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Grain · Yield & water · Efficiency

Water use efficiency

19 kg/ha/mm wheat

Grain grown per millimetre of growing-season rainfall (less an evaporation allowance) — the truest single measure of how well a season was converted into grain, independent of how wet or dry it was. Barley is inherently more water-efficient than wheat.

Worked example · kg grain/ha per mm · higher better
French-Schultz 22 19 23 20 Wheat Barley Farm avg
kg grain/ha per mm · higher better
The benchmark

The French-Schultz benchmark puts water-limited wheat at about 20 kg grain/ha per mm of growing-season water; modern varieties and agronomy push the achievable ceiling to 22–24 kg/ha/mm.

GRDC Water Use Efficiency ↗
What it signals

A gap between your WUE and the French-Schultz line is the yield you left in the paddock to weeds, poor nutrition, disease or a late sowing — the levers you can actually pull, as opposed to the rain you can’t.

Data required to calculate
Grain yieldkg/haGrowing-season rainfallmmEvaporation allowancemm

Silo pulls each of these from the sources the operation already uses, and keeps the figure current automatically.

How to improve it
01

Sow on time into stored moisture to maximise transpiration, not evaporation.

02

Remove the yield-robbers — weeds, root disease and nutrient shortfalls.

03

Retain stubble to cut evaporation and hold summer fallow moisture.

Questions & answers

What is water use efficiency?

Grain grown per millimetre of growing-season rainfall (less an evaporation allowance) — the truest single measure of how well a season was converted into grain, independent of how wet or dry it was. Barley is inherently more water-efficient than wheat.

What data do you need to calculate water use efficiency?

You need: Grain yield (kg/ha), Growing-season rainfall (mm), Evaporation allowance (mm). Silo pulls each of these from the sources the operation already uses and keeps the figure current automatically.

What is a good water use efficiency benchmark?

The French-Schultz benchmark puts water-limited wheat at about 20 kg grain/ha per mm of growing-season water; modern varieties and agronomy push the achievable ceiling to 22–24 kg/ha/mm.

How do you improve water use efficiency?

Sow on time into stored moisture to maximise transpiration, not evaporation. Remove the yield-robbers — weeds, root disease and nutrient shortfalls. Retain stubble to cut evaporation and hold summer fallow moisture.

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