Search results for " irrigation system"

Effects of irrigation on fruit ripening behavior and metabolic changes in olive

2012

Olive (Olea europaea, cv Leccino) fruits grown under different water regimes were analyzed by metabolomics and specific transcript accumulation analyses. The fruit from non-irrigated (rain-fed) and irrigated trees cultivated under field conditions, with a seasonal water amount equivalent to the calculated crop evapotranspiration (ETc) was compared in the last developmental phase and, in particular, at commercial harvest. Metabolomics (GC-MS) analysis identified several hundred metabolites in ripe mesocarp, 46 of which showed significantly different contents in the rain-fed and irrigated samples. Some compounds involved in primary metabolism (carbohydrates, amino acids, organic acids) and se…

A distributed agro-hydrological model for irrigation water demand assessment

2008

Abstract The actual irrigation water demand in a district in Sicily (Italy) was assessed by the spatially distributed agro-hydrological model SIMODIS (SImulation and Management of On-Demand Irrigation Systems) . For each element with homogeneous crop and soil conditions, in which the considered area can be divided, the model numerically solves the one-dimensional water flow equation with vegetation parameters derived from Earth Observation data. In SIMODIS, the irrigation scheduling is set by means of two parameters: the threshold value of soil water pressure head in the root zone, h m , and the fraction of soil water deficit to be re-filled, Δ . This study investigated the possibility of i…

Closed-form solutions of the energy balance equation for drip laterals under the Darcy-Weisbach resistance formula

2018

Many studies have investigated easy methods to design drip laterals, as well as the best resistance equation to use, which is fundamental to accurately account for friction losses. This paper addresses both the features of lateral design relationships and the influence of the friction-loss equation on the design variables. First, simple closed-form solutions of the energy balance equation for both sloped and horizontal drip laterals are derived with the simplified Darcy-Weisbach resistance formula by assuming the Darcy friction factor as invariant versus the Reynolds number. Second, an error analysis is performed assuming the friction factor as constant in the design, which is compared to u…

Closure to “Experimental Analysis of Local Pressure Losses for Microirrigation Laterals” by Giuseppe Provenzano and Domenico Pumo

2006

Prospective use of collected fog water in the restoration of degraded burned areas under dry Mediterranean conditions

2009

Abstract A mountainous plot located in the interior of the Valencia region (east coast of the Iberian Peninsula) was identified for reforestation using the fog-water collection potential prevailing in the area. Fog data were obtained by means of an instrument ensemble consisting of a passive cylindrical fog-water collector, a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Preliminary results gave rise to the additional deployment of a low-cost 18-m 2 flat-panel collector connected to three 1000-l tanks for larger scale fog-water collection and storage. The 2007 annual rate of fog water that could be derived from the instrument ensemble amounted to 3.3…

Metabolic profiling of ripe olive fruit in response to moderate water stress

2013

a b s t r a c t The concentrations of different metabolites in olive (Olea europaea (L.)) fruit at harvest can be affected by water availability, with significant consequences on the composition and the quality of the resulting oil. The aim of the present study was to profile the metabolic composition of ripe olives (cv. Cipressino) grown under water-stress and irrigated conditions applied during the last part of the fruit developmental cycle (from pit hardening to commercial harvest). The imposed conditions resulted in a moderate water stress (−3.5 MPa) at the end of the experimental period. Samples (pulp + skin) of fruit collected at the stage of complete epicarp pigmentation were analyze…

Analytical Approach Determining the Optimal Length of Paired Drip Laterals in Uniformly Sloped Fields

2015

Microirrigation plants, if properly designed, allow for water use efficiency to be optimized and high values of emission uniformity to be obtained in the field. Disposing paired laterals, for which two distribution pipes extend in opposite directions from a common manifold, can contribute to reducing the initial investment cost that represents a limiting factor for small-scale farmers of developing countries where in the last decade, the diffusion of such irrigation systems has been increasing. The objective of this paper is to propose an analytical approach to evaluate the maximum lengths of paired drip laterals for any uniform ground slope, respecting the criteria to maintain emitter flow…

Experimental Analysis of Local Pressure Losses for Microirrigation Laterals

2004

The accurate design of drip irrigation laterals needs to consider the variation of hydraulic head due to pipe elevation changes, head losses along the lines, and also, at a given operating pressure, emitter discharge variations related to manufacturing variability, clogging, and water temperature. Hydraulic head variations are consequent to both the friction losses and local losses due to the in-line or on-line emitters along the pipe, which determine the contraction and subsequent enlargement of the flow streamlines. Moreover, in-line emitters usually have a smaller diameter than the pipe, and therefore an additional friction loss must be considered. Evaluation of energy losses and consequ…

DIVERSITÀ BIOCULTURALE DI ALCUNI PAESAGGI MEDITERRANEI DI MONTAGNA

2016

The work presents a biocultural diversity interpretation of traditional Mediterranean agricultural landscapes. These landscapes are the result of complex interactions between biodiversity (at all levels, including species richness, ecosystem and biotope diversity) and cultural diversity, including material and immaterial aspects (architectural heritage, traditions, customs, local traditional agricultural practices, dialectal culture, etc.). The main theme is the traditional use of water related to traditional hydraulic systems, which in some areas date back to medieval times. Traditional agricultural landscapes grant a variety of ecosystem services and play a key role in biodiversity conser…

BioCultural Landscapes per la rigenerazione innovativa dei territori di montagna

2017

Simplification of agricultural systems, farmland abandonment, uncontrolled urbanization, together with global scale drivers, determine fast and unpredictable phenomena of hydrogeological instability, biodiversity decline and identity loss. Men should hence promote socio-economic resilience and place identity, using biocultural landscapes as a resource. These landscapes are the outcome of the historical relationship between man and nature, resulting from complex interactions between biodiversity (at all levels, including species richness, ecosystem and biotope diversity) and cultural diversity, including material and immaterial aspects (architectural heritage, traditions, customs, local trad…