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Carbon flows in the rhizosphere of ryegrass ( Lolium perenne )
Author(s) -
Domanski Grzegorz,
Kuzyakov Yakov,
Siniakina Svetlana V.,
Stahr Karl
Publication year - 2001
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/1522-2624(200108)164:4<381::aid-jpln381>3.0.co;2-5
Subject(s) - lolium perenne , rhizosphere , chemistry , soil respiration , agronomy , topsoil , sink (geography) , lolium , shoot , perennial plant , respiration , botany , soil water , poaceae , environmental science , soil science , biology , bacteria , genetics , cartography , geography
This study addresses the issue of carbon (C) fluxes through below ground pools within the rhizosphere of Lolium perenne using the 14 C pulse labeling. Lolium perenne was grown in plexiglas chambers on topsoil of a Haplic Luvisol under controled laboratory conditions. 14 C‐CO 2 efflux from soil, as well as 14 C content in shoots, roots, soil, dissolved organic C (DOC), and microbial biomass were monitored for 11 days after the pulsing. Lolium allocates about 48 % of the total assimilated 14 C below the soil surface, and roots were the primary sink for this C. Maximum 14 C content in the roots was observed 12 hours after the labeling and it amounts to 42 % of the assimilated C. Only half of the 14 C amount was found in the roots at the end of the monitoring period. The remainder was lost through root respiration, root decomposition, and rhizodeposition. Six hours after the 14 C pulse labeling soil accounted for 11 %, DOC for 1.1 %, and microbial biomass for 4.9 % of assimilated C. 14 C in CO 2 efflux from soil was detected as early as 30 minutes after labeling. The maximum 14 C‐CO 2 emission rate (0.34 % of assimilated 14 C h —1 ) from the soil occurred between four and twelve hours after labeling. From the 5 th day onwards, only insignificant changes in carbon partitioning occurred. The partitioning of assimilated C was completed after 5 days after assimilation. Based on the 14 C partitioning pattern, we calculated the amount of assimilated C during 47 days of growth at 256 g C m —2 . Of this amount 122 g C m —2 were allocated to below ground, shoots retained 64 g C m —2 , and 70 g C m —2 were lost from the shoots due to respiration. Roots were the main sink for below ground C and they accounted for 74 g C m —2 , while 28 g C m —2 were respired and 19 g C m —2 were found as residual 14 C in soil and microorganisms.