Com o objetivo de avaliar os efeitos de densidades de Aeschynomene rudis Benth. na cultura do arroz irrigado e a eficiência do herbicida ethoxysulfuron aplicado em duas épocas como pós-emergente, foi instalado um experimento no município de Taubaté, região do Vale do Paraíba-SP, no ano agrícola de 2001/2002. O cultivar de arroz Epagri 109 e a planta daninha A. rudis foram semeados em 30/10/2001 em solo drenado. Os tratamentos foram constituídos de quatro densidades de A. rudis (3, 6, 12 e 24 plantas por metro quadrado) e duas épocas de aplicação do herbicida ethoxysulfuron dentro de cada densidade (estádio de 4 e 6 folhas do A. rudis), e cinco parcelas testemunhas com densidades de 0, 3, 6, 12 e 24 plantas de A. rudis por metro quadrado sem a aplicação do produto, constituindo 13 tratamentos com 4 repetições, delineados em blocos ao acaso. O herbicida foi aplicado na dose de 80 g.ha-1, sendo adicionado à calda o adjuvante lauril éter sulfato de sódio na dose de 0,3 % base volume, e as pulverizações efetuadas nos dias 27/11/2001 e 04/12/2001. Os parâmetros avaliados foram: número de plantas, colmos e panículas por metro, altura das plantas de arroz, comprimento de panículas, número de espiguetas por panícula, número de grãos formados por panículas, rendimento de grãos, eficiência do herbicida no controle de A. rudis e fitointoxicação à cultura. Considerando-se os resultados obtidos pode-se concluir que: a) densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado, influenciam negativamente de forma linear, o número de colmos e de panículas por metro, o comprimento das panículas, o número de espiguetas e de grãos formados por panícula, o rendimento de grãos e o índice para colheita mecânica e não afetam o número de plantas por metro e a altura das plantas de arroz. b) o herbicida ethoxysulfuron é eficiente no controle de A. rudis nos estádios de 4 e de 6 folhas, nas densidades de 3, 6, 12 e 24 plantas por metro quadrado. c) ethoxysulfuron na dose de 80 g.ha-1, quando aplicado em pós-emergência precoce e mediana em densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado é seletivo para o cultivar de arroz Epagri 109, não interferindo nos parâmetros avaliados. / During the season 2001/2002, an experiment was conducted in Taubaté city, area of the Paraíba-SP valley, to evaluate the effect of Aeschynomene rudis Benth. densities on paddy rice, and the efficacy of the herbicide ethoxysulfuron applied in early and mid post emergence. The rice variety Epagri 109 and A. rudis were planted October 30, 2001 in dry soil. The treatments were four A. rudis densities (3, 6, 12 and 24 plants per square meter) and two application timings of the herbicide ethoxysulfuron in each density. The two application timings were at the 4 and 6 leaf stage of A. rudis. There were also untreated densities of 0, 3, 6, 12 and 24 plants of A. rudis per square meter without the herbicide application, resulting in 13 treatments with 4 replications delineated in randomized blocks. The herbicide was applied at 80 g.ha-1, with the adjuvant laurel ether sulfate of sodium at .3% v/v. The applications were made on November 27 and December 4, 2001. The assessed crop parameters were: number of plants, stems and panicles per meter, height of the plants, panicle length, number of spikelets by panicle, number of grains formed by panicles, income of grains, A. rudis control and crop damage. We can conclude from the results that A. rudis densities of 3, 6, 12 and 24 plants per square meter influence the crop negatively, in a linear way, the number of stems and panicles per meter, the length of the panicles, the number of spikelets and grains formed by panicles, the mechanical harvest index, and rice yield. There were no effects on the number of rice plants per meter or the height of the rice. Also, ethoxysulfuron was effective in controlling A. rudis at both the 4 and 6 leaf stage, in densities of 3, 6, 12 and 24 plants per square meter. Ethoxysulfuron at 80 g.ha-1, when applied early post or mid post emergence in densities of 3, 6, 12 and 24 plants per square meter was selective to the rice variety Epagri 109, not affecting the assessed parameters.

