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1.
Field measurements of CH4 emission from rice paddy field during cultivation periods were performed at all of 47 Japanese prefectures under the project
of ‘Research for evaluation of CH4 and N2O emissions from agricultural land, and improvement methods of soil, water and fertilizer management’ conducted by Agricultural
Production Bureau, the Ministry of Agriculture, Forestry and Fisheries. Although this project was carried out at 159 fields,
the data of 132 fields were used for this report because other 27 fields had not enough data to be suitable for the statistics
analyses.
The measurements at rice paddy fields in various locations in Japan showed that there were large temporal variations of CH4 flux and that the fluxes differed markedly with climate, characteristics of soil and paddy, application of organic matter
and mineral fertilizer, and agricultural management practices.
These data mainly indicated that CH4 emission from Gley soils was greater than those from other soil types such as Andosols, Upland soils, fine-textured Lowland
soils, medium and coarse-textured Lowlands soils and gravelly Lowland soils, and that water and organic matter managements
influenced CH4 emission. It is suggested that midsummer drainage treatment suppressed while the application of fresh organic matter such
as rice straw and wheat straw enhanced CH4 emission, respectively.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
2.
Methane Emission from Deepwater Rice Fields in Thailand 总被引:4,自引:0,他引:4
N. Chareonsilp C. Buddhaboon P. Promnart R. Wassmann R.S. Lantin 《Nutrient Cycling in Agroecosystems》2000,58(1-3):121-130
Field experiments were conducted in the Prachinburi Rice Research Center (Thailand) from 1994 to 1998. The major objective was to study methane (CH4) emission from deepwater rice as affected by different crop management. Irrigated rice was investigated in adjacent plots, mainly for comparison purposes. The 4-yr average in CH4 emission from deepwater rice with straw ash (burned straw) treatment was 46 mg m–2d–1 and total emission was 98 kg ha–1 yr–1. For irrigated rice, the average emission rate and total emission for the straw ash treatment was 79 mg m–2 d–1 and 74 kg ha–1 yr–1, respectively. Low emission rates may partially be related to acid sulfate soil of the experimental site. Without organic amendment, the seasonal pattern of CH4 emission from deepwater rice was correlated with an increase in biomass of rice plants. Emission rates from deepwater rice depend on the production of biomass and the straw management as well. Methane emission was greatest with straw incorporation, followed by straw compost incorporation, zero-tillage with straw mulching, and least with straw ash incorporation. The seasonal pattern of CH4 ebullition in deepwater rice was consistent with seasonal emission, and total ebullition corresponded to 50% of total emission. Dissolved CH4 concentrations in the surface soil (0–5 cm) were similar to those in the subsoil (5–15 cm), and the seasonal fluctuation of dissolved CH4 was also consistent with the seasonal CH4 emission. Increase in plant density and biomass of irrigated rice grown by pregerminated seed broadcasting enhanced CH4 emission as compared with transplanting. 相似文献
3.
Zu-Cong Cai 《Nutrient Cycling in Agroecosystems》1997,49(1-3):171-179
Based on key factors influencing CH4 fluxes from rice paddy fields in China, a category for estimation of total CH4 emission was suggested and the constraints for the estimation were discussed in the paper. Recently, CH4 fluxes measured in situ have been built up dramatically with the efforts of both Chinese scientists and those from abroad.
