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AbstractIntegrated rice–fish culture is a competitive alternative to rice monoculture for environmental sustainability and food productivity. Compared to rice monoculture, rearing fish in rice field ecosystems could increase food (rice and fish) production from this coculture. Moreover, the water productivity of rice–fish coculture is considerably higher than that of rice monoculture, because of double cropping. Despite these benefits, rice–fish coculture has not yet been broadly practiced. One of the potential challenges for the wider adoption of rice–fish coculture is water management. There are two forms of water involved in rice–fish cultivation: (1) blue water–surface and groundwater, and (2) green water–soil water from rainfall. The aim of this article is to focus on key factors determining the adoption of rice–fish cultivation through the effective utilization of blue–green water. We suggest that the efficient application of blue and green water in rice–fish coculture could help confronting water scarcity, reducing water footprint, and increasing water productivity.

Although rice production landscapes are often the scene of homicides, vertebrate decomposition and associated arthropods have never been described from rice paddies. Tropical rice landscapes are typically composed of irrigated/non-irrigated rice fields, fallow land (i.e., uncultivated fields), and low earthen levees (bunds) used as access pathways. The specific microclimatic and environmental conditions associated with each subunit of rice field landscapes are likely to impact carcass decomposition as well as the arthropod species associated with carrion. Here, we tested the hypothesis that the combined effects of constraints on arthropod colonization and survival, scarcity of necromass, limited habitat architecture, and recurrent disturbance limit the ability of carrion-related arthropods to colonize corpses and large carcasses in tropical rice-fields. Our results from monitoring pig carcasses in Philippine rice fields indicated that vertebrate decomposition in irrigated fields was slower and incomplete when compared to non-irrigated fields and bunds. Carcasses were colonized by a small complex of carrion-related arthropods that differed in composition and relative species abundance between dry bunds and relatively humid rice paddies. Fire ants (Solenopsis germinata) were observed frequently on carcasses exposed on bunds, rarely in non-irrigated fields, and almost never in irrigated fields. The presence of fire ants was associated with reduced blow fly (Chrysomya megacephala) abundance. Taken together, this indicates that the arthropod fauna associated with carcasses in tropical rice fields is relatively simple in contrast to the generally high arthropod diversity reported for other ecosystems at tropical latitudes. The limited richness of the community also means that an understanding of the development of one abundant calliphorid blow fly, C. megacephala, may be sufficient to investigate deaths and homicides under conditions similar to the ones described in th

Avian malaria and related haemosporidians (genera Haemoproteus, Plasmodium and Leucocytozoon) infect most clades of bird. Although these parasites are present in almost all continents, they have been irregularly studied across different geographical regions. Despite the high bird diversity in Asia, the diversity of avian haemosporidians in this region is largely unknown. Moreover, anthropogenic changes to habitats in tropical regions may have a profound impact on the overall composition of haemosporidian communities. Here we analyzed the diversity and host association of bird haemosporidians from areas with different degrees of anthropogenic disturbance in Myanmar, revealing an unexplored diversity of these parasites (27% of newly-discovered haemosporidian lineages, and 64% of new records of host–parasite assemblages) in these tropical environments. This newly discovered diversity will be valuable for detecting host range and transmission areas of haemosporidian parasites. We also found slightly higher haemosporidian prevalence and diversity in birds from paddy fields than in individuals from urban areas and hills, thus implying that human alteration of natural environments may affect the dynamics of vector-borne diseases. These outcomes provide valuable insights for biodiversity conservation management in threatened tropical ecosystems.

Management of the negative environmental impact of pesticides used in paddy fields requires the quantification of the emissions reaching relevant environmental compartments and the determination of the factors that influence such emissions. The present study is the first to develop a simulation model for estimating the fractions emitted to the air (fair), surface water (fsw), and the fractions that leach vertically (fvl) of pesticides applied in paddy fields for life cycle assessments (LCA). The emission quantification methods are based on the properties of the active ingredients of the pesticides and management aspects such as formulations (granular or liquid) and the water-holding period following application. The emission fractions of 37 pesticides used commonly in Japan were estimated using the presented model. A sensitivity analysis was conducted by adjusting parameters applied in the model to reveal their influence on the emission fractions. The parameters influencing fair included the formulation applied, while the water-holding period and waterproofing of the levee influenced fsw regardless of the formulation adopted, suggesting that local management could effectively reduce emissions to surface water. In addition, soil organic carbon content influenced fvl greatly, suggesting considerable regional variation in the emission factor. The developed model is expected to greatly improve the realism of impact assessment of pesticide in LCAs for paddy rice cultivation, considering it fills a gap in the fate model used in LCAs to estimate pesticide emissions to air, surface water, and soil in paddy fields.

