ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • carbon dynamics  (3)
  • rice cultivars  (3)
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Using a Crop/Soil Simulation Model and GIS Techniques to Assess Methane Emissions from Rice Fields in Asia. I. Model Development (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 141-159 
    Details
    ISSN: 1573-0867
    Keywords: methane ; rice ; Oryza sativa ; anaerobic ; model ; simulation ; carbon dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The development of the MERES (Methane Emissions in Rice EcoSystems) model for simulating methane (CH4) emissions from rice fields is described. The CERES-Rice crop simulation model was used as a basis, employing the existing routines simulating soil organic matter (SOM) decomposition to predict the amount of subsrate available for methanogenesis. This was linked to an existing submodel, described elsewhere in this volume (Arah & Kirk, 2000), which calculates steady-state fluxes and concentrations of CH4 and O2 in flooded soils. Extra routines were also incorporated to simulate the influence of the combined pool of alternative electron acceptors in the soil (i.e., NO3 −, Mn4+, Fe3+, SO4 2−) on CH4 production. The rate of substrate supply is calculated in the SOM routines of the CERES-Rice model from (a) the rate of decomposition of soil organic material including that left from the previous crop and any additions of organic matter, (b) root exudates (modified from the original CERES-Rice model using recent laboratory data), and (c) the decomposition of dead roots from the current crop. A fraction of this rate of substrate supply, determined by the concentration of the oxidized form of the alternative electron acceptor pool, is converted to CO2 by bacteria which outcompete the methanogenic bacteria, thereby suppressing CH4 production. Any remaining fraction of the substrate supply rate is assumed to be potentially available for methanogenesis. The CH4 dynamics submodel uses this potetial methanogenesis rate, along with a description of the root length distribution in the soil profile supplied by the crop model, to calculate the steady-state concentrations and fluxes of O2 and CH4. The reduced form of the alternative electron acceptor pool is allowed to reoxidize when soil pores fill with air if the field is drained. The MERES model was able to explain well the seasonal patterns of CH4 emissions in an experiment involving mid- and end-season drainage and additions of organic material at IRRI in the Philippines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009894619446
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Crop Management Affecting Methane Emissions from Irrigated and Rainfed Rice in Central Java (Indonesia) (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 85-93 
    Details
    ISSN: 1573-0867
    Keywords: closed chamber technique ; rainfall ; wet season crop ; dry season crop ; water regime ; farmyard manure ; straw ; rice cultivars ; mitigation strategies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Methane (CH4) emissions were determined from 1993 to 1998 using an automated closed chamber technique in irrigated and rainfed rice. In Jakenan (Central Java), the two consecutive crops encompass a gradient from low to heavy rainfall (wet season crop) and from heavy to low rainfall (dry season crop), respectively. Rainfed rice was characterized by very low emission at the onset of the wet season and the end of the dry season. Persistent flooding in irrigated fields resulted in relatively high emission rates throughout the two seasons. Average emission in rainfed rice varied between 19 and 123 mg CH4 m−2 d−1, whereas averages in irrigated rice ranged from 71 to 217 mg CH4 m−2 d−1. The impact of organic manure was relatively small in rainfed rice. In the wet season, farmyard manure (FYM) was completely decomposed before CH4 emission was initiated; rice straw resulted in 40% increase in emission rates during this cropping season. In the dry season, intensive flooding in the early stage promoted high emissions from organically fertilized plots; seasonal emissions of FYM and rice straw increased by 72% and 37%, respectively, as compared with mineral fertilizer. Four different rice cultivars were tested in irrigated rice. Average emission rates differed from season to season, but the total emissions showed a consistent ranking in wet and dry season, depending on season length. The early-maturing Dodokan had the lowest emissions (101 and 52 kg CH4 ha−1) and the late-maturing Cisadane had the highest emissions (142 and 116 kg CH4 ha−1). The high-yielding varieties IR64 and Memberamo had moderately high emission rates. These findings provide important clues for developing specific mitigation strategies for irrigated and rainfed rice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009834300790
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Using a Crop/Soil Simulation Model and GIS Techniques to Assess Methane Emissions from Rice Fields in Asia. II. Model Validation and Sensitivity Analysis (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 161-177 
    Details
    ISSN: 1573-0867
    Keywords: methane ; rice ; Oryza sativa ; anaerobic ; model ; simulation ; carbon dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The MERES (Methane Emissions from Rice EcoSystems) simulation model was tested using experimental data from IRRI and Maligaya in the Philippines and from Hangzhou in China. There was good agreement between simulated and observed values of total aboveground biomass, root weight, grain yield, and seasonal methane (CH4) emissions. The importance of the contribution of the rice crop to CH4 emissions was highlighted. Rhizodeposition (root exudation and root death) was predicted to contribute about 380 kg C ha−1 of methanogenic substrate over the season, representing 37% of the total methanogenic substrate from all sources when no organic amendments were added. A further 225 kg C ha−1 (22%) was predicted to come from previous crop residues, giving a total of around 60% originating from the rice crop, with the remaining 41% coming from the humic fraction of the soil organic matter (SOM). Sensitivity analysis suggested that the parameter representing transmissivity to gaseous transfer per unit root length (λr) was important in determining seasonal CH4 emissions. As this transmissivity increased, more O2 was able to diffuse to the rhizosphere, so that CH4 production by methanogens was reduced and more CH4 was oxidized by methanotrophs. These effects outweighed the opposing influence of increased rate of transport of CH4 through the plant, so that the overall effect was to reduce the amount of CH4 emitted over the season. Varying the root-shoot ratio of the crop was predicted to have little effect on seasonal emissions, the increased rates of rhizodeposition being counteracted by the increased rates of O2 diffusion to the rhizosphere. Increasing the length of a midseason drainage period reduced CH4 emissions significantly, but periods longer than 6–7 d also decreased rice yields. Organic amendments with low C/N were predicted to be more beneficial, both in terms of enhancing crop yields and reducing CH4 emissions, even when the same amount of C was applied. This was due to higher rates of immobilization of C into microbial biomass, removing it temporarily as a methanogenic substrate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009846703516
