Carbon flow through energycane agroecosystems established post‐intensive agriculture. Issue 10 (11th August 2020)

• Record Type: Journal Article
• Authors: Crow, Susan E.; Wells, Jon M.; Sierra, Carlos A.; Youkhana, Adel H.; Ogoshi, Richard M.; Richardson, Daniel; Tallamy Glazer, Christine; Meki, Manyowa N.; Kiniry, James R.
• Is Part Of: Global change biology. Volume 12:Issue 10(2020)
• Page Start: 806
• Page End: 817
• Publication Date: 2020-08-11
• Subjects: agroecosystem -- bioenergy -- carbon -- climate change energycane -- land degradation -- tropical perennial grasses; Biomass energy -- Periodicals; Biomass energy -- Environmental aspects -- Periodicals; Energy crops -- Periodicals; 662.88
• DOI: 10.1111/gcbb.12713
• Languages: English
• ISSNs: 1757-1693

Abstract

Abstract: As part of an integrated energy and climate system, biomass production for bioenergy based on the tropical perennial C4 grass energycane can both offset fossil fuels and store soil carbon (C). We measured energycane yields, root biomass, soil C pools, and soil C stocks in a 4 year field trial and modeled C flow from plants to soils in the surface layer of no‐till energycane planted after more than a century of intensive sugarcane agriculture. Aboveground yields ranged from 16.7 to 19.0 Mg C/ha over the 4 year trial. Although total C stocks did not significantly differ in the surface layer (approx. 0–20 cm) during the study, C in free and occluded light fractions decreased, whereas C in the mineral‐rich dense fraction increased over 4 years. Belowground system inputs, estimated from measurements and informed by convergence in the final soil fraction model, were set to 2.5 Mg C ha −1 year −1 . With this input value, we estimated that surface soils retained photosynthetically fixed C predominantly within the mineral‐associated organic matter pool for a mean and median transit time of 177 and 110 years, respectively. Although we did not model C flow to deep soil layers (approx. 0–100 cm), observed C accumulation (11.4 Mg C ha −1 year −1 ) and root growth down to 120 cm suggest that soil processes and resulting C sequestration at the surface are likely to persist deeper into the soil profile. Energycane, as a strong candidate for climate change mitigation and land degradation remediation, showed high biomass yields and allocation of resources to roots, with sequestered soil C expected to persist for over a century. Abstract : As part of an integrated energy and climate system, biomass production for bioenergy based on the tropical perennial C4 grass energycane can both offset fossil fuels and store soil carbon (C). Energycane cultivated on degraded lands showed high yield and allocation of resources to roots, with sequestered soil C expected to persist for over a century thereby amplifying the climate benefits of the tropical agroecosystem.