Search results for "use efficiency"
showing 10 items of 54 documents
Effects of Biochar on Irrigation Management and Water Use Efficiency for Three Different Crops in a Desert Sandy Soil
2020
This paper aimed at investigating if the application of biochar (BC) to desert sand (DS) from the United Arab Emirates (UAE), characterized by a very poor soil-water retention (SWR) and by a very low value of the maximum water available for crops (AWmax), could positively affect soil water balance, by reducing the irrigation needs (VIRR) and improving the irrigation water use efficiency (IWUE) and the water use efficiency (WUE). The analysis was performed for three crops, i.e., wheat (Triticum aestivum), sorghum (Sorghum vulgare) and tomato (Lycopersicon esculentum). BC was applied to the DS at different fractions, fBC (fBC = 0, 0.091, 0.23 and 0.33). Drip irrigation was adopted as a highly…
Fruit quality and volatile fraction of ‘Pink Lady’ apple trees in response to rootstock vigor and partial rootzone drying
2008
BACKGROUND: Partial rootzone drying (PRD) is a novel deficit irrigation technique consisting in the alternated wetting of only one side of the rootzone, which induces partial stomatal closure and increased water use efficiency. The effect of PRD and rootstock vigor on ‘Pink Lady’ apple fruit quality and aroma profile was studied using solid-phase micro-extraction in headspace and gas chromatography/mass spectrometry. RESULTS: PRD irrigation generally did not affect quality attributes, whereas it influenced the aroma of the apple fruit. In particular, PRD improved the aroma of the fruit flesh, while it decreased the volatile fraction in the peel, where most of the compounds are concentrated.…
Assessment of yield and water productivity of clementine trees under surface and subsurface drip irrigation
2018
Abstract Irrigation systems aimed to optimize water use efficiency in agriculture have become essential due to the increasing water limitations that agriculture is currently facing. Assessment of crop responses to different irrigation systems and strategies are therefore encouraged to find the most efficient options for each specific case. The main objective of this study was to assess the performance of a citrus crop under a surface (SI) and subsurface drip irrigation (SSI) with 7 (SI7, SSI7) or 14 emitters (SI14, SSI14) per plant, as well as a third SS treatment (SSIA), identical to SSI7 but equipped with and additional drip line buried between the tree rows. Evaluations were made in term…
Effects of Saline and Deficit Irrigation on Soil-Plant Water Status and Potato Crop Yield under the Semiarid Climate of Tunisia
2019
Water supplies have been decreasing in several semi-arid regions, and it is therefore necessary to adopt irrigation strategies aimed at maximizing water use efficiency. In this paper, the effects of saline and deficit irrigation on water use efficiency and on potato crop response, based on observations of soil and plant water status, were investigated. Experiments were carried out in Central Tunisia, by monitoring potato crop growth during two seasons in four distinct treatments (T1&ndash
Quantifying water stress effect on daily light use efficiency in Mediterranean ecosystems using satellite data
2016
16 pages, 2 figures, 6 tables, supplemental material https://dx.doi.org/10.1080/17538947.2016.1247301
Monitoring water stress in Mediterranean semi-natural vegetation with satellite and meteorological data
2014
In arid and semi-arid environments, the characterization of the inter-annual variations of the light use efficiency ε due to water stress still relies mostly on meteorological data. Thus the GPP estimation based on procedures exclusively driven by remote sensing data has not found yet a widespread use. In this work, the potential to characterize the water stress in semi-natural vegetation of three spectral indices (NDWI, SIWSI and NDI7) – from MODIS broad spectral bands – has been analyzed in comparison to a meteorological factor (Cws). The study comprises 70 sites (belonging to 7 different ecosystems) uniformly distributed over Tuscany, and three eddy covariance tower sites. An operational…
Soil wettability, runoff and erodibility of major dry-Mediterranean land use types on calcareous soils
2007
This study examines six land uses (pine woodland, long unburnt scrubland, recently burnt scrubland, orange grove, olive grove and cereal crop), typical for calcareous soils in a dry-Mediterranean region such as eastern Spain, with regard to soil surface water repellency occurrence, hydrological response and erodibility. For each land use, we performed water drop penetration time (WDPT) tests and rainfall simulations respectively on in situ soils at ten replicate plots for extremely dry antecedent conditions in summer 2002 and for wet winter conditions, in early 2003 in the Canyoles river valley. In contrasts to what might have been expected, water repellency was absent or subcritical (WDPT …
What do leaf anatomy and micromorphology tell us about the psammophilous Pancratium maritimum (Amaryllidaceae) in response to sand dune conditions?
2015
Abstract The present study aimed at verifying the morphological variation in leaf traits among different populations of Pancratium maritimum (sea daffodil) and the correlation between leaf diversity and climate conditions at different sites. Eleven populations of P. maritimum from Mediterranean coastal sand dunes were investigated with respect to leaf surface micro-morphology, leaf anatomy, and vascular pattern. Morphometric analysis was based on 29 quantitative foliar parameters. One-way analysis of variance (ANOVA), principal component analysis (PCA), discriminant function analysis (DFA), and clustering by Ward’s method were used for the statistical evaluation. Results revealed a rather u…
Daily GPP estimates in Mediterranean ecosystems by combining remote sensing and meteorological data
2015
The accurate representation of terrestrial CO2 uptake (GPP) using Monteith's approach requires a frequent and site-specific parameterization of the model inputs. In this work, an optimization of this approach has been carried out by adjusting the inputs (f(APAR), PAR and epsilon) for the study area, peninsular Spain, a typical Mediterranean region. The daily GPP images have been calculated for 2008 and 2011 with a 1-km spatial resolution and validated by comparison with in situ GPP estimates from the eddy covariance data (direct validation) and by inter-comparison with the MODIS GPP product. The direct validation has evidenced an excellent agreement with correlations up to 0.98 in 2008 and …
Carbon use efficiency variability from MODIS data
2017
[EN] Carbon use efficiency (CUE) describes how efficiently plants incorporate the carbon fixed during photosynthesis into biomass gain and can be calculated as the ratio between net primary production (NPP) and gross primary production (GPP). In this work, annual CUE has been obtained from annual GPP and NPP MODIS products for the peninsular Spain study area throughout eight years. CUE is spatially and temporally analyzed in terms of the vegetation type and annual precipitation and annual average air temperature. Results show that dense vegetation areas with moderate to high levels of precipitation present lower CUE values, whereas more arid areas present the highest CUE values. However, th…