Search results for "Irrigation"

A critical analysis of three remote sensing-based actual evapotranspiration assessment methods over sparse crops agricultural areas

2010

During last two decades the increasing availability of remotely sensed acquisitions in the thermal infrared part of the spectrum has encouraged hydrologist community to develop models and methodologies based on these kind of data. The aim of this paper is to compare three methods developed to assess the actual evapotranspiration spatial distribution by means of remote sensing data. The comparison was focused on the differences between the "single" (SEBAL) and "two" source (TSEB) surface energy balance approaches and the S-SEBI semi-empirical method. The first assumes a semiempirical internal calibration for the sensible heat flux assessment; the second uses a physically based approach in or…

Growth, yield and fruit quality of 'Tropic Snow' peach on size-controlling rootstocks under dry Mediterranean climates

2013

Abstract A six-year trial was carried out to evaluate the vegetative and productive performance of low-chill, early-ripening ‘Tropic Snow’ peach grown on five peach × almond rootstocks, different for their vigor. The study was conducted in south-western Sicily using 45 V-trained peach trees planted in 2005 and grafted on GF677, the most common rootstock in Sicily, and four low-vigor rootstocks selected at the Department of Agricultural, Food and Environmental Sciences, University of Pisa, namely IS5/8 (Polluce), IS5/19 (Castore), IS5/23, and IS5/29. Trunk circumference, winter and summer pruning weight, total number and weight of fruits per tree, and major fruit quality traits were recorded…

Irrigation Agrosystems in Eastern Spain: Roman or Islamic Origins?

1985

Abstract The long-standing controversy concerning Islamic diffusion of cultivars and irrigation technology to Spain is approached by comparing Roman and Islamic agrosystems at the general, regional, and local levels. We describe the Roman intensification of the older Mediterranean agrosystem and then examine the subsequent agricultural and demographic decline between A.D. 250 and 800. The operation, organization, and evolution of large, intermediate, and small-scale irrigation are analyzed in seven case studies from the Valencia region of eastern Spain. The largest systems were refurbished in Islamic times, but during a period when Berber and Arab settlement was thin and acculturation of th…

Feeding and management techniques to favour summer sheep milk and cheese production in the Mediterranean environment

2015

Sheep milk production in summer can lead to a diversification of milk products and to a more regular product distribution in the market throughout the year. However, in Mediterranean countries small ruminant production cycles are subjected to seasonal variations in forage resources. During summer, a key period for out of season production systems, nutrition plays a fundamental role in regulating the quantity and quality of milk production. In this review, feeding strategies and techniques that could be applied for out of season production in dairy ewes under different Mediterranean conditions are described for intensive, pasture-based and mixed systems. The most common feeding strategies us…

The crisis facing Tunisian drainage tunnels: identification, analysis and evaluation of water heritage in the Mediterranean region

2014

In regions with Mediterranean and steppe climates, the presence of surface water is sporadic, and a unique – but fragile and undervalued – element of water capture for irrigation and human supply is the ‘qanats’, ‘foggaras’, ‘mkoulas’ or water tunnels. The central objective of this project has been the full study of Tunisia's drainage tunnels. The inventory, analysis and heritage evaluation of Tunisia's ‘qanats’ have been possible through the application of a particular methodology during four annual sessions of fieldwork and analysis in the geographic information system (GIS) laboratory. The results have been: the creation of a spatial data and cartography infrastructure for the Tunisian ‘…

Assessing a computational fluid dynamic technique (CFD) to evaluate pressure losses in drip irrigation laterals

2005

Biocontrol of the Major Plant Pathogen Ralstonia solanacearum in Irrigation Water and Host Plants by Novel Waterborne Lytic Bacteriophages

2019

Three new lytic bacteriophages were found to effectively control the pathogen Ralstonia solanacearum, a quarantine bacterium in many countries, and causative agent of bacterial wilt, one of the most important vascular plant diseases. Bacterial wilt management has been carried out with fluctuating effects, suggesting the need to find alternative treatments. In this work, three lytic phages were isolated from environmental water from geographically distant regions in Spain. They proved to specifically infect a collection of R. solanacearum strains, and some of the closely related pathogenic species Ralstonia pseudosolanacearum, without affecting non-target environmental bacteria, and were abl…

Designing Trickle Irrigation Systems in Sloping Fields without Pressure-Compensating Emitters: Application of the IRRILAB Software

2022

When designing trickle irrigation systems in sloped fields, the use of pressure-compensating (PC) emitters is generally preferred to ensure the emitter distribution uniformity regardless of the land topography and the variable operating pressures. However, the cost of PC emitters is generally higher than non-pressure-compensating (NPC) ones; moreover, the compensating membrane installed inside the emitters can lose elasticity due to the exposition to solar radiation, water quality, and chemical applications. Recently, the irrigation laboratory (IRRILAB) version 1.0 software application was developed to design microirrigation systems for rectangular and planar sectors when using NPC emitters…

Desigualdad social y toma de decisiones en los comunales: El gobierno del mayor canal de riego de España (la Acequia Real del Júcar, Valencia) en el …

2021

espanolHacia 1850 la Acequia Real del Jucar era el mayor sistema comunitario de riego de Espana y se caracterizaba por la fuerte desigualdad social entre los regantes. El articulo analiza los cambios que experimentaron las instituciones para su gobierno en una etapa de profundas transformaciones sociales y politicas en la sociedad espanola, la segunda mitad del siglo XIX. Los organos de gobierno del canal estaban sujetos a una organizacion de tipo jerarquico que comprendia dos grandes niveles: por una parte, estaba la direccion del conjunto del sistema, en la que solo una reducida elite de terratenientes podia intervenir; por otra, habia organos de gestion local que administraban las sucesi…

Maximum and Actual Evapotranspiration for Barley (Hordeum vulgare L.) through NOAA Satellite Images in Castilla-La Mancha, Spain

1996

Abstract An easy-to-follow methodology is developed for the assessment of regional evapotranspiration in Castilla-La Mancha, a semi-arid region of Spain. The methodology is applied to barley crops to monitor the irrigation scheduling over the region, by using remote sensing techniques supplemented by ground measurements. The methodology can be based on either of two models. In the first one, established by Caselles and Delegido, 1 the reference evapotranspiration, ET o , derives from the expression ET o = AR g (T a ) m a x + BR g + C where A, B and C are empirical coefficients, depending on climatic parameters and determined for each region; R g is the daily global radiation; and ( T a ) m …