tailieunhanh - Climate Change and Managed Ecosystems - Chapter 6

Đất là không thể thiếu thành phần của hệ sinh thái tự nhiên. Chức năng của hệ sinh thái, bao gồm cả xe đạp của các yếu tố và chuyển giao khối lượng và năng lượng, được điều tiết qua đất. Tuy nhiên, trọng tâm của nghiên cứu khoa học đất trong thời gian 19 và 20 thế kỷ đã được chủ yếu là trên hai chức năng chính đất: (1) trung bình cho nhà máy (cây trồng, đồng cỏ và cây) tăng trưởng, và (2) nền tảng cho các cấu trúc dân dụng (đường giao thông, các tòa nhà, đập thuỷ lực) | 6 Carbon Dynamics in Agricultural Soils R. Lal CONTENTS Soil as Moderator of Earth s Soils and the Global Carbon Soil Carbon Soil Carbon Illuviation . 136 Secondary Carbonates. 136 Technological Options of Carbon Sequestration in Agricultural Rates of Soil Carbon Measurement Issues Related to Soil Carbon INTRODUCTION Soils are integral component of natural ecosystems. The functioning of ecosystems including the cycling of elements and transfer of mass and energy is moderated through soils. Yet the focus of soil science research during the 19th and 20th centuries has mainly been on two principal soil functions 1 the medium for plant crops pastures and trees growth and 2 the foundation for civil structures roads buildings hydraulic dams . The unprecedented growth in human population during the 20th century led to 1 widespread adoption of the Green Revolution technologies based on intensive management of plant nutrients and available water capacity of the soil in the effective root zone for enhancing crop yields 2 rapid expansion of urban centers which often necessitated use of fertile topsoil for brick making along with development of highways parking lots airports and recreational facilities and dams to create water reservoirs and hydroelectric generation facilities. Consequently the 20th century witnessed rapid advances in soil science with focus on soil as a medium for plant root growth . edaphology with specific reference to water and nutrient movement through the soil and uptake by plants elemental 127 2006 by Taylor Francis Group LLC 128 Climate Change and Managed Ecosystems balance aeration for root microbial respiration soil reaction and optimization of these properties and processes through anthropic interventions involving tillage or .