Submitted by William Justo Figueiro (williamjf) on 2015-07-06T23:27:47Z No. of bitstreams: 1 09a.pdf: 771261 bytes, checksum: c8d36f36fd0e9b6396c5bad8e1ea3681 (MD5) / Made available in DSpace on 2015-07-06T23:27:47Z (GMT). No. of bitstreams: 1 09a.pdf: 771261 bytes, checksum: c8d36f36fd0e9b6396c5bad8e1ea3681 (MD5) Previous issue date: 2014 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / UNISINOS - Universidade do Vale do Rio dos Sinos / Microrganismos vivendo no interior dos tecidos das plantas sem causar efeitos prejudiciais visíveis de sua presença são chamados endofíticos. As bactérias endofíticas podem promover o crescimento das plantas de várias maneiras: através da secreção de reguladores de crescimento vegetal, pela solubilização de fosfato, entre outras. Na busca de práticas agrícolas ambientalmente sustentáveis, tem sido dada considerável atenção à fixação biológica de nitrogênio atmosférico. Assim, o objetivo do presente estudo foi avaliar, através de métodos dependentes de cultivo, a ocorrência de bactérias endofíticas em colmos e folhas de duas amostras das variedades “RG 121” e “RG 900” de arroz irrigado, num sistema de cultivo convencional. Foram coletadas plantas de arroz de duas variedades na Estação Experimental do Arroz, do Instituto Rio Grandense do Arroz (EEA-IRGA), Cachoeirinha/RS, no ano agrícola 2012/2013. As plantas coletadas em campo foram submetidas à desinfecção superficial, seguida do isolamento e cultivo das bactérias endofíticas em meios de cultura semi-sólidos, livres de nitrogênio: NFb (Azospirillum brasilense/A. lipoferum), JNFb (Herbaspirillum seropedicae/H. rubrisubalbicans) e LGI-P (Gluconacetobacter diazotrophicus). Ao final desses procedimentos, foram obtidos 190 isolados bacterianos, os quais agruparam-se, de acordo com suas características fenotípicas, em 29 morfotipos. A partir disso, o padrão de distribuição dos morfotipos entre oito condições foi avaliado por Análise de Correspondência Destendenciada (DCA). As oito condições foram: C1 = amostra (planta) 1, variedade “RG 121”, colmos; C2 = amostra 1, variedade “RG 121”, folhas; C3 = amostra 1, variedade “RG 900”, colmos; C4 = amostra 1, variedade “RG 900”, folhas; C5 = amostra (planta) 2, variedade “RG 121”, colmos; C6 = amostra 2, variedade “RG 121”, folhas; C7 = amostra 2, variedade “RG 900”, colmos; C8 = amostra 2, variedade “RG 900”, folhas. Os dois primeiros eixos da DCA explicaram 28,5 % da variância total do conjunto de dados - 23,9 % de explicação somente pelo eixo 1. Ainda, foi realizada uma Análise de Componentes Principais (PCA) na tentativa de estabelecer quais morfotipos melhor explicam as diferenças observadas entre as condições. Deste modo, os eixos 1 e 2 da PCA tiveram uma proporção de explicação acumulada correspondente a 45,61 %, sendo o eixo 1 responsável por 25,91 % destes. Por fim, em função do número de isolados obtidos por grupo fenotípico, pôde-se calcular o índice de diversidade de Shannon-Weaver (H’), que relaciona a riqueza e uniformidade de espécies (morfotipos) para cada área (condição) em estudo. Estes foram testados par-a-par pelos métodos de bootstrapping e permutação quanto a possíveis diferenças significativas. De modo que valores de H’ estatisticamente diferentes apresentados por algumas das combinações de condições puderam ser relacionados à amostra (planta), à estrutura vegetal (colmos e folhas) e à variedade, isolada ou conjuntamente. O crescimento bacteriano em meios de cultura livres de nitrogênio, em condições microaerofílicas, infere a ocorrência da capacidade de fixação biológica de nitrogênio. / Microorganisms living within the tissues of plants without causing visible detrimental effects of their presence are known as endophytes. The endophytic bacteria can promote plant growth in various ways: by secreting plant growth regulators, by phosphate solubilization, among others. In pursuit of environmentally sustainable agricultural practices, considerable attention has been given to the biological nitrogen fixation. Thus, the aim of this study was to evaluate, by culture-dependent methods, the occurrence of endophytic bacteria in stems and leaves of two samples of varieties “RG 121” e “RG 900” of irrigated rice, on a conventional cropping system. Rice plants from two varieties were