Search results for "IRRIGATION"
showing 10 items of 342 documents
The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…
2017
Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …
Evaluation of subsurface drip irrigation emitters on a split-root container-grown citrus rootstock (citrange ‘Ccarrizo’)
2022
Among irrigation systems, subsurface drip irrigation allows obtaining values of water use efficiency higher than 90%. However, when emitters are installed below the soil surface, root intrusion can represent the main cause of emitter occlusion. To prevent this phenomenon, manufacturers normally include herbicides in the plastic matrix of the emitters. Objectives of this paper were: i) to evaluate the effectiveness of alternative anti-root agents embedded in the same emitter model and ii) to identify their possible effects on the growth of a commonly adopted citrus rootstock (citrange ‘Carrizo’). Five different anti-root agents were tested in 8 lined trees, planted in split-root containers i…
Responses of apple to partial root-zone drying. A review.
2013
Partial root-zone drying (PRD) is a relatively recent strategy aiming at substantial reduction of irrigation volume. It consists of the alternate irrigation of one portion of the root-zone with volumes reduced to about 40-50% of conventional water. PRD is based on the ability of roots in drying soil to produce hormonal signals, like abscissic acid (ABA), responsible for partial stomatal closure. In turn, partial stomatal closure would improve water use efficiency and increase fruit yield per unit of irrigation water. This technique has been tested on a number of fruit crops, including apple. In addition to climatic conditions, which mainly affect atmospheric water demand, soil properties an…
CO2 FLUXES OF OPUNTIA FICUS-INDICA MILL. TREES IN RELATION TO WATER STATUS
2013
Gas exchange pattern in O. ficus-indica(OFI), refers to the Crassulacean Acid Metabolism (CAM); trees have nocturnal stomata opening, so net CO2 uptake and water loss occur during the cooler part ofthe 24-hour cycle. Succulent cladodes skip severe periods of drought through their water storer tissue (parenchyma). To study carbon fluxes in stress and no stress conditions, an experiment was carried out on 3-year-old irrigated and non-irrigated OFI potted trees; whole tree gas exchange was measured continuously with a balloon system made up by a portable Infrared Gas Analyzer. Continuous measurements(nighttime) during the summer season were useful to assess differences in carbon uptake under s…
Continuous detection of new plant water status indicators in stage I of nectarine fruit growth
2019
Conventional irrigation management is often inefficient in responding to seasonal changes of tree water needs. The use of leaf- and fruit-based sensors might provide helpful insights on tree water status, although they have been poorly investigated so far. Fruit gauges and leaf patch clamp pressure (LPCP) probes were tested during stage I of nectarine fruit growth to evaluate if leaf turgor pressure and fruit size may serve as indicators of water deficit. This experiment was carried out in the 2017/18 season. Four irrigation levels were applied to ‘September Bright’ nectarine trees (100, 40, 20 and 0% of crop evapotranspiration, ETc) and data were collected during stage I of fruit growth. T…
Vegetative and Reproductive Behaviour of Vitis vinifera L. (cv. ‘Cabernet Sauvignon’) Vines Growing Under Non-Irrigated Conditions and Moderate Water…
2007
An experiment was carried out to evaluate the effect of different levels of water stress and different irrigation systems to the vegetative and reproductive behaviour of Cabernet Sauvignon ines/140Ru, vertically trained, during the growing season 2003-2004. The vineyard was located in Sicily (in the south of Italy); the soil was loamy-sand and the climate semi-arid. Were compared five treatments: four treatments irrigated, maintaining a moderate water stress level, by drip irrigation (T1) and sub-irrigation (T2, T3 and T4) and one treatment non-irrigated (T5). The sub-irrigation treatments were different by the number and the distance of the water tubes by the rows of vines. The results sho…
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…
Using Hydrus 2-D to assess the emitters optimal position for Eggplants under surface and subsurface drip irrigation
2014
The main objective of the work is to assess the emitters optimal position for Eggplant crop (Solanum melongena L.) in a sandy loam soil irrigated with surface or subsurface drip irrigation systems, by means of field measurements and simulations carried out with Hydrus-2D model. Initially, the performance of the model is evaluated on the basis of the comparison between simulated soil water contents (SWC) and the corresponding measured in two plots, in which laterals with coextruded emitters are laid on the soil surface (T0) and at 20 cm depth (T20), respectively. In order to choose the best position of the lateral, the results of different simulation runs, carried out by changing the install…
Diurnal irrigation timing affects fruit growth in late-ripening nectarines
2021
Little is known about the best diurnal irrigation timing for maximum fruit growth in stone fruit, despite fruit size being the most important focus for growers to achieve maximum marketable yield. This study investigated the effects of morning and afternoon irrigation on nectarine fruit growth in stage I (cell division) and stage III (cell expansion). In the 2017/18 season, ‘September Bright’ trees were subjected to morning (Iam) and afternoon (Ipm) irrigations. Fruit diameter was monitored continuously (15-min intervals) using fruit gauges and converted into fruit weight, relative growth rate (RGR) and fruit growth efficiency (FGE), with the latter representing RGR per unit of crop water s…
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…