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Vidal-Vazquez E.,University of La Coruna | Camargo O.A.,Instituto Agronomico Of Campinas Iac | Vieira S.R.,Instituto Agronomico Of Campinas Iac | Miranda J.G.V.,Federal University of Bahia | And 4 more authors.
Vadose Zone Journal | Year: 2013

Soil textural fractions, organic carbon content, pH, and attributes of the soil exchange complex were sampled parallel and perpendicular to land slope, along two transects. All data sets have been found to exhibit slight to strong multifractal behavior. Most variables showed different scaling properties between the two transects. The spatial variability of soil properties can be best characterized through concepts of scale invariance, fractals, and multifractals. The objectives of this study were to analyze and to compare the scaling patterns and structural heterogeneity of soil properties across two transects in Campinas, SP, Brazil, using the multifractal formalism. Two transects were marked parallel and perpendicular to land slope, with a length of 2.28 and 1.98 km, respectively. Soil samples were collected at the 0 to 20 cm depth every 30 m. The soil properties analyzed were: texture (sand, silt, clay), pH (H2O and KCl), organic carbon (OC) content, exchangeable Ca, H, and Al, exchangeable bases (SB), cation exchange capacity (CEC), and percent base saturation (V). Spatial variability of soil properties was controlled by natural causes, including parent material and topography, and by soil use and management. The variability of pH across the two transects was characterized by either quasi-monofractal behavior or by a relatively low degree of multifractality. The other soil properties studied showed stronger degrees of multifractality. Hence, the multifractality for OC and silt content was much higher at the transect perpendicular to land slope. Variables from the soil exchange complex, particularly exchangeable Al, Ca, and SB, were characterized by higher multifractal indices in the two transects. Patterns of spatial distribution assessed by multifractal analysis were linked to soil forming factors and processes. Our results suggest that scale heterogeneity in the spatial distribution of soil properties was enhanced by the interaction of various natural or anthropogenic sources of variability. © Soil Science Society of America 5585 Guilford Rd., Madison, WI 53711 USA. All rights reserved.

Cancela J.J.,University of Santiago de Compostela | Trigo-Cordoba E.,University of Santiago de Compostela | Martinez E.M.,University of Santiago de Compostela | Rey B.J.,University of Santiago de Compostela | And 3 more authors.
Agricultural Water Management | Year: 2016

Inter-annual climate variability, mainly rainfall temporal distribution, is a critical factor for scheduling irrigation. In order to efficiently manage precision irrigation systems for Vitis vinifera (L.), their effects on plant physiology, and vineyard soils, together with yield and quality parameters, need to be understood. The current study was conducted on two grapevine cultivars from Galicia (NW-Spain), cv. 'Albariño' and 'Godello', during 2012-2014, in two different Designations of Origin (DO): Rías Baixas and Valdeorras. The treatments were rainfed (R) and surface drip irrigation (DI) in DO Rías Baixas, adding subsurface drip irrigation (SDI) in DO Valdeorras, with four replicates (7 plants each). Irrigation was triggered at fruit set, when midday stem water potential (Ψstem) dropped to -0.5MPa, and stopped 15 days before harvest in DO Valdeorras; but it was managed by the vinegrower in DO Rías Baixas. Different bioclimatic indices were calculated to characterize each season and location. Soil water content and Ψstem were periodically measured to assess vineyard water status. Yield and juice quality attributes were determined. Water productivity indices were calculated to compare locations and cultivars. Differences between DOs were observed regarding bioclimatic indices, which indicated temperate and very cool nights for cv. 'Godello'. In the case of 'Albariño', warmer nights were observed. In DO Valdeorras, the differences between treatments in Ψstem were never higher than -0.19MPa; whereas they were almost null in DO Rías Baixas. Yield parameters showed a worse overall productive performance for the R treatment, with lower yields in 2012 and 2013. Qualitative parameters were stable over the three growing seasons studied. Adjusting irrigation schedules for a given season using Ψstem measurements and considering the phenological stage of the vine might help to obtain homogeneous harvests, both in yield and quality. Water productivity indices related with grape yield and pruning weight showed that, in a temperate climate, vegetative growth has an important weight in vineyard water use. © 2016 Elsevier B.V.

