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Title: The soil pore structure encountered by roots affects plant‐derived carbon inputs and fate
Summary Plant roots are the main supplier of carbon (C) to the soil, the largest terrestrial C reservoir. Soil pore structure drives root growth, yet how it affects belowground C inputs remains a critical knowledge gap. By combining X‐ray computed tomography with 14 C plant labelling, we identified root–soil contact as a previously unrecognised influence on belowground plant C allocations and on the fate of plant‐derived C in the soil. Greater contact with the surrounding soil, when the growing root encounters a pore structure dominated by small (< 40 μm Ø) pores, results in strong rhizodeposition but in areas of high microbial activity. The root system of Rudbeckia hirta revealed high plasticity and thus maintained high root–soil contact. This led to greater C inputs across a wide range of soil pore structures. The root–soil contact Panicum virgatum , a promising bioenergy feedstock crop, was sensitive to the encountered structure. Pore structure built by a polyculture, for example, restored prairie, can be particularly effective in promoting lateral root growth and thus root–soil contact and associated C benefits. The findings suggest that the interaction of pore structure with roots is an important, previously unrecognised, stimulus of soil C gains.  more » « less
Award ID(s):
1832042 2224712
NSF-PAR ID:
10464306
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
New Phytologist
Volume:
240
Issue:
2
ISSN:
0028-646X
Page Range / eLocation ID:
515 to 528
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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