This dataset includes high-resolution (~5 m) gridded estimates of aboveground biomass (AGB), aboveground necromass (AGN), and aboveground net primary productivity (ANPP) for herbaceous vegetation in the Atchafalaya and Terrebonne basins of the Mississippi River Delta in coastal Louisiana, USA, for the fall and spring seasons of 2021. AGB, AGN and ANPP were estimated from Bidirectional Reflectance Distribution Function (BRDF)-adjusted surface reflectance products from NASA's Airborne Visible Infrared Imaging Spectrometer - Next Generation (AVIRIS-NG) acquired over the study area in April and August 2021. The BRDF-adjusted reflectance was derived from hemispherical-directional surface reflectance with atmospheric correction. Local pixel reflectance spectra coincident with herbaceous vegetation AGB field samples from both Spring and Fall 2021 collections were used to generate a machine learning-based regression model to estimate AGB. This model was then scaled to the AVIRIS-NG mosaic imagery in accordance with vegetation type to map herbaceous AGB across the Atchafalaya and Terrebonne Basins. The AGN field data, separated from the AGB samples, were also used in conjunction with AVIRIS-NG-derived fractional coverage to derive AGN maps again employing machine learning. The AGB and AGN products were used together to map ANPP across the Atchafalaya and Terrebonne Basins. The data are provided in cloud optimized GeoTIFF (COG) format. This Version 3 dataset replaces the files provided in Version 2.