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We screened 20 different clones of willow and poplar species in hydroponic experiments for their metal resistance and accumulation properties. Plants were exposed for 4 weeks either to single additions of (microM) 4.45 Cd or 76.5 Zn, or a metal cocktail containing the same amounts of Cd and Zn along with 7.87 Cu and 24.1 Pb. Plant biomass, metal tolerance and metal accumulation pattern in roots and leaves varied greatly between clones. The leaf:root ratio of metal concentrations was clearly underestimated compared to soil experiments. The largest metal concentrations in leaves were detected in Salix dasyclados (315 mg Cdkg(-1) d.m.) and a Salix smithiana clone (3180 mg Znkg(-1) d.m.) but these species showed low metal tolerance. In spite of smaller Cd and Zn concentrations, the metal-tolerant clones Salix matsudana, Salix fragilis-1, and Salix purpurea-1 hold promise for phytoextraction as they produced large biomass and metal contents in leaves.

The establishment of phytoextraction crops on highly contaminated soils can be limited by metal toxicity. A recent proposal has suggested establishing support crops during the critical initial phase by metal immobilization through soil amendments followed by subsequent mobilization using elemental sulphur to enhance phytoextraction efficiency. This 'combined phytoremediation' approach is tested for the first time in a pot experiment with a highly contaminated soil. During a 14-week period, relatively metal-tolerant maize was grown in a greenhouse under immobilization (before sulphur (S) application) and mobilization (after S application) conditions with soil containing Cd, Pb and Zn contaminants. Apart from the control (C) sample, the soil was amended with activated carbon (AC), lignite (Lig) or vermicompost (VC) all in two different doses (dose 1~45 g additive kg-1 soil and dose 2~90 g additive kg-1 soil). Elemental S was added as a mobilization agent in these samples after 9 weeks. Biomass production, nutrient and metal bioavailability in the soil were determined, along with their uptake by plants and the resulting remediation factors. Before S application, Cd and Zn mobility was reduced in all the AC, Lig and VC treatments, while Pb mobility was increased only in the Lig1 and VC1 treatments. Upon sulphur application, Fe, Mn, Cd, Pb and Zn mobility was not significantly affected in the C, AC and VC treatments, nor total Cd, Pb and Zn contents in maize shoots. Increased sulphate, Mn, Cd, Pb and Zn mobilities in soil together with related higher total S, Mn, Pb and Zn contents in shoots were observed in investigated treatments in the last sampling period. The highest biomass production and the lowest metal toxicity were seen in the VC treatments. These results were associated with effective metal immobilization and showed the trend of steady release of some nutrients. The highest remediation factors and total elemental content in maize shoots were recorded in the VC treatments. This increased phytoremediation efficiency by 400% for Cd and by 100% for Zn compared to the control. Considering the extreme metal load of the soil, it might be interesting to use highly metal-tolerant plants in future research. Future investigations could also explore the effect of carbonaceous additives on S oxidation, focusing on the specific microorganisms and redox reactions in the soil. In addition, the homogeneous distribution of the S rate in the soil should be considered, as well as longer observation times.

