Home About us Contact
|
Home About us Contact | ||
|
|
||
Irrigation
Kinds of Irrigation Terms modified by Irrigation Selected AbstractsEVIDENCE-BASED EFFICACY OF OZONE FOR ROOT CANAL IRRIGATIONJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2008BDentSc, Edward Lynch MA, FDSRCS Ed, FDSRCS Lond Guest Expert, PhD Lond [source] Controls on Ground Water Chemistry in the Central Couloir Sud Rifain, MoroccoGROUND WATER, Issue 2 2010Lahcen Benaabidate Irrigation, urbanization, and drought pose challenges for the sustainable use of ground water in the central Couloir sud rifain, a major agricultural region in north-central Morocco, which includes the cities of Fès and Meknès. The central Couloir is underlain by unconfined and confined carbonate aquifers that have suffered declines in hydraulic head and reductions in spring flow in recent decades. Previous studies have surveyed ground water flow and water quality in wells and springs but have not comprehensively addressed the chemistry of the regional aquifer system. Using graphical techniques and saturation index calculations, we infer that major ion chemistry is controlled (1) in the surficial aquifer by cation exchange, calcite dissolution, mixing with deep ground water, and possibly calcite precipitation and (2) in the confined aquifer and warm springs by calcite dissolution, dolomite dissolution, mixing with water that has dissolved gypsum and halite, and calcite precipitation. Analyses of 2H and 18O indicate that shallow ground water is affected by evaporation during recharge (either of infiltrating precipitation or return flow), whereas deep ground water is sustained by meteoric recharge with little evaporation. Mechanisms of recharge and hydrochemical evolution are broadly consistent with those delineated for similar regional aquifer systems elsewhere in Morocco and in southern Spain. [source] SEM evaluation of root canal debridement with Sonicare CanalBrush irrigationINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2010M. I. Salman Salman MI, Baumann MA, Hellmich M, Roggendorf MJ, Termaat S. SEM evaluation of root canal debridement with Sonicare CanalBrush irrigation. International Endodontic Journal, 43, 363,369, 2010. Abstract Aim, To determine the efficacy of Sonicare CanalBrush irrigation for root canal cleaning. Methodology, Fifty human molar root canals were shaped with sequential NiTi rotary instruments up to size F3 (size 30, 0.09 taper; ProTaper system) and then enlarged apically with a Profile size 40, 0.04 taper. Five different irrigation protocols were tested (n = 10 canals per group) with 2 mL of distilled water (control, group I) or 2.5% NaOCl (control group II and test groups III, IV and V) between instrument size changes. Group III,IV received a final rinse with 17% EDTA for one min. This was extended by 30 s in group IV, whereas group V received this additional 30 s of 17% EDTA sonically dispersed with a Sonicare CanalBrush. For cleanliness evaluations, roots were split longitudinally, examined with scanning electron microscopy and scored according to Hülsmann et al. (1997) for debris and smear layer on the surface of the root canal wall. Walls were assessed at the coronal, middle and apical thirds. Data were analysed with the Kruskal,Wallis and Mann,Whitney tests. Results, Irrigation with 17% EDTA significantly reduced debris and smear layer scores (P < 0.05) compared to controls. The coronal and middle thirds had lower debris and smear layer scores than the apical third (P < 0.05). In all thirds, sonic agitation of the irrigant with a CanalBrush (group V) resulted in significantly cleaner canal walls compared to all other groups (P < 0.05). Conclusions, Irrigation by agitation with the Sonicare CanalBrush improved root canal debridement in the coronal, middle and particularly the apical thirds of the root canal. [source] The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTAINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2010O. E. Sobhani Sobhani OE, Gulabivala K, Knowles JC, Ng Y-L. The effect of irrigation time, root morphology and dentine thickness on tooth surface strain when using 5% sodium hypochlorite and 17% EDTA. International Endodontic Journal, 43, 190,199, 2010. Abstract Aim, To evaluate the effect of irrigation with 5% sodium hypochlorite (NaOCl) alone and in conjunction with 17% ethylenediaminetetraacetic acid (EDTA) on tooth surface strain (TSS) and to analyse the influence of irrigation time, root morphology and dentine thickness. Methodology, Thirty-six single-rooted pre-molars with single canals had their crown and enamel reduced and root canals prepared using a standardized protocol. Teeth were grouped according to anatomical criteria and randomly distributed to experimental irrigation groups: (A) saline (negative control); (B) 5% NaOCl (positive control); (C) 5% NaOCl alternated with 17% EDTA. TSS was measured using electrical strain gauges bonded to the cervico-proximal part