Rice and maize are global staple food and play an important role in world’s food security strategy. Vietnam is one of rice leading export countries but annually it has to import a considerate amount of maize for cattle food processing. Red River Delta in the north of Vietnam is the second rice bucket of the country, which is responsible formore than 20% of total rice production. The priority crops in the areas are rice and maize and rice-maize system is the leading cropping system in the area. Currently, it is reported that the rice-maize cropping system is not sustainable and its profit is reducing in most of production areas in the Red River Delta. Improving rice cropping system aims is not only to increase rice and maize yields and production but also to improve the land use efficiency, decline the cost of the production and to increase system sustainability. To increase sustainability there must be a linkage of various factors. This review emphasizes on increasing rice-maize crop sustainability by applying appropriate agriculture practices such as reducing chemical fertilization and intensive tillage. / Gạo và ngô là nguồn lương thực chính cho toàn cầu và đóng một vai trò quan trọng trong chiến lược an ninh lương thực của thế giới. Việt Nam là một trong những nước dẫn đầu về xuất khẩu gạo nhưng hàng năm vẫn phải nhập một số lượng lớn ngô để chế biến thức ăn gia súc. Đồng bằng sông Hồng là một trong hai vựa lúa lớn của Việt Nam sản xuất khoảng 20% sản lượng lúa gạo của cả nước. Ở đồng bằng sông Hồng, lúa và ngô là hai cây trồng chính là hệ canh tác lúa-ngô là cơ cấu cây trồng hàng đầu trong vùng. Tuy nhiên, trong những năm gần đây, rất nhiều đánh giá cho thấy hệ thống canh tác lúa-ngô là hệ thống canh tác không bền vững và các lợi nhuận của mang lại từ cơ cấu canh tác ở hầu hết các khu vực sản xuất ở vùng đồng bằng sông Hồng của Việt Nam đã và đang giảm dần. Do đó, việc cải thiện cơ cấu canh tác lúa-ngô không chỉ nhằm mục đích tăng năng suất lúa và ngô mà còn nâng cao hiệu quả sử dụng đất, giảm chi phí sản xuất và tăng cường hệ thống canh tác bền vững. Tuy nhiên, để tăng tính bền vững của hệ thống canh tác thì phải liên kết nhiều yếu tố khác nhau. Bài viết này dựa vào các kết quả nghiên cứu của các tác giả khác nhau để đưa ra những giải pháp tích cực làm tăng tính bền vững của hệ thống canh tác lúa-ngô bằng cách áp dụng các phương pháp canh tác hợp lý như giảm sử dụng phân hóa học và các biện pháp canh tác thâm canh như áp dụng phương pháp làm đất tối thiểu.

Rice and maize are global staple food and play an important role in world’s food security strategy. Vietnam is one of rice leading export countries but annually it has to import a considerate amount of maize for cattle food processing. Red River Delta in the north of Vietnam is the second rice bucket of the country, which is responsible formore than 20% of total rice production. The priority crops in the areas are rice and maize and rice-maize system is the leading cropping system in the area. Currently, it is reported that the rice-maize cropping system is not sustainable and its profit is reducing in most of production areas in the Red River Delta. Improving rice cropping system aims is not only to increase rice and maize yields and production but also to improve the land use efficiency, decline the cost of the production and to increase system sustainability. To increase sustainability there must be a linkage of various factors. This review emphasizes on increasing rice-maize crop sustainability by applying appropriate agriculture practices such as reducing chemical fertilization and intensive tillage. / Gạo và ngô là nguồn lương thực chính cho toàn cầu và đóng một vai trò quan trọng trong chiến lược an ninh lương thực của thế giới. Việt Nam là một trong những nước dẫn đầu về xuất khẩu gạo nhưng hàng năm vẫn phải nhập một số lượng lớn ngô để chế biến thức ăn gia súc. Đồng bằng sông Hồng là một trong hai vựa lúa lớn của Việt Nam sản xuất khoảng 20% sản lượng lúa gạo của cả nước. Ở đồng bằng sông Hồng, lúa và ngô là hai cây trồng chính là hệ canh tác lúa-ngô là cơ cấu cây trồng hàng đầu trong vùng. Tuy nhiên, trong những năm gần đây, rất nhiều đánh giá cho thấy hệ thống canh tác lúa-ngô là hệ thống canh tác không bền vững và các lợi nhuận của mang lại từ cơ cấu canh tác ở hầu hết các khu vực sản xuất ở vùng đồng bằng sông Hồng của Việt Nam đã và đang giảm dần. Do đó, việc cải thiện cơ cấu canh tác lúa-ngô không chỉ nhằm mục đích tăng năng suất lúa và ngô mà còn nâng cao hiệu quả sử dụng đất, giảm chi phí sản xuất và tăng cường hệ thống canh tác bền vững. Tuy nhiên, để tăng tính bền vững của hệ thống canh tác thì phải liên kết nhiều yếu tố khác nhau. Bài viết này dựa vào các kết quả nghiên cứu của các tác giả khác nhau để đưa ra những giải pháp tích cực làm tăng tính bền vững của hệ thống canh tác lúa-ngô bằng cách áp dụng các phương pháp canh tác hợp lý như giảm sử dụng phân hóa học và các biện pháp canh tác thâm canh như áp dụng phương pháp làm đất tối thiểu.

