1,252 research outputs found
Animal manures applied to soil: phosphorus bioavailability, losses to water and erosion
Comunicação oral da qual sĂł estĂĄ disponĂvel o resumo.Phosphorus (P) is a non renewable resource which highlights the
significance of developing and using alternative sources of P for a sustainable
agriculture. Animal manure is an option but its application to soils to meet crop
nitrogen needs requires careful management practices to minimize freshwater
eutrophication. The aim of this work was to evaluate the partitioning of applied P
between plant uptake, losses to water, and erosion losses when using different
animal manures and a mineral P fertilizer. A field trial was conducted at an erosion
experimental station. The treatments were: Control (0 kg P/ha); cattle manure; solid
fraction of pig and duck slurry and superphosphate, each applied at a rate of 50 kg
P/ha after Lolium sp was sown. Soil samples from each trial were collected over the
9-month study and the water extractable soil P determined. It was found that
desorption of P from all additions rapidly increased soon after P application (2
weeks). After that water extractable soil P remained fairly constant. While duck
slurry desorbed the largest concentration of P, all sources have the potential to
desorb P that could accelerate eutrophication. Plant uptake of P was greater with
cattle manure added and released the least amount of P to water compared with the
other sources of P. The partitioning of applied P between plant uptake and losses to
runoff and sediments ranged between 5-12 % with the higher values in Duck
treatment. Animal manures significantly increased soil Olsen-P, plant production and P
uptake relative to mineral fertilizer. Animal manures can be considered as a source of
available P nevertheless to avoid eutrophication risks increase plant P use efficiency is also
important
Speciation of phosphorus in a fertilized, reduced-till soil system: in-field treatment incubation study
Citation: Khatiwada, Raju, Ganga M. Hettiarachchi, David B. Mengel, and Mingwei Fei. âSpeciation of Phosphorus in a Fertilized, Reduced-Till Soil System: In-Field Treatment Incubation Study.â Soil Science Society of America Journal 76, no. 6 (2012): 2006â18. https://doi.org/10.2136/sssaj2011.0299.Phosphorus management in reduced-tillage systems is a great concern for farmers. Conclusive positive results of deep-banding P fertilizers compared with broadcast application and the chemistry of reduced-tillage systems remain unclear. Knowledge of the dominant solid P species present in soil following application of P fertilizers and the resulting potential P availability would help us understand and efficiently manage P in reduced-tillage systems. The objective of this research was to study the influence of placement (broadcast vs. deep-band P), fertilizer source (granular vs. liquid P), and time on the reaction products of P under field conditions. Changes in soil pH, resin-extractable P, total P, and speciation of P were determined at different distances from the point of fertilizer application at 5 wk and 6 mo after P application at a rate of 75 kg haâ1 to a soil system that was under long-term reduced tillage. Resin-extractable P was lower for broadcast treatments compared with deep-band treatments for both time periods. Resin-extractable P was greater in the liquid P-treated soils than in the granular P-treated soils. Speciation results showed that granular P fertilizers tended to form FeâP-like forms, whereas liquid forms remained in adsorbed P-like forms in the soil 5 wk after application; moreover, speciation results showed granular P fertilizers precipitated less when deep-banded. During the 6-mo period following application, reaction products of broadcast granular, broadcast liquid, and deep-band granular fertilizers transformed to Ca-phosphate or mixtures of Ca-, Fe- and adsorbed-phosphate-like forms, whereas deep-band liquid P remained as mainly adsorbed P-like forms. Deep-banding of P would most likely provide a solution that is both agronomically and environmentally efficient for reduced-till farmers
More than sense of place? Exploring the emotional dimension of rural tourism experiences
It is widely suggested that participation in rural tourism is underpinned by a sense of rural place or âruralityâ. However, although nature and the countryside have long been recognised as a source of spiritual or emotional fulfilment, few have explored the extent to which tourism, itself often claimed to be a sacred experience, offers an emotional/spiritual dimension in the rural context. This paper addresses that literature gap. Using in-depth interviews with rural tourists in the English Lake District, it explores the extent to which, within respondentsâ individual understanding of spirituality, a relationship exists between sense of place and deeper, emotional experiences and, especially, whether participation in rural tourism may induce spiritual or emotional responses. The research revealed that all respondents felt a strong attachment to the Lake District; similarly, and irrespective of their openness to spirituality, engaging in rural tourism activities resulted in highly emotive experiences for all respondents, the description/interpretation of such experiences being determined by individual âbeliefsâ. However, sense of place was not a prerequisite to emotional or spiritual experiences. Being in and engaging with the landscape ïżœ effectively becoming part of it ïżœ especially through physical activity is fundamental to emotional responses