of the tooth. Teeth, mounted in clear acrylic resin placed in a universal testing machine, were subjected to nine consecutive 10-min irrigation periods followed by non-destructive occlusal loading to record TSS. Statistical analysis was carried out using two-way hierarchical anova and post hoc multiple comparisons. Results, Two groups showed an increase in TSS from the baseline (initial 10-min irrigation with saline). Group A showed a negligible reduction of 1.2% (343,339 ,,), which was not statistically significant (P = 0.7). Group B showed a highly significant (P = 0.001) increase in TSS by 53.7% (178,253 ,,), and group C showed a significant (P = 0.02) increase in TSS by 17.4% (163,192 ,,). The rate of change in TSS was significantly different between test groups. The length of the tooth (P = 0.04) as well as the mesio-distal (P = 0.05) width had significant effects on TSS. Conclusions, Irrigation with 5% with or without 17% EDTA increased TSS. The increase was significantly greater with 5% NaOCl alone than with 5% NaOCl alternated with 17% EDTA in contrast to previous findings with longer duration of irrigant exposure. Tooth length and mesio-distal root width significantly contributed to the increase in TSS. [source] Effectiveness in cleaning oval-shaped root canals using Anatomic Endodontic Technology, ProFile and manual instrumentation: a scanning electron microscopic studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2005O. Zmener Abstract Aim, To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation. Methodology, Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at ×200 and ×400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 ,m square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal,Wallis nonparametric anova and Dunn's tests. Results, At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups. Conclusions, Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated. [source] Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2000A. M. Solovyeva Abstract Aim The aim of this study was to evaluate the potential of electrochemically activated (ECA) anolyte and catholyte solutions to clean root canals during conventional root canal preparation. Methodology Twenty extracted single-rooted human mature permanent teeth were allocated randomly into four groups of five teeth. The pulp chambers were accessed and the canals prepared by hand with conventional stainless steel endodontic instruments using a double-flared technique. One or other of the following irrigants was used during preparation: distilled water, 3% NaOCl, anolyte neutral cathodic (ANC) (300 mg L,1 of active chlorine), and a combination of anolyte neutral cathodic (ANC) (300 mg L,1 of active chlorine) and catholyte. The teeth were split longitudinally and the canal walls examined for debris and smear layer by scanning electron microscopy. SEM photomicrographs were taken separately in the coronal, middle and apical parts of canal at magnification of ×800 to evaluate the debridement of extra-cellular matrix and at a magnification of ×2500 to evaluate the presence of smear layer. Results Irrigation with distilled water did not remove debris in the apical part of canals and left a continuous and firm smear layer overlying compressed low-mineralized predentine. All chemically active irrigants demonstrated improved cleaning potential compared to distilled water. The quality of loose debris elimination was similar for NaOCl and the anolyte ANC solution. The combination of anolyte ANC and catholyte resulted in improved cleaning, particularly in the apical third of canals. The evaluation of smear layer demonstrated that none of the irrigants were effective in its total removal; however, chemically active irrigants affected its surface and thickness. Compared to NaOCl, the ECA solutions left a thinner smear layer with a smoother and more even surface. NaOCl enhanced the opening of tubules predominantly in the coronal and middle thirds of canals, whereas combination of ANC and catholyte resulted in more numerous open dentine tubules throughout the whole length of canals. Conclusions Irrigation with electrochemically activated solutions cleaned root canal walls and may be an alternative to NaOCl in conventional root canal treatment. Further investigation of ECA solutions for root canal irrigation is warranted. [source] Upscaling water savings from farm to irrigation system level using GIS-based agro-hydrological modelling,IRRIGATION AND DRAINAGE, Issue 1 2007Shahbaz Khan simulation d'irrigation; extrapolation; efficacité d'utilisation de l'eau; économie de l'eau Abstract Irrigation continues to be the main water user on a global scale despite the increase in water use by sectors other than agriculture. More efficient water application technologies and water management practices are ways of realising potential water savings, thus moderating the negative impacts of higher water use on farm incomes and environmental