After reviewing published data on CH4 fluxes from rice paddy fields, we found that although there are many other influencing factors, water regime and organic
manure application are two key factors controlling CH4 emission; thus, rice paddy fields in China were classified by these two factors to estimate CH4 emission. In the suggested category, the water regime of rice paddy fields was classified into mid-season aeration at least
once during the period of rice growth (MSA), continuous flooding during the period of rice growth but well-drained after rice
harvest (CFD), and permanent flooding (PF) even in winter, and fertilization was classified into mineral fertilizers only
(MIN), amendment with organic manures at the rate of less than or equal to 15 t ha-1 (MU < 15) and at the rate of higher than 15 t ha-1 (MU > 15), and with rice straw or other fresh plant materials (RS). Combining both water regime and fertilization together,
we classified rice paddy fields in China into 12 types. The seasonal mean CH4 flux of each type of rice paddy field was calculated by the data available and showed that the lowest CH4 flux was found in the type MSA-MIN, and the highest in PF-MU > 15. The total emission estimated by this category was 8.05
Tg CH4 yr-1 with a standard deviation of 3.69 Tg CH4 yr-1.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
Xianglan Li Jing Ma Yunjun Yao Shunlin Liang Guangbin Zhang Hua Xu Kazuyuki Yagi 《Nutrient Cycling in Agroecosystems》2014,100(1):65-76
Straw application and midseason drainage play role in controlling methane (CH4) and nitrous oxide (N2O) emissions from rice paddy fields, but little information is available on their integrative effect on CH4 and N2O emissions. A two-year field experiment was conducted to study the combined effect of timing and duration of midseason aeration and wheat straw incorporation on mitigation of global warming potential (GWP) of CH4 and N2O emissions from irrigated lowland rice paddy fields. Results showed that incorporation of wheat straw increased CH4 by a factor of 5–9 under various water regimes, but simultaneously decreased N2O emission by 19–42 % during the rice growing season. Without straw incorporation, prolonged aeration significantly reduced the net 100-year GWP of CH4 and N2O emissions by 6 %, but also decreased rice production when compared with normal aeration. With straw incorporation, the lowest GWP was found by early aeration, which reduced GWP by 7 and 20 % in 2007 and 2008, respectively. Estimation of net GWPs of CH4 and N2O emissions indicated that early midseason drainage with straw incorporation offered the potential to mitigate CH4 and N2O emissions from irrigated lowland rice paddies in China. 相似文献
5.
Urease and nitrification inhibitors to reduce emissions of CH4 and N2O in rice production 总被引:2,自引:0,他引:2
Xingkai Xu Pascal Boeckx Oswald Van Cleemput Likai Zhou 《Nutrient Cycling in Agroecosystems》2002,64(1-2):203-211
Strategies used to reduce emissions of N2O and CH4 in rice production normally include irrigation management and fertilization. To date, little information has been published on the measures that can simultaneously reduce both emissions. Effects of application of a urease inhibitor, hydroquinone (HQ), and a nitrification inhibitor, dicyandiamide (DCD) together with urea (U) on N2O and CH4 emission from rice growing were studied in pot experiments. These fertilization treatments were carried out in the presence and absence of wheat straw, applied to the soil surface. Without wheat straw addition, in all treatments with inhibitor(s) the emission of N2O and CH4 was significantly reduced, as compared with the treatment whereby only urea was applied (control). Especially for the U+HQ+DCD treatment, the total emission of N2O and CH4 was about 1/3 and 1/2 of that in the control, respectively. In the presence of wheat straw, the total N2O emission from the U+HQ+DCD treatment was about 1/2 of that from the control. The total CH4 emission was less influenced. Wheat straw addition, however, induced a substantial increase in emissions of N2O and CH4. Hence, simultaneous application of organic materials with a high C/N ratio and N-fertilizer (e.g. urea) is not a suitable method to reduce the N2O and CH4 emission. Application of HQ+DCD together with urea seemed to improve the rice growth and to reduce both emissions. The NO3
–-N content of the rice plants and denitrification of (NO3
–+NO2
–)-N might contribute to the N2O emission from flooded rice fields. 相似文献
6.
