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[en] Global food production must increase by 70% to feed the projected growth in the world’s population from about seven to nine billion people by 2050. This cannot be achieved without increasing land productivity and conserving soil and water resources in the face of the severe challenges posed, including climate change, soil erosion and salinization, and drought and flooding — all of which contribute to reducing the quantity and quality of soil and water resources. Global R&D efforts are accelerating to both develop and put into practice “win–win” systems of agricultural production, targeting a range of scales from field plots to farm and catchment levels, which are resilient against the negative consequences of these challenges, while at the same time enhance land productivity for sustainable food production and minimize the greenhouse gas (GHG) emissions which potentially contribute to climate change and variations. This publication is a compilation of selected papers presented during both oral and poster sessions at the International Symposium on “Managing Soils for Food Security and Climate Change Adaptation and Mitigation”, organized by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture on 23–27 July, 2012. The objective of this Symposium was to communicate the advances that have been made in using nuclear and conventional techniques to improve land management practices for: (i) enhancing productivity; (ii) increasing soil resilience to climate change; and (iii) reducing GHG emissions. The Symposium also sought to identify current gaps in our knowledge and to discuss ways in which soil (and water) resources can be better managed to meet the challenge of promoting food security through the dual approach of climate change adaptation and mitigation. Approximately 400 delegates from 80 Member States and representatives of international organizations including the FAO attended. Overall 85 oral and 136 poster papers were presented during the 5-day Symposium. These covered a wide range of topics during the plenary and six thematic sessions, including (i) managing soils for crop production and on-farm and area-wide ecosystem service efficiency; (ii) preserving and protecting soil resources; (iii) establishing soil and water conservation zones for pollution control; (iv) managing soils for climate change adaptation and mitigation through increasing soil carbon stocks (C sequestration) and reducing greenhouse gas emissions; (v) managing agricultural water for climate change adaptation; and (vi) recent advances in nuclear techniques and applications in land management research. It is hoped that the information presented in these Proceedings provides valuable guidance to scientists and land managers in both the public and private sectors, as well as to government and institutional policy- and decision-makers involved in addressing land management issues for climate smart agriculture and the conservation of natural resources for agricultural productivity and food security.
[en] As parties to two international conventions governing notification and assistance in the event of nuclear or radiological emergencies, the FAO and IAEA play a major role in international emergency response arrangements. A key activity of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture (Joint FAO/IAEA Division) in an emergency is to help provide Member States with information about radionuclides in food and agriculture, and to offer assistance and support to countries concerning the radiological consequences for food production. The paper explains the role of the Joint FAO/IAEA Division in nuclear emergency preparedness and response and gives examples of two current activities. Firstly, it highlights an international research project for developing food and soil data collection and analytical protocols, and state of the art information systems for both routine monitoring and also in emergency response to nuclear and radiological incidents. Secondly, the paper gives more information about the role of the Joint FAO/IAEA Division in implementing normative standards and guidance related to radioactivity in food, through the Codex Alimentarius Commission and the Codex Committee on Contaminants in Food. (author)
[en] A five-year coordinated research project (CRP) entitled “Selection and Evaluation of Food (Cereal and Legume) Crop Genotypes Tolerant to Low Nitrogen and Phosphorus Soils through the Use of Isotopic and Nuclear Related Techniques” that supports Member States in their efforts to optimize crop yields and soil productivity in low nitrogen (N) and phosphorus (P) environments was initiated in 10 developing countries in Africa, Asia and Latin America. The overall objective of the CRP was to develop integrated crop, soil and nutrient management practices to increase crop production in marginal lands by identifying and promoting the development of food crop genotypes with enhanced N and P use efficiency and greater productivity. The studies conducted within this CRP concerned two major food security cereal crops namely upland rice (Oryza sativa L.) and maize (Zea maize L.), and three legumes, namely common bean (Phaseolus vulgaris L.), soybean (Glycine max L.) and cowpea (Vigna unguiculata L.). Protocols for characterization of root traits contributing to enhanced N and P acquisition from low fertility soils with emphasis on rapid root phenotyping methods were developed and used to evaluate and select crop genotypes with superior N and P acquisition and/or utilization. Results showed that out of 150–200 genotypes from the five crops that were tested, 3–5 cultivars identified as N and P efficient in low N and P soils, had better root architecture and produced 15–20 percent higher yields than those with poor root architecture. Branching angle interval was identified as a suitable root selection parameter for soil N use efficiency, while adventitious rooting and root hair formation were identified as suitable plant parameters for selecting P use efficiency. The genotypes of rice, common bean, maize, soybean and cowpea identified in a number of cases provide valuable resources for plant breeding programmes aimed at enhancing P and N use efficiency in crops. The CRP created a database on how cereals and legumes can acquire N and P in low nutrient soils, and this database could be further expanded and interpreted using multivariate analysis on how cereal and legume crops can acquire N and P in low nutrient soils. (author)