impact on rivers and groundwater systems. This paper describes an integrated approach of agro-hydrological modelling for determining potential water savings achievable by adopting high-tech irrigation technologies at farm level and application of GIS techniques to upscale those benefits at the regional irrigation system level. The SWAP (Soil,Water,Atmosphere,Plant) model was used for the simulation of water use at the farm level. The results are promising, as the potential water saving ranges from 0.1 to 2.2,ML,ha,1 (10,220,mm) for different broad-acre crops, 1.0 to 2.0,ML,ha,1 (100,200,mm) in sprinkler and 2.0 to 3.0,ML,ha,1 (200,300,mm) in drip irrigation for citrus, 1.0 to 1.5,ML,ha,1 (100,150,mm) in sprinkler and up to 4.0,ML,ha,1 (400,mm) in drip irrigation for vineyards and 0.5 to 1.0,ML,ha,1 for vegetables (50,100,mm). SWAP simulations show crop water saving potential of 7% for maize, 15% for soybean, 17% for wheat, 35% for barley, 17% for sunflower and 38% for fababean from the current water use statistics in Australia. Spatial analysis in GIS environment is carried out to investigate the spatial variations of water use for a particular crop under different depths to water table and varying soil types. Maps of water need for all broad-acre crops are drawn and pixel-to-pixel comparison is performed to determine the water saving potential per unit area. The upscaling approach shows that considerable water amounts could be saved both in Murrumbidgee Irrigation Area (MIA) and Coleambally Irrigation Area (CIA) with potential water saving of 36 to 95,GL (MCM) in MIA and 42 to 72,GL (MCM) in CIA. Copyright © 2007 John Wiley & Sons, Ltd. L'irrigation reste l'usage principal de l'eau à l'échelle mondiale en dépit de l'augmentation des volumes utilisés par les secteurs autres que l'agriculture. L'amélioration des techniques d'irrigation et des procédures de gestion de l'eau permet de réaliser des économies d'eau potentielles, modérant ainsi les impacts négatifs d'une surconsommation d'eau sur les revenus agricoles et ses incidences sur l'environnement des cours d'eau et des aquifères. Cet article décrit comment un modèle agro-hydrologique intégré peut déterminer les économies d'eau réalisables grâce à l'adoption de technologies de pointe dans l'irrigation au niveau de l'exploitation agricole et à l'application des techniques de SIG à l'extension de ces avantages au niveau d'un système régional d'irrigation. Le modèle SWAP (Sol-Eau-Atmosphère-Plante) a été employé pour simuler l'utilisation de l'eau au niveau de l'exploitation. Les résultats sont prometteurs car l'économie d'eau potentielle va de 100 à 2 200 m3/ha (10 à 220 millimètres) pour différentes cultures de plein champ, de 1 000 à 2 000 m3/ha (100 à 200 millimètres) en aspersion et de 2 000 à 3 000 m3/ha (200 à 300 millimètres) en goutte à goutte sur des citronniers, de 1 000 à 1 500 m3/ha (100 à 150 millimètres) en aspersion et jusqu'à 4 000 m3/ha (400 millimètres) en goutte à goutte sur de la vigne, et de 500 à 1 000 m3/ha pour des légumes (50 à 100 millimètres). Les simulations de SWAP à partir de données statistiques australiennes courantes montrent un potentiel d'économie d'eau de 7% pour le maïs, 15% pour le soja, 17% pour le blé, 35% pour l'orge, 17% pour le tournesol et 38% pour les fèves. Une analyse par SIG permet d'étudier les variations spatiales de l'utilisation de l'eau pour une récolte particulière selon la profondeur de la nappe et le type de sol. Les besoins en eau de toutes les cultures de plein champ sont cartographiés et le potentiel d'économie d'eau par unité de surface est estimé pixel par pixel. L'extrapolation des résultats montre que des volumes d'eau considérables pourraient être économisés dans les zones irriguées de Murrumbidgee (MIA, économie potentielle de 36 à 95 millions de m3) et de Coleambally (CIA, économie potentielle de 42 à 72 m3). Copyright © 2007 John Wiley & Sons, Ltd. [source] The systematic approach to flooding problems,IRRIGATION AND DRAINAGE, Issue S1 2006J. (Hans) van Duivendijk maîtrise des crues; mesures non-structurelles; gestion des inondations Abstract Since 1987 one of the working groups of the International Commission on Irrigation and Drainage (ICID) has, inter alia, been preparing two manuals concerning approaches to flooding problems. The Manual on Non-Structural Approaches to Flood Management was issued in 1999 while the Manual on the Planning of Structural Approaches to Flood Management has been issued recently (2005). In this paper a broad outline of both manuals is presented. The first manual describes in detail the various planning and response measures in flood management, which are known as non-structural measures. The latter are measures which alter the exposure of life and property to flooding but do not change the flood(ing) phenomenon as such. The said planning and response measures comprise such actions as floodplain land use management, flood forecasting and