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Effetti dello spargimento sul terreno di quantità diverse di sanse umide su alcuni parametri fisiologici del girasole
No full textEffect of organic and mineral fertilization on faba bean (Vicia faba L.)
No full textThe aim of this research was to evaluate the effect of various combinations of organic and/or mineral fertilizers on faba bean (Vicia faba L.) to identify the best treatment for balancing yield, seed quality and composition and soil fertility maintenance over time. Wet olive pomace, an olive-mill by-product very abundant in olive oil producing countries, was used for fertilization trials. The use of wet olive pomace at 140 Mg ha−1, combined with half of the conventional N, P, and K dose of mineral fertilization, allowed to achieve the same faba bean productivity of full mineral fertilization. Higher levels of wet olive pomace did not induce further productivity increase. The highest protein content in dry faba bean seeds (276.05 g kg−1) was detected at full mineral fertilization. Phenolic compounds and antioxidant activity showed an opposite trend and tended to be lower in case of full mineral fertilization alone, whereas were higher in unfertilized control and in the trials fertilized with combinations of half mineral fertilization and olive pomace. The latter fertilizing condition also allowed to suppress the infesting flora. The use of wet olive pomace for agricultural purposes could therefore represent an environmentally friendly support to mineral fertilization, adding value to a by-product
Spatial distribution of roots and cracks in soils cultivated with sunflower
No full textThe aim of this research was to investigate the spatial distribution of roots and cracks in two clay soils cropped with sunflower under different inter-row spacing in order to identify the optimal management. A latin square experimental design was applied to compare bare soil and soil cropped with sunflower, with three plant densities, obtained by keeping constant the number of plants on the row (3 plants m−1) and varying the row spacing (0.4, 0.6, 0.8 m). The presence of the crop and the different distance between rows influenced soil moisture content as well as the root spatial distribution and thus the structural features of cracks. Increasingly lower values of moisture were found in both soils as the distance between rows decreased; an opposite trend was observed for both root density and crack size. The volume of cracks in the soil grown with sunflower at 0.4 m row spacing was 201.4 m3 ha−1, thus 8 times higher than the value on the bare soil and 2.5 times higher compared to the one grown at 0.8 m between rows. Optimal results in terms of root density, soil moisture and crack size were obtained with an inter-row spacing of 0.6 m
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
Effect of water salinity and irrigation regime on maize (Zea mays L.) cultivated on clay loam soil and irrigated by furrow in Southern Italy
No full textMaize is a crop with high irrigation needs in Italy. In many cultivated areas of the world, the water used for irrigation has a high salinity. To limit the damage caused by the salts provided by irrigation, suitable irrigation strategies can be adopted in relation to the crop, soil characteristics and rainfall regime. Therefore, in order to evaluate the most appropriate irrigation strategy to be used in the cultivation of maize on a clay loam red soil, subject to salinity, a research on a four-year crop rotation was carried out in southern Italy. Maize grain yield and yield characteristics irrigated by furrow with two water salinity levels and five different irrigation regimes, were compared. Grain yield was reduced by 34% in the third crop rotation year when the soil salinity, on average, raised from 3.8 to 7.4 dS m−1. Higher yield occurred restoring 100% of maximum crop evapotranspiration, instead of leaching requirement application which did not affect yield. Soil salinity improved grain protein content and reduced grain moisture content. Rainfall was not sufficient to leach all salts supplied by irrigation. The leaching requirements did not reduce the soil salinity and the harmful effect of salinity on maize yield, because of more salts supplied by higher irrigation volumes
Short-term soil amendment by sewage sludge anaerobic digestate in a tomato monoculture suppresses Fusarium vascular wilt disease by changing the taxonomic characteristics of soil microbiota
Full text linkDigestate incorporation into topsoil determines soil fertility improvement by changing composition and structure of soil microbiota. However, how microbiota responds to short-term soil amendment by sewage sludge anaerobic digestate (SSD) for suppressing Fusarium vascular wilt disease is unknown. This study compares the effects of three SSD-based treatments to suppress Fusarium oxysporum f. sp. lycopersici (Fol) in a long-term cherry tomato monoculture under field condition in a 3-year trial. Three sampling sites with two application times (two bulk soils at 3–12 weeks after amendment and one tomato rhizosphere soil at 12 weeks post-amendment) were chosen. Three digestate typologies (liquid, centrifuged, and dried) having physicochemical features and heavy metals content below the legal limits were tested at 50 l, 3.5 kg and 2.5 kg m−2y−1 dose, respectively. Fusarium wilt disease was measured for three consecutive years by severity index and Fol abundance in tomato vascular tissue was assessed by ITS rDNA gene sequencing. Fol abundance and taxonomic structure of Fusarium community in the rhizosphere were determined at specie level at the end of the trial by ITS rDNA and EF1α rDNA genes sequencing, respectively. The taxonomic