TY - JOUR

T1 - Carbon input and allocation by rice into paddy soils

T2 - A review

AU - Liu, Yalong

AU - Ge, Tida

AU - Zhu, Zhenke

AU - Liu, Shoulong

AU - Luo, Yu

AU - Li, Yong

AU - Wang, Ping

AU - Gavrichkova, Olga

AU - Xu, Xingliang

AU - Wang, Jingkuan

AU - Wu, Jinshui

AU - Guggenberger, Georg

AU - Kuzyakov, Yakov

N1 - Funding information: The authors thank the anonymous reviewers for their criticisms and insightful suggestions for improvement of the manuscript. This work was supported by the National Key Research and Development Program ( 2016YFE0101100 ), the Australia-China Joint Research Centre – Healthy Soils for Sustainable Food Production and Environmental Quality ( ACSRF48165 ), the National Natural Science Foundation of China ( 41671253 ; 41601305 ; 41807089 ; 41761134095 ), China Postdoctoral Science Foundation ( 2017M612573 ) and the International Postdoctoral Exchange Fellowship Program for 2018 ( 20180017 ), Hunan Province Base for Scientific and Technological Innovation Cooperation ( 2018WK4012 ) Chinese Academy of Sciences President's International Fellowship Initiative to Georg Guggenberger ( 2018VCA0031 ) and Youth Innovation Team Project of ISA, CAS ( 2017QNCXTD_GTD ). We especially thank the Public Service Technology Center, Institute of Subtropical Agriculture, Chinese Academy of Sciences for technical assistance. The publication was prepared with the support of the “RUDN University program 5-100.” We thank Soil Science Consulting for help with preparation of the paper.

PY - 2019/6

Y1 - 2019/6

N2 - Knowledge of belowground C input by rice plants and its fate is essential for managing C cycling and sequestration in paddy soils. Previous reviews have summarized C input and the pathways of root-derived C in upland soils by labeling with 14 C or 13 C ( 13/14 C), while rice rhizodeposition and C input in paddy soils have not been comprehensively evaluated. Here, we analyzed the results of 13/14 C pulse and continuous labeling studies using 112 datasets from 13 articles on the allocation and pathways of photosynthesized C by rice plants to assess C input, budget, and amount stabilized in paddy soils. Overall, 13/14 C partitioning estimated by continuous labeling was 72% to the shoots, 17% to the roots, 10% to the soil, and 1.3% was recovered in microbial biomass. Pulse-labeling studies showed a similar C partitioning: 79%, 13%, 5.5%, and 2.1%, respectively. The total belowground C input estimated based on continuous labeling was 1.6 Mg ha −1 after one rice season, of which rhizodeposition accounted for 0.4 Mg C ha −1 . Carbon input assessed by pulse labeling was slightly lower (total belowground C input, 1.4 Mg ha −1 ; rhizodeposition, 0.3 Mg C ha −1 ; 14 days after labeling). Rice C input after one cropping season was lower than that by upland plants (cereals and grasses, 1.5–2.2 Mg ha −1 ). In contrast to upland crops, most paddy systems are located in the subtropics and tropics and have two or three cropping seasons per year. We conclude that (1) pulse labeling underestimates the total belowground C input by 15%, compared with that by continuous labeling, and (2) rhizodeposition of rice accounts for approximately 26% of the total belowground C input, regardless of the labeling method used. Based on allocation ratios, we suggest a simple and practical approach for assessment of the gross C input by rice into the soil, for partitioning among pools and for long-term C stabilization in paddies.

AB - Knowledge of belowground C input by rice plants and its fate is essential for managing C cycling and sequestration in paddy soils. Previous reviews have summarized C input and the pathways of root-derived C in upland soils by labeling with 14 C or 13 C ( 13/14 C), while rice rhizodeposition and C input in paddy soils have not been comprehensively evaluated. Here, we analyzed the results of 13/14 C pulse and continuous labeling studies using 112 datasets from 13 articles on the allocation and pathways of photosynthesized C by rice plants to assess C input, budget, and amount stabilized in paddy soils. Overall, 13/14 C partitioning estimated by continuous labeling was 72% to the shoots, 17% to the roots, 10% to the soil, and 1.3% was recovered in microbial biomass. Pulse-labeling studies showed a similar C partitioning: 79%, 13%, 5.5%, and 2.1%, respectively. The total belowground C input estimated based on continuous labeling was 1.6 Mg ha −1 after one rice season, of which rhizodeposition accounted for 0.4 Mg C ha −1 . Carbon input assessed by pulse labeling was slightly lower (total belowground C input, 1.4 Mg ha −1 ; rhizodeposition, 0.3 Mg C ha −1 ; 14 days after labeling). Rice C input after one cropping season was lower than that by upland plants (cereals and grasses, 1.5–2.2 Mg ha −1 ). In contrast to upland crops, most paddy systems are located in the subtropics and tropics and have two or three cropping seasons per year. We conclude that (1) pulse labeling underestimates the total belowground C input by 15%, compared with that by continuous labeling, and (2) rhizodeposition of rice accounts for approximately 26% of the total belowground C input, regardless of the labeling method used. Based on allocation ratios, we suggest a simple and practical approach for assessment of the gross C input by rice into the soil, for partitioning among pools and for long-term C stabilization in paddies.

KW - Belowground assimilate allocation

KW - Carbon cycling

KW - Carbon isotope labeling

KW - Carbon sequestration

KW - Rhizodeposition and root exudation

KW - Rice production

UR - http://www.scopus.com/inward/record.url?scp=85062676396&partnerID=8YFLogxK

U2 - 10.1016/j.soilbio.2019.02.019

DO - 10.1016/j.soilbio.2019.02.019

M3 - Article

AN - SCOPUS:85062676396

VL - 133

SP - 97

EP - 107

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

SN - 0038-0717

ER -