Mechanisms of Crop Management Impact on Methane Emissions from Rice Fields in Los Baños, Philippines
R. Wassmann L.V. Buendia R.S. Lantin C.S. Bueno L.A. Lubigan A. Umali N.N. Nocon A.M. Javellana H.U. Neue 《Nutrient Cycling in Agroecosystems》2000,58(1-3):107-119
This article comprises 4 yr of field experiments on methane (CH4) emissions from rice fields conducted at Los Baños, Philippines. The experimental layout allowed automated measurements of CH4 emissions as affected by water regime, soil amendments (mineral and organic), and cultivars. In addition to emission records over 24 h, ebullition and dissolved CH4 in soil solution were recorded in weekly intervals. Emission rates varied in a very wide range from 5 to 634 kg CH4 ha–1, depending on season and crop management. In the 1994 and 1996 experiments, field drying at midtillering reduced CH4 emissions by 15–80% as compared with continuous flooding, without a significant effect on grain yield. The net impact of midtillering drainage was diminished when (i) rainfall was strong during the drainage period and (ii) emissions were suppressed by very low levels of organic substrate in the soil. Five cultivars were tested in the 1995 dry and wet season. The cultivar IR72 gave higher CH4 emissions than the other cultivars including the new plant type (IR65597) with an enhanced yield potential. Incorporation of rice straw into the soil resulted in an early peak of CH4 emission rates. About 66% of the total seasonal emission from rice straw-treated plots was emitted during the vegetative stage. Methane fluxes generated from the application of straw were 34 times higher than those generated with the use of urea. Application of green manure (Sesbania rostrata) gave only threefold increase in emission as compared with urea-treated plots. Application of ammonium sulfate significantly reduced seasonal emission as compared with urea application. Correlation between emissions and combined dissolved CH4 concentrations (from 0 to 20 cm) gave a significant R2 of 0.95 (urea + rice straw), and 0.93 (urea + Sesbania), whereas correlation with dissolved CH4 in the inorganically fertilized soils was inconsistent. A highly significant correlation (R2 =0.93) existed between emission and ebullition from plots treated with rice straw. These findings may stimulate further development of diagnostic tools for easy and reliable determination of CH4 emission potentials under different crop management practices. 相似文献
7.
Methane Emissions and Mitigation Options in Irrigated Rice Fields in Southeast China 总被引:1,自引:0,他引:1
W.F. Lu W. Chen B.W. Duan W.M. Guo Y. Lu R.S. Lantin R. Wassmann H.U. Neue 《Nutrient Cycling in Agroecosystems》2000,58(1-3):65-73
Methane (CH4) emissions from rice fields were monitored in Hangzhou, China, from 1995 to 1998 by an automatic measurement system based on the "closed chamber technique." The impacts of water management, organic inputs, and cultivars on CH4 emission were evaluated. Under the local crop management system, seasonal emissions ranging from 53 to 557 kg CH4 ha–1 were observed with an average value of 182 kg CH4 ha–1. Methane emission patterns differed among rice seasons and were generally governed by temperature changes. Emissions showed an increasing trend in early rice and a decreasing trend in late rice. In a single rice field, CH4 emissions increased during the first half of the growing period and decreased during the second half. Drainage was a major modifier of seasonal CH4 emission pattern. The local practice of midseason drainage reduced CH4 emissions by 44% as compared with continuous flooding; CH4 emissions could further be reduced by intermittent irrigation, yielding a 30% reduction as compared with midseason drainage. The incorporation of organic amendments promoted CH4 emission, but the amount of emission varied with the type of organic material and application method. Methane emission from fields where biogas residue was applied was 10–16% lower than those given the same quantity (based on N content) of pig manure. Rice straw applied before the winter fallow period reduced CH4 emission by 11% as compared with that obtained from fields to which the same amount of rice straw was applied during field preparation. Broadcasting of straw instead of incorporation into the soil showed less emission (by 12%). Cultivar selection influenced CH4 emission, but the differences were smaller than those among organic treatments and water regimes. Modifications in water regime and organic inputs were identified as promising mitigation options in southeast China. 相似文献
8.
