地理学报 ›› 2001, Vol. 68 ›› Issue (5): 505-514.doi: 10.11821/xb200105001

• 论文 •    下一篇

长江流域氮的生物地球化学循环及其对输送无机氮的影响——1968~1997年的时间变化分析

晏维金1, 章申1, 王嘉慧2   

  1. 1. 中国科学院地理科学与资源研究所,北京100101;
    2. 中国地质大学,北京100083
  • 收稿日期:2001-04-12 修回日期:2001-06-27 出版日期:2001-09-15 发布日期:2001-09-15
  • 基金资助:
    中国科学院知识创新工程项目(KZCX2-207);中科院地理科学与资源所知识创新工程领域前沿项目(CX10G-A00-06);国家自然科学基金资助项目(49801019)

Nitrogen Biogeochemical Cycling in the Changjiang Drainage Basin and its Effect on Changjiang River Dissolved Inorganic Nitrogen: Temporal Trend for the Period 1968~1997

YAN Wei jin1, ZHANG Shen1, WANG Jia hui 2   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. Geology University of China, Beijing 100083, China
  • Received:2001-04-12 Revised:2001-06-27 Online:2001-09-15 Published:2001-09-15
  • Supported by:
    The knowledge-innovation project of CAS,No.KZCX2-207;The knowledge-innovation project of the Institute of Geographic Sciences and Natural Resources Research,CAS,No.CX10G-A00-06;National Natural Science Foundation of China,No.49801019

摘要: 通过研究长江流域 1 968~ 1 997年氮的输入、输出、平衡的生物地球化学循环,表明长江流域 1 997年氮的输入量、输出量和储存量分别为 1 0 .0× 1 0 9、 6.7× 1 0 9、和 3.5× 1 0 9kg,分别是 1 968年氮输入量、输出量和储存量的 4、 5和 3倍。在氮的输入中,1 977年以前,长江流域氮输入主要是生物固氮,年均固氮量约 1 .0× 1 0 9kg;而在 1 985年后,化学氮肥年均输入量约5 .0× 1 0 9kg,占总氮输入的 5 0 %以上。在氮的输出中,1 997年通过长江大通站水体中溶解态无机氮 ( DIN)的浓度和通量分别是 1 .60 mg/ L和 1 .40× 1 0 9kg,从 1 968年到 1 997年约增加了1 0倍 ;大约 2 5 %的氮输入通过长江输送到东海,约 33%的氮输入通过反硝化和氨挥发进入大气中,剩余 42 %的氮输入储存在流域内。研究发现,长江流域的氮输入量,特别是化肥氮的输入量,是造成长江输送无机氮通量上升的主要因素。

关键词: 氮, 无机氮, 生物地球化学循环, 化肥, 长江流域

Abstract: In this paper, we present estimates of nitrogen (N) biogeochemical cycling in the Changjiang drainage basin, including N inputs, outputs and internal transfer for the period 1968 1997. The total N input, output and internal storage are approximately 10.0?10 9, 6.7?10 9, and 3.5?10 9 kg, respectively, in 1997, which is about fourfold, fivefold, and threefold of these in 1968, respectively. In terms of N inputs, N fixation was often a dominant input before 1977, providing about 1.0?10 9 kg year 1 ; while N fertilizer dominated N input after 1983, supplying an additional input of some 5.0?10 9 kg year 1 . In terms of N output, we estimate that the river dissolved inorganic nitrogen (DIN) concentration and flux have increased by about 10 fold from 1968 to 1997, reaching 1.60 mg L 1 and 1.40?10 9 kg, respectively, in 1997. Our study shows that about 25.0% of the total N input is transported through the river, while some 33% of the input is emitted by denitrification and volatilization, and the remaining 42% of the input is stored within the basin. The integrated N input, budget and storage have been linked to the increasing temporal trends of Changjiang River DIN. It is demonstrated that integrated N input, especially N fertilizer application, rather than human population density in the basin is the preferable predictor of the river DIN concentration and flux. Therefore, how N fertilizer is effectively applied is of crucial importance to the sustainable development of agriculture in the basin.

Key words: nitrogen, dissolved inorganic nitrogen, biogeochemical cycling, chemical fertilizer, Changjiang River, basin

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  • X142