Dark London: Dimensions and characteristics of dark tourism supply in the UK capital
This paper will investigate the characteristics of the supply of dark tourism in London, UK through an examination of the identified main dark sites in London, UK. Our methodology is based on web analysis of the presence of marketed and non-marketed dark tourist sites in London, their web visitation, the level of their commercialisation and the characteristics which place them in the various scales as categorised in current literature, notably Stone (2006). We identified that London offers a much more entertainment focussed tourism experience rather than accurate historical and authentic sites which utilised major aspects of dark tourism for purposes such as commemoration or remembrance. The authors found this surprising given Londonâs long and often dark history
Cyprus' imageâa sun and sea destinationâas a detrimental factor to seasonal fluctuations. Exploration into motivational factors for holidaying in Cyprus
Cyprus is established as a summer destination. To aid the destination in developing its winter season as well, this research uses a qualitative inductive approach to explore the touristsâ current image of the island and their motivations of visiting it. The research indicates that the current image, which essentially portrays Cyprus as a sun-and-sea destination is thought to dissuade tourists from perceiving the island as a year-round destination. Nonetheless, increasing the pull factors of the destination through the development of unique special interest products can help in extending the tourism season as well as broaden its narrow image
Planning and Leveraging Event Portfolios: Towards a Holistic Theory
This conceptual paper seeks to advance the discourse on the leveraging and legacies of events by examining the planning, management, and leveraging of event portfolios. This examination shifts the common focus from analyzing single events towards multiple events and purposes that can enable cross-leveraging among different events in pursuit of attainment and magnification of specific ends. The following frameworks are proposed: (1) event portfolio planning and leveraging, and (2) analyzing events networks and inter-organizational linkages. These frameworks are intended to provide, at this infancy stage of event portfolios research, a solid ground for building theory on the management of different types and scales of events within the context of a portfolio aimed to obtain, optimize and sustain tourism, as well as broader community benefits
Behavioral-variant frontotemporal dementia: Distinct phenotypes with unique functional profiles
Objective: To identify distinct behavioral phenotypes of behavioral variant frontotemporal dementia (bvFTD), and elucidate differences in functional, neuroimaging, and progression to residential care placement. Methods: Eighty-eight patients with bvFTD were included in a cluster analysis applying levels of disinhibition and apathy (Cambridge Behavioural Inventory-Revised) to identify phenotypic subgroups. Between-group (Kruskal-Wallis; Mann-Whitney U) functional differences (Disability Assessment for Dementia), and time to residential care placement (survival analyses) were examined. Cortical thickness differences (whole brain MRI) were analyzed in bvFTD patients versus healthy controls (n=30) and between phenotypic subgroups. Results: Four phenotypic subgroups were identified: âPrimary severe apathyâ (n=26), âSevere apathy and disinhibitionâ (n=26), âMild apathy and disinhibitionâ (n=27), âPrimary severe disinhibitionâ (n= 9). Severely apathetic phenotypes were more functionally impaired and had more extensive brain atrophy than those with mild apathy or severe disinhibition alone. Further imaging analyses indicated that the right middle temporal region is critical for the development of disinhibition, an association that remains with disease progression and in the context of severe apathy. Finally, no difference in time to residential care admission was found between phenotypes. Conclusions: This study reveals that different clinical behavioral phenotypes of bvFTD have differing profiles of functional decline and distinct patterns of associated cortical changes. These findings emphasize the importance of apathy in functional impairment, highlight the role of the right temporal region in disinhibition and suggest that disability may be a sensitive outcome measure for treatments targeting reduction of apathy. These phenotypes could also support understanding of prognosis and clinical management
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