Search results for " FAO-56"

Using scintillometry to assess reference evapotranspiration methods and their impact on the water balance of olive groves

2016

Abstract Reference evapotranspiration (ET 0 ) is widely used for irrigation scheduling, to promote an efficient use of water resources for a sustainable agro-ecosystem productivity, as well as to manage water quality and to face other environmental concerns. As suggested by ASCE-EWRI and FAO, standard Penman–Monteith methods are generally applied for an accurate estimation of ET 0 from hourly to daily scale. In absence of detailed meteorological information several simplified equations, using a limited number of variables, have been proposed as alternative. In this paper, the performance of different reference evapotranspiration methods, at hourly (Penman–Monteith, Pristley–Taylor, Makkink …

Sviluppi recenti e nuove tecnologie per la stima dei fabbisogni irrigui in ambiente mediterraneo

2008

Gestione dell’irrigazione del vigneto attraverso l’uso di modelli di simulazione e misure di campo.

2008

In the paper the applicability of a numerical model, i.e. SWAP (Soil Water Atmosphere Plant), and a functional model, i.e. FAO 56, for irrigation scheduling is assessed. Model validation was initially carried out through the comparison between simulated and measured water content of a soil profile. The two models were then used in order to verify the possibility to simulate the typical irrigation management of the study area. In particular, the attitude of the two models to simulate the number and the distribution of watering, as well as the seasonal water consumption found in the ordinary management irrigation was assessed. Different scenarios of irrigation management allowed the analysis …

Improvement of FAO-56 Model to Estimate Transpiration Fluxes of Drought Tolerant Crops under Soil Water Deficit: Application for Olive Groves

2014

[EN] Agro-hydrological models are considered an economic and simple tool for quantifying crop water requirements. In the last two decades, agro-hydrological physically based models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere system. Although very reliable, because of the high number of required variables, simplified models have been proposed to quantify crop water consumes. The main aim of this paper is to propose an amendment of the Food and Agricultural Organization (FAO) of the United Nations FAO-56 spreadsheet program to introduce a more realistic shape of the stress function, valid for mature olive orchards (Olea europaea L.). The mod…

Comparison of SWAP and FAO Agro-Hydrological Models to Schedule Irrigation of Wine Grapes

2012

This paper compares two agro-hydrological models that are used to schedule irrigation of a typical Mediterranean crop. In particular, a comparison between the Food and Agriculture Organization (FAO) model, which uses a black box approach, and the soil-water-atmosphere-plant (SWAP) model, which is based on the numerical analysis of Richards' equation, are shown for wine grape. The comparison was carried out for the 2005 and 2006 irrigation seasons and focused on hydrological balance components and on soil water contents. Next, the ordinary scheduling parameters were identified so that the performance of the two models, which aimed to evaluate the seasonal water requirements and the irrigatio…

Misura e Modellazione degli Scambi Idrici nel Sistema Continuo SPA e approfondimenti sulle Funzioni di Stress Idrico: Applicazione alla coltura dell’…

2010

Gli effetti negativi dovuti ai periodi di aridità che caratterizzano i Paesi del bacino del Mediterraneo (Rebetez et al. 2006) determinano nel suolo una ridotta disponibilità di acqua per le piante e quindi l’insorgenza inevitabile di una forma importante di stress abiotico (Nielsen et al., 1996). In particolare, nel bacino del Mediterraneo l'aridità ambientale viene ancor più accentuata da fattori climatici poiché, in corrispondenza del periodo estivo, alle scarse o assenti precipitazioni sono associate elevate temperature che si traducono in un aumento della domanda evapotraspirativa dell’atmosfera. Tali effetti sono più marcati nelle regioni semiaride del bacino del Mediterraneo e più in…