The Bac Hung Hai zone is the greatest basin in the Red River Delta in Vietnam and also one of the most densely populated regions of the planet. It is mainly a rural region and its economy is dominated by agriculture. In the context of frequent and larger floods in the Bac Hung Hai zone, causing deep socio-economical consequences, the focus of this study is to establish cartography of the high risk areas for flooding in the Bac Hung Hai region using remote sensing and GIS to assist land management. The preparation of a map describing land management in this region is more complicated because parcels for farming are very small and not homogeneous. A consistent and precise map of land use is essential for studies of flooding. The secondary objective is to improve the land use map. To this effect, a classification has been applied to the combination of the spectral bands and textures (TM and ETM[indice supérieur +]) of Landsat and a radar image (ERS). The addition of this information to the spectral bands increases the accuracy of classification by 1% to 4%, according to the dates selected. Additionally, in the study zone where there are few days without clouds, a problem related to the optical satellite image is the cloud cover. Then, the use of radar images will provide ground information for areas hidden by clouds where spectral images are not sufficient. To reach these goals, we have determined the main biophysical considerations that influence flooding. Then, these considerations have been combined in a multi-criteria analysis to evaluate the risks of flooding in the entire basin area. The results show that high to very high risks affect 47% of the area studied and that the south-east region, center, and north-east present the greatest risk.

No description available.

The Red River Delta in Vietnam is one of the regions whose quaternary aquifers are polluted by arsenic. Chronic toxification by arsenic can cause severe illnesses such as cancer, skin lesions, developmental defects, cardiovascular and neurological diseas-es, and diabetes. In this study, a food processing craft village in the Red River Delta was investigated regarding the potential risk faced by the population due to arsenic. The potential sources of arsenic are the groundwater, the crops grown in the sur-roundings, and animal products from local husbandry. However, the occurrence of arsenic in nature is variable, and its bioavailability and toxicity depend very much on its specification: trivalent compounds are more toxic and often more mobile than pen-tavalent compounds, while inorganic species are generally more toxic than organic ones. Local conditions, such as the redox potential, strongly influence its specification and thus potential bioavailability. The introduction to this work elucidates the key factors which potentially cause human exposure to arsenic: the geological setting of the study area, land and water use pat-terns, and the current state of research regarding the mobilization, bioavailability and plant uptake of arsenic. Although the study area is located in a region where the groundwater is known to be moderately contaminated by arsenic, the level of arsenic in the groundwater in the village had not previously been determined. In this study, water use in the village was examined by a survey among the farmers and by water analyses, which are present-ed in the following chapters. Four main water sources (rain, river, tube well and a pub-lic municipal waterworks) are used for the different daily activities; the highest risk to human health was found to be the bore well water, which is pumped from the shallow Holocene aquifer. The water from the bore wells is commonly used for cleaning and washing as well as to feed the animals and for food processing. Products like noodles and rice wine were examined as well as local pork and poultry. Vegetables from the gardens and rice plants from the surrounding paddy fields were sampled and ana-lyzed. All plants were found to have accumulated arsenic, leafy vegetables showing the highest arsenic concentrations. The results are discussed and compared, and conclusions are drawn in the last part. The reducing conditions in the paddy fields are likely to have a strong influence on arsenic uptake in rice plants and on transport to the aquifer. The installation of a wastewater treatment plant under the research project INHAND, which was funded by the BMBF German Ministry of Education and Research, led to lower arsenic concen-trations in the groundwater. Soaring industrialization, the growing population, and the consumers’ changing behav-ior will widely affect land and water use and hence the potential mobilization of arse-nic. In order to mitigate further human exposure to arsenic, wastewater needs to be treated and the reducing conditions in the rice fields need to be decreased by means of enhanced cultivation methods.

