Use Phosphorus Nutrition Index when you need to compute the phosphorus nutrition index as actual phosphorus percent divided by critical phosphorus percent; values below one indicate phosphorus dilution. Enter Actual phosphorus and Critical phosphorus using the definitions and units below so the result can be reproduced.

Actual phosphorus

Actual plant phosphorus concentration as a percentage; must not be negative.

Critical phosphorus

Critical phosphorus concentration as a percentage; must be greater than zero.

The published tool contract uses this rule: Compute the phosphorus nutrition index as actual phosphorus percent divided by critical phosphorus percent; values below one indicate phosphorus dilution.

Phosphorus nutrition index

Phosphorus nutrition index; below 1 indicates deficiency and above 1 indicates sufficiency.

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 Actual phosphorus and Critical phosphorus 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. Potassium Nutrition Index provides another view by helping you compute the potassium nutrition index as actual potassium percent divided by critical potassium percent; values below one indicate potassium dilution.

• Nitrogen Nutrition Index

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

• Potassium Nutrition Index

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

• PUE Calculator

  Compute phosphorus use efficiency as yield in kilograms divided by phosphorus applied in kilograms.