1,720,976 research outputs found
Short term effects of synergistic inorganic and organic fertilization on soil properties and yield and quality of plum tomato
No full textTomato is one of the most important crops in the world and its cultivation is usually based on a great use of inorganic fertilizers applied as broadcast fertilization and with several fertigations. For a more sustainable agriculture authors studied the synergistic effects of the application of two different composts, combined with an inorganic fertilizer, on the main chemical-physical soil properties and on the yield and qualitative parameters of a plum tomato variety. Two composts, obtained mixing sewage sludge or the organic fraction of the municipal solid wastes with pruning residues, grape marc, and exhausted olive pomace, were tested at 2 or 4.5 t ha−1 in a field experiment, replacing a part of the inorganic fertilization and respecting the N crop requirement.
From an environmental point of view, the addition of composts to the soil caused an increase in the total and available heavy metals content, even if no soil pollution has been recorded. The yield of tomatoes resulted higher with the combined application of amendments and inorganic fertilizer with respect to the sole inorganic fertilization.
The quality of tomatoes was apparently not affected by the fertilization and, although certain heavy metals tend to increase their tomato concentration with the application of composts, their concentrations did not exceed the legal thresholds
Geophysical field zoning for nitrogen fertilization in durum wheat (Triticum durum Desf.)
Full text linkThe current social context requires an increase in food production, improvement of its quality
characteristics and greater environmental sustainability in the management of agricultural
systems. Technological innovation plays a great role in making agriculture more efficient and
sustainable. One of the main aims of precision farming (PF) is optimizing yield and its quality,
while minimizing environmental impacts and improving the efficient use of resources. Variable rate techniques (VRT) are amongst the main management options for PF, and they
require spatial information. This work incorporates maps of soil properties from low induction
electromagnetic measurements into nitrogen (N) balance calculations for a field application
of VRT nitrogen fertilization of (Triticum durum Desf., var. Tirex). The trial was conducted in
2018–19 at Genzano di Lucania (PZ, Italy) geologically located on the clayey hillsides of the
Bradanica pit and the Sant’Arcangelo basin. Three soil homogeneous areas were detected
through low induction electromagnetic measurements and used as uniform management
zones. The amount of nitrogen fertilizer to be applied by VRT was calculated on the base of
estimated crop nitrogen uptake and soil characteristics of each homogeneous area. Crop
response to VRT was compared to uniform nitrogen application (UA) on the whole field. The
application of VRT resulted in a reduction of 25% nitrogen fertilizer with the same level of
yield respect to UA. Grain protein content, as well as gluten content and N content, were significantly higher in VRT than in UA. As a consequence of lower nitrogen input and higher levels of N removal, VRT reached a higher nitrogen use efficiency than UA, and this indicates a
lower environmental impact and a higher economic profitabilit
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effects of different pioneer and exotic species on the changes of degraded soils
Full text linkSoil degradation resulting from deforestation contributes to a dramatic decline in soil quality whose restoration must go through reforestation with pioneer species. We investigated the effects of cypress and black locust, pioneer but exotic species, on soil chemical properties and microbial and enzymatic activities of two marginal soils. The sampling sites were Lama Giulia and Locone lake in the Murge plateau of the Apulia Region, Italy. The soils at Lama Giulia presented a silty loam texture, while at Locone Lake site were sandy, and most likely due to the different texture, the former exhibited higher organic C, N, P and micronutrients contents than Locone Lake under black locust reforestation, despite the latter was reforested earlier. In addition, the higher microbial entropy and turnover of Locone Lake's soils suggested a less conservative soil state than Lama Giulia's soils. The effects of black locust reforestation at Lama Giulia on almost all soil parameters considered did not differ from those of the corresponding pasture, confirming the more conservative soil state in that site and suggesting that the time of reforestation was not enough to get differences between the reforested and not reforested soil. The soils reforested with cypress showed the significantly highest SOC, N, dissolved organic C and microbial biomass C content. In addition, it presented also the numerically largest dehydrogenase, phosphatase and beta-glucosidase activities, soluble carbohydrates, and phenolic compounds content. These results may be ascribed to the longer litter deposition occurred in cypress soils
