155,391 research outputs found
Management impacts on soil organic matter of tropical soils.
No full textIncreased soil organic matter (SOM) improves the cation exchange capacity of tropical weathered soils, and liming is required to achieve high yields in these soils. Despite a decrease in SOM in the short term, liming may increase SOM with time by improving cation chemical bonds with soil colloids. Soil C may also be increased in high dry matter input cropping systems. We evaluated C changes in a Typic Rhodudalf as affected by four production systems with increasing residue inputs, with or without limestone or silicate. Soil use intensification by increasing the number of species in rotation as well as acidity remediation resulted in higher plant residue production. Introducing a green manure or a second crop in the system increased plant residue by 89% over fallow, but when a forage crop was used, plant residues more than doubled. Soil acidity amelioration increased plant residue deposition by 21% over the control. The introduction of a forage crop increased labile SOM and C contents in the particulate fraction, and lime or silicate application led to increases in the more stable SOM fraction. High amounts of plant residues (>70 Mg ha?1 in 5 yr) are effective in raising soil labile C, but the alleviation of soil acidity results in increased soil stable C irrespective of crop rotations in tropical weathered soils, and in this case plant residue deposition can be lower. Lime and silicate are equally effective in alleviating soil acidity and increasing soil C, probably due to the formation of cation bridges with soil colloids
Adubação foliar da soja: II. Efeitos de NPK e micronutrientes em função do preparo do solo.
No full textEnsaio instalado em um Latossolo Vermelho-Escuro Orto, em Paranapanema, SP, para estudar os efeitos de adubos foliares com e sem micronutrientes, aplicados nas sementes, sobre a produção da soja (Glycine rnax (L.) Merrili), cv. UFV-1, em dois sistemas de preparo de solo: aração + gradagem, e subsolagem+ gradagem. Os tratamentos foliares foram: 1. testemunha; 2. três aplicações de 5 1/ha da fórmula 5-15-5 aos 30, 45 e 60 dias da emergência mais uma aplicação de 5 1/ha da fórmula 144-7 aos 75 dias da emergência; 3. duas aplicaçôes de 5 1/ha da fórmula 5-15-5 mais micronutrientes, aos 45 e 60 dias da emergência; 4. duas aplicaçõs de 5 1/ha da fórmula 5-15-5 aos 45 e 60 dias da emergência; 5. idem tratamento 4, com 10 1/ha; 6. idem tratamento 3, com 10 1/ha - todos com delineamento experimental em subsubparcelas. Foi observado efeito significativo sobre a produção da soja quando o solo foi subsolado e gradeado. A aplicação de micronutrientes às sementes apresentou tendência a diminuir a produção. Os adubos aplicados às folhas não causaram diferenças significativas. ABSTRACT - A field experiment was carried out on a Dark-Red Latosol Orto at Paranapanema, SP, Brazil, to study the effects of fertilization on soybeans (GIycine max (L.) Merrill), cv. UFV-1, with micronutrients applied or not to the seeds, in two tillage methods: plowing + disking, and subsoiling + disking. The foliar treatments were: 1. control; 2. three aplications of 5 1/ha of the formula 5-15-5 at 30,45 and 60 days froru seedling emergence, plus 5 1/ha of the formula 14-4-7 at 75 days from seedling emergence; 3. two applications of 5 1/ha of 5-15-5 plus micronutrients at 45 and 60 days from seedling emergence; 4. two applications of 5 1/ha of 5-15-5 at 45 and 60 days from seedling emergence; 5. idem treatment 4, utilizing 10 1/ha; 6. idem treatment 3, utilizing 10 1/ha. A sub-subplot experimental design was used in all these treatments. An effect of tillage on soybean yield was noticed, which was higher on the plots where the soil was subsoiled and disked. There were not significative effects of micronutrients or foliar fertilization on soybean yields
Adubação foliar da soja: II. Efeitos do NPK e micronutrientes em função do preparo do solo.
No full textFoi instalado um ensaio em condição de campo, em solo classificado como Latossol Vermelho Escuro orto, no município de Paranapanema, Estado de são Paulo, com o objetivo de estudar os efeitos de adubos foliares com e sem micronutrientes aplicados às sementes na produção da soja cultivada em dois sistemas de preparo de solo: aração + gradagem e subsolagem + gradagem
Resposta de crescimento, matéria seca e fotossíntese do algodoeiro pelo uso de cloreto de Mepiquat.
