1,720,993 research outputs found
Atti del XXV Convegno Nazionale di Agrometeorologia. L’Agrometeorologia per la gestione delle risorse e delle limitazioni ambientali in agricoltura
No full textLa razionale gestione delle risorse ambientali e naturali ha nella modellistica agrometeorologia il suo supporto di base. Del resto, le note e tristi vicende che negli ultimi giorni hanno duramente interessato i territori dell’Emilia-Romagna e delle Marche, impongono alla comunità scientifica e ai gestori del territorio un’attenta valutazione degli effetti che il cambiamento climatico ha sul territorio. Pertanto, i modelli agrometeorologici sono uno strumento essenziale per il processo gestionale e decisionale sia nell’ambito dei sistemi colturali che in quello zootecnico. Numerosi sono gli studi sui meccanismi e sulle relazioni che regolano le dinamiche ambientali e produttive del territorio stesso per descrivere le sue reali potenzialità produttive e quindi, pianificare e razionalizzare l’uso delle risorse utilizzate nel processo produttivo. La caratterizzazione meteorologica è uno dei primi passi da intraprendere per la conoscenza di un territorio, valutando non solo l’andamento dei valori medi dei principali parametri misurati al suolo, ma soprattutto la loro variabilità spaziotemporale. AIAM 2023 è l’appuntamento annuale tra i ricercatori e i tecnici dei servizi agrometeorologici regionali per presentare i risultati degli studi e dei progetti di ricerca per la gestione degli stress abiotici, dei mezzi di previsione e gestione delle avversità che interessano il mondo agricolo, con riferimento alle politiche di sviluppo agricolo del PSN 2023-27
Atti Dei : XX Convegno nazionale dell'Associazione italiana di Agrometeorologia (AIAM); XLVI Convegno nazionale della Società italiana di Agronomia (SIA). “Strategie integrate per affrontare le sfide climatiche e agronomiche nella gestione dei sistemi agroalimentari. Integrated strategies for agro-ecosystem management to address climate change challenges”
No full textProceedings of the National conference of two of the main scientific societies dealing with agricultural sciences (Italian Society of Agronomy and Italian Association of AgroMeteorology), this year carried out jointly. The conference dealt with the problems and new integrated strategies to face the climatic and agronomic challenges in the management of agri-food systems
Agro-phenological observation and modeling of cereals in Padana Plain in the period 2003-2012
Full text linkAgro-phenological observation is a fundamental activity to obtain a significant and useful description of the seasonal development of crops, which is driven by environmental variables, among which temperature plays a primary role. The aim of this paper is to study the relation between thermal resources and phenological development in the agrophenological station of Cadriano (Bologna) on winter wheat, barley, maize and sorghum. This was achieved a) analysing eleven years (2003-2012) of phenological observations, expressed using the BBCH scale, and b) developing a thermal model based on Normal Heat Hours for phenological development of the four crops in Cadriano. Once the thermal model was calibrated it was used to evaluate the variability of thermal resources on a long time series (1984- 2013) recorded in the same site. The statistical analysis on the observed phenological data shows high stability, apart from the first stages, until the tillering of the winter crops. The phenological model evidences a satisfactory performance, in particular for summer crops, and a good correlation between phenology and thermal resources accumulation. Finally, the long time series analysis evidences an increase in time of thermal resources availability
The evolution of cereal yields in Italy over the last 150 years: The peculiar case of rice
No full textThis study examined Italian yields for wheat (Triticum spp.), maize (Zea mays L.), and rice (Oryza sativa L.) over the period 1870–2018, in order to identify the periods when the most significant growth in yields occurred, compared to France, United Kingdom, and United States. From 1870 to 2018, yields in Italy increased by 347, 865, and 178% for wheat, maize, and rice, respectively. In wheat and maize, 84 and 95% of the increase, respectively, occurred since the end of World War II. Similar trends can also be observed in France, United Kingdom, and the United States. However the timing is slightly different. For wheat and maize in the United States, rapid yield growth occurred during the 1930s, whereas wheat yield growth occurred in the United Kindom during the 1940s, and in France yield growth occurred after World War II. The significant post-war trend of increasing yields in Italy, which is still going on for wheat, almost stopped for maize about 20 yr ago, probably due to the lack of availability of genetically modified (GM) varieties and related technologies. If the current approach against the adoption of new plant-breeding techniques is maintained, the yield gap between Italy and Europe, as a whole, is likely to widen further. In the case of rice, a significant increase in yields began to occur as early as the end of the 19th century. Between 1895 and 1940 yields in this crop increased by about three times. In the United States, a similar increase in rice yields occurred only after World War II
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
Comparison of Greenhouse Energy Requirements for Rose Cultivation in Europe and North Africa
Full text linkThe ornamental plant production in greenhouses is widespread. A quantitative assessment of greenhouse energy consumption and its variability in space and time is strategic to improve the sustainability of the cultivation. The specific environmental features of the cultivation areas can strongly affect the sustainability of the production. A dynamic simulation model of greenhouse energy balance with an hourly time step was developed and parameterized for a state-of-the-art greenhouse to evaluate the heating requirements for cut-flower roses. This ornamental crop has been used as model species for its high energy requirement for flower production. The energy demand for rose production has been analyzed with an energy balance model with an hourly time step. After a preliminary analysis on the period 1973–2019, the final analysis was carried out on the 30-year period (1990–2019), representative of the current climate. Results show a gradient southwest–northeast of energy needs with relevant effects on economic and environmental sustainability. More specifically, four large sub-areas are identified, namely the central-southern Mediterranean (yearly requirements below 600 MJ m−2 year), the northern Mediterranean, and the area influenced by the mitigating effect of the Atlantic Ocean (600–1200), the central-European area (requirements of 1200–1800), and the Northern European area (above 1800)
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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