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1.
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
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A Four-Year Record of Methane Emissions from Irrigated Rice Fields in the Beijing Region of China 总被引:2,自引:0,他引:2
Z.Y. Wang Y.C. Xu Z. Li Y.X. Guo R. Wassmann H.U. Neue R.S. Lantin L.V. Buendia Y.P. Ding Z.Z. Wang 《Nutrient Cycling in Agroecosystems》2000,58(1-3):55-63
Methane (CH4) emissions from irrigated rice fields were measured using an automatic sampling-measuring system with a closed chamber method in 1995–98. Average emission rates ranged from 11 to 364 mg m–2 d–1 depending on season, water regime, and fertilizer application. Crop management typical for this region (i.e., midseason drainage and organic/mineral fertilizer application) resulted in emission of 279 and 139 mg CH4 m–2 d–1 in 1995 and 1997, respectively. This roughly corresponds to emissions observed in other rice-growing areas of China. Emissions were very intense during the tillering stage, which accounted for 85% of total annual emission, but these were suppressed by low temperature in the late stage of the season. The local irrigation practice of drying at mid-season reduced emission rates by 23%, as compared with continuous flooding. Further reduction of CH4 emissions could be attained by (1) alternate flooding/drying, (2) shifting the drainage period to an earlier stage, or (3) splitting drainage into two phases (of which one is in an earlier stage). Emission rates were extremely sensitive to organic amendments: seasonal emissions from fields treated with pig manure were 15–35 times higher than those treated with ammonium sulfate in the corresponding season. On the basis of identical carbon inputs, CH4 emission potential varied among organic amendments. Rice straw had higher emissions than cattle manure but lower emissions than pig manure. Use of cultivar Zhongzhuo (modern japonica) reduced CH4 emission by 56% and 50%, in 1995 and 1997, respectively, as compared with Jingyou (japonica hybrid) and Zhonghua (tall japonica). The results give evidence that CH4 emissions from rice fields in northern China can be reduced by a package of crop management options without affecting yields. 相似文献
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K. Bharati S. R. Mohanty P.V.L. Padmavathi V. R. Rao T. K. Adhya 《Nutrient Cycling in Agroecosystems》2000,58(1-3):389-394
The influence of six nitrification inhibitors (NI) on CH4 production in an alluvial soil under flooded condition was studied in a laboratory incubation experiment. The inhibition of CH4 production followed the order of sodium azide > dicyandiamide (DCD) > pyridine > aminopurine > ammonium thiosulfate > thiourea. Inhibition of CH4 production in DCD-amended soils was related to a high redox potential, low pH, low Fe2+ and lower readily mineralizable carbon content as well as lower population of methanogenic bacteria and their activity. In the presence of higher levels of urea N (40 g), the inhibitory effect of DCD was only partially alleviated. Results indicate that several NIs can differentially regulate CH4 production in a flooded alluvial soil. 相似文献
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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
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Methane (CH4) is produced in flooded rice fields by anaerobic decomposition of applied organic residues, root-derived materials and native soil organic matter (SOM). Since CH4 is an important greenhouse gas it is important to understand, and to be able to model, the processes which produce it. Anoxic incubation of soils employed in the cultivation of irrigated rice, with and without the addition of various potentially-available organic substrates, provides information on potential CH4 emissions which can be incorporated into process-based models. In this study, a simple two-pool model is employed to simulate the CH4 production of a number of anaerobically-incubated rice soils, and their responses to amendment with a variety of organic substrates. The model differs from most accounts of SOM transformation in that kinetics are microbially-mediated rather than first-order. Simulation yields a reproduction of the general trends of CH4 production in response to amendments of acetate, glucose and rice straw. 相似文献
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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
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Tween80对稻草水解及同步糖化与发酵产乳酸的影响 总被引:2,自引:0,他引:2
在生物转化纤维原料产乳酸的过程中,酶解纤维原料产还原糖是限速步骤。为了获得较高的产物产率,需较高的酶用量,这使大规模酶解废弃纤维原料的成本很高。对吐温80在酶解稻草纤维素产糖,以及耐高温乳酸菌同步糖化发酵稻草产乳酸过程中的作用进行了考察。初步结果表明,吐温80加入可使保持同等程度的水解率所需的酶用量降低,添加0.2 g/g底物的吐温80到酶用量10 FPU/g体系,水解120 h的糖产率为292.2 mg/g,比不加表面活性剂体系的糖产率增加了11%;添加0.7 g/L的吐温80进行同步糖化与发酵72 h,能使乳酸产量提高24.2%。 相似文献
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自水解预处理对稻草化学成分及酶解性能的影响 总被引:1,自引:3,他引:1
研究了自水解处理对稻草秸秆主要化学成分及酶解糖化效率的影响。结果显示:在100~160℃下对稻草进行自水解预处理,酸溶木质素的脱除程度随着自水解温度的升高而增大,而Klason木质素含量几乎没有变化,几乎全部SiO2仍然保留在预处理后草片中;稻草高聚糖的降解程度随着自水解温度的升高而增加,但由于自水解液酸性较弱,大量高聚糖仍保留在草片中;自水解预处理有利于促进稻草的酶解糖化,随着自水解预处理温度的升高和酶用量的增大,酶解液中各种聚糖得率均有不同程度的提高,但自水解温度的影响显得更为重要;经160℃自水解预处理的稻草在40 FPU/g混合酶用量下,葡聚糖和木聚糖的总转化率约为68%和45%,总糖转化率近60%。 相似文献
