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Ensuring adequate food availability to an increasing world population constitutes one of the biggest challenges faced by humankind. Scientific and technological advances in food production during the last century enabled agriculture to cope with the concomitant increase in food demand. For example, cereal yields have more than doubled from a global average of 1.5 metric tons per hectare in the 1960s up to 3.2 metric tons per hectare in 2018. This was made possible by the work in different research fields such as agronomy, engineering, and plant sciences, showing that an inter and multidisciplinary approach is indispensable for significant progress. This manuscript is aimed at generating reflexion and analysis about the challenges that agriculture faces at present to satisfy projected food demands, which implies a further doubling of food production by 2050, according to the latest estimates. Relevant issues related to food production (climate change, pollution of water and soils by pesticides and fertilizers, loss of germplasm and biodiversity) are discussed and potential solutions to achieve food security in quantity and quality are reviewed, mainly from the plant breeding and crop-production perspectives, always associated with environmental health preservation and improvement. A broad transdisciplinary effort is needed to increase the impact of science and technology to provide more people with healthier and safer food, produced in a sustainable way. Nonetheless, science and technology alone will not succeed to meet those challenges. Education and knowledge transfer strategies are needed to guarantee responsible production and consumption everywhere, therefore allowing the benefits of scientific and technological progress reach the world population. Simultaneously, adequate action by regulatory authorities and governments concerted at international level, with thorough application of the Precautionary Principle, and aiming at environmental and social justice are

Ensuring adequate food availability to an increasing world population constitutes one of the biggest challenges faced by humankind. Scientific and technological advances in food production during the last century enabled agriculture to cope with the concomitant increase in food demand. For example, cereal yields have more than doubled from a global average of 1.5 metric tons per hectare in the 1960s up to 3.2 metric tons per hectare in 2018. This was made possible by the work in different research fields such as agronomy, engineering, and plant sciences, showing that an inter and multidisciplinary approach is indispensable for significant progress. This manuscript is aimed at generating reflexion and analysis about the challenges that agriculture faces at present to satisfy projected food demands, which implies a further doubling of food production by 2050, according to the latest estimates. Relevant issues related to food production (climate change, pollution of water and soils by pesticides and fertilizers, loss of germplasm and biodiversity) are discussed and potential solutions to achieve food security in quantity and quality are reviewed, mainly from the plant breeding and crop-production perspectives, always associated with environmental health preservation and improvement. A broad transdisciplinary effort is needed to increase the impact of science and technology to provide more people with healthier and safer food, produced in a sustainable way. Nonetheless, science and technology alone will not succeed to meet those challenges. Education and knowledge transfer strategies are needed to guarantee responsible production and consumption everywhere, therefore allowing the benefits of scientific and technological progress reach the world population. Simultaneously, adequate action by regulatory authorities and governments concerted at international level, with thorough application of the Precautionary Principle, and aiming at environmental and social justice are

Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 (131I) and cesium isotopes (137Cs and 134Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous 131I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous 131I and the large underestimation of the total 131I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous 131I fraction to total 131I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the 134Cs to 137Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total 131I inventory that has passed over Europe during this period was

Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 (131I) and cesium isotopes (137Cs and 134Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous 131I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous 131I and the large underestimation of the total 131I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous 131I fraction to total 131I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the 134Cs to 137Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total 131I inventory that has passed over Europe during this period was

Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils

Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils

Deposits of radioactive materials in the former uranium-vanadium mining village of Urgeirica comprise about 6 000 000 tonnes of mill tailings and fine mud resulting from treatment of acid mine drainage. Most of these have been deposited on the ground and are exposed to weathering, with run-off draining into a river that includes the main water reservoir for central Portugal. Other rivers flowing through the mining region may also receive drainage from the areas of old uranium mines. Concentrations of radionuclides in the tailings and mud are 10-180 times higher than in agricultural soils of the region, but analysis of waters and sediments in the main rivers indicated that they do not disperse far from the mine/mill sites. The local stream displays strongly enhanced radioactivity but there is no significant increase in levels for the rivers and the two main water reservoirs do not show any enhancement. Nevertheless, precauitions should be taken to keep the wastes confined and to prevent unusual rainfall from causing radiological emergencies., Deposits of radioactive materials in the former uranium-vanadium mining village of Urgeirica comprise about 6 000 000 tonnes of mill tailings and fine mud resulting from treatment of acid mine drainage. Most of these have been deposited on the ground and are exposed to weathering, with run-off draining into a river that includes the main water reservoir for central Portugal. Other rivers flowing through the mining region may also receive drainage from the areas of old uranium mines. Concentrations of radionuclides in the tailings and mud are 10-180 times higher than in agricultural soils of the region, but analysis of waters and sediments in the main rivers indicated that they do not disperse far from the mine/mill sites. The local stream displays strongly enhanced radioactivity but there is no significant increase in levels for the rivers and the two main water reservoirs do not show any enhancement. Nevertheless, precauitions should be taken to keep the wastes confined and to prevent unusual rainfall from causing radiological emergencies.

Past U mining near the village of Cunha Baixa in Portugal resulted in the contamination of subsurface waters used for agricultural irrigation. High radionuclide concentrations are currently found in the mine water as well as in solid mining waste and the sludge from mine water treatment. Nuclide transfer to plants was investigated using two side-by-side parcels of land, each divided into four replicate lots, which were used for the growth of the potato species Solanum tuberosum L. One parcel was irrigated with water with a high U concentration of 13.7 Bq/l and the other with water with a low U concentration of 0.3 Bq/l. The potato crop was collected and samples with or without peel were analysed for the U isotopes 238-U, 235-U and 234-U, 238-U daughters and the alpha-emitting radionuclides 230-Th, 226-Ra, 210-Po. The results showed a significant uptake of Ra and minor uptake of other radionuclides by the potatoes. Ra transfer was enhanced in the parcel of land irrigated with water with high Ra concentrations, but radionuclide concentrations in irrigation water had a minor effect on the transfer of U, Th and Po. Radionuclides were largely accumulated in the peel and in general peeling removed most of the radioactivity. Since the Ra may be transferred to man through the food chain it should be monitored in agricultural zones near U mine areas., Past U mining near the village of Cunha Baixa in Portugal resulted in the contamination of subsurface waters used for agricultural irrigation. High radionuclide concentrations are currently found in the mine water as well as in solid mining waste and the sludge from mine water treatment. Nuclide transfer to plants was investigated using two side-by-side parcels of land, each divided into four replicate lots, which were used for the growth of the potato species Solanum tuberosum L. One parcel was irrigated with water with a high U concentration of 13.7 Bq/l and the other with water with a low U concentration of 0.3 Bq/l. The potato crop was collected and samples with or without peel were analysed for the U isotopes 238-U, 235-U and 234-U, 238-U daughters and the alpha-emitting radionuclides 230-Th, 226-Ra, 210-Po. The results showed a significant uptake of Ra and minor uptake of other radionuclides by the potatoes. Ra transfer was enhanced in the parcel of land irrigated with water with high Ra concentrations, but radionuclide concentrations in irrigation water had a minor effect on the transfer of U, Th and Po. Radionuclides were largely accumulated in the peel and in general peeling removed most of the radioactivity. Since the Ra may be transferred to man through the food chain it should be monitored in agricultural zones near U mine areas.