The Red River Delta in Vietnam is one of the regions whose quaternary aquifers are polluted by arsenic. Chronic toxification by arsenic can cause severe illnesses such as cancer, skin lesions, developmental defects, cardiovascular and neurological diseas-es, and diabetes. In this study, a food processing craft village in the Red River Delta was investigated regarding the potential risk faced by the population due to arsenic. The potential sources of arsenic are the groundwater, the crops grown in the sur-roundings, and animal products from local husbandry. However, the occurrence of arsenic in nature is variable, and its bioavailability and toxicity depend very much on its specification: trivalent compounds are more toxic and often more mobile than pen-tavalent compounds, while inorganic species are generally more toxic than organic ones. Local conditions, such as the redox potential, strongly influence its specification and thus potential bioavailability. The introduction to this work elucidates the key factors which potentially cause human exposure to arsenic: the geological setting of the study area, land and water use pat-terns, and the current state of research regarding the mobilization, bioavailability and plant uptake of arsenic. Although the study area is located in a region where the groundwater is known to be moderately contaminated by arsenic, the level of arsenic in the groundwater in the village had not previously been determined. In this study, water use in the village was examined by a survey among the farmers and by water analyses, which are present-ed in the following chapters. Four main water sources (rain, river, tube well and a pub-lic municipal waterworks) are used for the different daily activities; the highest risk to human health was found to be the bore well water, which is pumped from the shallow Holocene aquifer. The water from the bore wells is commonly used for cleaning and washing as well as to feed the animals and for food processing. Products like noodles and rice wine were examined as well as local pork and poultry. Vegetables from the gardens and rice plants from the surrounding paddy fields were sampled and ana-lyzed. All plants were found to have accumulated arsenic, leafy vegetables showing the highest arsenic concentrations. The results are discussed and compared, and conclusions are drawn in the last part. The reducing conditions in the paddy fields are likely to have a strong influence on arsenic uptake in rice plants and on transport to the aquifer. The installation of a wastewater treatment plant under the research project INHAND, which was funded by the BMBF German Ministry of Education and Research, led to lower arsenic concen-trations in the groundwater. Soaring industrialization, the growing population, and the consumers’ changing behav-ior will widely affect land and water use and hence the potential mobilization of arse-nic. In order to mitigate further human exposure to arsenic, wastewater needs to be treated and the reducing conditions in the rice fields need to be decreased by means of enhanced cultivation methods.:Abstract III Zusammenfassung V Acknowledgements VII Contents IX List of abbreviations XIII List of tables XVII 1 Scope of this work 1 2 Introduction 2 2.1 Geographical and geological setting of the study area 2 2.2 Hydrological situation 5 2.2.1 Surface water 5 2.2.2 Impact of human activities on surface water quality and distribution 6 2.2.3 Hydrogeology 7 2.3 Arsenic occurrence 7 2.3.1 Arsenic toxicity 8 2.3.2 Risk potential of arsenic in diet 10 2.4 Arsenic contamination in the groundwater resources of the Red River Delta 11 2.4.1 Occurrence and origin of arsenic in the Red River Delta 12 2.4.2 Mobilization processes 13 2.4.3 As mobilization in paddy fields 15 2.5 Arsenic occurrence in daily rural activities 16 2.5.1 Arsenic in soil 17 2.5.2 Arsenic in drinking water 19 2.5.3 Phytoaccumulation: Current state of research 20 2.5.4 Bioavailablity 22 2.5.5 Arsenic uptake in rice plants 23 2.5.6 Arsenic in meat and animal products 26 2.5.7 Arsenic uptake in golden apple snails 27 2.5.8 Processing: Wine and noodles 28 2.5.9 Arsenic concentrations in wastewater, activated sludge and digestate 29 2.6 Iron and manganese in the nutrient chain 30 2.7 Land and water use in the Red River Delta 31 2.7.1 Historical and political aspects of rural development in Vietnam 33 2.7.2 Craft villages in the Red River Delta 34 3 Materials