Carbon input and allocation by rice into paddy soils: A review

Publication date: Available online 3 March 2019Source: Soil Biology and BiochemistryAuthor(s): Yalong Liu, Tida Ge, Zhenke Zhu, Shoulong Liu, Yu Luo, Yong Li, Ping Wang, Olga Gavrichkova, Xingliang Xu, Jingkuan Wang, Jinshui Wu, Georg Guggenberger, Yakov KuzyakovAbstractKnowledge 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 14C or 13C (13/14C), while rice rhizodeposition and C input in paddy soils have not been comprehensively evaluated. Here, we analyzed the results of 13/14C 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, 13/14C 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...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research