Rice rhizodeposition and carbon stabilisation in paddy soil are regulated via drying-rewetting cycles and nitrogen fertilisation

摘要: This study aimed to better understand the stabilisation of rice rhizodeposition in paddy soil under interactive effects different N fertilisation and water regimes. We continuously labelled (‘Zhongzao 39’) with 13CO2 a combination regimes (alternating flooding-drying vs. continuous flooding) addition (250 mg N kg−1 urea no addition) then followed 13C incorporation into plant parts as well fractions. increased shoot biomass, rhizodeposition, formation (new plant-derived C) rhizosphere soils both By day 22, interaction alternating significantly root allocations by 17 22%, respectively, over flooding condition. The effect also led 46% higher allocation soil. Alone, management deposition 43%. In contrast, macroaggregates regimes, but did not foster macroaggregation itself. treatment percentage microaggregates silt clay-size fractions soil, pattern that was Overall, our data indicated combined application stabilised rhizodeposited C more effectively than other tested conditions. Thus, they are desirable practices for improving cropping, capable reducing cost, increasing use efficiency, raising sequestration.