Laboratory experiments were conducted to study the variation of CH4 oxidation patterns in flooded rice soil profiles. The results indicated that surface soil presented the strongest CH4 oxidation activities as shown by the highest values of the two kinetic parameters of CH4 oxidation, Vmax and Km in the ecosystem without rice plants. Vmax and Km decreased significantly from top to bottom in the paddy rice soil profile, ranging from 12.5 to 1.2 μg h-1 g-1 and 165 to 4.1 μg g-1, respectively. In addition, we studied the effect of headspace N2, O2 and their ratio on CH4 emission and oxidation to provide information on the sensitivity of methanogens and methanotrophs to soil redox change resulted
from gas transportation through arenchyma. Methane emission rate increased, however, CH4 oxidation rate decreased with a decrease of O2 concentration in the headspace. Headspace H2 increased CH4 emission rate substantially. In addition to H2 being a substrate for CH4 formation, the change of soil redox potential to a considerably low level H2 should also contribute to the increase in CH4 emission.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
Quantitative dependence of methane emission on soil properties 总被引:3,自引:0,他引:3
Yao Huang Yan Jiao Lianggang Zong Xunhua Zheng Ronald L. Sass Frank M. Fisher 《Nutrient Cycling in Agroecosystems》2002,64(1-2):157-167
To identify the key soil parameters influencing CH4 emission from rice paddies, an outdoor pot experiment with a total of 18 paddy soils was conducted in Nanjing Agricultural University during the 2000 rice growing season. The seasonal average rate of CH4 emission for all 18 soils was 6.42±2.70 mg m–2 h–1, with a range of 1.96 to 11.06 mg m–2 h–1. Correlation analysis indicated that the seasonal average of CH4 emission was positively dependent on soil sand content and negatively on total N as well as NH4
+-N determined before rice transplanting. Copper content of soils had a significant negative impact on CH4 emission. No clear relationship existed between CH4 emission and soil carbon content. In addition, soil type cannot explain the variability in CH4 emission. Soil parameters influencing CH4 emission were different as rice growth and development proceeded. A further investigation suggested that the seasonal average rate of CH4 emission could be quantitatively determined by a linear combination of soil NH4
+-N, available copper, the ratio of available to total sulphur, and the ratio of available to total iron. Moreover, the average rates of CH4 emission in the vegetative, reproductive and ripening stages could be also respectively described by a linear combination of different soil variables. 相似文献
10.
Methane Emission from Irrigated and Intensively Managed Rice Fields in Central Luzon (Philippines) 总被引:3,自引:0,他引:3
T.M. Corton J.B. Bajita F.S. Grospe R.R. Pamplona C.A. Assis Jr. R. Wassmann R.S. Lantin L. V. Buendia 《Nutrient Cycling in Agroecosystems》2000,58(1-3):37-53
Methane (CH4) emissions were measured with an automated system in Central Luzon, the major rice producing area of the Philippines. Emission records covered nine consecutive seasons from 1994 to 1998 and showed a distinct seasonal pattern: an early flush of CH4 before transplanting, an increasing trend in emission rates reaching maximum toward grain ripening, and a second flush after water is withdrawn prior to harvesting. The local practice of crop management, which consists of continuous flooding and urea application, resulted in 79–184 mg CH4 m–2 d–1 in the dry season (DS) and 269–503 mg CH4 m–2 d–1 in the wet season (WS). The higher emission in the WS may be attributed to more labile carbon accumulation during the dry fallow period before the WS cropping as shown by higher % organic C. Incorporation of sulfate into the soil reduced CH4 emission rates. The use of ammonium sulfate as N fertilizer in place of urea resulted in a 25–36% reduction in CH4 emissions. Phosphogypsum reduced CH4 emissions by 72% when applied in combination with urea fertilizer. Midseason drainage reduced CH4 emission by 43%, which can be explained by the influx of oxygen into the soil. The practice of direct seeding instead of transplanting resulted in a 16–54% reduction in CH4 emission, but the mechanisms for the reducing effect are not clear. Addition of rice straw compost increased CH4 emission by only 23–30% as compared with the 162–250% increase in emissions with the use of fresh rice straw. Chicken manure combined with urea did not increase CH4 emission. Fresh rice straw has wider C/N (25 to 45) while rice straw compost has C/N = 6 to 10 and chicken manure has C/N = 5 to 8. Modifications in inorganic and organic fertilizer management and water regime did not adversely affect grain yield and are therefore potential mitigation options. Direct seeding has a lower yield potential than transplanting but is getting increasingly popular among farmers due to labor savings. Combined with a package of technologies, CH4 emission can best be reduced by (1) the practice of midseason drainage instead of continuous flooding, (2) the use of sulfate-containing fertilizers such as ammonium sulfate and phosphogypsum combined with urea; (3) direct seeding crop establishment; and (4) use of low C/N organic fertilizer such as chicken manure and rice straw compost. 相似文献
11.