A Plant Microbial Fuel Cell (Plant-MFCs) has been studied both in the lab and in a field. So far, field studies were limited to a more conventional Plant-MFC design, which submerges the anode in the soil and places the cathode above the soil surface. However, for a large scale application a tubular Plant-MFC is considered more practical since it needs no topsoil excavation. In this study, 1 m length tubular design Plant-MFC was installed in triplicate in a paddy field located in West Kalimantan, Indonesia. The Plant-MFC reactors were operated for four growing seasons. The rice paddy was grown in a standard cultivation process without any additional treatment due to the reactor instalation. An online data acquisition using LoRa technology was developed to investigate the performance of the tubular Plant-MFC over the final whole rice paddy growing season. Overall, the four crop seasons, the Plant-MFC installation did not show a complete detrimental negative effect on rice paddy growth. Based on continuous data analysis during the fourth crop season, a continuous electricity generation was achieved during a wet period in the crop season. Electricity generation dynamics were observed before, during and after the wet periods that were explained by paddy field management. A maximum daily average density from the triplicate Plant-MFCs reached 9.6 mW/m2 plant growth area. In one crop season, 9.5-15 Wh/m2 electricity can be continuously generated at an average of 0.4 ± 0.1 mW per meter tube. The Plant-MFC also shows a potential to be used as a bio sensor, e.g., rain event indicator, during a dry period between the crop seasons.

[EN] The cultivation of rice (Oriza sativa L.) under Mediterranean conditions regularly requires the use of treated wastewater due to shortage of freshwater. As a consequence, the intensification of rice production to supply the uprising demand of grain could break the stability between agriculture and environment. In this work, we studied the occurrence and distribution of pyrethroids in surface water and groundwater collected during two periods (flooding and dry soil conditions) in paddy fields located in the Spanish Mediterranean coast. Pyrethroids were detected at concentrations ranging from 14 to 1450 ng L-1 in surface water and from 6 to 833 ng L-1 in groundwater. The results obtained were valuated statistically using principal component analysis, and differences between both sampling campaigns were found, with lower concentrations of the target compounds during the flooding sampling event. Moreover, a geographic information system program was used to represent a model distribution of the obtained results, showing wastewater treatment plants as the main sources of contamination and the decrease of pyrethroids during flooding condition when water flows over the paddy fields. The impact of these compounds on water quality was discussed.

[EN] The cultivation of rice (Oriza sativa L.) under Mediterranean conditions regularly requires the use of treated wastewater due to shortage of freshwater. As a consequence, the intensification of rice production to supply the uprising demand of grain could break the stability between agriculture and environment. In this work, we studied the occurrence and distribution of pyrethroids in surface water and groundwater collected during two periods (flooding and dry soil conditions) in paddy fields located in the Spanish Mediterranean coast. Pyrethroids were detected at concentrations ranging from 14 to 1450 ng L-1 in surface water and from 6 to 833 ng L-1 in groundwater. The results obtained were valuated statistically using principal component analysis, and differences between both sampling campaigns were found, with lower concentrations of the target compounds during the flooding sampling event. Moreover, a geographic information system program was used to represent a model distribution of the obtained results, showing wastewater treatment plants as the main sources of contamination and the decrease of pyrethroids during flooding condition when water flows over the paddy fields. The impact of these compounds on water quality was discussed.

Silicon (Si) enhances the stress resistance of rice plants. Silicon cycling in paddy fields is, however, still poorly studied. We examined relationships between Si forms in topsoil and plant Si uptake for four Vietnamese and three Philippine regions (ten fields per region). Mean rice straw Si concentrations within regions ranged from 3.0 to 8.4 %. For most of the Vietnamese fields they were lower than the critical value of 5.0 %, suggesting Si limitation of plant growth. For fields with low Si availability, straw Si concentrations were positively related to acetate-extractable Si in topsoil (i.e., dissolved and adsorbed Si). Such a relationship was not found for fields with high Si availability, presumably due to a maximum Si uptake capacity of rice plants. Mean annual Si uptake by rice within regions ranged from 0.31 to 1.40 Mg Si ha−1 year−1. They are determined by the continuous supply of plant-available Si during the cropping season and by aboveground biomass production. Weatherable silicate minerals mainly determine spatial differences in supply of plant-available Si. Concentrations of alkaline carbonate-extractable Si in topsoil (an estimate of amorphous Si) largely differed between regions; (regional means of 2.2–16.7 g Si kg−1). The differences in concentrations and amounts in topsoil are not related to phytolith (i.e., amorphous Si in straw) input, presumably due to other yet uncertain factors on carbonate-extractable Si in soil (e.g., differences in phytolith solubility or contribution of non-phytolith sources to Si in the extracts).