Land use/land cover (LULC) change has serious implications for environment as LULC is directly related to land degradation over a period of time and results in many changes in the environment. Monitoring the locations and distributions of LULC changes is important for establishing links between regulatory actions, policy decisions, and subsequent LULC activities. The normalized difference vegetation index (NDVI) has the potential ability to identify the vegetation features of various eco-regions and provides valuable information as a remote sensing tool in studying vegetation phenology cycles. Similarly, the normalized difference built-up index (NDBI) may be used for quoting built-up land. This study aims to detect the pattern of LULC, NDBI, and NDVI change in Lodhran district, Pakistan, from the Landsat images taken over 40 years, considering four major LULC types as follows: water bodies, built-up area, bare soil, and vegetation. Supervised classification was applied to detect LULC changes observed over Lodhran district as it explains the maximum likelihood algorithm in software ERDAS imagine 15. Most farmers (46.6%) perceived that there have been extreme changes of onset of temperature, planting season, and less precipitation amount in Lodhran district in the last few years. In 2017, building areas increased (4.3%) as compared to 1977. NDVI values for Lodhran district were highest in 1977 (up to + 0.86) and lowest in 1997 (up to - 0.33). Overall accuracy for classification was 86% for 1977, 85% for 1987, 86% for 1997, 88% for 2007, and 95% for 2017. LULC change with soil types, temperature, and NDVI, NDBI, and slope classes was common in the study area, and the conversions of bare soil into vegetation area and built-up area were major changes in the past 40 years in Lodhran district. Lodhran district faces rising temperatures, less irrigation water, and low rainfall. Farmers are aware of these climatic changes and are adapting strategies to cope with the effects but require support from government.

Experiments in growth chambers with controlled atmosphere were performed to compare the effects on the productivity of two treatments stimulating photosynthesis: the doubling of CO2 concentration, the doubling of irradiance; the combining of both was also tested. A large effect of light was noticed: (i) the accumulation of carbon was, contrarily to CO2 effect, amplified within time, and led to the most important dry matter production. (ii) the specific leaf weight was about two-fold increased. (iii) the nitrate content was 2-3 fold less. A significant positive effect of CO2 was detected on the fresh biomass production and the iron content of lettuce. A synergy was observed on dry matter production by the interaction of the two factors.

An experiment of Artificial Ecosystem in closed growth chambers is described. It comprises a biomass producer compartment coupled with a decomposer compartment. A model of carbon cycle is presented, simulating the CO2 changes in atmosphere and the carbon status in plants and in the decomposer system. Results of variation in several parameters such as photoperiod, rate of photosynthesis, percentage of harvested biomass introduced in decomposer, kinetics of biomass decomposition, are presented. Positive conclusions are deduced about the feasability of real experiments without particular control of CO2 nor buffering system. Applications in studies on plant-soil-atmosphere ecosystems, for spatial and terrestrial researches, are discussed.

The most important challenge to use phytoremediation is how to improve its efficiency by increasing the accumulation of metals in plants, or by improving key plant biological traits that should enhance metal uptake. In this paper, we used open-top chambers to investigate the effects of elevated CO2 (860 microL L(-1)) on biomass and Cs uptake by a Sorghum vulgare x Sorghum vulgare var. sudanense hybrid and Trifolium pratense L. growing on soils spiked with various levels of cesium (0, 300, 1500 and 3000 mg Cs kg(-1)). The results showed that elevated CO2 not only increased aboveground biomass of the Sorghum and Trifolium species by 32-111%, and by 8-11%, respectively, compared to the ambient CO2 treatment, but also caused more accumulation of Cs by Sorghum species (up to 73%) than Trifolium species (up to 43%). It was speculated that the increase in biomass and the improvement in Cs accumulation ability at elevated CO2 could be related to lowered soil pH values, and changes in number and kind of microorganisms in the rhizospheres of the two tested species. This is the first report of a link among elevated CO2, increased biomass and hyperaccumulation of Cs by Sorghum and Trifolium species.

Alcohols, ketones and aldehydes have been identified in the profiles of volatile substances in blood serum. A 5-ml sample is required in order to obtain a complete gas chromatographic profile, selective profiles of alcohols or individual ketones by computer mass fragmentography, and to permit mass spectrometric identification of the compounds. The quantitative determination of total 4-heptanone using an extraction and gas chromatographic-mass fragmentographic procedure demonstrated concentrations of 10-50 nmole/l in normal serum, whereas in the serum of patients with chronic renal insufficiency the concentrations were 10- to 40-fold higher. Ethanol and total acetone were quantitatively measured by direct injection of serum. For 10 patients, concentrations between 25 and 85 mumole/l of acetone and 10-170 mumole/l of ethanol were determined.

