Ecosystem level carbon and moisture fluxes from a high biomass fibre producing jute crop (Corchorus olitorius L): An eddy covariance-based analysis.

Jute (Corchorus olitorius L) is the second-largest natural fibre producing crop in the world and plays a key role in the rural economy of South Asia particularly India and Bangladesh. It has diverse use due to its long length, lusture, biodegradability, high tensile strength, heat resistance and bendability. Jute is also fast-growing high biomass crop and quantification of the carbon / moisture exchanges is need of the hour towards its sustainability. The study aims at quantitative estimation of the ecosystem level CO 2 and H 2 O exchanges at diurnal, daily, and seasonal scales from jute crop cultivated in the alluvial soil of the Gangetic delta under a tropical hot and moist sub-humid climate during the years 2021–23. An eddy covariance flux tower with suite of meteorological sensors were established at the jute growing farm to assess the high frequency ecosystem level exchanges of CO 2 , H 2 O and biometeorological parameters. Concurrent crop bio-physical parameters were also measured. The flux data were processed, quality checked, gap-filled and partitioned to construct seamless time-series of half-hourly fluxes for further analysis towards its dynamics, driving parameters, photosynthetic response and derived eco-physiological parameters. The half-hourly CO 2 fluxes exhibited significant variations across different growth stages of the jute crop, reaching peak values during the fibre development to maturity stages [mean Net Ecosystem CO 2 Exchange (NEE) ranging from −20 to −22 µmol m−2 s−1; mean Gross Primary Production (GPP) ranging from 25 to 30 µmol m−2 s−1; and mean Ecosystem Respiration (R eco) ranging from 8 to 10 µmol m−2 s−1]. Seasonal GPP values was found to be high (902–1038 gC m−2) with moderate NEE value of −150 to −223 gC m−2. Seasonal mean Ecosystem Water Use Efficiency (EWUE) was high (2.5–2.7 gC kg−1 H 2 O) compared to other C3 crop. The daily Crop Coefficient (K c) peaked at 1–1.2 during 90–110 Days After Sowing (DAS), indicative of high physiological activities. Despite relatively short crop duration but high biomass (peak Leaf Area Index, LAI ∼6 m2m−2), the jute crop proved to be a robust gross CO 2 sink. Due to the rapid growth, the jute crop allocates a significant portion of GPP as R eco (78–84 %), resulting in a relatively lower seasonal NEE. The high EWUE coupled with a net positive CO 2 exchange positioned jute as a potential climate-resilient crop. This study provides valuable insights into the ecosystem exchanges of the jute crop, which in turn contribute to the global carbon and moisture budget. [Display omitted] • Jute crop was strong gross CO 2 sink with peak influx of 25–30 μmol [CO 2 ] m−2 s−1. • Seasonal GPP and ET varied 902–1034gC m−2 and 346–380 mm respectively during 2021–23. • R eco /GPP was high 0.78–0.84, leading to lower seasonal NEE (-149 to - 223gC m−2). • Seasonal mean EWUE was high (2.5–2.7 gC kg−1 H 2 O), with maximum K c value of 1–1.2. [ABSTRACT FROM AUTHOR]