The effect of using low densities of different dispensing technologies on mating disruption of the striped rice stem borer, Chilo suppressalis Walker, was evaluated in the rice-growing area of Valencia (Spain) from 2011 to 2013. The reduction of the current number of release points (30 polymeric dispensers/ha) was investigated by installing 3 aerosol devices per ha (Experiments 1 and 2) or with clusters of hand-applied dispensers (10 or 5 release points/ha; Experiment 3). The influence of pheromone blend on disruption was also studied by loading aerosol devices with the three-component blend or only the main pheromone compound, Z-11-hexadecenal. Results showed that the installation of 3 aerosol devices/ha or clusters of passive dispensers (total dose: 6.6-7.9 g/ha) proved equally effective as the conventional treatment with 30 Selibate (R) CS dispensers/ha (similar to 5 g/ha), reducing damage below 1% of infested plants. Although the treatment with 3 aerosol devices/ha loaded with Z-11-hexadecenal provided control of damage comparable to the conventional mating disruption treatment, the higher captures recorded suggest that mating disruption with the incomplete pheromone blend is only slightly effective in the tested conditions. These changes in the number of point sources and pheromone blend could represent important advantages for the implementation of mating disruption against C. suppressalis. (C) 2016 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved.

Methane emissions are affected by agricultural practices. Agriculture has increased in scale and intensity because of greater food, feed and energy demands. The application of chemical fertilizers in agriculture, particularly in paddy fields, has contributed to increased atmospheric methane emissions. Using organic fertilizers may improve crop yields and the methane sink potential within agricultural systems, which may be further improved when combined with beneficial microbes (i.e. biofertilizers) that improve the activity of methane oxidizing bacteria such as methanotrophs. Biofertilizers may be an effective tool for agriculture that is environmentally beneficial compared to conventional inorganic fertilizers. This review highlights and discusses the interplay between ammonia and methane oxidizing bacteria, the potential interactions of microbial communities with microbially-enriched organic amendments and the possible role of these biofertilizers in augmenting the methane sink potential of soils. It is suggested that biofertilizer applications should not only be investigated in terms of sustainable agriculture productivity and environmental management, but also in terms of their effects on methanogen and methanotroph populations.

Rice fields provide not only a staple food but are also bio-diverse and multi-functional ecosystems. Wild food plants are important elements of biodiversity in rice fields and are critical components to the subsistence of poor farmers. The spatial and seasonal distribution of wild food plants were analysed across different sub-systems occurring within paddy ecosystems in two adjacent rice farming villages in Kalasin, Northeast Thailand. Data were collected in 102 sampling sites corresponding to seven sub-systems including tree rows, mounds, field margins, shelters, ponds, pond margins and levees. Frequency of occurrence and absolute abundance were quantified for each species in the two seasons of two years, and data on uses of wild food plant species were collected through focus group discussions. A total of 42 species from 28 botanical families were reported, and one third of these have been classified as weeds of rice by other authors. Results show that species abundance, frequency of occurrence and diversity varied seasonally and spatially within paddy rice ecosystems. Higher diversity indexes were observed in the monsoon in most sub-systems. The most diverse sub-systems in the monsoon were shelters, mounds and pond margins, and tree rows and mounds in the dry season. Field margins, ponds and levees presented lower diversity, but are habitat of aquatic species important for the local diet, such as Ipomoea aquatica and Marsilea crenata. The herbs Lobelia sp. and Glinus oppositifolius, classified as rice weeds, were most abundant species in the dry season and frequently consumed. Leucaena leucocephala, of which the roots, leaves and fruits are commonly consumed as vegetable, was the most abundant tree in most sub-systems. More than half of the species were specific to one or two sub-systems due to particular niche requirements. Three quarters of wild food plant species had additional uses besides food; with ten different types of use and multiple use categories occ

Concerns have been raised over the sustainability of intensive rice cultivation, where the use of chemical fertilizers and pesticides has been associated with numerous environmental problems. The objective of this study was to test the effect of the herbicide azimsulfuron on important soil functions as affected by amendment with a byproduct of the olive oil industry. Soil was collected from a Mediterranean rice field. Part of it was amended with alperujo compost (AC). Amended and unamended soils were incubated for 43 days in presence or not of azimsulfuron, under anoxic-flooded (AF) and oxic-unflooded (OU) conditions. We monitored the dissipation of the herbicide azimsulfuron, C mineralization, soil microbial biomass (SMB) and dissolved organic carbon (DOC) content and its nature. Under AF conditions, the application of compost produced an increase in the dissipation of the herbicide (up to 12.4%). It was related with the higher DOC content, 4 times higher than under OU conditions. Though increases in carbon turnover (under AF and OU conditions) and reduction of SMBC after herbicide application (only under AF conditions) were observed, the differences were not statistically significant. The application of this organic amendment is presented as an efficient management strategy to increase C turnover in agricultural soils and reduce some of the negative effects derived from the application of azimsulfuron under flooded conditions.