No full textUse of cotton plant growth regulators provides smaller plants, but causes morphology and leaves energy relationships changes. Therefore, this work aimed to study changes in reproductive and vegetative parts of cotton cultivars, as well as the photoassimilates production changes caused by use of mepiquat chloride. The experiment was conducted in greenhouse conditions with six cotton cultivars: 'FMX 966', 'FMX 977', 'DeltaPenta', 'DeltaOpal', 'FMT 501' e 'FMT 701' and four doses of the plant growth regulator "gibberellin synthesis inhibitor" based on mepiquat chloride (0,0 g ha-1 ; 7,5 g ha-1 ; 15,0 g ha-1 and 22,5 g ha-1 of the active ingredient). The experimental design was a 6 x 4 factorial in complete randomized blocks with four replications. Leaf area, dry matter production and drop reproductive structures number decrease by plant growth regulator application, with differences responses among cultivars. Differences in CO2 assimilation rate were not significant among cotton cultivars. All cotton cultivars increased spad index due to increase of dose applied of mepiquat chloride.O uso de reguladores de crescimento proporciona algodoeiros menores, mas provoca mudanças na morfologia e nas relações de energia das folhas. Dessa forma, o objetivo deste trabalho foi estudar as alterações na parte reprodutiva e vegetativa em cultivares de algodoeiro, bem como alterações na produção de fotoassimilados causadas pelo uso de cloreto de mepiquat. O experimento foi realizado em casa-de-vegetação com seis cultivares: 'FMX 966', 'FMX 977', 'DeltaPenta', 'DeltaOpal', 'FMT 501' e 'FMT 701', e quatro doses do regulador de crescimento "inibidor da síntese de giberelinas" à base de cloreto de mepiquat: 0,0 g ha-1; 7,5 g ha-1; 15,0 g ha-1 e 22,5 g ha-1 de i.a. O delineamento experimental foi em blocos casualizados, com quatro repetições, num esquema fatorial 6 x 4. A área foliar, produção de matéria seca e número de estruturas reprodutivas abortadas decrescem pela aplicação de regulador de crescimento, com diferenças de respostas entre cultivares. As diferenças na taxa de assimilação líquida de CO2 não foram significativas entre as cultivares estudadas. Todas as cultivares apresentam aumento do índice spad pelo uso de cloreto de mepiquat em virtude do aumento da dose aplicada
O. A. C. Review Volume XLVI Issue 5, February 1934
No full textThe focus of this issue is the preparation for College Royal and recognizing its tenth anniversary. This month's agricultural article is a report from the Dominion Parasite Laboratory on the biological control of pests. Other articles provide an account of the activities of a stage manager and the development of the field of home economics at Macdonald College in Quebec. Campus news addresses the success of the 1934 Conversazione, the commemorating of the sixtieth anniversary of the founding of O. A. C., the attendance at the Canadian Author Lecture, and the successful productions of "The Apple Cart" and "Iolanthe". The Macdonald Institute column comments on the Conversat and women's athletics activities in basketball and the rifle club. The Alumni Record supplies alumni updates.EditorialTen Years of the RoyalRamblings on the RoyalBlame it on the stage managerBiological control of insect pests in CanadaNot for girls onlyCollege lifeLiterary sectionO. A. C. sportsfolioAlumni recordMacdonald newsLetters to the editoradvertisin
O. A. C. Review Volume XXXVI Issue 12, August 1924
No full textThis slim summer issue contains the address given by the agricultural section of the British Association for the Advancement of Science, and a report on the visit of this association to the O. A. C. Other articles include instructions on increasing strawberry production and a biography of the author John Masefield. The editorial comments on Rhodes Scholars. The Alumni column provides an update of alumni activities. This issue does not contain a Macdonald column.JoyPresent-day problems in crop productionAfter the strawberry harvestJohn MasefieldVisit of the Agricultural Section of the British Association for the Advancement of ScienceEditorialCollege lifeAlumniadvertisin
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
The Thursday Murder Club: Launching a megabrand author - a publishing case study
No full textIn 2020, the Christmas book charts in the UK made headlines: Barack Obama’s eagerly awaited autobiography, The Promised Land, was beaten to the top spot by The Thursday Murder Club by Richard Osman, a debut cosy crime novel set in a retirement village. Not only did Osman’s book beat the former US president’s expected bestseller, it also broke records, becoming the fastest-selling debut crime novel of all time. Although Osman has a certain level of fame in the UK from his TV appearances on shows such as Pointless, his celebrity status does not entirely explain the novel’s huge sales. This article tracks the acquisition, publication, and promotion journey of The Thursday Murder Club in order to understand the industry and cultural context of its success and to interrogate the role of celebrity in the creation of author brands. The findings suggest that the unexpected scale of the success of the book owed to a number of factors, including in-depth editing by the novel’s agent, editor, and author to tighten up the plot, an extensive and strategic promotional campaign, the pandemic (which drove interest in the book’s genre and themes), and the quality of the writing. We find that the book’s success was accentuated by Osman’s celebrity status rather than being entirely reliant on it. This research adds to the growing scholarship on celebrity authorship by means of an in-depth case study and provides insight into the processes behind publishing a ‘celebrity’ book and launching a megabrand author
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