collected in the Estação Experimental do Arroz, from Instituto Riograndense do Arroz (EEA-IRGA), Cachoeirinha/RS, in the agricultural year 2012/2013. Plants collected in the field were submitted to surface disinfection, followed by isolation and cultivation of endophytic bacteria in semisolid, nitrogen-free, culture media: NFb (Azospirillum brasilense/A. lipoferum), JNFb (Herbaspirillum seropedicae/H. rubrisubalbicans) and LGI-P (Gluconacetobacter diazotrophicus). At the end of these procedures, 190 bacterial isolates were obtained, which were grouped, according to their phenotypic characteristics, in 29 morphotypes. From this, the pattern of distribution of morphotypes in eight conditions was assessed by Detrended Correspondence Analysis (DCA). The eight conditions were: C1 = sample (plant) 1, variety "RG 121", stems; C2 = sample 1, variety "RG 121", leaves; C3 = sample 1, variety "RG 900", stems; C4 = sample 1, variety "RG 900", leaves; C5 = sample (plant) 2, variety "RG 121", stems; C6 = sample 2, variety "RG 121", leaves; C7 = sample 2, variety "RG 900", stems; C8 = sample 2, variety "RG 900", leaves. The first two axes of DCA explained 28.5 % of the total variance of the data set - 23.9 % of explanation only by axis 1. In addition, a Principal Components Analysis (PCA) was performed in attempt to establish which morphotypes best explain the observed differences between the conditions. Thus, the axes 1 and 2 of the PCA had a proportion of accumulated explanation corresponding to 45.61 %, being the axis 1 responsible for 25.91 % of them. Finally, according to the number of isolates obtained by phenotypic group, the Shannon-Weaver diversity index (H’) were calculated, which relates the richness and evenness of species (morphotypes) for each area (condition) in study. These were tested pair-to-pair by bootstrapping and permutation methods for possible significant differences. Thus, statistically different values of H' presented by some of the combinations of conditions could be related to the sample (plant), plant structure (stems and leaves) and variety, individually or together. The bacterial growth in nitrogen-free culture media, under microaerophilic conditions, implies the occurrence of biological nitrogen fixation capacity.

Submitted by Fabricia Fialho Reginato (fabriciar) on 2015-07-07T22:34:22Z No. of bitstreams: 1 CarolineFrizzo.pdf: 250681 bytes, checksum: b1437627a8ce128c5c1dd643c3097503 (MD5) / Made available in DSpace on 2015-07-07T22:34:22Z (GMT). No. of bitstreams: 1 CarolineFrizzo.pdf: 250681 bytes, checksum: b1437627a8ce128c5c1dd643c3097503 (MD5) Previous issue date: 2007 / CT-Hidro - Fundo Setorial de Recursos Hídricos / O presente estudo, inserido na Linha de Pesquisa Conservação e Manejo de Ecossistemas e de Vida Silvestre, teve como objetivo avaliar a qualidade da água de irrigação e a diversidade de bacilos em diferentes áreas inundadas de arrozais do Rio Grande do Sul (RS). As amostras de água foram coletadas em cinco regiões produtoras de arroz: Campanha, Litoral Norte, Litoral Sul, Depressão Central e Fronteira Oeste, correspondendo aos municípios: Dom Pedrito, Santo Antônio da Patrulha, Camaquã, Cachoeira do Sul e Uruguaiana, respectivamente. Os ensaios das análises microbiológicas da qualidade da água, isolamento, multiplicação e caracterização das amostras de água foram realizados no Laboratório de Microbiologia da Unisinos. Os resultados obtidos, quanto à análise da qualidade microbiológica da água, revelam que os índices de coliformes totais registrados nas cinco regiões foram mais elevados que os índices de coliformes fecais, os quais, quando presentes nas amostras, foram encontrados em baixas freqüências. Na análise quantitativa dos bacilos foi verificada maior freqüência de bactérias na fase vegetativa, cujo valor reduziu na fase reprodutiva da cultura do arroz irrigado, sendo identificadas nas referidas amostras 18 espécies de bacilos. O resultado da análise, que compara os índices de diversidade, indica que não há diferença significativa entre os índices das cinco regiões orizícolas (F2,4=1,600; P>0,05) e entre os canais de irrigação e parcelas de cultivo (F2,4=1,392; P>0,05). Os gêneros bacterianos mais abundantes registrados nas amostras de água foram Bacillus, Corynebacterium e