Chemically functionalized Eggs capsules of Sea Snail (ess) banded dye-murex for bioremediation applications
Full text linkamong materials proposed in literature to remediate the environment, biohybrid composites at the interface between material science, chemistry and biology are the most promising. In this paper, we first contemplate the use of porous capsules, released by marine murex snails after eggs hatching, as a natural matrix capable of adsorbing organic pollutants. This study starts to investigate chemical and morphological features of this envisaging, unexplored protein material. Then, the chemical topography of egg capsules has been potentiated via a surface decoration with the polyphenol gallic acid, leading to enhance the bioremediation potential of the final biohybrid material. This moiety helped to give a huge activation of the adsorption towards a specific organic pollutant: the drug Tetracycline. The bioorganic methodology begins with bioconjugation via direct targeting of the exposed Lysine residues with polyphenol moieties. The material was morphologically investigated via high-resolution X-ray micro-computed tomography (HR X-ray μ-CT), and characterized using Raman spectroscopy, Fourier Transformed Infrared-attenuated total reflectance (FTIR-ATR), micro-IR, elemental, and BET analysis, after the bioorganic decoration. For the in vitro environmental remediation test, Tetracycline was chosen as a model drug molecule, and the specific adsorption was tested concerning the mass of the investigated material, different pH conditions (considering limit values), till evaluating the recycle of the material. The functionalization efficiently sparked the properties of the starting material, leading to an increase in the biosorption of the model urban pharmaceutical pollutant Tetracycline. Compared to the natural material, the functionalized matrix showed a sorbing capacity 12.5 times higher, leading to the sorption of about 25 mmol of Tetracycline per g of sorbent. In addition, the functionalized material remained active up to 5 sorption cycles. This outcome represents an achievement made from the combination of natural materials and Nature inspired molecular moieties to act as efficient platforms for self-cleaning, leading to environmental remediation
Fate of selected contaminants of emerging concern (CECs) in an olive tree soil-plant system irrigated with treated municipal wastewater
No full textThe global emergency of ever-increasing demand for water and the scarcity of this resource bring attention back to the potential use of wastewater. Unfortunately, water reuse presents some risks for human and ecosystem health related to the presence of waterborne contaminants. In this study, preliminary data on contaminants of emerging concern (CECs) dynamics of uptake, distribution and accumulation by olive trees (Olea europaea L.) within a plant-soil system were reported. The trial was conducted on olives grown in pots and irrigated with freshwater (control) and treated municipal wastewater. The treated municipal wastewater used for irrigation was spiked with four CECs (Carbamazepine, Fluconazole, Clarithromycin and Metoprolol) at a concentration of approximately 200 μg L-1 (1×). The fate of these CECs in this soil-plant system was then investigated. The irrigation volume applied per plant in one season was approximately 150 L, adding approximately 30 mg of each compound per plant. Translocation and accumulation of CECs in plants can be explained by their physico-chemical properties, mainly their hydrophobicity/hydrophilicity, chemical structure and charge. QuEChERS method was used to extract CECs from soil and plants and samples were analysed using high resolution mass spectrometry coupled with liquid chromatography (LC-HRMS/MS). The data obtained from the trial showed that two of the four CECs evaluated, Carbamazepine and Fluconazole accumulated in soil (approximately 80 and 86%) and plant (approximately 5 and 6%), respectively, with lower degradation rates (15 and 7%). The other two CECs (Metoprolol and Clarithromycin) accumulated only in soil and plant below ground parts, with degradation of the applied compound exceeding 90%. These preliminary results show different accumulation pathways for each compound. Further research is needed to better investigate the fate of CECs from wastewater used for irrigation in soil-plant ecosystems aiming to ensure food safety through the definition of appropriate irrigation strategies
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