mm), geometric mean diameter (59.51 mm), equatorial diameter (63.16 mm), average bulb weight (112.05 g) and yield (38.52 t.ha-1) of white onion was found in treatment combination I2P4 followed by I3P4.