Use WUE Calculator when you need to compute intrinsic water use efficiency as net photosynthesis in micromoles per square metre per second divided by transpiration in millimoles per square metre per second. Enter Net photosynthesis and Transpiration using the definitions and units below so the result can be reproduced.

Net photosynthesis

A finite measured or assumed value greater than or equal to 0, expressed in µmol/m²/s.

Transpiration

A finite measured or assumed value, expressed in mmol/m²/s.

The published tool contract uses this rule: Compute intrinsic water use efficiency as net photosynthesis in micromoles per square metre per second divided by transpiration in millimoles per square metre per second.

Water use efficiency

The calculated water use efficiency in µmol/mmol.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small.

Retain the original Net photosynthesis and Transpiration values and their units alongside the result. Intrinsic WUE is useful when you instead need to compute intrinsic water use efficiency in micromoles per millimole as the net photosynthesis rate divided by the stomatal conductance. PNUE provides another view by helping you compute photosynthetic nitrogen use efficiency PNUE in micromoles per mole as the net photosynthesis rate divided by the leaf nitrogen per unit area.

• Intrinsic WUE

  Compute intrinsic water use efficiency in micromoles per millimole as the net photosynthesis rate divided by the stomatal conductance.

• PNUE

  Compute photosynthetic nitrogen use efficiency PNUE in micromoles per mole as the net photosynthesis rate divided by the leaf nitrogen per unit area.

• NUE Calculator

  Compute nitrogen use efficiency as grain yield in kilograms divided by nitrogen applied in kilograms.