Effect of Land Management in Winter Crop Season on CH4 Emission During the Following Flooded and Rice-Growing Period 总被引:1,自引:0,他引:1
A greenhouse pot experiment was carried out to study the effect of land management during the winter crop season on methane (CH4) emissions during the following flooded and rice-growing period. Three land management patterns, including water management, cropping system, and rice straw application time were evaluated. Land management in the winter crop season significantly influenced CH4 fluxes during the following flooded and rice-growing period. Methane flux from plots planted to alfalfa (ALE) in the winter crop season was significantly higher than those obtained with treatments involving winter wheat (WWE) or dry fallow (DFE). Mean CH4 fluxes of treatments ALE, WWE, and DFE were 28.6, 4.7, and 4.1 mg CH4 m–2 h–1 in 1996 and 38.2, 5.6, and 3.2 mg CH4 m–2 h–1 in 1997, respectively. The corresponding values noted with continuously flooded fallow (FFE) treatment were 6.1 and 5.2 times higher than that of the dry fallow treatment in 1996 and 1997, respectively. Applying rice straw just before flooding the soil (DFL) significantly enhanced CH4 flux by 386% in 1996 and by 1,017% in 1997 compared with rice straw application before alfalfa seed sowing (DFE). Land management in the winter crop season also affected temporal variation patterns of CH4 fluxes and soil Eh after flooding. A great deal of CH4 was emitted to the atmosphere during the period from flooding to the early stage of the rice-growing season; and CH4 fluxes were still relatively high in the middle and late stages of the rice-growing period for treatments ALE, DFL, and FFE. However, for treatments DFE and WWE, almost no CH4 emission was observed until the middle stage, and CH4 fluxes in the middle and late stages of the rice-growing period were also very small. Soil Eh of treatments ALE and DFL decreased quickly to a low value suitable for CH4 production. Once Eh below –150 mV was established, the small changes in Eh did not correlate to changes in CH4 emissions. The soil Eh of treatments DFE and WWE did not decrease to a negative value until the middle stage of the rice-growing period, and it correlated significantly with the simultaneously measured CH4 fluxes during the flooded and rice-growing period. 相似文献
12.
Field and incubation experiments were conducted during 2007–2009 to study the effect of drainage in the fallow season on CH4 production and emission from permanently flooded rice fields. It was found that drainage in the fallow season significantly
affected the temporal variations of CH4 production and emission from permanently flooded rice fields. CH4 production and emission from permanently flooded rice fields (Treatment FF) mainly occurred during the rice season, where
they were found to be much lower in the late fallow season. No CH4 flux was detected from drained fields (Treatment DF) in the fallow season. Compared with Treatment FF, Treatment DF was delayed
not only its onset of CH4 production and emission, but also appearance of the highest peak of CH4 production during the rice season. A significant positive relationship was observed between CH4 production rates of paddy soil and corresponding CH4 fluxes (P < 0.01). CH4 production in rice roots was the highest in rate at the rice booting stage, but was obviously lower at the rice tillering,
grain filling and ripening stages, and the highest value reached at the same time as the peak of CH4 production occurred in the paddy soil. Drainage in the fallow season significantly decreased CH4 production and emission from Treatment FF. Compared with Treatment FF, Treatment DF was about 42–61% lower in mean CH4 production rate in the paddy soil during the rice season, and was reduced by approximately 56% in mean CH4 production rate in rice roots. Accordingly, Treatment DF was 20.6–30.2 g CH4 m−2, 39–52% lower than Treatment FF in total CH4 emission during the rice season, and 44–57% lower in annual total CH4 emission. Rice yield in Treatment DF tended to be 4–7% lower than that in Treatment FF. 相似文献
13.
To reduce the involved uncertainties in the methane budget estimation from rice paddy fields, the methodologies of methane budget estimation have been revised mainly on the basis of measurements undertaken in the Methane Asia Campaign (MAC-98). Studies from other continuous measurements of methane emission from rice paddy fields over last few years in other Asian countries were also used. The Asian Development Bank (ADB) sponsored Methane Asia Campaign (MAC-98) in which India, China, Indonesia, Philippines, Vietnam and Thailand participated during 1998–99.The resulting CH4 measurements have shown that apart from water management, soil organic carbon also plays a significant role in determination of methane emission factors from rice paddy fields. The available data from participating countries reveal that paddy soils can be broadly classified into low soil organic carbon (<0.7%C) and high soil organic carbon (>0.7% C) classes which show average methane emission factors of 12 (5–29) and 36 (22–57) g m–2 respectively for continuously flooded (CF) fields without organic amendments compared to the IPCC–96 emission factor of 20 g m–2. Similarly for irrigated paddy fields with intermittently flooded multiple aeration (IF-MA) without organic amendments, the MAC-98 gives average emission factors of 2 (0.06–3) and 6 (0.6–24) g m–2, respectively, for low and high organic carbon soils compared to IPCC–96 emission factor of 4 (0–10) g m–2. Incorporation of soil organic carbon along with classification based on water management and organic amendments in the estimation of CH4 emissions from rice paddy fields yields more characteristic emission factors for low and high organic carbon soils and is, therefore, capable of reducing uncertainties. 相似文献
14.
