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Structure and Function in Agroecosystem Design and Management - Chapter 18

Đó là ước tính đó Up Cho đến khi cuộc cách mạng công nghiệp trong mười tám thế kỷ, nồng độ CO2 trong khí quyển ([CO2]) Đã được khoảng 280 ppmv (phần triệu theo thể tích). Kể từ đó, [CO2] Có đến 370 ppmv Phục Sinh hiện nay và IS Dự kiến sẽ giữ tăng với tốc độ khoảng 15 ppmv một thập kỷ. Các Tăng [CO2] là do hoạt động con người như như đốt nhiên liệu hóa thạch và phá rừng (Houghton et al., 1996). Đó là dự đoán đó các Tăng sẽ tiếp tục vào thế kỷ XXI, Kết quả là nồng. | 920103_CRC20_0904_CH18 1 13 01 11 21 AM ge 371 CHAPTER 18 Growth and Yield of Paddy Rice Under Free-air CO2 Enrichment Kazuhiko Kobayashi Mark Lieffering and Han Yong Kim CONTENTS Introduction.371 Atmospheric CO2 and Rice.371 Objectives of the Rice FACE Experiment.373 Growing Crops under Elevated CO2 .374 Chamber Studies.374 FACE Systems.374 Rice FACE System Description.375 Ring Description.376 CO2 Control and Monitoring.376 Temporal and Spatial Control of CO2 1999 .377 The Effects of FACE on the Growth and Yield of Paddy Rice.378 Materials and Methods.378 Results.380 Discussion.387 Conclusions and Implications.390 References.392 INTRODUCTION Atmospheric CO2 and Rice It is estimated that up until the industrial revolution in the eighteenth century atmospheric CO2 concentrations CO2 were about 280 ppmV parts 0-8493-0904-2 01 0.00 .50 2001 by CRC Press LLC 371 920103_CRC20_0904_CH18 1 13 01 11 21 AM Page 372 372 STRUCTURE AND FUNCTION IN AGROECOSYSTEMS DESIGN AND MANAGEMENT per million by volume . Since then the CO2 has risen to 370 ppmV at present and is expected to keep increasing at a rate of about 15 ppmV per decade. The increase in CO2 is attributed to human activities such as fossil fuel burning and deforestation Houghton et al. 1996 . It is predicted that the increase will continue into the twenty-first century resulting in a CO2 concentration somewhere between 450 and 550 ppmV around the year 2050 Houghton et al. 1996 . Because CO2 is a greenhouse gas the increase in CO2 is predicted to affect the global radiation energy balance and thereby climate. The predicted changes in climate most notably include an increase in the Earth s mean surface temperature and alterations in rainfall patterns both factors which strongly affect biomass production in both agricultural and natural ecosystems worldwide Reilly 1996 . Besides the indirect effects on plant growth induced by climate change elevated CO2 can also directly alter plant processes most importantly .