氮素是一種重要的生命元素,對于維持生態(tài)系統(tǒng)的組成、功能、健康等具有重要的作用。土壤氮素礦化作用、硝化作用和反硝化作用是關鍵的氮素循環(huán)過程,明確其速率及其影響因素對于認識土壤氮動態(tài)具有重要的意義。亞熱帶地區(qū)是中國重要的工農業(yè)生產(chǎn)基地,集中了全國22.5%的人口。為了滿足人們對各種農業(yè)產(chǎn)品的需求,近70年來,該地區(qū)農業(yè)生產(chǎn)快速發(fā)展,土地利用方式發(fā)生了急劇的變化。該地區(qū)氣候條件具有高溫多雨的特點,淋溶非常強烈,土壤侵蝕嚴重,有機碳、氮含量普遍較低。土壤為酸性可變電荷土壤,脫硅富鐵鋁明顯,土壤強酸性是限制農業(yè)生產(chǎn)的障礙因子之一。隨著土地利用方式的變化,以及施化肥、有機肥、石灰等管理方式的改變,會顯著影響土壤物理、化學、生物性質,進而可能影響土壤氮轉化過程和土壤氮去向,引發(fā)與活性氮有關的環(huán)境問題。因此,闡明土地利用方式對紅壤氮轉化過程的影響,明確其主要驅動因子,對于制定針對性的管理措施,實現(xiàn)紅壤氮素的合理調控具有重要的意義。江西省是中國典型的紅壤分布區(qū)域,區(qū)域內林地、茶園、旱地、水田是主要的農、林業(yè)土地利用方式,其各占區(qū)域總面積的63.1%、0.3%、2.0%和10.5%。其中,毛竹是本區(qū)重要的... 

【文章來源】：南京師范大學江蘇省 211工程院校

【文章頁數(shù)】：182 頁

【學位級別】：博士

【文章目錄】：
Abstract
摘要
論文選題簡介
研究目標、研究內容、研究方案和技術路線簡介
論文核心研究結果簡介
Chapter 1. Introduction
    1.1 Background
    1.2 Research Problem and Objectives
        1.2.1 Problem
        1.2.2 Objectives
        1.2.3 Novelty
Chapter 2. Literature Review
    2.1. Ecosystem
        2.1.1. Ecosystem Services
        2.1.2. Human Alteration ecosystem
        2.1.3. Land use, ecosystem, and ecosistem service
    2.2. Soils in the ecosystem
        2.2.1. The Role of Soils
        2.2.2. Soil Organic Matter (SOM)
        2.2.4. Antropoghenic Impacts,Litter Decomposition, and Soil OrganicMatter
    2.3. Nitrogen Cycle
        2.3.1 Nitrogen cycle in terrestrial ecosystem
        2.3.2. Mineralization and its affecting factors
        2.3.3. Nitrification and its affecting factors
        2.3.4. Denitrification and its affecting factors
        2.3.5. N_2O Emission from Nitirification and denitrification
    2.4. Subtropical region of China
    2.5. Site description and soil sample in this study
Chapter 3. Effects of land use on net rates of soil N mineralization andnitrification and nitrous oxide (N_2O) emission in subtropicalregion of China
    3.1. Introduction
    3.2. Materials and methods
        3.2.1. Site Description and soil sample
        3.2.2. Laboratory incubation for determining net N mineralization and netnitrification
        3.2.3. Determination of N_2O and CO_2 concentration
        3.2.4. Examine abundance of AOA and AOB
        3.2.5. Calculation
        3.2.6. Statistical Analysis
    3.3. Result
        3.3.1. Soil properties
        3.3.2. Ammonia oxidizer abundance (AOA and AOB)in the soil
        3.3.3. CO_2 and N_2O emission
        3.3.4. Net nitrification and N mineralization rates
    3.4. Discussion
Chapter 4. The denitrification potential and gas products in red soil underdifferent land use
    4.1.Introduction
    4.2. Materials and Methods
        4.2.1. Research area overview
        4.2.2. Anaerobic incubation experiment
        4.2.3. Sample analysis method
        4.2.4. Data processing and statistical methods
        4.2.5. Data analysis
    4.3. Results
        4.3.1 Soil properties
        4.3.2 nirS,nirK, and nosZ gene abundance
        4.3.3. N_2O and N_2 emission rate
        4.3.4. Denitrification potential
    4.4. Discussion
        4.4.1. Soil organic carbon is the main factor controlling the denitrificationpotential, N_2O and N_2 emission rate of red soil in different utilizationmodes
        4.4.2. Soil pH influences Different utilization methods N_2/N_2O ratio ofdenitrified gaseous products in red soil
    4.5. Conclusion
Chapter 5. The effect of soil pH on net rate of soil nitrogen mineralizationand nitrification in red soil and its mechanism
    5.1 Introduction
    5.2 Material and Method
        5.2.1 Soil Sampling and Preparation
        5.2.2 pH treatment and aerobic incubation experiment
        5.2.3 Calculation of Nitrogen Conversion Rate
        5.2.4 AOB and AOA Determination of abundance
        5.2.5 Data Calculation and Statistical Analysis
    5.3 Result
        5.3.1 Dynamics of Soil Inorganic Nitrogen Treated with Different pHValues
        5.3.2 Net Rate of Nitrogen Mineralization and Nitrification
        5.3.3 Variation of Abundance of AOB and AOA
    5.4 Discussion
        5.4.1 Effect of pH on Net Nitrogen Mineralization Rate
        5.4.2 Effects of pH and Mineralization on Net Nitrification Rate
Chapter 6. Effects of long-term manure and lime application on nitrogentransformation and fate in an upland soil in subtropical region
    6.1 Introduction
    6.2 Materials and methods
        6.2.1 Site description and long-term fertilization experiment design
        6.2.2 Soil column simulation test
        6.2.3 Laboratory ~(15)N tracing experiment
        6.2.4 ~(15)N tracing model
        6.2.5 Statistical analysis
    6.3 Result
        6.3.1 Physical and chemical properties of soil
        6.3.2 Gross N transformation rate
        6.3.5 N losses of each treatment in red soil
    6.4 Discussion
        6.4.1 Effects of long-term fertilizer management measures on Ntransformation in red soil
        6.4.2 The relationship between the characteristics of soil N transformationand N fate
    6.5 Conclusion
Chapter 7. General Conclusion
References
Appendix
Acknowledgement



本文編號：3447980