warning, flood fighting, flood proofing, etc. It is explained that such measures are sometimes the only ones feasible in the prevailing circumstances and that, moreover, non-structural measures should always be added to the so-called structural measures if the latter are considered feasible (i.e. feasible from a technical, economic, socio-economic and ecological point of view). In the second manual a methodology is presented for the planning of structural measures. This type of measure alters the physical characteristics of the floods and in this connection one must think of the operation of flood storage reservoirs, upstream catchment management, modification to river channels, construction of levees, special flood diversion channels (bypasses) and operation of hydraulics works. The idea behind this methodology is that it is difficult for planners and decision makers to select the appropriate flood protection system for a given situation including a range of possible floods if the problem is not approached in a systematic manner. Copyright © 2006 John Wiley & Sons, Ltd. Depuis 1987 un des groupes de travail de la CIID prépare, entre autres, deux manuels sur la manière d'approcher les problèmes d'inondation. Le ,Manuel d'approche non-structurelle de la gestion des crues' a été publié en 1999, tandis que le ,Manuel de la planification de l'approche structurelle de la gestion des crues' a été publié plus récemment (2005). Le présent article présente une vue d'ensemble de ces deux manuels. Le premier manuel donne une description détaillée des différentes mesures de préparation et de réponse à la gestion des crues, connues comme étant non-structurelles. Ces mesures changent l'exposition de la vie et des propriétés aux inondations mais ne modifient pas le phénomène proprement dit des crues et des inondations. Elles comprennent des actions telles que la gestion de l'espace dans les plaines d'inondations, les prévisions et alertes, la lutte contre les crues, la protection contre les inondations, etc. On y explique que ces mesures sont parfois les seules faisables dans les circonstances données et que, en outre, des mesures non-structurelles devraient toujours être ajoutées aux mesures dites structurelles si ces dernières sont considérées comme faisables (c'est-à-dire faisables d'un point de vue technique, économique, socio-économique et écologique). Dans le second manuel une méthodologie est présentée pour la planification des mesures structurelles. Ce type de mesures modifie les caractéristiques physiques des crues, comme par exemple réservoirs d'écrétage de crue, gestion des hauts bassins, modification des lits des fleuves, construction de digues, canaux spéciaux de déviation des crues (courts circuits) et fonctionnement d'ouvrages hydrauliques. L'idée qui est derrière cette méthodologie est qu'il est difficile aux planificateurs et aux décideurs de choisir le système de protection contre les crues correspondant exactement à une situation comprenant une large gamme d'inondations possibles si le problème n'est pas approché de manière systématique. Copyright © 2006 John Wiley & Sons, Ltd. [source] Irrigation and drainage systems research and development in the 21st century,IRRIGATION AND DRAINAGE, Issue 4 2002Bart Schultz irrigation; drainage; développement durable; système de réseau Abstract One critical problem confronting mankind today is how to manage the intensifying competition for water between expanding urban centres, traditional agricultural activities and in-stream water uses dictated by environmental concerns. In the agricultural sector, the dwindling number of economically attractive sites for large-scale irrigation and drainage projects limits the prospects of increasing the gross cultivated area. Therefore, the required increase in agricultural production will necessarily rely largely on a more accurate estimation of crop water requirements on the one hand, and on major improvements in the construction, operation, management and performance of existing irrigation and drainage systems, on the other. The failings of present systems and the inability to sustainably exploit surface and groundwater resources can be attributed essentially to poor planning, design, system management and development. This is partly due to the inability of engineers, planners and managers to adequately quantify the effects of irrigation and drainage projects on water resources and to use these effects as guidelines for improving technology, design and management. To take full advantage of investments in agriculture, a major effort is required to modernize irrigation and drainage systems and to further develop appropriate management strategies compatible with the financial and socio-economic trends, and the environment. This calls for a holistic approach to irrigation and drainage management and monitoring so as to increase food production, conserve water, prevent soil salinization and waterlogging, and