Use Nitrogen Balance Index when you need to compute grain protein yield per kilogram of applied nitrogen, converting grain protein percentage to a decimal mass fraction before dividing by nitrogen input. Enter Grain protein, Nitrogen applied, and Yield using the definitions and units below so the result can be reproduced.

Grain protein

Grain protein percentage; must not be negative.

Nitrogen applied

Nitrogen applied in kilograms; must be greater than zero.

Yield

Grain yield in kilograms.

The published tool contract uses this rule: Compute grain protein yield per kilogram of applied nitrogen, converting grain protein percentage to a decimal mass fraction before dividing by nitrogen input.

Nitrogen balance index

Kilograms of grain protein per kilogram of applied nitrogen.

A ratio or percentage can conceal the scale of its numerator and denominator and becomes sensitive to measurement error when the denominator is small. Grain protein must remain between 0 and 100.

Retain the original Grain protein, Nitrogen applied, and Yield values and their units alongside the result. Nitrogen Nutrition Index is useful when you instead need to compute the nitrogen nutrition index as actual nitrogen percent divided by critical nitrogen percent; values below one indicate nitrogen dilution. NUE Calculator provides another view by helping you compute nitrogen use efficiency as grain yield in kilograms divided by nitrogen applied in kilograms.

• Nitrogen Nutrition Index

  Compute the nitrogen nutrition index as actual nitrogen percent divided by critical nitrogen percent; values below one indicate nitrogen dilution.

• NUE Calculator

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

• BrdU Labeling Index

  Compute the BrdU labeling index as the percentage of BrdU-labeled nuclei.