The effect of nitrogen fertilizer use and other practices on methane emission from flooded rice 总被引:1,自引:0,他引:1
K. Minami 《Nutrient Cycling in Agroecosystems》1995,40(1):71-84
Methane (CH4) flux measurements from rice paddy fields in the world and its controlling factors, especially fertilizer effects are summarized. The measurements at rice paddy fields in various locations of the world showed that there were large temporal variations of CH4 flux and that the flux differed markedly with climate, characteristics of soil and paddy, application of organic matter and mineral fertilizer, and agricultural practices. From the data, it appears that identifying and controlling CH4 flux factors have a potential to reduce CH4 emission from rice cultivation. Potential mitigation options include: the form and amount of nitrogen and other chemical fertilizers, the method of fertilizer applications, the application of other chemical amendments, water management and cultivation practices. 相似文献
15.
Effects of Elevated CO2 and Temperature on Methane Production and Emission from Submerged Soil Microcosm 总被引:1,自引:0,他引:1
Incubation experiments were conducted under controlled laboratory conditions to study the interactive effects of elevated carbon dioxide (CO2) and temperature on the production and emission of methane (CH4) from a submerged rice soil microcosm. Soil samples (unamended soil; soil + straw; soil + straw + N fertilizer) were placed in four growth chambers specifically designed for a combination of two levels of temperature (25 °C or 35 °C) and two levels of CO2 concentration (400 or 800 mol mol–1) with light intensity of about 3000 Lx for 16 h d–1. At 7, 15, 30, and 45 d after incubation, CH4 flux, CH4 dissolved in floodwater, subsurface soil-entrapped CH4, and CH4 production potential of the subsurface soil were determined. The results are summarized as follows: 1) The amendment with rice straw led to a severalfold increase in CH4 emission rates, especially at 35 °C. However, the CH4 flux tended to decrease considerably after 15 d of incubation under elevated CO2. 2) The amount of entrapped CH4 in subsurface soil and the CH4 production potential of the subsurface soil were appreciably larger in the soil samples incubated under elevated CO2 and temperature during the early incubation period. However, after 15 d, they were similar in the soil samples incubated under elevated or ambient CO2 levels. These results clearly indicated that elevated CO2 and temperature accelerated CH4 formation by the addition of rice straw, while elevated CO2 reduced CH4 emission at both temperatures. 相似文献
16.
Crop Management Affecting Methane Emissions from Irrigated and Rainfed Rice in Central Java (Indonesia) 总被引:4,自引:0,他引:4
P. Setyanto A.K. Makarim A.M. Fagi R. Wassmann L.V. Buendia 《Nutrient Cycling in Agroecosystems》2000,58(1-3):85-93
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. 相似文献
17.
Prabhat K. Gupta C. Sharma Sumana Bhattacharya A.P. Mitra 《Nutrient Cycling in Agroecosystems》2002,64(1-2):19-31
A comprehensive scientific assessment of CH4 budget estimation for Indian rice paddies, based on a decade of measurements in India, is presented. Indian paddy cultivation areas contain soils that have low to medium levels of soil organic carbon. The average seasonally integrated CH4 flux (E
sif) values calculated from these measurements were 15.3 ± 2.6 g m–2 for continuously flooded (CF), 6.9 ± 4.3 g m–2 for intermittently flooded (IF) single aeration (SA) and 2.2 ± 1.5 g m–2 for IF multiple aeration (MA) rice ecosystems. For CF and IF (MA) rice ecosystems having high soil organic carbon, without organic amendments, the CH4 flux (E
sif) may be increased by 1.7 times relative to low soil organic carbon, whereas it may enhance by 5.3 for CF if amended organically. Organic amendment and high soil organic carbon paddy areas do not alter the methane budget estimates for India (3.6±1.4 TgY–1) much, due to their small paddy harvested area. Methane estimated using average emission factors (E
sif) for all paddy water regimes, which include harvested areas having soils with high organic carbon and organic amendments, may give a budget of 5 TgY–1 for India. 相似文献
18.