and methods 36 3.1 Soil sample analyses 36 3.2 Well sampling 37 3.3 Wastewater and sludge analyses 37 3.4 Food analyses 38 3.5 Site visit and field observations 39 3.6 Questionnaire 39 4 Results 40 4.1 Soil samples 40 4.1.1 Total arsenic and total heavy metal concentrations 40 4.1.2 Sequential fractionation procedure 41 4.2 Arsenic in the water cycle in Dai Lam 43 4.2.1 Groundwater analyses 43 4.2.2 Water use in Dai Lam 47 4.2.3 Wastewater in Dai Lam 50 4.3 Arsenic in sewage sludge 51 4.4 Arsenic in manure samples 52 4.5 Arsenic in food samples 52 4.5.1 Rice 52 4.5.2 Arsenic in leaf vegetables 53 4.5.3 Arsenic in poultry products 56 4.5.4 Arsenic in pork samples 57 4.5.5 Arsenic in snails 57 4.6 Economic and demographic development potential 58 5 Discussion 61 5.1 Soil samples 61 5.2 Groundwater samples 62 5.2.1 High arsenic concentrations 62 5.2.2 Strong temporal and spatial variation 63 5.2.3 Weak correlation between measured parameters 69 5.3 Wastewater and sewage sludge 70 5.4 Pig manure 71 5.5 Daily exposure to As from dietary intake 71 5.6 Effects of land and water use on water quality and public health 76 5.7 Against the background of the transition economy 77 6 Conclusion 80 7 Perspectives (further work) 85 8 References 86 9 Annex 110

Between 1961 and 1976 Häi Hung province -- present day Häi Duong and Hung Yên -- lost the equivalent of two entire districts of agricultural land. How could so much land be abandoned under a collectivised agriculture system? And what role did poor water control infrastructure play in creating such a situation?¶ I answer these questions by examining the historical patterns of hydraulic development in northern Vietnam from the beginning of the 19th century until the introduction of the Production Contract system in 1981. Underlying both the French colonial and communist visions of modernity and economic development was a belief that improving agricultural productivity, of which large-scale hydraulic infrastructure was an important component, could catalyse growth in the rural economy, which could then finance industrialisation. I argue throughout this thesis that developing large-scale hydraulic infrastructure in the Red River delta has relied upon the creation of a hydraulic bargain between the state and water users. This is in contrast to Wittfogel's theory of the hydraulic state, insofar as developing hydraulic infrastructure has depended upon the active political and economic participation and support of water users, and not the absolute power of the state. The political economic history of the hydraulic bargain highlights the relative power of peasants to influence the direction of large-scale hydraulic development and, as such, the shape of the Red River delta's wet-rice economy.

Zur Einschätzungen und Bewertung der Nachhaltigkeit der gegenwärtigen Gemüseproduktion im Roten-Fluss-Delta, Vietnam, erfolgten empirische Untersuchungen zur Ermittlung und Bewertung eines Nachhaltigkeitsindex unter Nutzung verschiedener Lösungsansätze. Die Analysen und Einschätzungen wurden aus ökologischer ökonomischer und sozialer Sicht vorgenommen. Die erfassten Daten wurden unter Nutzung von zwei Methoden ausgewertet, der Mehr-Kriterien-Bewertungsmethode Analytic Hierarchy Process (AHP) und der Fuzzy Bewertungsmethode. In Workshops wurden mit den Farmern Präferenzen als Element der AHP, zu den Kriterien die Ausdruck der Nachhaltigkeit sind, erarbeitet. Es wurde herausgearbeitet, dass im ländlichen Raum, die Gemüseproduktion nachhaltig ist, im Peri-urbanen Raum wurde eine geringe Nachhaltigkeit ermittelt und im urbanen Raum keine Nachhaltigkeit. Im Ergebnis der Forschungsarbeit wurde herausgearbeitet, dass für einen nachhaltigen Gemüse-Anbau im Roten-Fluss-Delta, die Farmer ihr Kontrollsystem und System der Nachverfolgbarkeit verbessern müssen. Gleichermaßen ist es erforderlich die sozialen Bedingungen so zu gestalten, das die Prinzipien der‚ Guten Landwirtschaftlichen Praxis‘ greifen. Im Rahmen der Forschungsarbeit konnte gleichfalls eine Bewertung der Nachhaltigkeit unter Nutzung der Fuzzy Methode erfolgreich eingesetzt werden. Diese Ergebnisse sind geeignet, sowohl den Farmern, als auch den politischen Entscheidungsträgern, die geeigneten Werkzeuge für die Entwicklung einer nachhaltigen Gemüse Kultivierung in der Zukunft zu geben. / This study is empirical research by applying different sustainability assessment approaches to evaluate and to compare