1,720,973 research outputs found
CONTRIBUTION OF AGROECOLOGICAL MEASURES TOWARDS CLIMATE-SMART AND MULTIFUNCTIONAL FARMING SYSTEMS
No full textLa continua crescita della popolazione mondiale, il progressivo degradamento dei suoli e il cambiamento climatico globale sono tra le più grandi sfide per l’umanità nel prossimo futuro. Pratiche non sostenibili di gestione del suolo e delle colture in agricoltura convenzionale hanno danneggiato lo stato di salute dell’agro-ecosistema e favorito il cambiamento climatico, attraverso la mineralizzazione della sostanza organica e il rilascio di forme reattive dell’azoto nelle acque e in atmosfera. L’adozione di nuove pratiche agricole sostenibili è stata indicata come una delle strade percorribili per l’adattamento dei sistemi agricoli ai cambiamenti climatici e per ridurre l’impatto negativo sull’ambiente. L’obiettivo principale di questa tesi è quello di valutare le performance delle pratiche sostenibili e clima-intelligenti (p.e., no-till, cover crop, e sub-irrigazione) in termini di potenziale produttivo delle colture, di incremento della qualità del suolo, e di riduzione dell’impatto climatico. Dai risultati emerge come le pratiche conservative (no-till e cover crop) siano in grado di generare rese colturali paragonabili ai sistemi convenzionali, mentre i sistemi irrigui efficienti (sub-irrigazione) siano particolarmente efficaci in condizioni climatiche siccitose. Inoltre, l’introduzione di queste pratiche agricole sostenibili ha consentito di preservare la qualità del suolo aumentandone il contenuto di azoto e carbonio e, allo stesso tempo, riducendo l’impatto climatico grazie al minor rilascio di nutrienti nell’ambiente.Growing population, land degradation and climate change are significant threats to food security and human development. Conventional intensive farming is usually associated with soil quality depletion and environment pollution, through soil organic matter mineralization as carbon dioxide (CO2) and nitrogen release as reactive forms to atmosphere and water, thus promoting global climate change.
The adoption of sustainable agroecosystems management is key for adapting to climate change while increasing soil quality and lowering agricultural impact on global warming. The main objective of this thesis is to evaluate the performances of climate-smart practices (i.e., no-till, cover crops, and subsurface drip irrigation) in terms of crop yield potential, soil quality increase and reduced impact on climate change. We concluded that conservation practices (no-till and cover crops) may ensure comparable crop yields to conventional system while high-efficient micro-irrigation systems (subsurface drip irrigation) are particularly effective under dry climate conditions. Moreover, such sustainable farming practices may (i) positively affect soil quality by enhancing carbon and nitrogen content into the soil, as well as (ii) reduce agricultural impact on climate change by lowering the release of nutrients to the environment
Driving crop yield, soil organic C pools, and soil biodiversity with selected winter cover crops under no-till
No full textNo-till (NT) and cover crops (CCs) have been repeatedly recommended for building-up resilience of agro-ecosystems, enhancing soil biodiversity, and steering efficient nutrients cycling and yield. Yet, the overall impact of CCs on soil properties and dynamics during transition may highly change depending on CC species and interactions with field condition. In the present 3-yr field study, we (i) examined how selected CCs (i.e. rye [Secale cereale L.]; phacelia [Phacelia tanacetifolia Benth.] + white mustard [Sinapis alba L.]; Italian ryegrass [Lolium multiflorum Lam.] + crimson clover [Trifolium incarnatum L.] + Persian clover [Trifolium resupinatum L.]; hairy vetch [Vicia villosa Roth] + crimson clover) affect yield performance in a crop sequence of maize (Zea mays L.), soybean (Glycine max L. Merr.), and maize under NT, and (ii) assessed the effects of CCs on inputs to the soil (i.e. biomass, carbon [C], and nitrogen [N]), soil organic C (SOC) and pools, as well as microarthropods and earthworms abundance and diversity. Grain yield during the initial 2-yr period was on average reduced with CCs by 1–23% in maize, and 1–33% in soybean. This effect was less evident with CC residues having low C:N ratio ([removed]3-yr term. We concluded that CC mixtures that allow the best compromise between the high amount of residue and the low residue C:N ratio should be preferred for: (i) reducing possible detrimental effects on grain yield of maize and soybean, and (ii) enhancing soil C cycling and biodiversity. Therefore, selecting appropriate CC species in mixtures represents the main challenge at the field level for pursuing both objectives in the shortest timeframe. Within all options in summer crop sequences, here we reported that mixtures including leguminous cover crops might be primarily considered
Superficiale o sotterranea, la goccia conviene
No full textLe tecniche di microirrigazione (sia superficiale, sia sotterranea) garantiscono su mais e pomodoro un evidente risparmio della risorsa idrica e rese agronomiche paragonabili o superiori all’irrigazione per aspersione. Anche sul fronte della concentrazione di nitrati nel terreno i vantaggi sono indiscutibil