R. Wassmann H.U. Neue R.S. Lantin K. Makarim N. Chareonsilp L.V. Buendia H. Rennenberg 《Nutrient Cycling in Agroecosystems》2000,58(1-3):13-22
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. 相似文献
19.
Xianglan Li Wenping Yuan Hua Xu Zucong Cai Kazuyuki Yagi 《Nutrient Cycling in Agroecosystems》2011,91(3):293-305
Midseason aeration (MSA) of rice paddy fields functions to mitigate CH4 emission by a large margin, while simultaneously promoting N2O emission. Alternation of timing and duration of MSA would affect CH4 and N2O emissions from intermittently irrigated rice paddies. A pot trial and a field experiment were conducted to study the effect
of timing and duration of MSA on CH4 and N2O emissions from irrigated lowland rice paddy soils in China. Four different water regimes, i.e., early aeration, normal aeration
(the same as the local practice in timing and duration of aeration), delayed aeration, and prolonged aeration, were adopted
separately and compared with respect to global warming potential (GWP) of CH4 and N2O emissions and rice yields as well. Total emission of CH4 from the rice fields ranged from 28.6 to 64.1 kg CH4 ha−1, while that of N2O did from 1.71 to 6.30 kg N2O–N ha−1 during the study periods. Compared with the local practice, early aeration reduced CH4 emission by 13.3–16.2% and increased N2O emission by 19.1–68.8%, while delayed aeration reduced N2O emission by 6.8–26.0% and increased CH4 emission by 22.1–47.3%. The lowest GWP of CH4 and N2O emissions occurred in prolonged aeration treatment, however, rice grain yield was reduced by 15.3% in this condition when
compared with normal practice. It was found in the experiments that midseason aeration starting around D 30 after rice transplanting,
just like the local practice, would optimize rice yields while simultaneously limiting GWPs of CH4 and N2O emissions from irrigated lowland rice fields in China. 相似文献
20.
Factors influencing methane emission from peat soils: Comparison of tropical and temperate wetlands 总被引:2,自引:0,他引:2
K. Inubushi S. Otake Y. Furukawa N. Shibasaki M. Ali A. M. Itang H. Tsuruta 《Nutrient Cycling in Agroecosystems》2005,71(1):93-99
Methane (CH4) emissions from peat soils in tropical and temperate wetlands were compared. Annual CH4 emission rates in Ozegahara, the largest wetland on Honshu main island, Japan, were higher than in drained forest wetland areas examined in Indonesia. Methane emissions from the lowland paddy fields examined in Indonesia were higher than those of peaty paddy fields in Japan. There was generally a positive correlation (r2 = 0.09; P < 0.1) between CH4 emissions and CH4 production activities in wetland soils. In Ozegahara, there was a positive relationship (r2 = 0.80; P < 0.01) between CH4 production activities and soil pH, but there was no such relationship in Indonesia. The range of soil pH in Ozegahara was 5–7, while pH values in the Indonesian sites were lower than 5. There was a positive response of CH4 emission with respect to groundwater level in all of these areas. In Indonesia, land-use change from swamp and drained forest to cassava or coconut field lowered groundwater levels and decreased CH4 emission, while change to lowland paddy raised the groundwater level and increased CH4 emission. Addition of acetate generally inhibited CH4 production during the early period (until 2 weeks) of incubation, then enhanced it afterward in both Ozegahara and Indonesian wetland soils. Addition of hydrogen mostly enhanced CH4 production. From the results of this study, CH4 fluxes from peat soil to the atmosphere were positively correlated with CH4 production activities, and CH4 production activity in peat soil was regulated by soil pH, while land-use change from wetland to upland crop lowered groundwater level and thus reduced CH4 production and enhanced CH4 oxidation. 相似文献