the sustainability index of the existing vegetable cultivation systems in the Red River Delta - the largest vegetable production land area of Vietnam in terms of environment, economic and social dimensions. In addition, this study also incorporated farmers'' perceptions as well as their preferences into the weight of criteria by using Analytic Hierarchy Process (AHP) in multi-criteria evaluation method, and rules formed in fuzzy evaluation method. The results from the sustainability assessment for the vegetable cultivation systems show that in the rural area, the sustainability are acceptable whereas in the peri-urban area are only conditionally acceptable, and in the urban area are not sustainable. The results from this study indicate that, to achieve sustainable vegetable cultivation systems in the Red River Delta in Vietnam, the farmers need improved internal controls and tracing systems as well as strict social control in order to implement good agricultural practices guidelines. This study result also shows that the sustainability assessment by fuzzy evaluation approach appears to be well suited to provide quantitative answers pertaining to sustainability that can help policy maker in choosing the tool for sustainability assessment in the future.

L'enjeu de cette recherche ethnologique consiste à saisir quelques traits et expressions de la socialité vietnamienne à travers l'étude de la circulation non marchande dans un village au Nord du Vietnam. La première partie vise à définir les manifestations concrètes, la nature et le fonctionnement de la circulation non marchande telle qu'elle se déploie dans le village. La deuxième partie s'attache à analyser les significations et les fonctions sociales de ce système de prestations symboliques. La description ethnographique de ce système montre qu'il s'affirme comme un dispositif de transferts ritualisés, selon lequel les agents sociaux donnent, lors d'occasions définies, à celui qui en a besoin au moment où il en a besoin. Ce système de dons cérémoniels est fondé sur l'entraide, la réciprocité des gestes et l'entretien de dettes morales. L'examen des rapports sociaux en jeu dans la circulation des dons permet de dresser une carte de l'organisation des relations sociales selon les degrés de proximité relationnelle. Cette étude se termine sur la fonction sociale de ces prestations réciproques, qui consiste à inaugurer et à perpétuer des relations tình cảm, c'est-à-dire des relations chargées d'affection spontanée et morale à la fois. En tant que dons d'alliance qui participent à réguler les relations personnelles, nous estimons que les transferts cérémoniels incarnent l'« instant fugitif où la société prend » (Mauss, 1999 : 275) en milieu rural au Nord du Vietnam. La conclusion tente une généralisation du propos à travers la description du giao lưu, qui consiste à se rencontrer et à échanger en vue d'actualiser, de sceller et de renforcer des relations sociales. / The following ethnological research aims at grasping a few characteristic features of the Vietnamese principles of sociality, through the study of non-commercial transactions taking place in a village located in the Northern Vietnam. The first part of the doctoral thesis lists the forms, the practices and the nature of non-commercial transactions occurring in the village. The second part analyses the social meanings and functions of those symbolics transactions. The ethnographic description of the system shows that most of the transactions occurring are ritualized : on defined occasions, villagers give a gift to someone else in need and at the moment when they need it. Those non-commercial transactions can be defined as a system of ceremonial gif-giving based on mutual aid, gesture reciprocity, and moral debt. The study of the connections between the gifts given and the social relations involved in the transactions allow us to map out the organization of the social relations according to the degrees of closeness. This study ends with the analysis of the social function entailed by mutual gifts. Their role is mainly to create and strengthen tình cảm, relationships, that is to say relationships filled with spontaneous and moral feelings. Because those « bonding gifts » participate to the regulation of the personnel relationship in the village, we can consider that they embody that «fleeting moment when society sets » (Mauss, 1999: 275) in rural area in Northern Vietnam.