施氮和水分管理对光合碳在土壤-水稻系统间分配的量化研究

发布时间：2018-05-16 16:19

本文选题：水稻 + 根际沉积　；参考：《环境科学》2017年03期

【摘要】：施肥和水分管理是影响水稻生长的两个关键因素,探讨水肥耦合条件下光合碳在"水稻-土壤"系统输入与分配动态,对深入解析稻田土壤碳循环具有重要意义.本研究通过盆栽试验,选用籼性常规水稻品种(中早39),采用13C-CO_2连续标记技术,量化研究施氮和水分管理对光合碳在"水稻-土壤"系统中分配的影响.结果表明:施氮增加了水稻地上部干物质重和碳、氮含量,却显著降低了水稻根冠比;干湿交替使施氮条件下的水稻地上部全碳、全氮含量较持续淹水处理分别提高了22%和33%,根系中全碳、全氮含量分别提高了36%、44%,这表明施氮有利于水稻地上部生长,而干湿交替显著促进了水稻根系的生长.施氮显著增加水稻地上部13C含量,与不施氮处理相比增加了32%~83%;施氮使光合碳在水稻地上部的回收率增加6%~32%,在根系的回收率减少18%~59%.水分管理对13C分配的影响表现为:连续标记22 d后,在施氮条件下,干湿交替使水稻地上部、根系13C量均有一定量的增加;不施氮条件下,干湿交替与持续淹水处理相比,地上部13C量减少10.3mg·pot-1,回收率降低了11%~12%;根系13C量增加1.9 mg·pot-1,回收率提高了24%~57%.施氮和干湿交替都显著增加了13C在根际土壤中的累积与回收率.因此,施氮增加了光合碳在土壤-水稻系统中的累积,但降低了光合碳在根系中的分配,干湿交替比持续淹水更利于光合碳向土壤中的传输与累积,水肥耦合管理显著调控了光合碳的传输与分配.该研究进一步量化了水肥管理条件下水稻光合碳的分配及其在土壤有机碳库中的传输特征,为稻田水肥管理、水稻土有机质积累持续机制提供了理论依据和数据支撑.
[Abstract]:Fertilization and water management are two key factors affecting rice growth. It is very important to study the input and distribution dynamics of photosynthetic carbon in "rice-soil" system under the coupling of water and fertilizer. In this study, the effects of nitrogen application and water management on the distribution of photosynthetic carbon in "rice-soil" system were quantitatively studied by using 13C-CO_2 continuous marker technique and pot experiment. The results showed that nitrogen application increased the dry matter weight, carbon and nitrogen content, but significantly decreased the root / shoot ratio of rice, and the dry and wet alternately increased the total carbon content in the aboveground part of rice under the condition of nitrogen application. Total nitrogen content increased by 22% and 33%, total carbon and total nitrogen content in root increased by 36% and 44%, respectively, compared with continuous flooding treatment, which indicated that nitrogen application was beneficial to the growth of rice shoot, while dry and wet alternation significantly promoted the growth of rice root system. Nitrogen application significantly increased the content of 13C in the aboveground part of rice, and increased the yield of photosynthetic carbon in the aboveground part of rice by 32 ~ 83% compared with that of the treatment without nitrogen application, and increased the recovery rate of photosynthetic carbon in the aboveground part of rice by 6 ~ 32 ~ 32%, and decreased the recovery rate in the root system by 18 ~ 59 ~ 59%. The effects of water management on 13C distribution were as follows: under the condition of nitrogen application, dry and wet alternately increased the root 13C content in the shoot of rice after 22 days of continuous labeling, and under the condition of no nitrogen application, the dry and wet alternating treatments were compared with the continuous flooding treatment. The amount of 13C in aboveground decreased 10.3mg pot-1, and the recovery rate decreased by 110.122.The root 13C content increased 1.9 mg pot-1, and the recovery rate increased 2457.The amount of 13C in root increased by 1.9mg pot-1, and the recovery increased by 24mg. The accumulation and recovery of 13C in rhizosphere soil were significantly increased by nitrogen application and dry wet alternating. Therefore, nitrogen application increased the accumulation of photosynthetic carbon in soil-rice system, but decreased the distribution of photosynthetic carbon in root system. Water and fertilizer coupling management significantly regulated the transport and distribution of photosynthetic carbon. This study further quantified the distribution of photosynthetic carbon in rice and its transport characteristics in soil organic carbon pool under the condition of water and fertilizer management, which provided theoretical basis and data support for the management of paddy water and fertilizer and the sustainable mechanism of accumulation of organic matter in paddy soil.
【作者单位】：中国科学院亚热带农业生态研究所亚热带农业生态重点实验室;中国科学院大学资源与环境学院;湖北大学资源环境学院;
【基金】：国家自然科学基金项目(41301276,41501321) 政府间国际科技创新合作重点专项项目(S2016G0053)
【分类号】：S511;S154.4

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