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Using a Crop/Soil Simulation Model and GIS Techniques to Assess Methane Emissions from Rice Fields in Asia. IV. Upscaling to National Levels (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 201-217 
    Details
    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
    URL: http://dx.doi.org/10.1023/A:1009850804425
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Methane Transport Capacity of Rice Plants. I. Influence of Methane Concentration and Growth Stage Analyzed with an Automated Measuring System (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 357-366 
    Details
    ISSN: 1573-0867
    Keywords: plant-mediated gas transfer ; methane emissions ; rice cultivars ; rhizosphere ; automated methane measurements ; plant growth stages ; global warming ; greenhouse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A major portion (60–90%) of the methane (CH4) emitted from rice fields to the atmosphere is transported through the aerenchyma of the rice plants. However, a rapid and accurate method to study the CH4 transport capacity (MTC) of rice plants is not available. We developed a gas sampling and analytical device based on a closed two-compartment chamber technique and analyzed the enrichment of the CH4 mixing ratio inside the shoot compartment of cylindrical cuvettes enclosing individual rice plants under ambient conditions. The computer-controlled analytical system consists of a gas chromatograph (GC) and a pressure-controlled autosampler for eight cuvettes (seven for plants and one for CH4-calibration gas). The system automates closure and opening of plant cuvettes using pneumatic pressure, air sample collection and injection into the GC, and CH4 analysis. It minimizes sources of error during air sampling by continuously mixing headspace air of each cuvette, maintaining pressure and composition of the headspace inside the cuvettes, purging the dead volumes between the sampler induction tube and GC, and running a reference CH4-calibration gas sample in each cycle. Tests showed that the automated system is a useful tool for accurate sampling of headspace air of cylindrical cuvettes enclosing individual rice plants and enables rapid and accurate fully automated analysis of CH4 in the headspace air samples. A linear relationship was obtained between CH4 transported by rice plants of two cultivars (IR72, a high-yielding dwarf, and Dular, a traditional tall cultivar) and concentration of CH4 up to 7,500 ppm used for purging the nutrient culture solution surrounding the roots in the root compartment of the chamber. Further increase in CH4 emission by shoots was not observed at 10,000 ppm CH4 concentration in the root compartment of the chamber. The MTC of IR72 was measured at six development stages; it was lowest at seedling stage, increasing gradually until panicle initiation. There was no further change at flowering, but a marked decrease at maturity was noted. These results suggest that the plants have 45–246% greater potential to transport CH4 than the highest CH4 emission rates reported under field conditions, and plants would not emit CH4 at early growth and at a reduced rate close to ripening.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009831712602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Methane Transport Capacity of Rice Plants. II. Variations Among Different Rice Cultivars and Relationship with Morphological Characteristics (2000)
    Springer
    Nutrient cycling in agroecosystems 58 (2000), S. 367-375 
    Details
    ISSN: 1573-0867
    Keywords: plant-mediated gas transfer ; methane emissions ; rice cultivars ; rhizosphere ; automated methane measurements ; plant growth stages ; global warming ; greenhouse effects ; plant biomass ; plant tillers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Of the total methane (CH4) emitted from a rice field during the growing season 60–90% is emitted through the rice plants. We determined the methane transport capacity (MTC) of rice plants at different physiological growth stages using an automatic measuring system under greenhouse conditions. A total of 12 cultivars (10 inbred varieties and 2 hybrids) were studied in sets of two experiments and was distinguished into three groups according to the patterns of MTC development. MTC is generally increasing from seedling stage to panicle initiation (PI), but differs in the development from PI to maturity. While the hybrid showed a gradual increase in MTC, the inbred cultivars showed either minor changes in MTC or a drastic decrease from flowering to maturity. Among tall cultivars, Dular showed the highest MTC, followed by B40; the lowest MTC was found in Intan. High-yielding dwarf cultivars showed MTC in the descending order of IR72 〉 IR52 〉 IR64 〉 PSBRc 20. New plant type cultivars showed very low MTC with IR65600 exhibiting the smallest MTC at PI, flowering, and maturity. Hybrids (Magat and APHR 2) showed the largest MTC that continued to increased with plant growth. The MTC patterns were attributed to growth parameters and the development of morphological characteristics of the aerenchyma. These results suggest that in tall, dwarf, and NPT cultivars, increase in root or aboveground biomass during initial growth determines a corresponding increase in MTC. Once aerenchyma has fully developed, further increase in plant biomass would not influence MTC. However, in the case of hybrids, a positive relationship of MTC with root + shoot biomass (r = 0.672, p ≥ 0.05) and a total plant biomass including grain (r = 0.849, p ≥ 0.01) indicate continuous development of aerenchyma with plant growth, resulting in enhanced MTC. In all cultivars, tiller number, but not height, was linearly related to MTC, indicating that the number of outlets/channels rather than plant size/biomass determines the transport of CH4. These results clearly demonstrate that rice cultivars differ significantly in MTC. Therefore, the use of high-yielding cultivars with low MTC (for example, PSBRc 20, IR65598, and IR65600) could be an economically feasible, environmentally sound, and promising approach to mitigate CH4 emissions from rice fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009839929441
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...