What’s the most efficient irrigated wheat system?
Irrigation seasons tend to start off with lower allocations and market water options making it a difficult decision for farmers to plan their winter crop irrigation strategies.
The Finley Discussion Groups have been benchmarking irrigation strategies to assist farmers obtain the best efficiencies from their water use.
The results from 2014, 2015 and 2017 are discussed.
The results showed spray and flood spring water use above 2ML/ha had the highest water efficiencies over the three years.
In 2017 each megalitre applied produced 1.8-1.9 tonnes wheat which is a high efficiency.
In 2015 the spray efficiency was 1.9t/ML but the flood was much lower at 1.3t/ML because of the very hot day in early October affecting higher biomass crops.
Yields for these systems over the three years have ranged from 6.1 to 7.4t/ha.
Last season the spray yielded 6.8t/ha and the flood 7.4t/ha.
The 1.5 to 2ML/ha system of two spring irrigations had efficiencies of 1.3t/ML in 2017 to 1.9t/ML in 2014 with yield range 5.4 to 6.2t/ha.
Last season the system yielded 5.7t/ha.
The lower than 1.5ML/ha system of 1-2 spring irrigations had efficiencies of 1t/ML in 2014,1.6t/ML in 2015 and 1.3t/ML last season.
In 2014 the yield was 4.2t/ha, 2015 4.8t/ha and in 2017 5t/ha.
The pre-watering and spring watering system had the lowest efficiencies of 0.7 to 1.3t/ML with 1t/ML last season. Yield in 2014 was 4.9t/ha, 5.9t/ha in 2015 and 6.2t/ha last season.
John Lacy (pictured) is an independent agriculture consultant based in Finley.