title: [Input and distribution of rice photosynthesized carbon in the tillering stage under different nitrogen application following continuous 13C labeling].
abstract: The input of rice-photosynthesized carbon (C) into soil plays an important role in soil C cycling. A 13C-labelled microcosm experiment was carried out to quantify the input of photosynthesized C into soil C pools in a rice-soil system during the tillering stage. Growing rice (Oryza sativa L. ) was continuously fed with 13C-labeled CO, ( C-CO, ) in a closed chamber without nitrogen (NO), or at different rates of N supply (N10,N20, N30, N40 or N60). The results showed that there were significant differences in rice shoot (1.58 g plot-1 to 4.35 g plot-1) and root (1.05 g plot-1 to 2.44 g plot-1 ) biomass among the N treatments after labeling for 18 days. The amounts of 13C in shoots and roots ranged from 44.0 g plot-1 to 157.6 g.plot-1 and 8.3 g.plot-1 to 49.4 g.plot-1, respectively, and generally followed the order of N60 > N40 > N20 > N10 > NO. The contents of rice-planted 13C-SOC, 13C-DOC and 13C-MBC in soil carbon pool were much higher than those of CK (without rice and N supply). The amount of 13C-SOC ranged from 11.1 g plot - to 23.7 gplot-1 , depending on the rate of N addition, accounting for 10.2% -18. 1% of the net assimilation. The amounts of 13C-DOC and 13C-MBC ranged from 4. 82-14.51 microg kg-1 and 526. 1-1 478.8 microg kg-1 , both depending on the N application rate. In addition, at 18-day of labeling, the 13C-SOC, 13C-DOC and 13C-MBC concentration was positively correlated with the rice biomass. Therefore, our results suggest that paddy soils can probably sequester more C from the atmosphere if more photosynthesized C enters the soils and N application can stimulate C rhizodeposition during the tillering stage.
authors: Li-Min
authors: LM
authors: Tan
authors: Hao
authors: H
authors: Wu
authors: Hui
authors: H
authors: Li
authors: Ping
authors: P
authors: Zhou
authors: Ke-Lin
authors: KL
authors: Li
authors: Jiu-Rong
authors: JR
authors: Wang
authors: Ti-Da
authors: TD
authors: Ge
authors: Hong-Zhao
authors: HZ
authors: Yuan
authors: Jin-Shui
authors: JS
authors: Wu
mesh_terms: D002244:Carbon / Q000032:analysis*; D057486:Carbon Cycle; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring; D005308:Fertilizers; D009584:Nitrogen / Q000737:chemistry*; D012275:Oryza / Q000254:growth & development*; D010788:Photosynthesis; D018517:Plant Roots / Q000737:chemistry; D012987:Soil / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D005308:Fertilizers; D012987:Soil; D002244:Carbon; D009584:Nitrogen