LAI

The leaf area index (LAI) measures the leaf area per area ground. The leaf area index thus is a measure of how efficiently the plants can capture the incoming light. Depending on the architecture, thickness and other properties of the leaf, almost all light (i.e. energy) is intercepted at an LAI of 3 (e.g. maize) to 5.

The LAI is closely related to the fpar computations based on Lambert and Beer’s law

but this may not be suitable for all crops. It works well for wheat, but not for maize.
For maize, which basically does not ever reach LAI values of >5, a linear relationship of LAI and fpar has been described,

For the phenology of crops, a maximum LAI (LAImax) is prescribed, currently at country level, which can vary between 7 (5 for maize) and 1.

See more details in the calibration of agricultural production intensity. The current calibration of agricultural production intensity uses a combined calibration of LAImax (plant performance, density), alphaA (homogeneity of the stand) and harvest index (high-yielding varieties in intensely managed stands only).

See also

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