大型鰓脚類の分布状況を把握するため，佐渡を除く新潟県の水田において調査を行った．累計で8000筆を超える水田を調査した結果，5種の大型鰓脚類が見つかった：カイエビ，トゲカイエビ，ムスジヒメカイエビ，タマカイエビ，ホウネンエビ．このうち，カイエビは越後平野北部で連続性のいい分布を持ち，その南限は歴史的な景観の境界と一致する．, Surveys of large branchiopods of the rice paddies in Niigata Prefecture excluding Sado Island, Japan, were performed to identify the distribution. Five species were found as a result of the surveys conducted in more than 8,000 paddies (cumulative): Caenestheriella gifuensis (Ishikawa), Lepthersteria kawachiensis Ueno, Eulimnadia packardiana Ishikawa, Lynceus biformis (Ishikawa) and Branchinella kugenumaensis (Ishikawa). Of these, C. gifuensis has a continuous wide distribution in the north part of the Echigo Plain with a sharp border in the south, which is corresponding to the historical landscape border.

富山県における大型鰓脚類の分布調査を行い次の４種を確認した：カイエビ，ムスジヒメカイエビ，タマカイエビ，ホウネンエビ．このうち3種が常願寺川扇状地扇央に生息し，黒部川扇状地の扇央から扇端では大半の水田からカイエビが確認された．越後平野の大型鰓脚類は扇状地を避けるように分布するが，富山県では扇状地が大型鰓脚類の主要な生息地となっている．この差異は土地利用の履歴の違いが大きく作用していると考えられる．, Distribution of large branchiopods inhabited rice paddies were investigated in Toyama Prefecture, Japan. Four species were found: Caenestheriella gifuensis (Ishikawa), Eulimnadia packardiana Ishikawa, Lynceus biformis (Ishikawa) and Branchinella kugenumaensis (Ishikawa). Of these three inhabit at the center of Joganji-gawa alluvial fan, and C. gifuensis inhabits in many paddies at the toe and center of Kurobe-gawa alluvial fan. Thus the paddies of alluvial fans are important habitat for large branchiopods in this area, but the population of the Echigo Plain is low or not distributed at the alluvial fans. The difference should be mainly due to the differences in the land-use history.

En el año 2013 se detectó la presencia de Leersia oryzoides en campos de arroz de la zona arrocera valenciana. El objetivo de este trabajo ha sido realizar un seguimiento de las parcelas de arroz en donde aparecieron en el año 2013 y detectar la presencia de esta especie en otros campos de arroz de la zona. Efectivamente se ha identificado individuos de Leersia oryzoides en parcelas en las que no se tenía constancia previa de esta mala hierba, pasando de 4 parcelas en el año 2013 a 23 en 2014. En algunas parcelas los niveles de infestación han sido importantes, superiores a un 50% de recubrimiento, llegándose en algún caso a la destrucción total de cultivo y malas hierbas por parte de los propietarios, mediante tratamiento con glifosato, con el fin de controlar el problema., In 2013 Leersia oryzoides was detected in rice fields in Valencia. The aim of this study was to track the rice paddies where Leersia was detected in 2013 and survey in 2014 for L. oryzoides presence in other rice fields in the area. The presence of L. oryzoides has been detected in plots with no previous evidence of the presence of this weed, passing from 4 plots in 2013 to 23 in 2014. In some plots the level of infestation level has been important, exceeding 50 % of coverage. In order to stop the problem, in some of those plots total destruction of the crop and weeds have been adopted using a glyphosate treatment by the owners.

Background and aims Silicon (Si) is beneficial for rice plants. It increases their resistance against pests and diseases. Although Si uptake of rice crops is often higher than nitrogen uptake, studies on forms and fluxes of plant-available Si in paddy systems are scarce. Methods In 2011/12 we assessed acetate-, oxalate-, and carbonate-extractable Si in topsoil (i.e., Si forms that contribute to the pool of ‘readily soluble Si’) and related them to plant-Si-uptake (n = 10 paddies; Laguna region; Philippines). In the wet season 2013, we determined changes in (i) plant-Si-uptake, (ii) dissolved Si (dSi) and (iii) acetate-extractable Si in topsoils in a high temporal resolution (n = 5 paddies, every ~10 days), and assessed dSi fluxes via irrigation, rain, drainage and percolation (n = 3 paddies). Results Si storage in plants at harvest was 0.73 ± 0.12 Mg ha−1 (>78 % in straw), and not related to different Si forms in topsoils. Large stocks of carbonate-extractable Si (2–29 Mg ha−1) suggest an accumulation of ‘phytoliths’ (amorphous Si oxides in straw) in topsoil due to irrigation. Acetate-extractable Si in topsoils hardly changed during plant growth, suggesting dSi and absorded Si was continuously contributed by irrigation and phytolith dissolution. Conclusions Geo-/pedologic conditions, irrigation, and straw management are major determinants on Si storage and fluxes in irrigated rice paddies.

