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Urea is the most common nitrogen (N) fertilizer in agriculture, due to its cheaper price and high N content. Although the reciprocal influence between NO3- and NH4+ nutrition are well known, urea (U) interactions with these N-inorganic forms are poorly studied. Here, the responses of two tomato genotypes to ammonium nitrate (AN), U alone or in combination were investigated. Significant differences in root and shoot biomass between genotypes were observed. Under AN+U supply, Linosa showed higher biomass compared to UC82, exhibiting also higher values for many root architectural traits. Linosa showed higher Nitrogen Uptake (NUpE) and Utilization Efficiency (NUtE) compared to UC82, under AN+U nutrition. Interestingly, Linosa exhibited also a significantly higher DUR3 transcript abundance. These results underline the beneficial effect of AN+U nutrition, highlighting new molecular and physiological strategies for selecting crops that can be used for more sustainable agriculture. The data suggest that translocation and utilization (NUtE) might be a more important component of NUE than uptake (NUpE) in tomato. Genetic variation could be a source for useful NUE traits in tomato; further experiments are needed to dissect the NUtE components that confer a higher ability to utilize N in Linosa.

AbstractBACKGROUND: Inappropriate utilisation of biosolids may adversely impact agrosystem productivity. Here, we address the response of wheat (Triticum durum) to different doses (0, 40, 100, 200 and 300 t ha−1) of either municipal solid waste (MSW) compost or sewage sludge in a greenhouse pot experiment. Plant growth, heavy metal uptake, and antioxidant activity were considered.RESULTS: Biomass production of treated plants was significantly enhanced at 40 t ha−1 and 100 t ha−1 of MSW compost (+48% and +78% relative to the control, respectively). At the same doses of sewage sludge, the increase was only 18%. Higher doses of both biosolids restricted significantly the plant growth, in concomitance with the significant accumulation of heavy metals (Ni2+, Pb2+, Cu2+ and Zn2+), especially in leaves. Leaf activities of antioxidant enzymes (ascorbate peroxidase, glutathione reductase, catalase and superoxide dismutase) were unchanged at 40 t ha−1 MSW compost or sewage sludge, but were significantly stimulated at higher doses (200–300 t ha−1), together with higher leaf concentration of reduced glutathione.CONCLUSION: This preliminary study suggests that a MSW supply at moderate doses (100 t ha−1) could be highly beneficial for wheat productivity. Copyright © 2010 Society of Chemical Industry

AbstractAutotrophs play an essential role in the cycling of carbon and nutrients, yet disease‐ecosystem relationships are often overlooked in these dynamics. Importantly, the availability of elemental nutrients like nitrogen and phosphorus impacts infectious disease in autotrophs, and disease can induce reciprocal effects on ecosystem nutrient dynamics. Relationships linking infectious disease with ecosystem nutrient dynamics are bidirectional, though the interdependence of these processes has received little attention. We introduce disease‐mediated nutrient dynamics (DND) as a framework to describe the multiple, concurrent pathways linking elemental cycles with infectious disease. We illustrate the impact of disease–ecosystem feedback loops on both disease and ecosystem nutrient dynamics using a simple mathematical model, combining approaches from classical ecological (logistic and Droop growth) and epidemiological (susceptible and infected compartments) theory. Our model incorporates the effects of nutrient availability on the growth rates of susceptible and infected autotroph hosts and tracks the return of nutrients to the environment following host death. While focused on autotroph hosts here, the DND framework is generalizable to higher trophic levels. Our results illustrate the surprisingly complex dynamics of host populations, infection patterns, and ecosystem nutrient cycling that can arise from even a relatively simple feedback between disease and nutrients. Feedback loops in disease‐mediated nutrient dynamics arise via effects of infection and nutrient supply on host stoichiometry and population size. Our model illustrates how host growth rate, defense, and tissue chemistry can impact the dynamics of disease–ecosystem relationships. We use the model to motivate a review of empirical examples from autotroph–pathogen systems in aquatic and terrestrial environments, demonstrating the key role of nutrient–disease and disease–nutrient relationships in real systems. By assessing existing evidence and uncovering data gaps and apparent mismatches between model predictions and the dynamics of empirical systems, we highlight priorities for future research intended to narrow the persistent disciplinary gap between disease and ecosystem ecology. Future empirical and theoretical work explicitly examining the dynamic linkages between disease and ecosystem ecology will inform fundamental understanding for each discipline and will better position the field of ecology to predict the dynamics of disease and elemental cycles in the context of global change.