La culture du maïs est souvent devenue le seul moyen pour de nombreux agriculteurs familiaux en Asie du Sud-Est d'obtenir rapidement un revenu en espèces. Cependant, l'intensification des systèmes de culture à base de maïs suscite des inquiétudes quant à sa durabilité environnementale. Cette étude a contribué à des approches sur le terrain pour l'évaluation ex post de la durabilité des systèmes de culture actuels dans les exploitations agricoles et pour la conception de prototypes plus durables, dans des conditions où les informations nécessaires pour estimer les indicateurs de durabilité ne sont pas facilement disponibles. Un diagnostic agronomique régional sur 3 ans a été associé à une évaluation multicritère et à une procédure de prototypage. Ce dernier visait à augmenter les performances sur les indicateurs qui montraient des niveaux critiques sur les systèmes actuels. Une diversité locale de champs de maïs au Laos a été utilisée pour tester l'approche. Nous avons défini et utilisé des indicateurs représentant les objectifs socio-économiques et les risques pour l'environnement des agriculteurs. Les indicateurs de durabilité ont été calculés à l'aide de données extraites des enquêtes sur les exploitations agricoles, de mesures directes dans les champs gérés par les agriculteurs et de la modélisation des cultures. Notre analyse a montré que les faiblesses les plus fréquentes dans tous les systèmes de culture actuels à base de maïs étaient (i) une faible productivité des terres et du travail, (ii) une forte sensibilité à l'infestation de mauvaises herbes, (iii) un risque élevé de lessivage des herbicides, (iv) un risque d'épuisement de la fertilité des sols, (v) un risque d'érosion des sols. Aucun des systèmes de culture actuels n'a bien fonctionné simultanément sur les deux indicateurs de productivité des terres/du travail et de contrôle du lessivage des herbicides. Ces problèmes de durabilité résultent principalement des difficultés à maîtriser l'établissement de cultures mécanisées. En prenant le système de culture actuel comme point de départ, les prototypes avec une implantation réussie des cultures grâce à une mécanisation bien maîtrisée amélioreraient considérablement les indicateurs de durabilité suivants : contrôle du lessivage des herbicides (amélioré de 130 à 340 %), rendement (multiplié par 1,3 à 2,3), marge brute (multipliée par 1,3 à 2,2), lutte contre les mauvaises herbes (améliorée de 180 à 430 %) et productivité du travail (multipliée par 1,4 à 3,4). Cependant, cela augmenterait l'érosion (contrôle de l'érosion divisé par 1,6-7) et les sorties de trésorerie saisonnières augmenteraient (multipliées par 1,1-2). Dans l'ensemble, l'amélioration de l'établissement des cultures augmenterait la durabilité (score de durabilité globale multiplié par 1,1-1,6). Nos résultats suggèrent que fournir aux agriculteurs une capacité accrue à maîtriser l'établissement des cultures ne résoudrait pas tous les problèmes de durabilité de la culture du maïs, mais au moins aiderait à éviter une surutilisation catastrophique des herbicides dans ce contexte. El cultivo de maíz a menudo se ha convertido en la única forma para que muchos agricultores familiares en el sudeste asiático obtengan rápidamente ingresos en efectivo. Sin embargo, la intensificación de los sistemas de cultivo a base de maíz está generando preocupaciones sobre su sostenibilidad ambiental. Este estudio contribuyó a los enfoques basados en el campo para la evaluación ex post de la sostenibilidad de los sistemas de cultivo actuales en las granjas y para el diseño de prototipos más sostenibles, en