Search results for " deficit irrigation"
showing 10 items of 13 documents
Agro-hydrological models and field measurements to assess the water status of a citrus orchard irrigated with micro-sprinkler and subsurface drip sys…
2021
Compared to the micro-sprinkler irrigation, traditionally used in citrus orchards, subsurface drip systems (SDS) allow increasing the water use efficiency (WUE); when coupled with water-saving strategies, like regulated deficit irrigation (RDI), further increase of WUE are possible. Combining measurements of soil water content (SWC) and weather data with measurements of midday stem water potential (MSWP) makes it possible to identify irrigation scheduling parameters for the RDI. However, measurements of MSWP are destructive and time-consuming, and also require skilled operators. For all these reasons, the use of the agro-hydrological models, such as the FAO-56 model, can be considered a sur…
Fruit yield and quality responses of apple cvars Gala and Fuji to partial rootzone drying under Mediterranean conditions
2012
SUMMARYIncreasing irrigation efficiency is a major goal for fruit production in dry Mediterranean environments. The present study was conducted in three consecutive years (2007–09) under typical Mediterranean conditions and tested the effect of partial rootzone drying (PRD) on yield and fruit quality of two apple cultivars: Gala, with fruit maturing in summer and Fuji, with fruit maturing in autumn. Three irrigation treatments were imposed: conventional irrigation (CI), PRD (0·50 of CI water on one side of the rootzone, which was alternated periodically) and continuous deficit irrigation (DI, 0·50 of CI water on both sides of the rootzone). During the 2008 and 2009 irrigation seasons, DI re…
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
Verifica dell’applicabilità del metodo irriguo sub-superficiale su colture agrumicole e ottimizzazione dell’uso della risorsa idrica
2020
Gli impianti di subirrigazione (SDI), in relazione alla posizione interrata dei gocciolatori permettono la riduzione dei consumi irrigui, garantendo la possibilità di utilizzo di risorse altrimenti non utilizzabili. Tuttavia, i costi di investimento iniziali risultano maggiori di quelli relativi ai tradizionali impianti di microirrigazione e pertanto, diventano economicamente vantaggiosi, se l'efficienza del sistema viene garantita per periodi di almeno 15-20 anni. La SDI, inoltre, permette di ottenere valori elevati di efficienza d’uso dell’acqua, spesso superiori al 90%, se associata ad un monitoraggio continuo dello stato idrico del suolo e della pianta e ad una corretta stima delle esig…
Relationship between tree water status and physiology, yield, and fruit quality in the table olive (Olea europaea sativa L.) cultivar ‘Nocellara del …
2012
Although the olive (Olea europaea sativa l.) is considered a xerophytic species, long periods of water stress and high temperatures during summer months can greatly affect plant physiology and productivity. In recent years, the use of plant-based water status indicators have become popular in the study of plant-water relationships and in the design of irrigation programs, particularly midday stem water potential (ψstem). The current trend in the irrigation of olive trees is in the development of Deficit Irrigation (DI) systems whereby the water is applied at a rate which is lower than evapotranspiration needs, resulting in only very small reductions in yield. Rather than working towards min…
Effects of partial rootzone drying and rootstock vigour on dry matter partitioning of apple trees (Malus domesticacvar Pink Lady)
2011
SUMMARYThe effects of partial rootzone drying (PRD) and rootstock vigour on dry matter accumulation and partitioning among leaves, shoots, fruits, frame and roots of apple trees (Malus domesticaBorkh. cvar Pink Lady) were investigated in 2005 near Caltavuturo, in Sicily. In a first field trial, trees on MM.106 rootstock were subjected to: conventional irrigation (CI), maintaining soil moisture above 0·80 of field capacity; PRD irrigation, where alternating sides of the rootzone received 0·50 of the CI irrigation water; and continuous deficit irrigation (DI), where 0·50 of the CI water was equally applied to both sides of the rootzone. In a second trial, trees on M.9 or MM.106 were subjected…
Effects of irrigation treatments on the quality of table olives produced with the Greek-style process
2016
The irrigation of olive orchards is commonly applied to produce table olives with optimal size. No data have been published on the microbiological quality of drupes from irrigated olive groves during fermentation. The trials T100 and T50 (receiving a water amount equivalent to 100 % and 50 % of the required amount, respectively) and control T0 (rainfed trial) were monitored during two consecutive years. The results showed a significant increase of equatorial diameter and flesh:pit ratio of irrigated drupes. The decrease of pH and the numbers of lactic acid bacteria (LAB) registered for the irrigated trials during the fermentation were more consistent than those displayed by control T0. Lact…
Assessing Hydrus-2D model to investigate the effects of different on-farm irrigation strategies on potato crop under subsurface drip irrigation
2019
The objective of this paper was to assess the performance of Hydrus-2D model to simulate the effects of different on-farm irrigation strategies applied on potato crop. The ability of the model to simulate the stress coefficient (Ks), obtained as the ratio between actual and maximum transpiration, and to define the productive function of potato crop under the semi-arid conditions of central Tunisia were also evaluated. Experiments were carried out on potato crop under full (FI) and deficit irrigation (DI) and two different water qualities supplied by means of a subsurface drip irrigation system. Results evidenced that the model, despite some discrepancies locally observed, can fairly accurat…
Implementing a cyber-physical system to monitor soil water status and environmental variables for irrigation scheduling
2018
The most advanced research on irrigation at farm scale, following the paradigm “more crop per drop”, has been aimed at the definition of strategies of precision irrigation, in order to optimize crop water productivity and to maximize the economic benefits without affecting environmental quality.Water saving management strategies, such as regulated deficit irrigation (RDI), can be effectively applied if supported by the real time control of soil/plant water status allowing the identification of appropriate irrigation scheduling parameters (irrigation timing and doses). This challenge can be achieved by integrating sensing technologies, internet of things and cloud computing supported with co…
Subsurface Drip Irrigation and ICT for the Innovative Irrigation Water Management: Application to a Citrus Crop (C. reticulata cv. Tardivo di Ciacull…
2020
Subsurface drip irrigation (SDI) is considered one of the most efficient irrigation systems because it allows the optimization of crop water productivity maximizing, at the same time, farmers’ economic benefit. However, to take full advantage of SDI systems it is necessary to prevent emitter obstructions caused by root intrusion, as well as to apply water-saving strategies, such as regulated deficit irrigation (RDI). Regarding the first aspect, manufacturers are claiming different techniques to protect emitters from root intrusion, such as mechanical barriers, addition with different chemical compounds into the emitter itself or chemicals into irrigation water. On the other hand, the applic…