En el año 2013 se detectó la presencia de Leersia oryzoides en campos de arroz de la zona arrocera valenciana. El objetivo de este trabajo ha sido realizar un seguimiento de las parcelas de arroz en donde aparecieron en el año 2013 y detectar la presencia de esta especie en otros campos de arroz de la zona. Efectivamente se ha identificado individuos de Leersia oryzoides en parcelas en las que no se tenía constancia previa de esta mala hierba, pasando de 4 parcelas en el año 2013 a 23 en 2014. En algunas parcelas los niveles de infestación han sido importantes, superiores a un 50% de recubrimiento, llegándose en algún caso a la destrucción total de cultivo y malas hierbas por parte de los propietarios, mediante tratamiento con glifosato, con el fin de controlar el problema., In 2013 Leersia oryzoides was detected in rice fields in Valencia. The aim of this study was to track the rice paddies where Leersia was detected in 2013 and survey in 2014 for L. oryzoides presence in other rice fields in the area. The presence of L. oryzoides has been detected in plots with no previous evidence of the presence of this weed, passing from 4 plots in 2013 to 23 in 2014. In some plots the level of infestation level has been important, exceeding 50 % of coverage. In order to stop the problem, in some of those plots total destruction of the crop and weeds have been adopted using a glyphosate treatment by the owners.

Very high resolution image available.

En el año 2013 se detectó la presencia de Leersia oryzoides en campos de arroz de la zona arrocera valenciana. El objetivo de este trabajo ha sido realizar un seguimiento de las parcelas de arroz en donde aparecieron en el año 2013 y detectar la presencia de esta especie en otros campos de arroz de la zona. Efectivamente se ha identificado individuos de Leersia oryzoides en parcelas en las que no se tenía constancia previa de esta mala hierba, pasando de 4 parcelas en el año 2013 a 23 en 2014. En algunas parcelas los niveles de infestación han sido importantes, superiores a un 50% de recubrimiento, llegándose en algún caso a la destrucción total de cultivo y malas hierbas por parte de los propietarios, mediante tratamiento con glifosato, con el fin de controlar el problema., In 2013 Leersia oryzoides was detected in rice fields in Valencia. The aim of this study was to track the rice paddies where Leersia was detected in 2013 and survey in 2014 for L. oryzoides presence in other rice fields in the area. The presence of L. oryzoides has been detected in plots with no previous evidence of the presence of this weed, passing from 4 plots in 2013 to 23 in 2014. In some plots the level of infestation level has been important, exceeding 50 % of coverage. In order to stop the problem, in some of those plots total destruction of the crop and weeds have been adopted using a glyphosate treatment by the owners.

Identification of landscape structures that predict the distribution of aquatic organisms has the potential to provide a practical management tool for species conservation in agricultural drainage channels. We tested the hypothesis that sites with imperiled freshwater mussels have distinct rural landscape structures and are characterized by the presence of diverse fish communities. In central Japan, the proportion of developed land use in surrounding areas was compared among sites with mussel populations (mussel sites) and randomly chosen sites (random sites) across multiple spatial scales (with a radius ranging from 100 to 3,000 m). Mussel sites were characterized by a much lower proportion of developed land (mean 5-18 %) compared with random sites (mean 32-35 %) at a scale of a parts per thousand currency sign300 m. The areas that met the landscape criteria for mussel sites across multiple scales constituted only 0.23 % of the area that was presumed to have suitable slope and elevation as a mussel habitat. Landscape metrics derived from mussel sites to locate unknown populations had a low predictability (16.7 %). Sites with mussels were located close to each other and had fish communities with higher taxonomic diversity than in sites without mussels. In addition, mussel taxonomic richness was a good predictor of fish community diversity. The quantitative measures of landscape structure may serve as a useful tool when prioritizing or identifying areas for conservation of mussels and fish if spatially autocorrelated distribution of habitat and other critical environmental factors such as habitat connectivity are also considered.