Alpine grasslands on the Qinghai-Tibetan Plateau are sensitive and vulnerable to climate change and human activities. Climate warming and overgrazing have already caused degradation in a large fraction of alpine grasslands on this plateau. However, it remains unclear how human activities (mainly livestock grazing) regulates vegetation dynamics under climate change. Here, alpine grassland productivity (substituted with the normalized difference vegetation index, NDVI) is hypothesized to vary in a nonlinear trajectory to follow climate fluctuations and human disturbances. With generalized additive mixed modelling (GAMM) and residual-trend (RESTREND) analysis together, both magnitude and direction of climatic (in terms of temperature, precipitation, and radiation) and anthropogenic impacts on NDVI variation were examined across alpine meadows, steppes, and desert-steppes on the Qinghai-Tibetan Plateau. The results revealed that accelerating warming and greening, respectively, took place in 76.2% and 78.8% of alpine grasslands on the Qinghai-Tibetan Plateau. The relative importance of temperature, precipitation, and radiation impacts was comparable, between 20.4% and 24.8%, and combined to explain 66.2% of NDVI variance at the pixel scale. The human influence was strengthening and weakening, respectively, in 15.5% and 14.3% of grassland pixels, being slightly larger than any sole climatic variable across the entire plateau. Anthropogenic and climatic factors can be in opposite ways to affect alpine grasslands, even within the same grassland type, likely regulated by plant community assembly and species functional traits. Therefore, the underlying mechanisms of how plant functional diversity regulates nonlinear ecosystem response to climatic and anthropogenic stresses should be carefully explored in the future.

Biomass derived from marine microalgae and macroalgae is globally recognized as a source of valuable chemical constituents with applications in the agri-horticultural sector (including animal feeds and health and plant stimulants), as human food and food ingredients as well as in the nutraceutical, cosmeceutical, and pharmaceutical industries. Algal biomass supply of sufficient quality and quantity however remains a concern with increasing environmental pressures conflicting with the growing demand. Recent attempts in supplying consistent, safe and environmentally acceptable biomass through cultivation of (macro- and micro-) algal biomass have concentrated on characterizing natural variability in bioactives, and optimizing cultivated materials through strain selection and hybridization, as well as breeding and, more recently, genetic improvements of biomass. Biotechnological tools including metabolomics, transcriptomics, and genomics have recently been extended to algae but, in comparison to microbial or plant biomass, still remain underdeveloped. Current progress in algal biotechnology is driven by an increased demand for new sources of biomass due to several global challenges, new discoveries and technologies available as well as an increased global awareness of the many applications of algae. Algal diversity and complexity provides significant potential provided that shortages in suitable and safe biomass can be met, and consumer demands are matched by commercial investment in product development.

Abstract It is known how the complete gasification of liquefied natural gas (LNG) can return about 230 kWh/t of energy. Nevertheless out of fifty-one gasification plants in the world, only thirty-one of them are equipped with systems for the partial recovery of the available energy. At the moment most of these plants mainly produce electric energy; however the employment of the cold energy results very interesting, in fact, it can be recovered for agro-food transformation and conservation as well as for some loops in the cold chain. Cold energy at low temperatures requires high amounts of mechanical energy and it unavoidably increases as the required temperature diminishes. Cold energy recovery from LNG gasification would allow considerable energy and economic savings to these applications, as well as environmental benefits due to the reduction of climate-changing gas emissions. The task of this work is to assess the possibility to create around a gasification plant an industrial site for firms working on the transformation and conservation of agro-food products locally grown. The cold energy recovered from gasification would be distributed to those firms through an opportune liquid carbon dioxide network distribution capable of supplying “the cold” to the different facilities. A LNG gasification plant in a highly agricultural zone in Sicily would increase the worth of the agro-food production, lower transformation and conservation costs when compared to the traditional systems and bring economic and environmental benefits to the interested areas.

