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中国农学通报 ›› 2017, Vol. 33 ›› Issue (1): 89-95.doi: 10.11924/j.issn.1000-6850.casb16060060

所属专题: 玉米

• 资源 环境 生态 土壤 气象 • 上一篇    下一篇

不同施氮水平下玉米农田土壤呼吸及碳平衡研究

熊简安然,张丛志,张佳宝,陈金林   

  1. 南京林业大学林学院,中国科学院南京土壤研究所,中国科学院南京土壤研究所,南京林业大学林学院
  • 收稿日期:2016-06-12 修回日期:2016-12-23 接受日期:2016-08-10 出版日期:2017-02-04 发布日期:2017-02-04
  • 通讯作者: 陈金林
  • 基金资助:
    国家自然科学基金委员会面上基金项目“秸秆还田和根系及其分泌物对潮土有机质积累和团聚体形成的协同作用机制”(41471182);中国 科学院战略性先导科技专项课题“土壤-作物系统高效利用氮磷的综合调控原理与技术集成”(XDB15030302);国家重点研发计划课题“秸秆还田养 分高效利用机理”(2016YFD0200107)。

Soil Respiration and Carbon Balance Under Different Nitrogen Application Levels in Maize Field

  • Received:2016-06-12 Revised:2016-12-23 Accepted:2016-08-10 Online:2017-02-04 Published:2017-02-04

摘要: 氮肥施用是影响农田碳源汇的关键因素,定量评估不同氮肥施用下农田土壤呼吸和碳平衡对于保障土壤地力和调控生态环境碳排放均具有重要意义。本研究利用野外管栽模拟和田间定位试验,研究不同施氮水平下玉米生长季农田的土壤呼吸速率动态变化,并在此基础上解析了农田生态系统的碳平衡状况。结果表明,不同氮肥水平下农田玉米生物量(地上部和根系)固定有机碳量为5660.71~8106.00 kg C/hm2;土壤呼吸释放的总碳量为9209.04~16510.40 kg C/hm2之间,裸地微生物呼吸释放的总碳量为2827.36~6951.68 kg C/hm2之间。玉米生长季中根系呼吸量对土壤总呼吸量的贡献分别为57.9%~69.3%之间。在玉米种植条件下,不同生育期的碳平衡发生了显著变化。在拔节期,不同处理下净生态系统生产力(NEP)均为负值,表现为大气CO2的源;在玉米抽雄期和成熟期,不同处理下NEP均为正值,表现为大气CO2的汇,不同施肥水平下碳汇的程度不同。从不同施氮水平来看,NEP值在不同的生育期随施氮水平增加的变化趋势不同,在拔节期提高氮肥的施用水平,NEP值显著低于不施氮处理,在抽雄期和成熟期提高氮肥的施用水平,NEP值高于不施氮处理。

关键词: 人工增雨, 人工增雨, 降温, 防控太湖蓝藻, 效果分析, 蓝藻面积遥感资料

Abstract: Application of nitrogen fertilization is a key factor which affects the agricultural carbon balance, quantitative assessment of soil respiration and carbon balance under different nitrogen fertilizer levels are important to the protection of the ecological environment on soil fertility and regulation of carbon emissions. In this study, field tube experiment and field experiment were conducted to explore the dynamic changes of soil respiration rate and the carbon balance of agricultural ecosystem under different nitrogen levels. The results showed that, maize biomass (shoot and root) fixed the amount of organic carbon of 5660.71~8106.00 kg C/hm2. The total amount of soil respiration(carbon release) was 9209.04 ~ 16510.40 kg C/hm2. On bare land, the total amount of microbial respiration(carbon release) was from 2827.36 kg C/hm2 to 6951.68 kg C/hm2. Root respiration contributed 57.9% ~ 69.3% to the total amount of soil respiration. Under maize-plant condition, carbon balance of different growth stages changed significantly during different growth stages. In the jointing stage, net ecosystem productivity (NEP) were negative under all treatments,which indicated soil was the source of atmospheric CO2. In the tasseling stage and the mature stage, NEP were positive and the soil presented as the sink of atmospheric CO2. The trend of NEP were different with the increase of nitrogen fertilizer application in the three growth stages: nitrogen fertilizer application significantly decreased NEP in the jointing stage, however, in the tasseling stage and the mature stage, NEP in the treatment of the nitrogen fertilizer application was higher than that without N application.

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