Identification of landscape structures that predict the distribution of aquatic organisms has the potential to provide a practical management tool for species conservation in agricultural drainage channels. We tested the hypothesis that sites with imperiled freshwater mussels have distinct rural landscape structures and are characterized by the presence of diverse fish communities. In central Japan, the proportion of developed land use in surrounding areas was compared among sites with mussel populations (mussel sites) and randomly chosen sites (random sites) across multiple spatial scales (with a radius ranging from 100 to 3,000 m). Mussel sites were characterized by a much lower proportion of developed land (mean 5-18 %) compared with random sites (mean 32-35 %) at a scale of a parts per thousand currency sign300 m. The areas that met the landscape criteria for mussel sites across multiple scales constituted only 0.23 % of the area that was presumed to have suitable slope and elevation as a mussel habitat. Landscape metrics derived from mussel sites to locate unknown populations had a low predictability (16.7 %). Sites with mussels were located close to each other and had fish communities with higher taxonomic diversity than in sites without mussels. In addition, mussel taxonomic richness was a good predictor of fish community diversity. The quantitative measures of landscape structure may serve as a useful tool when prioritizing or identifying areas for conservation of mussels and fish if spatially autocorrelated distribution of habitat and other critical environmental factors such as habitat connectivity are also considered.

Identification of landscape structures that predict the distribution of aquatic organisms has the potential to provide a practical management tool for species conservation in agricultural drainage channels. We tested the hypothesis that sites with imperiled freshwater mussels have distinct rural landscape structures and are characterized by the presence of diverse fish communities. In central Japan, the proportion of developed land use in surrounding areas was compared among sites with mussel populations (mussel sites) and randomly chosen sites (random sites) across multiple spatial scales (with a radius ranging from 100 to 3,000 m). Mussel sites were characterized by a much lower proportion of developed land (mean 5-18 %) compared with random sites (mean 32-35 %) at a scale of a parts per thousand currency sign300 m. The areas that met the landscape criteria for mussel sites across multiple scales constituted only 0.23 % of the area that was presumed to have suitable slope and elevation as a mussel habitat. Landscape metrics derived from mussel sites to locate unknown populations had a low predictability (16.7 %). Sites with mussels were located close to each other and had fish communities with higher taxonomic diversity than in sites without mussels. In addition, mussel taxonomic richness was a good predictor of fish community diversity. The quantitative measures of landscape structure may serve as a useful tool when prioritizing or identifying areas for conservation of mussels and fish if spatially autocorrelated distribution of habitat and other critical environmental factors such as habitat connectivity are also considered.

[EN] Rice fields contribute substantially to global warming of the atmosphere through emission of methane (CH4). This article reviews the state of the art of factors affecting CH4 emissions in rice fields, focusing on soil organic matter content and water management practices. A quantitative relationship between these factors was established through a meta-analysis based on a literature survey. This relationship can be useful to update emission factors used to estimate CH4 in the National Emission Inventories. Methane emissions in rice fields can be as much as 90% higher in continuously flooded rice fields compared with other water management practices, independent from straw addition. Water management systems that involve absence of flooding in total or for part of the growing period such as midseason drainages, intermittent flooding, and percolation control, can reduce CH4 emissions substantially. Moreover, CH4 emissions increase with the amount of straw added up to 7.7 t/ha for continuously flooded soils and up to 5.1 t/ha for other water regimes. Above these levels, no further increase is produced with further addition of straw. With regard to rice straw management mitigation strategies, recommended practices are composting rice straw, straw burning under controlled conditions, recollecting rice straw for biochar production, generation of energy, to be used as a substrate, or to obtain other byproducts with added value. This review improves the understanding of the relationship between straw application rate, water regimes, and CH4 emissions from rice fields to date. This relationship can help to select the most appropriate management practices to improve current mitigation strategies to reduce atmospheric CH4. © 2012 Mary Ann Liebert, Inc.

Background Wild food plants are a critical component in the subsistence system of rice farmers in Northeast Thailand. One of the important characteristics of wild plant foods among farming households is that the main collection locations are increasingly from anthropogenic ecosystems such as agricultural areas rather than pristine ecosystems. This paper provides selected results from a study of wild food conducted in several villages in Northeast Thailand. A complete botanical inventory of wild food plants from these communities and surrounding areas is provided including their diversity of growth forms, the different anthropogenic locations were these species grow and the multiplicity of uses they have. Methods Data was collected using focus groups and key informant interviews with women locally recognized as knowledgeable about contemporarily gathered plants. Plant species were identified by local taxonomists. Results A total of 87 wild food plants, belonging to 47 families were reported, mainly trees, herbs (terrestrial and aquatic) and climbers. Rice fields constitute the most important growth location where 70% of the plants are found, followed by secondary woody areas and home gardens. The majority of species (80%) can be found in multiple growth locations, which is partly explained by villagers moving selected species from one place to another and engaging in different degrees of management. Wild food plants have multiple edible parts varying from reproductive structures to vegetative organs. More than two thirds of species are reported as having diverse additional uses and more than half of them are also regarded as medicine. Conclusions This study shows the remarkable importance of anthropogenic areas in providing wild food plants. This is reflected in the great diversity of species found, contributing to the food and nutritional security of rice farmers in Northeast Thailand

