Plant-mediated effects of elevated CO2 and rice cultivars on soil carbon dynamics in a paddy soil.
Soil organic carbon (SOC) sequestration under elevated CO2 concentration (eCO2 ) is a function of carbon (C) input and C retention. Nitrogen (N) limitation in natural ecosystems can constrain plant responses to eCO2 and their subsequent effects on SOC, but the effect of eCO2 on SOC in N-enriched agroecosystems with cultivars highly responsive to eCO2 is largely unknown. We reported results of SOC dynamics from a field free-air CO2 enrichment experiment with two rice cultivars having distinct photosynthetic capacities under eCO2 . A reciprocal incubation experiment was further conducted to disentangle the effect of changes in litter quality and soil microbial community on litter-derived C dynamics. eCO2 significantly increased total SOC content, dissolved organic C and particulate organic C under the strongly responsive cultivar, likely due to enhanced organic C inputs originated from CO2 stimulation of shoot and root biomass. Increases in the residue C : N ratio and fungal abundance induced by eCO2 under the strongly responsive cultivar reduced C losses from decomposition, possibly through increasing microbial C use efficiency. Our findings suggest that applications of high-yielding cultivars may substantially enhance soil C sequestration in rice paddies under future CO2 scenarios.
['Hu|Zhengkun|Z|0000-0002-5697-6518', 'Chen|Xiaoyun|X|', 'Yao|Junneng|J|', 'Zhu|Chunwu|C|', 'Zhu|Jianguo|J|', 'Liu|Manqiang|M|0000-0001-6654-7795']
D002244:Carbon D002245:Carbon Dioxide D009584:Nitrogen D012275:Oryza D012987:Soil
rice soil organic carbon microbial community carbon (C) use efficiency cultivar varieties global change plant productivity