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Karolina Oszust Magdalena Fr?c Agata Gryta Nina Bilińska 《International journal of molecular sciences》2014,15(6):9907-9923
The knowledge about microorganisms—activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions) significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential). Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a) ecological based on the use of probiotic preparations and organic fertilization (b) conventional—with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA) was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP) of PCR ammonia monooxygenase α-subunit (amoA) gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application. 相似文献
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研究了醋酸预处理对稻草主要化学成分及酶水解糖化效率的影响。在160℃下以不同的醋酸用量(0~4%)对稻草进行处理,预处理后稻草的Klason木质素含量基本保持不变,约60%的酸溶木质素被脱除;灰分含量(质量分数)约下降30%,灰分中SiO2则几乎全部保留在预处理浆料中。预处理醋酸用量的增加对酸溶木质素和灰分含量的变化均无显著影响。预处理后高聚糖的降解程度随醋酸用量的增加而上升,其中半纤维素的降解程度尤为显著,阿拉伯聚糖、半乳聚糖大量溶出。对经醋酸预处理稻草的酶水解研究表明,预处理中醋酸用量的增加无助于酶水解液中还原糖得率的提高。稻草于160℃下经不添加醋酸的自水解预处理后,其酶解还原糖得率均高于经醋酸预处理的稻草,当纤维素酶用量为40 FPU/g(对底物)时,稻草中高聚糖的酶水解转化效率最高,葡聚糖、木聚糖的转化率分别为67.8%和45.3%,总糖转化率为58.8%。 相似文献
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《化肥工业》2015,(5)
通过"3414"田间试验设计,对氮、磷、钾肥配施进行试验研究,获得豫南稻区水稻最佳产量及最高产量氮、磷、钾肥施肥配比。试验研究结果表明:当氮、磷、钾肥用量分别为176.32 kg/hm2,92.87 kg/hm2和112.40 kg/hm2时,水稻最高产量可达9 139.72 kg/hm2,施肥质量比N∶P∶K=1.000∶0.527∶0.637;当氮、磷、钾肥施用量分别为164.05 kg/hm2,108.40 kg/hm2和115.68 kg/hm2时,水稻最佳产量为9 035.70 kg/hm2,施肥质量比N∶P∶K=1.000∶0.661∶0.705。 相似文献
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前期研究发现,平菇预处理稻草表现出比较好的脱木素选择性和纤维素酶水解效果。为了使预处理后的稻草在纤维素酶水解过程中得到更多的单糖,通过向平菇预处理稻草固体培养基中添加麸皮、玉米皮和木聚糖,研究外加碳源对平菇降解稻草木素的选择性及后续酶水解效果的影响。结果表明,添加适量的麸皮和木聚糖可提高平菇处理稻草的脱木素选择性。麸皮和木聚糖添加量为稻草粉的10%时,脱木素选择系数分别由对照的1.86增加至2.58和2.03;预处理样品酶解后原料中总糖的46.8%和45.9%转化为可发酵单糖,分别比对照的35.5%提高了30%和28%。添加玉米皮对平菇预处理酶解效果影响相对较小,添加量为5%时,预处理样品酶解后总糖转化率仅比对照提高15%,增加添加量酶解总糖转化率反而低于对照样品。 相似文献
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Jana er Florence Huynh Faith Ly tpn Vinter Markta Kadle
kov Vendula Krtk Daniela M
alov Marek Koutný Christopher Wallis 《International journal of molecular sciences》2022,23(24)
Conventional and also biodegradable polymer microplastics have started to be broadly present in the environment, if they end up in soil, they may influence both abiotic and biotic soil properties. In this study, the interactions of polyethylene wax together with three biodegradable polyesters PLA, PHB and PBAT with a soil matrix were investigated over a 1-year incubation period. Soil organic matter content was measured using UV–VIS, the microbial biomass amount was measured using qPCR, the mineralisation of polymers was measured using UGA 3000, the surface of polymers was observed with SEM, live/dead microorganisms were determined by fluorescent microscopy and microbial consortia diversity was analyzed using NGS. The amount of humic substances was generally higher in incubations with slowly degrading polyesters, but the effect was temporary. The microbial biomass grew during the incubations; the addition of PHB enhanced fungal biomass whereas PE wax enhanced bacterial biomass. Fungal microbial consortia diversity was altered in incubations with PHB and PBAT. Interestingly, these two polyesters were also covered in biofilm, probably fungal. No such trend was observed in a metagenomic analysis of bacteria, although, bacterial biofilm was probably formed on the PE520 surface. Different methods confirmed the effect of certain polymers on the soil environment. 相似文献
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As part of a series of papers describing the use of a simulation model to extrapolate experimental measurements of methane (CH4) emissions from rice fields in Asia and to evaluate the large-scale effect of various mitigation strategies, the collation and derivation of the spatial databases used are described. Daily weather data, including solar radiation, minimum and maximum temperatures, and rainfall were collated from 46 weather stations from the five countries in the study, namely China, India, Indonesia, Philippines, and Thailand. Quantitative soil data relevant to the input requirements of the model were derived by combining data from the World Inventory of Soil Emissions (WISE) database, the ISIS database, and the FAO Digital Soil Map of the World (FAO-DSMW). These data included soil pH; organic carbon content; sand, silt, and clay fractions; and iron content for top and subsoil layers, and average values of bulk density and available water capacity for the whole profile. Data on the areas allocated to irrigated, rainfed, upland, and deepwater rice at the province or district level were derived from the Huke & Huke (1997) database developed at IRRI. Using a geographical information system (GIS), a series of georeferenced data sets on climate, soils, and land use were derived for each country, at the province or district level. A summary of the soil-related derived databases is presented and their applicationn for use in global change modeling discussed. 相似文献