tWhen crops senescence, leaves remain until they fall off or are harvested. Hence, leaf area index (LAI)stays high even when chlorophyll content degrades to zero. Current LAI approaches from remote sensingtechniques are not optimized for estimating LAI of senescent vegetation. In this paper a two-step approachhas been proposed to realize simultaneous LAI mapping over green and senescent croplands. The firststep separates green from brown LAI by means of a newly proposed index, ‘Green Brown Vegetation Index(GBVI)’. This index exploits two shortwave infrared (SWIR) spectral bands centred at 2100 and 2000 nm,which fall right in the dry matter absorption regions, thereby providing positive values for senescent veg-etation and negative for green vegetation. The second step involves applying linear regression functionsbased on optimized vegetation indices to estimate green and brown LAI estimation respectively. Whilethe green LAI index uses a band in the red and a band in the red-edge, the brown LAI index uses bandslocated in the same spectral region as GBVI, i.e. an absorption band located in the region of maximumabsorption of cellulose and lignin at 2154 nm, and a reference band at 1635 nm where the absorption ofboth water and dry matter is low. The two-step approach was applied to a HyMap image acquired overan agroecosystem at the agricultural site Barrax, Spain.