The fate and transport of tricyclazole and imidacloprid in paddy plots after nursery-box application was monitored. Water and surface soil samples were collected over a period of 35 days. Rates of dissipation from paddy waters and soils were also measured. Dissipation of the two pesticides from paddy water can be described by first-order kinetics. In the soil, only the dissipation of imidacloprid fitted to the simple first-order kinetics, whereas tricyclazole concentrations fluctuated until the end of the monitoring period. Mean half-life (DT50) values for tricyclazole were 11.8 and 305 days, respectively, in paddy water and surface soil. The corresponding values of imidacloprid were 2.0 and 12.5 days, respectively, in water and in surface soil. Less than 0.9% of tricyclazole and 0.1% of imidacloprid were lost through runoff during the monitoring period even under 6.3 cm of rainfall. The pesticide formulation seemed to affect the environmental fate of these pesticides when these results were compared to those of other studies.

*This article is free to read on the publisher's website* Experiments were carried out to verify the effectiveness of the excess water storage depth (EWSD) in reducing runoff losses of simetryn and thiobencarb from paddy fields upon appreciable rainfall events. A paddy plot having an EWSD of 2 cm was effective in controlling runoff with the herbicide losses of less than 1% of the applied herbicides. Meanwhile, a plot with 0-cm EWSD lost 18.1 and 3.7% of the applied mass of simetryn and thiobencarb, respectively. Therefore, an appropriate EWSD is essential during the recommended 7-day water holding period in order to completely hold the water inside the field in case of rainfall.

現地水田におけるプレチラクロールとベンチオカーブの収支動態を総合的に解明し,考察するための研究を行った。広島県内で稲作を行っている営農形態の異なる3軒の稲作農家(第一種兼業A,第二種兼業B,無農薬専業C)において1996年4月から10月の間,水田,用水,排水の農薬分析,水質測定(用水源,及び排水排出河川も含む)及び調査票による農薬・肥料の使用量,作業時間,収穫量,経済収支調査等を行った。 除草剤に含まれるプレチラクロールとベンチオカーブを農薬成分として選び,その消長をガスクロマトグラフを用いて調べた。田面水中のプレチラクロールが最高濃度を示したのは,農家Aで散布後1-2日目に104-218μg/l,農家Bで1日目に110-465μg/lであった。ベンチオカーブが最高濃度を示したのは,農家Bで散布後5-8日目に5.02-75 .4μg/1であった。検出された期間はプレチラクロールが農家Aで散布直後から22-28日まで,農家Bで11-24日まで,ベンチオカーブでは農家Bで31日までであった。排水によるプレチラクロールの流出量,流出率はそれぞれ農家Aの二つの田で1190mg,1.17%,及び,1120mg,0.82%であった。農家Cの無農薬水田から農薬のベンチオカーブと思われるものが検出され,周辺の慣行栽培水田からの影響(汚染)が認められた。 農家A,Bとも基準量に対する農薬の使用量は,除草剤,殺虫殺菌剤ともほぼ適正であり,肥料の標準的な使用量に対する実際の使用量では元肥より追肥が多かった。農家A,Bの単位面積当りの作業時間では,施肥を除くほとんどの項目で農家Aの方が大きかった。農家Cの作業時間は農家A,Bと比べかなり大きかった。各農家の経費の特徴は,農家Aは肥料,特に土壌改良材の占める割合が大きく,農家Bは農薬の占める割合が大きく,農家Cはほとんどがアイガモの費用であった。各農家の収入/支出の比は,農家A:8.6,農家B:9.5,農家C:31となり,農家Cの作業時間の大きい分は収入によって補償されていた。, Mass and economic overall input-output balance was studied between paddy fields which is steady system and their environment. Concentration of pesticides and manures in paddy fields, usage of pesticides, working times, the crop yields and economic balances were investigated during April to October in 1996 in three farmhouses (A, B, C) in Hirosima prefecture. Behaviors of pretilachlor and benthiocarb in herbicides in paddy fields were analysed by gas chromatography. Maximum concentration of pretilachlor in paddy fields of farmhouses A and B were 99.6-201μg/l in one day after spraying and 119-461 μg/1 in 1-2 days after spraying, respectively. Maximum concentration of benthiocarb in paddy fields of farmhouse B was 7.48.113 μg/l in 5-8 days after spraying. Pretilachlor in paddy fields of farmhouses A and B was detected until 22-28 days after spraying and 11-24 days after spraying, respectively. Benthiocarb in paddy fields of farmhouse B was detected until 31 days after spraying. pretilachlor outflow through drain and its rate to total sprayed pretilachlor were 1110 mg, 1.09% and 1043 mg, 0.77% respectively, in two paddy fields of farmhouse A. Since some pesticides (one is supposed to be benthiocarb) were detected in paddy fields of farmhouse C which does not use pesticides at all, a contamination of pesticides from surrounding p addy fields was observed. Amount of sprayed pesticides to standard usage was appropriate for both farmhouses A and B. Working time per paddy fields area was larger for farmhouse A than B except spraying manures. Working time of farmhouse C was much larger than those of A and B. Main expences of farmhouses A, B and C were manures&soil improvement, pesticides and ducks which eat insects and grass, respectively. Since ratios of income to expenses for farmhouses A, B and C were 8.6, 9.5 and 31, larger working time of farmhouse C was conpensated by larger incomes.

