Search results for "IRRIGATION"
showing 10 items of 342 documents
USING ROTATING SPRINKLER GUNS IN CENTRE‐PIVOT IRRIGATION SYSTEMS †
2019
The use of centre-pivot irrigation systems has significantly increased in the last few decades, since they are easier and less time-consuming to manage compared to other irrigation systems. Standard high-pressure impact sprinklers, low-pressure spray sprinklers or LEPA (Low Energy Precision Application) systems are usually combined with a centre-pivot irrigation system (CP-SYS). However, when applying waste water or with reclaimed effluents that are extremely dirty, small nozzle sizes that require CP-SYS could get plugged. As an alternative to common centre-pivot irrigation systems, this paper analyses the ‘geometry’ of areas irrigated by rotating sprinkler guns in a centre-pivot irrigation…
Centre-pivot irrigation system design for uniform water application rate
2020
<p>In the last few decades, the use of centre-pivot irrigation systems has significantly increased, since it makes farming easier, is more efficient and less time-consuming compared to the other irrigation systems. Several studies have been focused on the hydraulics of the centre-pivot systems. Standard high-pressure impact sprinklers or low-pressure spray sprinklers or Low Energy Precision Application (LEPA) systems are generally mounted on the pipeline.</p><p>To ensure the uniformity of water application, the centre-pivot design requires increasing the flow rates along the lateral, because the sprinklers farther from the pivot move faster, and th…
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…
Field non-destructive determination of nectarine quality under deficit irrigation
2021
This study investigated the effects of deficit irrigation (DI) at different fruit growth stages and tree orientation on fruit quality of ‘September Bright’ nectarines (Prunus persica L. Batsch). Control trees were fully irrigated throughout the entire fruit development period, whereas deficit irrigation was supplied at fruit growth stage I (cell division, DI-I), II (pit hardening, DI-II), IIIa (cell expansion, DI-IIIa) and IIIb (fruit maturation, DI-IIIb). Non-destructive measurements of fruit maturity and quality were carried out using portable devices based on near-infrared spectrometry and pigment fluorescence on west- and east-oriented trees of an Open Tatura system. Chlorophyll degrada…
A randomized controlled trial of endodontic treatment using ultrasonic irrigation and laser activated irrigation to evaluate healing in chronic apica…
2019
Background Aim of this trial was to evaluate the combined clinical and radiographic success rate of endodontic treatment using passive ultrasonic irrigation (PUI) and laser activated irrigation (LAI) as compared to conventional syringe irrigation. Material and methods Permanent incisors and single rooted premolars were assessed for eligibility and 69 patients were randomly divided into three treatment groups (n=23) by allocation concealment method and irrigation was performed in accordance with the allocated group. Teeth were evaluated clinically and radiographically with CBCT after 6 months and 12 months of the treatment. Results A significant difference was observed in the radiographic he…
Recurrent deficit irrigation and fruit harvest affect tree water relations and fruitlet growth in ‘valencia’ orange
2019
Background – Partial rootzone drying is an irrigation strategy known for increasing water use efficiency without significantly affecting tree water status. ‘Valencia’ oranges have a very long development period and nearly mature fruit and new fruitlets may be present at the same time on the tree, competing for water and assimilates. Objectives – The present study investigates the effect of recurrent deficit irrigation and fruit harvest on tree water status and fruitlet growth of ‘Valencia’ orange. Methods – Forty-eight adult trees were exposed to three irrigation treatments for seven years (2007–2013): irrigation with 100% of ETc (CI), continuous deficit irrigation (DI, 50% of CI) and parti…
Measuring water-use in response to climate change: an analysis of the efficiency of Italian crop production system
2017
Official meteo-climatic statistics show the variability of weather conditions. Their effects on socioeconomic and natural environments should be analyzed in multi-dimensional studies. Among sectors, agriculture is expected to be the most sensitive as well as water resources availability. The aim of our analysis is to measure the performance of Italian regions in crop production by estimating both production technology - including a measure of irrigation water used as input - output elasticities and returns to scale and productive efficiency or technical efficiency where rainfalls and temperatures are proxies of CC conditions in the period 2000-2010 at Italian regional level, using the stoch…
The Economic Impact of Restricted Water Supply: a Computable General Equilibrium Analysis
2007
Water problems are typically studied at the level of the river catchment. About 70% of all water is used for agriculture, and agricultural products are traded internationally. A full understanding of water use is impossible without understanding the international market for food and related products, such as textiles. The water embedded in commodities is called virtual water. Based on a general equilibrium model, we offer a method for investigating the role of water resources and water scarcity in the context of international trade. We run five alternative scenarios, analyzing the effects of water scarcity due to reduced availability of groundwater. This can be a consequence of physical con…
Current anthropogenic pressures on agro-ecological protected coastal wetlands
2015
Coastal wetlands are areas that suffer from great pressure. Much of it is due to the rapid development of the surrounding artificial landscapes, where socio-economic factors lead to alterations in the nearby environment, affecting the quality of natural and agricultural systems. This work analyses interconnections among landscapes under the hypothesis that urban-artificial impacts could be detected on soils and waters of an agro-ecological protected area, L'Albufera de Valencia Natural Park, located in the vicinity of the City of Valencia, Spain. The methodological framework developed addresses two types of anthropogenic pressure: (1) direct, due to artificialisation of soil covers that cau…
EVASPA (EVapotranspiration Assessment from SPAce) tool: an overview
2013
International audience; Evapotranspiration (ET) is a fundamental variable of the hydrological cycle and its estimation is required for irrigation management, water resources planning and environmental studies. Remote sensing provides spatially distributed cost-effective information for ET maps production at regional scale. We have developed EVASPA too for mapping ET from remote sensing data at spatial and temporal scales relevant to hydrological or agronomica studies. EVASPA includes several algorithms for estimating evapotranspiration and various equations for estimating the required input information (net radiation, ground heat flux, evaporative fraction…), which provides a way to assess …