Abstract A multi-disciplinary approach based on the biorefinery of microalgae biomass (Chlorella sorokiniana) to remove the lipid fraction responsible of the green color and the ‘fishy’ aroma and vacuum impregnation technique to create innovative apple snacks with improved nutritional properties has been investigated. The pressure (150 mbar – 650 mbar), vacuum time (1–7 min) and relaxation time (3–13 min) were modulated by using a Box-Behnken experimental design. The filling of apple pores occurred with a maximum gaining weight of 19.5% and a reduction of porosity fraction from 15.32% to less than 5% but only the pressure and relaxation time significantly affect the level of impregnation. While the texture did not show any difference compared to fresh apples, the color of impregnated apple was affected with minor change in comparison. Industrial relevance Results positively fuel the food chain sustainability by proposing multidisciplinary tools that combine microalgae cultivation, biorefinery and vacuum impregnation processing capable to improve the nutritional quality of fruit products. Biorefinery is proved to be an essential technology for fractionating chemical compounds from raw microalgae and improving their potential use in food industry as source of nutrient by eliminating some undesired components such as lipid fractions related to the fishy aroma. Finally, the obtained results may be used as basic protocols for the optimization of VI treatments aiming to enrich fruit product of proteins and micronutrients.

Abstract In Italy 1.5 Tg dry matter of residues are estimated to be produced by the agri-food sector. Approximately 30% of them are represented by residues of wine industry sector: grape marc. Referring to its production, it is possible to evaluate about 10 Mg of grapes from each vineyard hectare that generate, as wine industry residue, 2.7 Mg of grape marc, corresponding to about 19 GJ in terms of energy content. This kind of biomass is heterogenous and composed of stalks, grape skins and seeds. In this paper, in order to investigate the possibility of an energy and industrial utilization, the physical-chemical characteristics of each single component of grape marc are examined. In addition, a mechanical extraction test on the seed was performed to evaluate the vegetable oil production and the characteristics of the cake. Results on grape marc components put in evidence some difference in terms of ash and chemical elements content, which represent, specifically for these materials, the most critical aspects to take into account in combustion heating systems.

Abstract The purpose of this article is to analyse, in the humanitarian context, the key links between energy and food security, energy-related challenges faced by affected populations, current barriers to sustainable energy access, opportunities for addressing energy needs and existing gaps in current research on energy issues. Ensuring access to energy is a major challenge for some 3.1 billion people living in low- and middle-income countries, especially in remote and off-grid areas. Lack of safe, affordable and sustainable energy for cooking, heating, lighting and powering has cross-sectoral implications and is particularly constrained for the roughly 60 million people living in complex emergencies and protracted crisis. Some 80 percent of refugees and displaced people in camps have little access to energy entailing additional exposure to security risks, health hazards and restricted economic and education opportunities. Often people have no choice but to depend on biomass to meet their immediate energy needs. The traditional use of solid biomass and inefficient technologies for cooking, heating and other energy needs, can be harmful to their well-being and food security while being largely unsustainable. The consumption of safe, healthy and nutritious meals often depends on access to energy, allowing for proper preparation and utilisation of food. The inability for people to meet their energy needs for cooking may seriously affect food and nutrition security not only in terms of utilisation, but also has the potential to impair sustainable food systems. The humanitarian system is unable to face the energy challenge and increasing needs if current response measures are not improved. Actions and a substantial change in policy are needed, in order to significantly reduce the total number of people relying on solid fuels by 2030. This article will discuss how underlying barriers are contributing to inadequate access and use of energy and cooking technologies in humanitarian settings and the subsequent adverse impacts on people’s lives and environments. The projected effects of the current energy poverty crisis in humanitarian settings is discussed while some of the solutions to address energy needs, including examples based on innovative technologies and new mechanisms, are examined in general terms. Furthermore, the challenges, opportunities and future areas of interest associated with these technologies and mechanisms are also considered.