The three volumes consist of a collection of all significant papers presented at the 8th International Conference. Subjects include: Tyre-soil interaction; theoretical aspects of ride dynamics; track-soil interaction; practical aspects of ride dynamics; operation in paddy fields; operation on steep slopes; soil compaction; steering; computer modelling; vehicle component design; measurement of soil and snow properties and soil bin facilities; and vehicle design. (Author), For sales information of individual items see AD-P004 283 - AD-P004 308. See also Volume 1, AD-A148 634. Portions of test in German.

In this paper, the producing process of the driving wheel thrust of paddy field tractor is analyzed through experiments made in a soil bin. In essence, it is a process in which the wheel lugs are moved against the soil so that the soil in the neighborhood of contact surface is compressed and sheared. The methods for predicting the driving wheel thrust and the lug motion trajectory of paddy field tractor are proposed. The predicted values of the thrust are compared with those obtained through experiments. It shows that the predicted thrust agrees fairly satisfactorily with the measured results. (Author), This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p507-519.

The Burgers model and its modified form have generally been considered as the rheological model of clayey soils since 1950's through tests and analyses. Six samples of paddy soils from four provinces in South China have been collected and tested. The Burgers model is accepted as the general model of these clayey soils., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p539-543.

Wheels with a narrow rim and large lugs are widely used in Southeast Asia on tractors for paddy fields. The lugs of these wheels perform one or both of the following two functions: developing tractive effort and supporting vehicle weight. A great deal of field data on the performance of these wheels have been accumulated over the years. The mechanics of this type of wheel, however, has not yet been fully elucidated. To reach a better understanding of the physical nature of the problem, an investigation into the interaction between the lugs of the wheel and the soil was carried out., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11,' 1984, AD-A148 635, p545-559.

In East Asia, approximately one million small-sized rice combines have been used on paddy fields. The objective of this study is to carry out fundamental investigations on the mobility of small combines associated with changes in the position of the center of gravity. The relationship between the position of the center of gravity and the performance of the combine in straight and circular drive was analysed. (Author), This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p521-537.

This paper discussed the kinematics and dynamics of the paddy wheel with movable lugs penetrating into and coming out from soil perpendicularly. The calculation of the electric computer shows that for the requirement of a certain tractive force the wheel should have a certain sinkage so that it has the optimal tractive efficiency. The experiment on the specific test bench designed by the author shows: this type of wheel has a less rolling resistance and a higher tractive efficiency. (Author), This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p495-505.

Performances of prototype in soil-machine systems have been investigated and predicted by scale model data using similitude theory. However, a satisfactory prediction is not attained especially in common soil conditions where distortions occur, since present knowledge of soil-machine interactions is meager. The objective of this study is to investigate the usefulness or feasibility of an analog predicting torques on rotary blades which bring about a considerable high speed interaction. An analog prediction technique developed by Schafer et al. was used., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11,' 1984, AD-A148 635, p561-573.

The lug of a rigid lugged wheel for the paddy-field tractor is the basic element to interact with soil. The lug angle has significant effect on the tractive performance of a rigid lugged wheel in rice field. This paper analyses the interaction process between lug and soil. A calculating method of soil reaction on a single lug based on the equation of passive pressure in two dimensional soil failure is presented. It is shown that there is a good agreement between the measured and predicted pull and lift forces developed by a single lug within the test range., This article is from 'Proceedings of the International Conference on the Performance of Off-Road Vehicles and Machines (8th). Volume 2. Held at Cambridge, England on August 5-11, 1984,' AD-A148 635, p575-591.