Lactobacillus. Os dados microbiológicos obtidos na presente pesquisa servirão de subsídio ao conhecimento da microbiota das águas superficiais nas regiões orizícolas do RS e ao manejo do agroecossistema de arroz irrigado. / This study, within the Research Line Preservation and Management of Ecosystems and Wildlife, aims at the assessment of the quality of the irrigation water, and the bacilli diversity in various flooded areas in rice growing fields in Rio Grande do Sul. (RS). Water samples were collected in five rice-producing areas: Campaign, Northern Littoral, Southern Littoral, Central Depression and Western Border, corresponding to the Dom Pedrito, Santo Antônio da Patrulha, Camaquã, Cachoeira do Sul and Uruguaiana counties, respectively. Trials of microbiological analysis of the water quality, isolation, multiplication and characterization of the water samples were carried out at the Microbiology Laboratory of UNISINOS. The obtained results for the analysis of the water microbiological quality show that the indexes of total coliforms recorded in the five regions were higher than the ones of fecal coliforms which, when present in the samples were found in low frequencies. The bacilli quantitative analysis showed a higher frequency of bacteria in the vegetative phase, of which the value was decreased in the reproduction phase of the paddy rice culture, with the identification of 18 bacilli species in the previously mentioned samples. The analysis result which compares the diversity indexes point to the lack of a significant difference among the indexes for the five rice growing areas (F2,4=1,600; P>0,05), and between the irrigation channels and the cultivation plots (F2,4=1,392; P>0,05). The most abundant bacterial genera in the water samples were Bacillus, Corynebacterium, and Lactobacillus. Microbiological data from this research will subsidize the knowledge of the microbiota of the shallow waters in the rice growing areas of RS and the management of the paddy rice agroecosystem, as well.

Com o objetivo de avaliar os efeitos de densidades de Aeschynomene rudis Benth. na cultura do arroz irrigado e a eficiência do herbicida ethoxysulfuron aplicado em duas épocas como pós-emergente, foi instalado um experimento no município de Taubaté, região do Vale do Paraíba-SP, no ano agrícola de 2001/2002. O cultivar de arroz Epagri 109 e a planta daninha A. rudis foram semeados em 30/10/2001 em solo drenado. Os tratamentos foram constituídos de quatro densidades de A. rudis (3, 6, 12 e 24 plantas por metro quadrado) e duas épocas de aplicação do herbicida ethoxysulfuron dentro de cada densidade (estádio de 4 e 6 folhas do A. rudis), e cinco parcelas testemunhas com densidades de 0, 3, 6, 12 e 24 plantas de A. rudis por metro quadrado sem a aplicação do produto, constituindo 13 tratamentos com 4 repetições, delineados em blocos ao acaso. O herbicida foi aplicado na dose de 80 g.ha-1, sendo adicionado à calda o adjuvante lauril éter sulfato de sódio na dose de 0,3 % base volume, e as pulverizações efetuadas nos dias 27/11/2001 e 04/12/2001. Os parâmetros avaliados foram: número de plantas, colmos e panículas por metro, altura das plantas de arroz, comprimento de panículas, número de espiguetas por panícula, número de grãos formados por panículas, rendimento de grãos, eficiência do herbicida no controle de A. rudis e fitointoxicação à cultura. Considerando-se os resultados obtidos pode-se concluir que: a) densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado, influenciam negativamente de forma linear, o número de colmos e de panículas por metro, o comprimento das panículas, o número de espiguetas e de grãos formados por panícula, o rendimento de grãos e o índice para colheita mecânica e não afetam o número de plantas por metro e a altura das plantas de arroz. b) o herbicida ethoxysulfuron é eficiente no controle de A. rudis nos estádios de 4 e de 6 folhas, nas densidades de 3, 6, 12 e 24 plantas por metro quadrado. c) ethoxysulfuron na dose de 80 g.ha-1, quando aplicado em pós-emergência precoce e mediana em densidades de 3, 6, 12 e 24 plantas de A. rudis por metro quadrado é seletivo para o cultivar de arroz Epagri 109, não interferindo nos parâmetros avaliados. / During the season 2001/2002, an experiment was conducted in Taubaté