Rice rhizodeposition and carbon stabilisation in paddy soil are regulated via drying-rewetting cycles and nitrogen fertilisation
Rice rhizodeposition and carbon stabilisation in paddy soil are regulated via drying-rewetting cycles and nitrogen fertilisation
复制标题
通过干燥-再湿润循环和施氮来调节稻田土壤中的水稻根际沉积和碳稳定
DOI：
10.1007/s00374-017-1190-4
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发表时间：
2017-05-01
影响因子：
6.5
通讯作者：
Wu, Jinshui
中科院分区：
文献类型：
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作者：
Atere, Cornelius Talade;Ge, Tida;Wu, Jinshui
本研究旨在更好地了解不同氮肥和水分制度交互作用下水稻根系沉积在水稻土中的稳定性。我们连续用(CO2)-C-13标记水稻（‘中稻39’），并在不同的水处理（交替淹水干燥vs连续淹水）和N添加（250 mg N kg（-1）尿素vs不添加）的组合下进行标记，然后将C-13掺入植物部分和土壤组分中。在两种水分条件下，施氮增加了水稻芽生物量、根际沉积和根际土壤中碳-13（新植物源碳）的形成。到第22天，与连续淹水条件相比，淹干交替和施氮互作显著提高了地上部和根系的碳-13分配，分别提高了17%和22%。互作效应还导致根际土壤碳-13分配增加46%。单是交替水管理就使碳-13沉积增加了43%。相反，在两种水分条件下，N的添加增加了根际土壤大团聚体中的C-13沉积，但本身没有促进大团聚体。氮处理还增加了根际土壤微团聚体、粉土和粘土组分中C-13的沉积和百分比，且在交替处理下更高。总体而言，我们的数据表明，施氮和洪水干燥联合处理比其他试验条件更有效地稳定了土壤中根际沉积的碳。因此，它们是改善水稻种植的理想做法，能够降低成本，提高水利用效率，提高碳固存。
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 (CO2)-C-13 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 C-13 incorporation into plant parts as well as soil fractions. N addition increased rice shoot biomass, rhizodeposition, and formation of C-13 (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 C-13 allocations by 17 and 22%, respectively, over the continuous flooding condition. The interaction effect also led to a 46% higher C-13 allocation to the rhizosphere soil. Alone, alternating water management increased C-13 deposition by 43%. In contrast, N addition increased C-13 deposition in rhizosphere soil macroaggregates under both water regimes, but did not foster macroaggregation itself. N treatment also increased C-13 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.