condiciones en las que la información requerida para estimar los indicadores de sostenibilidad no está fácilmente disponible. Se combinó un diagnóstico agronómico regional de 3 años con una evaluación multicriterio y un procedimiento de prototipado. Este último tenía como objetivo aumentar el rendimiento de los indicadores que mostraban niveles críticos en los sistemas actuales. Se utilizó una diversidad local de campos de maíz en Laos para probar el enfoque. Definimos y utilizamos indicadores que representan los objetivos socioeconómicos de los agricultores y los riesgos para el medio ambiente. Los indicadores de sostenibilidad se calcularon utilizando datos extraídos de encuestas agrícolas, mediciones directas en campos gestionados por los agricultores y modelos de cultivos. Nuestro análisis mostró que las debilidades más frecuentes en todos los sistemas actuales de cultivo a base de maíz fueron (i) baja productividad de la tierra y la mano de obra, (ii) alta susceptibilidad a la infestación de malezas, (iii) alto riesgo de lixiviación de herbicidas, (iv) riesgo de agotamiento de la fertilidad del suelo, (v) riesgo de erosión del suelo. Ninguno de los sistemas de cultivo actuales funcionó bien simultáneamente en ambos indicadores de productividad de la tierra/mano de obra y control de la lixiviación de herbicidas. Estos problemas de sostenibilidad se debieron principalmente a las dificultades para dominar el establecimiento mecanizado de cultivos. Tomando como punto de partida el sistema de cultivo actual, los prototipos con un establecimiento de cultivos exitoso gracias a una mecanización bien dominada mejorarían significativamente los siguientes indicadores de sostenibilidad: control de la lixiviación de herbicidas (mejorado en un 130-340%), rendimiento (multiplicado por 1.3–2.3), margen bruto (multiplicado por 1.3-2.2), control de malezas (mejorado en un 180-430%) y productividad laboral (multiplicado por 1.4–3.4). Sin embargo, aumentaría la erosión (control de la erosión dividido por 1,6-7) y aumentaría la salida de efectivo estacional (multiplicada por 1,1-2). En general, mejorar el establecimiento de cultivos aumentaría la sostenibilidad (la puntuación general de sostenibilidad se multiplicaría por 1,1-1,6). Nuestros resultados sugieren que proporcionar a los agricultores una mayor capacidad para dominar el establecimiento de cultivos no resolvería todos los problemas de sostenibilidad del cultivo de maíz, pero al menos ayudaría a evitar un uso excesivo catastrófico de herbicidas en ese contexto. Maize cropping has often become the only way for many family farmers in Southeast Asia to rapidly obtain a cash income. However, the intensification of maize-based cropping systems is raising concerns about its environmental sustainability. This study contributed to field-based approaches for ex post sustainability assessment of current cropping systems on farms and for the design of more sustainable prototypes, in conditions where the information required for estimating sustainability indicators are not readily available. A 3-year regional agronomic diagnosis was combined with a multicriteria assessment and a prototyping procedure. The latter aimed to increase the performances on the indicators that showed critical levels on current systems. A local diversity of maize fields in Laos was used to test the approach. We defined and used indicators representing farmers' socio-economic objectives and risks for the environment. Sustainability indicators were calculated using data extracted from farm surveys, direct measurements in fields managed by the farmers and crop