ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1573-0867
    Keywords: water regime ; soil aeration ; mineral fertilizer ; rainfall ; acid sulfate soil ; soil pH ; Indonesia ; Thailand ; Philippines ; mitigation options
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Methane (CH4) emission rates were recorded automatically using the closed chamber technique in major rice-growing areas of Southeast Asia. The three experimental sites covered different ecosystems of wetland rice--irrigated, rainfed, and deepwater rice--using only mineral fertilizers (for this comparison). In Jakenan (Indonesia), the local water regime in rainfed rice encompassed a gradual increase (wet season) and a gradual decrease (dry season) in floodwater levels. Emission rates accumulated to 52 and 91 kg CH4 ha−1 season−1 corresponding to approximately 40% of emissions from irrigated rice in each season. Distinct drainage periods within the season can drastically reduce CH4 emissions to less than 30 kg CH4 ha−1 season−1 as shown in Los Baños (Philippines). The reduction effect of this water regime as compared with irrigated rice varied from 20% to 80% from season to season. Methane fluxes from deepwater rice in Prachinburi (Thailand) were lower than from irrigated rice but accumulated to equally high seasonal values, i.e., about 99 kg CH4 ha−1 season−1, due to longer seasons and assured periods of flooding. Rice ecosystems with continuous flooding were characterized by anaerobic conditions in the soil. These conditions commonly found in irrigated and deepwater rice favored CH4 emissions. Temporary aeration of flooded rice soils, which is generic in rainfed rice, reduced emission rates due to low CH4 production and high CH4 oxidation. Based on these findings and the global distribution of rice area, irrigated rice accounts globally for 70–80% of CH4 from the global rice area. Rainfed rice (about 15%) and deepwater rice (about 10%) have much lower shares. In turn, irrigated rice represents the most promising target for mitigation strategies. Proper water management could reduce CH4 emission without affecting yields.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-0867
    Keywords: irrigated ; climate ; crop management ; organic amendments ; China ; India ; Thailand ; Philippines ; Indonesia ; mitigation options
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Interregional Research Program on Methane Emissions from Rice Fields established a network of eight measuring stations in five Asian countries. These stations covered different environments and encompassed varying practices in crop management. All stations were equipped with a closed chamber system designed for frequent sampling and long-term measurements of emission rates. Even under identical treatment--e.g., continuous flooding and no organic fertilizers--average emission rates varied from 15 to 200 kg CH4 ha−1 season−1. Low temperatures limited CH4 emissions in temperate and subtropical stations such as northern China and northern India. Differences observed under given climates, (e.g., within the tropics) indicated the importance of soil properties in regulating the CH4 emission potential. However, local variations in crop management superseded the impact of soil- and climate-related factors. This resulted in uniformly high emission rates of about 300 kg CH4 ha−1 season−1 for the irrigated rice stations in the Philippines (Maligaya) and China (Beijing and Hangzhou). The station in northern India (Delhi) was characterized by exceptionally low emission rates of less than 20 kg CH4 ha−1 season−1 under local practice. These findings also suggest opportunities for reducing CH4 emission through a deliberate modification of cultural practice for most irrigated rice fields.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-0867
    Keywords: rice ; model ; simulation ; carbon dynamics ; China ; India ; Indonesia ; Philippines ; Thailand ; estimates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The process-based crop/soil model MERES (Methane Emissions from Rice EcoSystems) was used together with daily weather data, spatial soil data, and rice-growing statistics to estimate the annual methane (CH4) emissions from China, India, Indonesia, Philippines, and Thailand under various crop management scenarios. Four crop management scenarios were considered: (a) a 'baseline' scenario assuming no addition of organic amendments or field drainage during the growing season, (b) addition of 3,000 kg DM ha−1 of green manure at the start of the season but no field drainage, (c) no organic amendments but drainage of the field for a 14-d period in the middle of the season and again at the end of the season, and (d) addition of 3,000 kg DM ha−1 of green manure and field drainage in the middle and end of the season. For each scenario, simulations were made at each location for irrigated and rainfed rice ecosystems in the main rice-growing season, and for irrigated rice in the second (or 'dry') season. Overall annual emissions (Tg CH4 yr−1) for a province/district were calculated by multiplying the rates of CH4 emission (kg CH4 ha−1 yr−1) by the area of rice grown in each ecosystem and in each season obtained from the Huke and Huke (1997) database of rice production. Using the baseline scenario, annual CH4 emissions for China, India, Indonesia, Philippines, and Thailand were calculated to be 3.73, 2.14, 1.65, 0.14, and 0.18 Tg CH4 yr−1, respectively. Addition of 3,000 kg DM ha−1 green manure at the start of the season increased emissions by an average of 128% across the five countries, with a range of 74–259%. Drainage of the field in the middle and at the end of the season reduced emissions by an average of 13% across the five countries, with a range of −10% to −39%. The combination of organic amendments and field drainage resulted in an increase in emissions by an average of 86% across the five countries, with a range of 15–176%. The sum of CH4 emissions from these five countries, comprising about 70% of the global rice area, ranged from 6.49 to 17.42 Tg CH4 yr−1, depending on the crop management scenario.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...