Trigo-Cordoba E.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Trigo-Cordoba E.,University of Santiago de Compostela | Bouzas-Cid Y.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Orriols-Fernandez I.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Miras-Avalos J.M.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL
Agricultural Water Management | Year: 2015

Galicia is a region located in NW Spain characterized by high rainfall amounts; however, climate change is altering the temporal and spatial distribution of rainfall. Thus, vinegrowers are concerned about this climate variability that may affect grape production and quality and, therefore, drip irrigation systems are increasingly being installed in Galician vineyards. Hence, the development of efficient irrigation management practices is required. In this regard, a field experiment was carried out over three seasons (2012-2014) on white Vitis vinifera L. cv. 'Godello' and 'Treixadura' in order to assess the effects of deficit irrigation on vine performance and must and wine composition. Rain-fed vines were compared with a treatment irrigated to 50% of the estimated crop evapotranspiration (ETc) from bloom to two weeks before harvest. Both cultivars showed more positive plant water status under irrigation than under rain-fed conditions; however, stomatal conductance and chlorophyll fluorescence attributes were similar between treatments. Yield was unaffected by irrigation except for Treixadura cultivar in 2014 (25% increase). On the contrary, irrigation increased pruning weight, around 15%, for both cultivars. Total soluble solids of the must decreased and total acidity increased with irrigation; however, the wines were very similar between treatments. Water productivity was higher under rain-fed conditions for Godello, which led to similar gross incomes between treatments but with a lower production cost for rain-fed. In the case of Treixadura, significantly higher gross incomes were estimated for irrigation only in the last year of studies, which may not justify the use of irrigation. Therefore, irrigation does not seem an economically viable agricultural practice under the conditions of this trial. © 2015 Elsevier B.V.

Arrieta-Garay Y.,Rovira i Virgili University | Lopez-Vazquez C.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Blanco P.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Perez-Correa J.R.,University of Santiago de Chile | And 2 more authors.
Journal of the Institute of Brewing | Year: 2014

The impact of the distillation system and yeast strain on the chemical and aromatic profile of kiwi spirits was investigated. Three fermentations of kiwi fruits were carried out, two with selected yeasts (KL1 and KL2) and one spontaneous (KL3). The obtained kiwi wines were distilled using two distillation systems (Charentais alembic and packed column), and the resulting spirits were analysed by direct injection gas chromatography. Kiwi spirits obtained with the packed column had the highest concentrations of esters C6-C10 and monoterpenols, while the alembic spirits had the highest concentrations of ethyl acetate, methyl acetate and higher alcohols. Three principal components derived from the chemical composition data explained 96.6% of the variance. Principal component 1 differentiated alembic from packed column distillates, principal component 2 distinguished KL3 spirits and principal component 3 distinguished KL1 spirits. Kiwi spirits distilled with the packed column were preferred by consumers. The predominant sensory descriptors in the packed column kiwi spirits were floral, fruity and spicy, while burnt/smoky and pungent were the principal aroma descriptors in alembic spirits. Moreover, significantly higher ethanol yields and ethanol strengths were obtained with the packed column distillation system. The observed influence of the yeast strains on preference and ethanol yields was minor. © 2014 The Institute of Brewing & Distilling.

Trigo-Cordoba E.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Bouzas-Cid Y.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Orriols-Fernandez I.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL | Miras-Avalos J.M.,Estacion de Viticultura e Enoloxia de Galicia EVEGA INGACAL
Ciencia e Tecnica Vitivinicola | Year: 2014

This study aimed to assess the effect of irrigation on the sensory profile of wines from three Galician white grapevine cultivars. Field experiments were carried out in 2011 and 2012 at the research farm of the Estación de Viticultura e Enoloxía de Galicia (EVEGA), where two treatments were imposed: rain-fed and irrigation to the 50% of potential evapotranspiration. A panel of seven judges tasted the wines in six sessions (one per cultivar and year) for evaluating their sensory profile. In the case of 'Albariño', three descriptors, although not the same for both years, were significantly different between treatments. For 'Godello', several descriptors differed between treatments, and citric was present in both years. In 'Treixadura' white fruit and persistence were present in 2011 and 2012. Several descriptors contributed to the hedonic index, but differed between wines; however, balance was common for all the cultivars and years. In conclusion, 'Albariño' and 'Godello' wines from the rain-fed treatment received higher marks than those from the irrigation treatment; whereas Treixadura wines from the irrigation treatment were better valued.

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