modelling. Our analysis showed that the most frequent weaknesses in all current maize-based cropping systems were (i) low land and labour productivity, (ii) high susceptibility to weed infestation, (iii) high risk of herbicide leaching, (iv) risk of soil fertility depletion, (v) risk of soil erosion. None of the current cropping systems performed well simultaneously on both indicators of land/labour productivity and control of herbicide leaching. These sustainability issues mainly resulted from difficulties in mastering mechanised crop establishment. Taking the current cropping system as a starting point, prototypes with successful crop establishment thanks to well mastered mechanisation would significantly improve the following sustainability indicators: control of herbicide leaching (improved by 130–340%), yield (multiplied by 1.3–2.3), gross margin (multiplied by 1.3–2.2), weed control (improved by 180–430%) and labour productivity (multiplied by 1.4–3.4). However, it would increase erosion (erosion control divided by 1.6–7) and seasonal cash outflow would increase (multiplied by 1.1–2). Overall, improving crop establishment would increase sustainability (overall sustainability score multiplied by 1.1–1.6). Our results suggest that providing farmers with enhanced capacity to master crop establishment would not solve all sustainability issues of maize cultivation, but at least help avoid a catastrophic overuse of herbicides in that context. غالبًا ما أصبح محصول الذرة الطريقة الوحيدة للعديد من المزارعين الأسريين في جنوب شرق آسيا للحصول بسرعة على دخل نقدي. ومع ذلك، فإن تكثيف نظم المحاصيل القائمة على الذرة يثير المخاوف بشأن استدامتها البيئية. ساهمت هذه الدراسة في النهج الميدانية للتقييم اللاحق للاستدامة لأنظمة المحاصيل الحالية في المزارع ولتصميم نماذج أولية أكثر استدامة، في ظروف لا تتوفر فيها المعلومات المطلوبة لتقدير مؤشرات الاستدامة بسهولة. تم الجمع بين التشخيص الزراعي الإقليمي لمدة 3 سنوات مع تقييم متعدد المعايير وإجراء النماذج الأولية. يهدف الأخير إلى زيادة الأداء على المؤشرات التي أظهرت مستويات حرجة على الأنظمة الحالية. تم استخدام التنوع المحلي لحقول الذرة في لاوس لاختبار هذا النهج. حددنا واستخدمنا مؤشرات تمثل الأهداف الاجتماعية والاقتصادية للمزارعين ومخاطرهم على البيئة. تم حساب مؤشرات الاستدامة باستخدام البيانات المستخرجة من المسوحات الزراعية والقياسات المباشرة في الحقول التي يديرها المزارعون ونمذجة المحاصيل. أظهر تحليلنا أن نقاط الضعف الأكثر شيوعًا في جميع أنظمة المحاصيل الحالية القائمة على الذرة هي (1) انخفاض إنتاجية الأراضي والعمالة، (2) قابلية عالية للإصابة بالأعشاب الضارة، (3) ارتفاع خطر ترشيح مبيدات الأعشاب، (4) خطر استنفاد خصوبة التربة، (5) خطر تآكل التربة. لم يكن أداء أي من أنظمة الزراعة الحالية جيدًا في وقت واحد على كل من مؤشرات إنتاجية الأرض/العمالة والسيطرة على رشح مبيدات الأعشاب. نتجت قضايا الاستدامة هذه بشكل أساسي عن الصعوبات في إتقان إنشاء المحاصيل الآلية. مع الأخذ في الاعتبار نظام المحاصيل الحالي كنقطة انطلاق، فإن النماذج الأولية ذات الإنشاء الناجح للمحاصيل بفضل الميكنة المتقنة ستحسن بشكل كبير مؤشرات الاستدامة التالية: التحكم في رشح مبيدات الأعشاب (تحسن بنسبة 130-340 ٪)، والمحصول (مضروبًا في 1.3–2.3)، والهامش الإجمالي (مضروبًا في 1.3–2.2)، ومكافحة الأعشاب الضارة (تحسن بنسبة 180-430 ٪) وإنتاجية العمل (مضروبًا في 1.4–3.4). ومع ذلك، فإنه سيزيد من التآكل (التحكم في التآكل مقسومًا على 1.6-7) وسيزيد التدفق النقدي الموسمي (مضروبًا في 1.1–2). بشكل عام، سيؤدي تحسين إنشاء المحاصيل إلى زيادة الاستدامة (درجة الاستدامة الإجمالية مضروبة في 1.1–1.6). تشير نتائجنا إلى أن تزويد المزارعين بقدرة معززة على إتقان إنشاء المحاصيل لن يحل جميع قضايا الاستدامة المتعلقة بزراعة الذرة، ولكنه على الأقل يساعد في تجنب الإفراط الكارثي في استخدام مبيدات الأعشاب في هذا السياق.