TY - JOUR

T1 - Rice rhizodeposition and carbon stabilisation in paddy soil are regulated via drying-rewetting cycles and nitrogen fertilisation

AU - Atere, Cornelius Talade

AU - Ge, Tida

AU - Zhu, Zhenke

AU - Tong, Chengli

AU - Jones, Davey L.

AU - Shibistova, Olga

AU - Guggenberger, Georg

AU - Wu, Jinshui

N1 - Funding information: This study was financially supported by the National Natural Science Foundation of China (41671292; 41371304), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB15020401), the Royal Society Newton Advanced Fellowship (NA150182), and the Recruitment Program of High-end Foreign Experts of the State Administration of Foreign Experts Affairs, awarded to Prof. Georg Guggenberger (GDT20164300013), Public Service Technology Center, Institute of Subtropical Agriculture, Chinese Academy of Sciences. Also, Mr. Cornelius T. Atere acknowledges the PhD training grant from the Nigerian Tertiary Education Trust Fund through the Obafemi Awolowo University, Ile-Ife, Nigeria.

PY - 2017/5/22

Y1 - 2017/5/22

N2 - This study aimed to better understand the stabilisation of rice rhizodeposition in paddy soil under the interactive effects of different N fertilisation and water regimes. We continuously labelled rice (‘Zhongzao 39’) with 13CO2 under a combination of different water regimes (alternating flooding-drying vs. continuous flooding) and N addition (250 mg N kg−1 urea vs. no addition) and then followed 13C incorporation into plant parts as well as soil fractions. N addition increased rice shoot biomass, rhizodeposition, and formation of 13C (new plant-derived C) in the rhizosphere soils under both water regimes. By day 22, the interaction of alternating flooding-drying and N fertilisation significantly increased shoot and root 13C allocations by 17 and 22%, respectively, over the continuous flooding condition. The interaction effect also led to a 46% higher 13C allocation to the rhizosphere soil. Alone, alternating water management increased 13C deposition by 43%. In contrast, N addition increased 13C deposition in rhizosphere soil macroaggregates under both water regimes, but did not foster macroaggregation itself. N treatment also increased 13C deposition and percentage in microaggregates and in the silt and clay-size fractions of the rhizosphere soil, a pattern that was higher under the alternating condition. Overall, our data indicated that combined N application and a flooding-drying treatment stabilised rhizodeposited C in soil more effectively than other tested conditions. Thus, they are desirable practices for improving rice cropping, capable of reducing cost, increasing water use efficiency, and raising C sequestration.

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

KW - C continuous labelling

KW - Carbon stabilisation

KW - Paddy soils

KW - Recent assimilates

KW - Rhizodeposition

KW - Root exudation

UR - http://www.scopus.com/inward/record.url?scp=85015858953&partnerID=8YFLogxK

U2 - 10.1007/s00374-017-1190-4

DO - 10.1007/s00374-017-1190-4

M3 - Article

AN - SCOPUS:85015858953

VL - 53

SP - 407

EP - 417

JO - Biology and fertility of soils

JF - Biology and fertility of soils

SN - 0178-2762

IS - 4

ER -