city, area of the Paraíba-SP valley, to evaluate the effect of Aeschynomene rudis Benth. densities on paddy rice, and the efficacy of the herbicide ethoxysulfuron applied in early and mid post emergence. The rice variety Epagri 109 and A. rudis were planted October 30, 2001 in dry soil. The treatments were four A. rudis densities (3, 6, 12 and 24 plants per square meter) and two application timings of the herbicide ethoxysulfuron in each density. The two application timings were at the 4 and 6 leaf stage of A. rudis. There were also untreated densities of 0, 3, 6, 12 and 24 plants of A. rudis per square meter without the herbicide application, resulting in 13 treatments with 4 replications delineated in randomized blocks. The herbicide was applied at 80 g.ha-1, with the adjuvant laurel ether sulfate of sodium at .3% v/v. The applications were made on November 27 and December 4, 2001. The assessed crop parameters were: number of plants, stems and panicles per meter, height of the plants, panicle length, number of spikelets by panicle, number of grains formed by panicles, income of grains, A. rudis control and crop damage. We can conclude from the results that A. rudis densities of 3, 6, 12 and 24 plants per square meter influence the crop negatively, in a linear way, the number of stems and panicles per meter, the length of the panicles, the number of spikelets and grains formed by panicles, the mechanical harvest index, and rice yield. There were no effects on the number of rice plants per meter or the height of the rice. Also, ethoxysulfuron was effective in controlling A. rudis at both the 4 and 6 leaf stage, in densities of 3, 6, 12 and 24 plants per square meter. Ethoxysulfuron at 80 g.ha-1, when applied early post or mid post emergence in densities of 3, 6, 12 and 24 plants per square meter was selective to the rice variety Epagri 109, not affecting the assessed parameters.

No description available.

<p>To address increasing irrigation water demand consecutive to the increasing population pressure in terms of food demand, there is an imperative of developing relevant mechanisms to regulate irrigation water consumption patterns. A radical shift from uncontrolled flooding irrigation as currently practiced by farmers in Mugerero paddy farming zone towards efficient allocation and use of water resources is important to save water that could be allocated to other water users.</p><p>This paper surveys current and past views on the way irrigation water is allocated in the irrigation scheme of Mugerero and how farmers are using water for paddy production purpose. The existing irrigation water practices as well as paddy productivity are assessed and the results are expected to be useful for water policy professionals, while addressing the growing water demand. According to the respondents, the causes of low paddy yields are the increasing and uncontrolled extension of paddy farming, non adapted irrigation infrastructure and water pricing systems as well as lack of updated knowledge and technologies on irrigation. These issues faced by the paddy farmers have led to pronounced economic, social and environmental consequences which are manifested in conflicts over irrigation water use, increasing soil salinity and pollution, destruction of infrastructure and above all, low irrigation paddy yields.The identification of the core problem in the irrigation system might be important for water managers as it would provide a starting point to establish comprehensive baseline towards efficient irrigation water allocation and use. This would improve paddy productivity within the formal as well as the growing informal paddy farming referred to “hors- perimeter” in the low land of Imbo region.</p>

