Search results for "Irrigation management"
showing 10 items of 27 documents
EVASPA (EVapotranspiration Assessment from SPAce) tool: an overview
2013
International audience; Evapotranspiration (ET) is a fundamental variable of the hydrological cycle and its estimation is required for irrigation management, water resources planning and environmental studies. Remote sensing provides spatially distributed cost-effective information for ET maps production at regional scale. We have developed EVASPA too for mapping ET from remote sensing data at spatial and temporal scales relevant to hydrological or agronomica studies. EVASPA includes several algorithms for estimating evapotranspiration and various equations for estimating the required input information (net radiation, ground heat flux, evaporative fraction…), which provides a way to assess …
Cambio tecnológico, privatización y recuperación de la autogestión comunitaria del riego. El caso de Senyera (València)
2018
[ES] Los procesos de cambio de tecnología del riego están facilitando la penetración silenciosa de la empresa privada en los sistemas de gestión colectiva del riego en numerosos lugares de España y otros países mediterráneos. Este artículo analiza este fenómeno a partir del caso de estudio de Senyera (València), siguiendo la privatización, la disputa y la posterior recolectivización de la gestión por parte de los usuarios del riego. El trabajo muestra como la privatización menoscaba la autonomía de los agricultores y eleva los costes de gestión en un contexto de escasa transparencia. También revela la capacidad de los regantes para reelaborar su pasada acción colectiva, dando lugar a una nu…
Mass and surface energy balance approaches for monitoring water stress in vineyards
2013
Abstract Tree crops are representing one of most widespread agricultural systems in Mediterranean regions, thus contributing in a substantial way to the economy and productivity of primary sectors of the countries interested. Besides the aspects concerning their economical relevance, tree crops like vineyards, olive and orange orchards are also typical elements of the Mediterranean landscape, and their ecological role has been recently revitalised in consideration of their function as carbon sinks for the Kyoto agreement. The environmental and economical sustainability of these agricultural systems in arid and semi-arid zones has to cope with the availability and management of water resourc…
The impact of agricultural management on selected soil properties in citrus orchards in Eastern Spain: A comparison between conventional and organic …
2017
The agricultural management of citrus orchards is changing from flood irrigated managed orchards to drip irrigated organic managed orchards. Eastern Spain is the oldest and largest European producer of citrus, and is representative of the environmental changes triggered by innovations in orchard management. In order to determine the impact of land management on different soil quality parameters, twelve citrus orchards sites were selected with different land and irrigation management techniques. Soil samples were taken at two depths, 0-2. cm and 5-10. cm for studying soil quality parameters under the different treatments. Half of the studied orchards were organically managed and the other si…
Comparing actual evapotranspiration and plant water potential on a vineyard
2011
Agricultural water requirement in arid and semi-arid environments represents an important fraction of the total water consumption, suggesting the need of appropriate water management practices to sparingly use the resource. Furthermore the quality and quantity of some crops products, such as grape, is improved under a controlled amount of water stress. The latter is related, on a side to actual evapotranspiration (ET) through water demand, on the other side to plant water content through leaf water potential. Residual energy balance approaches based on remote sensing allow to estimate the spatial distribution of daily actual ET at plant scale, representing an useful tool to detect its spati…
Water Deficit Affects the Growth and Leaf Metabolite Composition of Young Loquat Plants
2020
Water scarcity in the Mediterranean area is very common and understanding responses to drought is important for loquat management and production. The objective of this study was to evaluate the effect of drought on the growth and metabolism of loquat. Ninety two-year-old plants of &lsquo
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…
Transpiration and Water Use of an Irrigated Traditional Olive Grove with Sap-Flow Observations and the FAO56 Dual Crop Coefficient Approach
2021
The SIMDualKc model was applied to evaluate the crop water use and the crop coefficient (Kc) of an irrigated olive grove (Olea europaea L.) located in Sicily, Italy, using experimental data collected from two crop seasons. The model applies the FAO56 dual Kc approach to compute the actual crop evapotranspiration (ETc act) and its components, i.e., the actual tree transpiration (Tc act), obtained through the basal crop coefficient (Kcb), and soil evaporation according to an evaporation coefficient (Ke). Model calibration was performed by minimizing the difference between the predicted Tc act and the observed daily tree transpiration measured with sap flow instrumentation (TSF field) acquired…
Determining Optimal Seasonal Irrigation Depth Based on Field Irrigation Uniformity and Economic Evaluations: Application for Onion Crop
2016
The crop water production function (WPF), representing the relationship between crop yield and seasonal irrigation water, is a useful tool for irrigation planning purposes. The objective of the paper is to propose a methodology to evaluate the optimal seasonal irrigation depth based on the crop production function, the field distribution uniformity, and economic considerations. An extended unpublished database experimentally obtained on the onion crop on the island of Kula, Hawaii, was initially used to assess the crop WPF. The combination between the crop WPF and the model representing the field distribution uniformity allowed determining the area subjected to underirrigation and overirrig…
Determining water use of sorghum from two-source energy balance and radiometric temperatures
2011
Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (<i>Sorghum bicolor</i>) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was …