structure (α-, β-diversity) of soil bacterial community (SBC) was characterized from phylum up to genus level at the end of the trial in all the sites by 16S rRNA gene sequencing. The results showed that dry SSD reduced disease severity in field up to 18 % and Fol abundance in tomato up to 0.9 ITS copies g−1 tissue. Fol abundance was decreased in the rhizosphere up to 0.0027 ng μl−1 DNA, while the Fusarium community shifted between treated-soils and un-amended. The SBC composition (α-diversity) changed in the rhizosphere by applying dry digestate, while the SBC structure (β-diversity) shifted either among treatments or sites. Bacterial members related to Fol suppression (Bacillus, Chitinophaga, Flavihumibacter, Flavobacterium, Pseudomonas and Terrimonas) increased in the rhizosphere (P < 0.01, P < 0.001) more than in the bulk soils by applying both dewatered-SSDs. Thus, digestate soil amendment carried out for three consecutive years has affected tomato Fusarium wilt severity by changing the taxonomic characteristics of fusaria and bacteria communities of the amended soil
Maize Yield Response, Root Distribution and Soil Desiccation Crack Features as Affected by Row Spacing
Full text linkPlant density is among the most critical factors affecting plant yields and resource use efficiency since it drives the exploitation of the available resources per unit area, root distribution and soil water losses by direct evaporation from the soil. Consequently, in fine-textured soils, it can also affect the formation and development of desiccation cracks. The aim of this study, carried out on a sandy clay loam soil in a typical Mediterranean environment, was to investigate the effects of different row spacings of maize (Zea mais L.) on yield response, root distribution and the main features of desiccation cracks. The field experiment compared bare soil and soil cropped with maize using three plant densities (6, 4 and 3 plants m−2), obtained by keeping the number of plants in a row constant and varying the distance between the rows (0.5–0.75–1.0 m). The highest kernel yield (16.57 Mg ha−1) was obtained with the greatest planting density (6 plants m−2) with a row spacing of 0.5 m; significantly lower yields were recorded with spacings of 0.75 and 1 m, with a decrease of 8.09% and 18.24%, respectively. At the end of the growing season, soil moisture in the bare soil was on average 4% greater in comparison to the cropped soil and was also affected by row spacing, decreasing with the decrease in the inter-row distance. An inverse behaviour was observed between soil moisture and both root density and desiccation crack size. Root density decreased to the increase in soil depth and to the increase in distance from the row. The pluviometric regime occurred during the growing season (total rainfall of 343 mm)-resulted in the formation of cracks of reduced size and with an isotropic behaviour in the bare soil, whereas in the cultivated soil, the cracks were parallel to the maize rows and increased in size with decreasing inter-row distance. The total volume of the soil cracks reached a value of 135.65 m3 ha−1 in the soil cropped with a row distance of 0.5 m, and was about ten times greater in comparison to the bare soil and three times greater in comparison to a row spacing of 1 m. Such a volume would allow a recharge of 14 mm in the case of intense rainy events on soil characterised by low permeability
Green compost influences yield and quality of carrots (Daucus carota L.) by enhancing root rot suppression to Sclerotinia sclerotiorum (Lib. De Bary)
No full textThe aim of this research, carried out in Bari and Policoro (Southern Italy) from March to June 2018, was to evaluate the effects of two different green composts on yield, quality, and root rot suppression of carrot (Daucus carota L.) cv. Rubrovitamin when compared to a mineral fertilizer and a plant growing media of peat-pumice. Green composts obtained from the municipal solid waste (Biovegetal) and olive pomace by olive mill were used in outdoor crop as fertilizer to enhance root yield and quality and in glasshouse to evaluate root rot suppression against Sclerotinia sclerotiorum. A randomized complete block design with six replicates was used. A total of eight treatments was compared in outdoor (mineral fertilization, three levels of each compost and unfertilized control). A total of five treatments was used in glasshouse: carrot was cropped in a growing media made of peat and pumice and fertilized with the two composts at two different levels, compared to an un-sterile potting mix of 60% peat with 40% pumice used as control. In the carrot grown outdoors the different composts did not influence either the length of the phenological phases or the entire crop cycle, but the highest dose of olive pomace (30 Mg ha-1) favored the greatest root production with an increase of 19.9% if compared to the mineral fertilizer. Biovegetal at the highest dose (30 Mg ha-1) provided non-statistically differences in root production from that obtained with the mineral fertilization, as well as the lowest rate (15 Mg ha-1) of composted olive pomace supplemented with 50 kg N ha-1. The highest carotenoids content, total soluble solids and specific weight were recorded by the amendment with the highest composted olive pomace rate. Concerning the root rot suppression effect, Biovegetal showed to be more effective than composted olive pomace. Thus, the use of green compost could represent a useful alternative to mineral fertilization and soil-borne disease control by synthetic fungicides through an adding-value due to by-products reusing and waste recycling
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
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