水源，是水田利用最重要的因素，直接影響了水田所展現的多功能性。多功能性之概念，係表彰農業生產已由經濟功能轉變為兼具其他服務功能，強調農業生產不僅創造商品的價值，亦提供其他產出的非商品價值。並可歸納出具有生產經濟、生態環境與社會文化功能。而倡導多功能性之最終目的，在於農業永續發展。 本研究個案位於彰化縣溪州鄉。此鄉因有莿仔埤圳引入濁水溪灌溉，生產著名的濁水米，且莿仔埤圳亦為溪州鄉農業之命脈。近二十年來，溪州鄉歷經「集集共同引水」工程、中科四期搶水事件、護水行動與水田濕地計畫等，更加強調農業用水的重要性，以及守護土地的決心。而在護水行動落幕後，溪州鄉的水稻栽培方式，轉變成以無毒農法施作的水田濕地。本研究以文獻評析與深度訪談的方式，探討溪州鄉之水田利用歷程，並以護水行動為界，將溪州鄉水田利用方式劃分為慣行與無毒水田利用。並分別比較兩種水田利用方式，所展現出多功能性之差異。研究結果顯示，無毒水田之利用，特別是在生態環境的層面，較能夠為溪州鄉延續土地、動植物與人體健康，進而創造永續價值。 進而，本研究再以Jordan & Warner（2010）所提出的多功能性發展模式，探討模式中產業發展、農業生態夥伴關係與超級系統中，溪州鄉無毒水田利用所面臨之發展困境與課題。研究結果顯示，溪州鄉的無毒水田利用，已具備產業發展層次，並約略形成農業生態夥伴關係，惟超級系統層次尚未成形。此表示溪州鄉無毒水田利用的多功能性推廣，仍有其完備與不足之處。本研究認為，認為若能解決在內部管理、無毒水田的集中化管理，以及政府機關的資源整合、產業輔導、有機資材取得問題，並將有助於凝聚溪州全鄉之永續發展意識，使更多農民投入無毒水田栽培，或能成為傳統慣行農鄉轉變為無毒農鄉之典範。 / Water is the most important factor of paddy field utilization, and affect its multifunctionality directly. The concept of multifunctionality recognizes that the economic function of agricultural production has been transformed into other services, not only creating commodities, but also providing the value of non-commodity outputs. In fact, the goal of multifunctionality is to develop sustainable agriculture. This case study is located in Xizhou Township, Changhua County. Because Chi Tsai Pi furrow irrigation noses Chuo Shui River into Xizhou, this township can produce famous Chuo Shui rice. And for sure, Chi Tsai Pi furrow irrigation is the heart of agriculture in this township. In the past two decades, the township had gone through Chi Chi Conjunctive Diversion Project, grabbing water events of Central Taiwan Science Park’s (CTSP) fourth-phase, defending water action and paddy wetlands plan, people in this township has a great emphasis on the use of water in agriculture, as well as the protection of the land. After the defending water action, the rice cultivation methods in Xizhou has changed into chemical-free farming facilities for paddy wetlands. This research adopts literature and in-depth interviews two ways to explore the use of paddy fields in Xizhou, and compares the use of two separate methods of paddy fields, conventional farming and chemical-free farming, finds out the differences of multifunctionality between these two methods. And the results shows that the chemical-free farming paddy creates the sustainable value. Furthermore, this research explores plights and problems of the chemical-free paddy fields in Xizhou with the multifunctionality development presented by Jordan & Warner (2010),which includes three levels, enterprise development, agroeological partnership and supersystem. The results show that paddy field utilization of Xizhou has formed enterprise development and agroeological partnership, however, supersystem not yet. This represents there are some problems in Xizhou still. This study suggests that if these problems like nternal management, chemical-free paddy centralized management, industry guidance of government agencies, organic materials issues, are solved , will help unite awareness of Xizhou, and made more farmers into chemical-free paddy cultivation.

To address increasing irrigation water demand consecutive to the increasing population pressure in terms of food demand, there is an imperative of developing relevant mechanisms to regulate irrigation water consumption patterns. A radical shift from uncontrolled flooding irrigation as currently practiced by farmers in Mugerero paddy farming zone towards efficient allocation and use of water resources is important to save water that could be allocated to other water users. This paper surveys current and past views on the way irrigation water is allocated in the irrigation scheme of Mugerero and how farmers are using water for paddy production purpose. The existing irrigation water practices as well as paddy productivity are assessed and the results are expected to be useful for water policy professionals, while addressing the growing water demand. According to the respondents, the causes of low paddy yields are the increasing and uncontrolled extension of paddy farming, non adapted irrigation infrastructure and water pricing systems as well as lack of updated knowledge and technologies on irrigation. These issues faced by the paddy farmers have led to pronounced economic, social and environmental consequences which are manifested in conflicts over irrigation water use, increasing soil salinity and pollution, destruction of infrastructure and above all, low irrigation paddy yields.The identification of the core problem in the irrigation system might be important for water managers as it would provide a starting point to establish comprehensive baseline towards efficient irrigation water allocation and use. This would improve paddy productivity within the formal as well as the growing informal paddy farming referred to “hors- perimeter” in the low land of Imbo region.

