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Annual self-reseeding legumes and their application into Mediterranean Organic cropping systems
No full textSelf-reseeding winter annual legumes are an essential component of the Mediterranean natural resources. This study aimed to investigate self-establishment potential, ability of biological nitrogen fixation (BNF), of seven annual self-reseeding legumes and their short–term pre-crop effect on succeeding zucchini and lettuce crops. Results are presented from field experiment in Apulia region, South of Italy, where the self-reseeding legumes were screened during two cropping cycles.
For the first cropping cycle (2005-2006) preliminary results suggested that Trifolium spp. performed better than Medicago spp. Among the seven species, five were more suitable to the site’s conditions. T. angustifolium and M. polymorpha gave the best results. T. angustifolium fixed 131.7 kg ha-1 of nitrogen (15N isotopic dilution method), produced 1976 kg ha-1 of seeds and 8.7 t ha-1 of dry matter (DM). M. radiata and M. rigidula were the less performing. During the second cropping cycle (2006-2007) results showed that Trifolium spp. self-established better than Medigaco spp. Regenerated species appeared to sustain optimum level of BNF. Again T. angustifolium was the best performing species producing the highest DM (7.7 t.ha-1) and fixing nitrogen (146.7 kg ha-) symbiotically. In contrast, M. polymorpha, was the less performing (0.3 t.ha-1 of DM and 11.5 kg ha1 of BNF) while M. rigidula and M. radiata did not regenerate. Instead, the regenerated species, used as green manure, induced positive effects on both zucchini and lettuce growth parameters. Zucchini and lettuce marketable yield were significantly increased affected by preceding legumes, respectively in average 53% and 24% over the control. T. angustifolium was the best promising species. It induced the best effect on all zucchini and lettuce parameters including crop yield (respectively 42.66 and 48 t ha-1). Given the overall performance of all species, it was determined that T. angustifolium had the greatest potential for further development in this environment
Annual self-reseeding legumes and their application into mediterranean cropping systems.
No full textSoil fertility management is a major concern in organic farming. According to the EEC Regulation 2092/91, soil fertility must be maintained and/or increased by legumes cultivation. Native Mediterranean legumes ecotypes are more persistent than commercial varieties but their use in catch crop sequences is still limited. The N2-fixing legumes crops as a local resource can be considered as an alternative to improve nitrogen nutrition and to increase crop yields. This study aimed to investigate the agronomic performance of seven annual self-reseeding legumes and the short–term effect of nitrogen supply on the subsequent crops. Results are presented from field experiment on sandy-clay soil, pH 8.1 and 1.6% of organic matter, in the south of Italy, where the self-reseeding legumes were evaluated during two cropping cycles for their adaptability and integration into Mediterranean cropping systems. Biological nitrogen fixation (BNF)performance was also measured using 15N isotopic dilution method.
For the first cropping cycle, Trifolium spp. performed better than Medicago spp. and of the seven tested species, five were more suitable to the site conditions. These species could be used for managing soil fertility and enhancing biodiversity in orchards. Trifolium angustifolium and Medicago polymorpha were the most performing species. They fixed 132 and 90 kg N ha-1 of BNF, produced 1976 and 731 kg ha-1 of seeds and 8.7 and 5.5 t ha-1 of dry biomass (DM) respectively. In contrast, Medicago radiata and M. rigidula were the least performing species.
For the second cropping cycle, their self-establishment capacity and their effect as green manure on two subsequent crops of zucchini and lettuce were investigated. Results showed again that Trifolium spp. performed better than Medicago. Except for M. radiata and M. rigidula, regenerated species appear to sustain optimum level of soil-available nitrogen and induced positive effects on both zucchini and lettuce growth parameters. Zucchini and lettuce marketable yield significantly increased influenced by the preceding legumes, on average 53% and 24% respectively over the control. T. angustifolium was again the best performing and promising species producing the highest DM (7.74 t ha-1) and fixing nitrogen (146.7 kg N ha-1) symbiotically. It induced the best effect on all zucchini and lettuce parameters including crop yield (42.66 and 48 t ha-1 respectively). In contrast, M. polymorpha was less performing (0.3 t ha-1 of DM and 11.5 kg ha-1 of BNF). Given the overall performance of all species, it was determined that T. angustifolium had the greatest potential for further development in this environment
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
CONSERVATION AGRICULTURE BETWEEN CONCEPT AND APPLICATION
No full textThe challenges of agricultural sustainability have become more intense in recentyears with the sharp rise in the cost of food, energy and production inputs, climatechange and water scarcity. The question is how to meet such challenges? Howshould be agriculture in the 21st century? The worldwide scientific and empiricalevidences highlighted the important role could be achieved through rapid adoptionand spread of conservation agriculture (CA). Experience worldwide over the pastfour decades has demonstrated how CA through the simultaneous application of aset of practices of minimal mechanical soil disturbance, organic soil cover anddiversified cropping can lead to greater and stable yields, better use of productioncosts, enhanced crops, soil and ecosystem health, and improved climate changeadaptability and mitigation. However, despite of the beneficial effects of the CA onthe environment sustainability and in improving productivity and economics, yetthe question arise: why CA is not spreading faster and why then do the majority offarmers are still using other tillage implements? This could be mainly attributed tothe fact that much of the current production system science and education as wellas the policy and institutional support systems for the modern tillage-basedagricultural practices are not suitable to transformation towards enhanceconservation agriculture. Furthermore for a greater number of countries there islack of knowledge about CA systems and their management and absence of fundedresearch and extension services. The needed enabling policies, and practical actionsto promote the transformation of current production systems towards CA ones willbe fully discussed in this paper
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