Research: Onion irrigation trials
In 2004, trials were conducted using a drip irrigation system to investigate the effect of irrigation frequency (how often a crop is watered) on the quality of onions.1
Soil moisture levels were recorded to determine the length of the watering time on each interval day.
Different irrigation frequencies at 2 day, 4 day and 7 day intervals were used to find that, among three different varieties of onions, the highest marketable yields were recorded from crops exposed to 2 day interval watering. This frequency of watering also provided the biggest bulb, with an average of 60% of bulbs larger than 75 mm in diameter.
When water is limited, however, this research showed that 4-day watering intervals provided the most product for the least amount of water, with 11.6 tonnes of onions produced per megalitre of water. Four-day watering intervals make the most efficient use of water available. By comparison, the 2 day watering interval produced 10.4 tonnes of onions per megalitre of water used, and the 7 day watering interval produced 10.6 tonnes of onions per megalitre.
This research is valuable in that onion farmers now know with some certainty that adopting less frequent watering can be profitable, provided soil moisture levels are monitored and that drip lines provide even water distribution.
Return to Research
Return to Horticulture research - making better use of water
1Hickey, M., Hoogers, R., Singh, R., Christen, E., Henderson, C., Ashcroft, B., Top, T., O’Donnell, D., Sylvia, S., & Hoffmann, H. (2006) Maximising returns from water in the Australian vegetable industry: national report. Horticulture Australia Limited facilitated project (HAL) published by NSW Department of Primary Industries.