No description available.

The uptake of elements from paddy soils into shoot, husk, and unpolished grain of rice plants was investigated in Mekong, Huong, and Red River areas in Vietnam. The transferability of most studied soil elements into plant parts decreases in the order: shoot > husk > grain. Exceptions are Mg, S, Cd, Cu, Zn, and Mo, whose transfer drops in the rder: shoot > grain > husk, the transfer of P falls in the order grain > shoot > husk. The translocation of the most health relevant elements into the different plant parts is affected by soil parameters like pH, organic matter, Fe- and Mn-phases, and clay minerals. Health risk assessment approaches for the average daily rice consumption are performed for noncancer risk (Hazard Index - HI) including the elements As, Cd, Pb, Co, Cu, Mn, Mo, and Ni as well as for cancer risk for the elements As and Pb (Incremental Lifetime Cancer Risk - ΣILCR). All rice studied grain samples exceed the safe HI-index of below 1. 81% of the grain samples were within the level of concern ranging between 1.4 < HI < 5, 18% varied between 5 < HI < 8.4, although their corresponding soils showed only a little pollution. Cd, As, Mn, and Pb were the most important elements causing non-cancer risks for rice-consuming people. The cancer-risk values ΣILCR were mean 2.2 x 10⁻³ and are considerably higher than the safe threshold of 10⁻⁴ to 10⁻⁶. Arsenic is the dominant factor for cancer risk. Rice-eating people living in Red River and Huong River areas face mainly health risks of exposure to As and Cd in the Mekong River area in addition to Pb. / Sự di chuyển của các nguyên tố từ đất vào các bộ phận khác nhau của cây lúa được tiến hành nghiên cứu tại cùng đồng bằng sông Mekông và sông Hồng, và tại sông Hương, và sông Hồng ở Việt Nam. Sự vận chuyển của hầu hết các nguyên tố đi vào cây lúa có xu hướng giảm dần theo thứ tự: thân > vỏ trấu > hạt. Ngoại trừ sự vận chuyển của các nguyên tố Mg, S, Cd, Cu, Zn, và Mo giảm dần theo thứ tự: thân > hạt > vỏ trấu; và nguyên tố P giảm dần từ: hạt > thân > vỏ trấu. Sự vận chuyển các nguyên tố vào các bộ phận của cây bị ảnh hưởng bởi các điều kiện của đất như pH, hàm lượng chất hữu cơ, dạng Fe và Mn, và các khoáng sét. Đánh giá các rủi ro sức khỏe của người dân khi tiêu thụ gạo hàng ngày được thể hiện thông qua các chỉ số rủi ro không ung thư (HI) của các nguyên tố As, Cd, Pb, Co, Cu, Mn, Mo, và Ni; cùng với chỉ số rủi ro ung thư của As và Pb (ΣILCR). Tất cả các mẫu gạo được phân tích vượt quá chỉ số an toàn HI < 1. 81% của các mẫu có chỉ số HI nằm trong khoảng 1.4 < HI < 5 và 18% các mẫu trong 5 < HI < 8.4, mặc dù các mẫu đất tương ứng được kiểm tra đều khônghoặc rất ít thể hiện sự ô nhiễm. Các nguyên tố Cd, As, Mn, và Pb là những tác nhân quan trọng nhất gây ra các rủi ro không ung thư cho những người tiêu thụ gạo. Rủi ro ung thư ΣILCR có giá trị trung bình 2.2 x 10⁻³ và cao hơn đáng kể so với ngưỡng an toàn 10⁻⁴ - 10⁻⁶, trong đó As là một tác nhân gây ung thư nổi bật. Những người sống ở khu vực sông Hồng và sông Hương đang đối mặt với sự phơi nhiễm As và Cd; trong khi đó người dân ở khu vực sông Mekông bị phơi nhiễm thêm Pb từ gạo.