[en] This paper summarizes key findings and identifies the main lessons learnt from a 5-year (2002-2008) coordinated research project (CRP) on Assessing the effectiveness of soil conservation measures for sustainable watershed management and crop production using fallout radionuclides (D1.50.08), organized and funded by the International Atomic Energy Agency through the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. The project brought together nineteen participants, from Australia, Austria, Brazil, Canada, Chile, China, Japan, Morocco, Pakistan, Poland, Romania, Russian Federation, Turkey, United Kingdom, United States of America and Vietnam, involved in the use of nuclear techniques and, more particularly, fallout radionuclides (FRN) to assess the relative impacts of the different soil conservation measure on soil erosion and land productivity. The overall objective of the CRP was to develop improved land use and management strategies for sustainable watershed management through effective soil erosion control practices, by the use of 137Cs (half-life of 30.2 years), 210Pbex (half-life of 22.3 years) and 7Be (half-life of 53.4 days) for measuring soil erosion over several spatial and temporal scales. The environmental conditions under which the different research teams applied the tools based on the use of fallout radionuclides varied considerably - a variety of climates, soils, topographies and land uses. Nevertheless, the achievements of the CRP, as reflected in this overview paper, demonstrate that fallout radionuclide-based techniques are powerful tools to assess soil erosion/deposition at several spatial and temporal scales in a wide range of environments, and offer potential to monitor soil quality. The success of the CRP has stimulated an interest in many IAEA Member States in the use of these methodologies to identify factors and practices that can enhance sustainable agriculture and minimize land degradation. (author)
[en] Information on soil organic matter (SOM) pools is of vital importance for studying the impact of soil management and environmental factors on soil organic carbon, an important part of the global carbon cycle. Several conceptual SOM pools with different turnover rates are available to feed models or to study carbon cycles. The fractionation scheme of Zimmermann allows isolating the labile particulate organic matter (POM) pool. Besides its use in conventional soil organic carbon dynamics studies and modelling, this pool can be determining as well in the evaluation of soil organic carbon stability based on the use of stable "1"5N and "1"3C isotopes
[en] Limited water resources and prolonged periods of water stress can have severe effects on crop growth and production. Current research efforts are directed towards finding and selecting more drought tolerant species and a better understanding of drought on crop performance. A pot experiment was conducted in a climate chamber, using the soybean variety Sigalia and summer wheat (Triticum aestivum) as a reference crop. The experiment consisted of two watering regimes, one optimal and one stressed, with 12 replicates each. There were two stages of treatments; from 0-15 days all plants were well watered to ensure plant growth and from 15-42 days crops were subjected to either optimal or stress treatment. Plants were weighed daily and weight changes recorded to determine irrigation gifts (Figure 1). Stress symptoms became visible after 14 days of the start of the second treatment stage. Plants were harvested after a total growing period of 42 days. The aim of the experiment was to test carbon isotopic discrimination (CID) and the isotope dilution method by using the stables isotopes of 13C and 15N and to determine the effects of drought stress on water use efficiency (WUE) and biological nitrogen fixation (BNF). The isotope dilution method was used as a tool to determine the amount and source of N within the crops. The δ13C values varied in the range of -27 to -30‰ for well-watered and -25 to -28‰ for stressed soybeans, indicating a clear and significant effect of water treatments on the isotopic signature. BNF was ultimately not measurable in soybeans at the point of harvest. Instead the same data were used to assess the fertilizer N utilisation rate of the applied starter fertilizer, in both soybean and wheat. Water treatments showed a significant influence on the N utilisation rate with average values of 76% for well-watered and 27% for stressed soybeans. WUE was highest for well-watered plants with an average of 2.2 kg/m3 and 1.1 kg/m3 for stressed plants. This result is unusual and could be an effect of the application of the water treatments and the N availability in the crops.
[en] The impacts of climate change are highly visible in polar regions and high mountains. Accelerated glacier retreat results in changed water availability and altered sedimentation patterns. Warming soils emit greenhouse gases, thus further feeding back to global warming. However, understanding and monitoring these impacts in such difficult to access areas, is challenging. Through fingerprinting and dating, nuclear and isotopic techniques offer a way to obtain time series data at the landscape level with single-site visits. From 25 June to 6 July 2018, the SWMCN Laboratory hosted a two-week training course for twelve scientists from seven Member States, in collaboration with the University of Vienna’s Department of Microbiology and Ecosystem Science and the Department of Geography and Regional Science at Graz University. The course was organized under the project INT5153 “Assessing the impact of climate change and its effects on soil and water resources in polar and mountainous regions”. In this project, soil and water resources in eleven benchmark sites on five continents were characterized. (authors)
[en] The SWMCNL explored the possibility of using δ18O isotopic signature in phosphate for screening phosphorus (P) movement in the landscape. Phosphorus is essential for crop production, but extensive use of P fertilizer and animal manure can lead to eutrophication of rivers and lakes. To study these effects, numerous studies on P movement in the soil plant system and P transformation processes have been performed in the past decades. Assessing losses of P through erosion processes, however, is challenging – particularly at the landscape level and on a longer timescale. Using the isotopic signature of stable oxygen isotope (18O) in the phosphate ion as a tracer could be a cost-effective way to study P movements. This approach is already applied as a paleotemperature proxy (the fractionation between phosphate and water is temperature dependent) and can be used for quantifying P losses through leaching into surface and groundwater, as oxygen exchange between phosphate and water is slow in the absence of biological activity.
[en] To characterize soil carbon loss, soil respiration rates often need to be measured in situ or at least measured in the lab using freshly collected soils. This restricts analysis of archived samples or samples that require longer transportation from farther away destinations. Using SWMCNL newly produced standard gases and laser spectroscopy techniques that can accurately measure CO2 produced by soil respiration, we are evaluating if we can rejuvenate archived soils to measure soil carbon loss when mulch application is applied. By comparing CO2 production from archived soils, rejuvenated soils and freshly collected soils, we can determine if we can restore soil processes so that we can, in the future, perform similar analysis on soils that may be submitted to our laboratory by counterparts in faraway member states.
[en] The ratio of stable oxygen isotopes in phosphate has been used successfully to study the biological cycling of phosphorus in seawater and marine sediments, and now this approach is being applied to study phosphorus cycling in agricultural soils. As an important major element, phosphorus can limit agricultural production and on the other hand excess of phosphorus can lead to water pollution. A better understanding of phosphorus cycling is essential to improve agricultural and environmental management