Balancing legume-cereal proportions in cover crop mixtures to minimize N2O emissions
Full text linkLegume-cereal cover crop mixtures offer a promising approach to reduce nitrate leaching and enhancing soil fertility. However, the impacts of these mixtures on N2O emissions during both the cover cropping and post-incorporation phases, as well as the relative contribution of roots and shoots to N2O emission, remain uncertain. To address these knowledge gaps, we conducted a two-phase greenhouse experiment. In the first phase, cover crops were grown encompassing six treatments: control (no cover crop), pure vetch (Vicia villosa Roth), pure rye (Secale cereale L.), and mixtures with 33 %, 50 % and 66 % of the pure rye sowing rate paired with 66 %, 50 % and 33 % of the pure vetch sowing rate, respectively. In the second phase, focusing on the post-incorporation effects, the same treatments were arranged in mesocosms with both roots and shoots, and in mesocosms with roots only. During the first phase, the proportion of fine/very fine roots and root length density were negatively correlated with mineral N content and N2O emissions. Mixing rye with vetch increased total dry biomass and N yield for all mixtures compared to rye alone. In mixtures, the proportion of fine roots, root length density, and the root C:N ratio decreased compared to rye. Most of the N2O emissions occurred after cover crop incorporation, with roots contributing more (average 57 %) than shoots (average 31 %). Total N2O emissions increased with increasing proportion of vetch, but the mixture with 33 % vetch and 66 % rye maintained N2O emissions as low as rye monoculture. Our study indicates that adjusting the seed proportion in legume-cereal mixtures serves as an effective tool to balance the benefits of pure legume (increased total biomass, and C and N yields) and pure cereal (decreased N2O emissions and soil mineral N pool) cover cropping
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
CONTRIBUTION OF AGROECOLOGICAL MEASURES TOWARDS CLIMATE-SMART AND MULTIFUNCTIONAL FARMING SYSTEMS
Full text linkLa continua crescita della popolazione mondiale, il progressivo degradamento dei suoli e il cambiamento climatico globale sono tra le più grandi sfide per l’umanità nel prossimo futuro. Pratiche non sostenibili di gestione del suolo e delle colture in agricoltura convenzionale hanno danneggiato lo stato di salute dell’agro-ecosistema e favorito il cambiamento climatico, attraverso la mineralizzazione della sostanza organica e il rilascio di forme reattive dell’azoto nelle acque e in atmosfera. L’adozione di nuove pratiche agricole sostenibili è stata indicata come una delle strade percorribili per l’adattamento dei sistemi agricoli ai cambiamenti climatici e per ridurre l’impatto negativo sull’ambiente. L’obiettivo principale di questa tesi è quello di valutare le performance delle pratiche sostenibili e clima-intelligenti (p.e., no-till, cover crop, e sub-irrigazione) in termini di potenziale produttivo delle colture, di incremento della qualità del suolo, e di riduzione dell’impatto climatico. Dai risultati emerge come le pratiche conservative (no-till e cover crop) siano in grado di generare rese colturali paragonabili ai sistemi convenzionali, mentre i sistemi irrigui efficienti (sub-irrigazione) siano particolarmente efficaci in condizioni climatiche siccitose. Inoltre, l’introduzione di queste pratiche agricole sostenibili ha consentito di preservare la qualità del suolo aumentandone il contenuto di azoto e carbonio e, allo stesso tempo, riducendo l’impatto climatico grazie al minor rilascio di nutrienti nell’ambiente.Growing population, land degradation and climate change are significant threats to food security and human development. Conventional intensive farming is usually associated with soil quality depletion and environment pollution, through soil organic matter mineralization as carbon dioxide (CO2) and nitrogen release as reactive forms to atmosphere and water, thus promoting global climate change.
The adoption of sustainable agroecosystems management is key for adapting to climate change while increasing soil quality and lowering agricultural impact on global warming. The main objective of this thesis is to evaluate the performances of climate-smart practices (i.e., no-till, cover crops, and subsurface drip irrigation) in terms of crop yield potential, soil quality increase and reduced impact on climate change. We concluded that conservation practices (no-till and cover crops) may ensure comparable crop yields to conventional system while high-efficient micro-irrigation systems (subsurface drip irrigation) are particularly effective under dry climate conditions. Moreover, such sustainable farming practices may (i) positively affect soil quality by enhancing carbon and nitrogen content into the soil, as well as (ii) reduce agricultural impact on climate change by lowering the release of nutrients to the environment
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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