to protect the environment. All this requires, among others, enhanced research and a variety of tools such as water control and regulation equipment, remote sensing, geographic information systems, decision support systems and models, as well as field survey and evaluation techniques. To tackle this challenge, we need to focus on the following issues: affordability with respect to the application of new technologies; procedures for integrated planning and management of irrigation and drainage systems; analysis to identify causes and effects constraining irrigation and drainage system performance; evapotranspiration and related calculation methods; estimation of crop water requirements; technologies for the design, construction and modernization of irrigation and drainage systems; strategies to improve irrigation and drainage system efficiency; environmental impacts of irrigation and drainage and measures for creating and maintaining sustainability; institutional strengthening, proper financial assessment, capacity building, training and education. Copyright © 2002 John Wiley & Sons, Ltd. Résumé Aujourd'hui le problème critique pour l'humanité est comment manier la compétition intensifiante pour de l'eau entre les centres urbains en expansion, pour des activités traditionnellement agricoles et pour l'usage de l'eau fluviale prescrit par des conditions écologistes. Dans le secteur agricole les perspectives d'agrandir les champs cultivés bruts sont limitées par le nombre diminuant des terrains économiquement attractifs pour des projets d'irrigation et du drainage de grande envergure. Par conséquent l'augmentation nécessaire de la production agricole comptera surtout sur une évaluation plus précise du besoin des plantes d'un côté, et de l'autre sur de grandes améliorations dans la construction, dans l'opération, dans le management et dans la performance des systèmes d'irrigation et du drainage. On peut attribuer les défauts des systèmes actuels et l'incompétence d'exploiter durablement les ressources hydriques de surface et souterraines au planification, au système de la gestion de l'eau et au système du développement. Cela est partiellement dû à l'incapacité des ingénieurs, des planificateurs et des gérants, de quantifier adéquatement les effets des projets d'irrigation et de drainage sur les ressources hydriques et d'utiliser ces résultats pour améliorer la technologie, la planification et la gestion de l'eau. Pour profiter le mieux possible des investissements dans l'agriculture, on exige un effort considérable pour moderniser les systèmes d'irrigation et de drainage et pour développer des stratégies de gestion de l'eau qui doivent être appropriées et compatibles avec les tendances financières et socio-économiques et avec l'environnement. Ceci a besoin d'une procédure holistique pour la gestion et le monitorage de l'eau, pour augmenter la production d'aliments, pour conserver l'eau, pour prévenir la salination du sol et pour protéger l'environnement. Tout cela demande, entre autres choses, une recherche d'avant-garde et une variété d'instruments comme les contrôles du régime hydrique et les appareils de régulation, la télédétection, les systèmes de l'information géographique, les systèmes et les modèles de support de décision et de même les levés sur le terrain et les techniques d'évaluation. Pour entreprendre ce défi nous devons nous concentrer sur les questions suivantes: capacité de mettre enoeuvre des technologies nouvelles; le développement des procédures pour intégrer la planification et la gestion des systèmes d'irrigation et de drainage; l'analyse pour identifier les causes et les effets de forcer à la performance des systèmes d'irrigation et de drainage; l'évapotranspiration et les méthodes de calcul en question; l'évaluation des exigences hydriques des cultures; les technologies pour le dessein, la construction et la modernisation des projets d'irrigation et de drainage; les stratégies pour améliorer l'efficacité des systèmes d'irrigation et de drainage; les impacts des projets d'irrigation et de drainage et des mesures appropriées pour créer et entretenir la durabilité; l'amélioration du contexte institutionnel, l'évaluation financière, la formation et l'amélioration des compétences techniques. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effects of Deficit Irrigation and Salinity Stress on Common Bean (Phaseolus Vulgaris L.) and Mungbean (Vigna Radiata (L.) Wilczek) Grown in a Controlled EnvironmentJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2010M. Bourgault Abstract As water for irrigation purposes becomes increasingly scarce because of climate change and population growth, there is growing interest in regulated deficit irrigation (RDI) as a way to improve efficiency of water usage and farm productivity in arid and semi-arid areas. Salinity is also becoming an important problem in these same regions. Experiments were performed to investigate the effects of RDI and salt stress on two legumes crops, common bean (Phaseolus vulgaris L.) and mungbean (Vigna radiata (L.) Wilczek); previous work showed contrasting responses to RDI by these two crops under field conditions. The seed and biomass yields of both crops were reduced as a result of increasing water deficit stress; however, mungbean was able to maintain the same proportion of its biomass in reproductive structures and maintain its harvest index under stress, whereas common bean's decreased. In addition, photosynthesis in mungbean was higher than in common bean and higher at the same levels of transpiration. Finally, salinity stress did not affect the water potential, harvest index or the specific leaf weight of either crop. There were no interactions between salinity and crops or RDI levels, which suggest that the two crops do not differ in their response to salinity stress, and that RDI levels do not modify this response. [source] Irrigation Level Affects Isoflavone Concentrations of Early Maturing Soya Bean CultivarsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2007A. M. Al-Tawaha Abstract Field experiments were conducted in 2003/2004 in Québec to determine the effects of irrigation levels (none, low and high) and cultivars (AC Orford, AC Proteina and Golden) on soya bean [Glycine max (L.) Merr.] isoflavone concentrations and yields. Seed yield, yield components, and oil and crude protein (CP) concentrations were concurrently determined. Response to irrigation was greater in 2003, which was substantially warmer and drier than in 2004. In both years, most responses were observed with the lower of the two irrigation levels evaluated, which increased total isoflavones concentration by an average of 45 % compared with a non-irrigated control. Cultivars, however, responded differently to irrigation. In 2003, response of AC Proteina was greater than that of AC Orford, while Golden did not respond. In 2004, some responses were observed with AC Proteina and Golden but none with AC Orford. Overall, in both years, AC Proteina had the greatest isoflavone concentrations and AC Orford the lowest. Responses of seed yield and yield components depended on the year and were also greater in 2003. Both irrigation treatments generally increased seed yield and yield components compared with a non-irrigated control; the response was greater with the higher irrigation level. Irrigation had no effect on oil and CP concentrations. Finally, isoflavone yield response to irrigation was again greater in 2003, and depended on the cultivar. Results thus demonstrate that specific soil moisture levels will maximize soya bean isoflavone concentrations, excess irrigation sometimes negating any potential benefits. [source] Seedling Growth of Agronomic Crops in Crude Oil Contaminated SoilJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2006I. Issoufi Abstract Phytoremediation of hydrocarbon-contaminated soil shows promise as a low-cost alternative to most remediation methods. This study evaluated seedling growth of six crop species in crude oil contaminated soils. The experiments were conducted in a greenhouse. Weathered crude oil was added to an Ipava silt loam soil at the rate of 0 (control), 10, 50 and 100 g of crude oil kg,1 of soil, which was then placed into pots. Irrigation was used to maintain soil moisture at approximately field capacity. Five seeds of Zea mays, Meticago sativa, Lolium perenne, Triticum aestivum, Glycine max or Vicia villosa were sown per pot. The experimental design was completely randomized with five replications per treatment. Germination and seedling height data were recorded on day 7, 14, 21 and 28. Plants were harvested on day 28, separated into shoots and roots and dried to measure biomass. Analysis of variance was used to determine treatment significance. Significant treatment mean values were separated using Tukey's Honestly Significant Difference Test. Based upon percent emergence and plant biomass production in contaminated soil, Z. mays and G. max seedlings show the greatest potential to enhance remediation. [source] Hydrogen Peroxide and Calcium Chloride Added to Irrigation Water as a Strategy to Reduce Bacterial Populations and Improve Quality of Fresh MushroomsJOURNAL OF FOOD SCIENCE, Issue 6 2005Naveen Chikthimmah ABSTRACT The quality and value of fresh mushrooms are often diminished by the presence of high bacterial populations that cause a brown, blotchy appearance. The objective of the present research was to evaluate the addition of hydrogen peroxide and/or calcium chloride to irrigation water as a means to reduce total bacterial populations on fresh mushrooms. Crops were grown using commercial mushroom growing practices except for the addition of 0.75% hydrogen peroxide and/or 0.3% calcium chloride irrigation water added to the crop starting 11 d after the casing layer was applied on top of mushroom compost. Irrigation water without the added treatments acted as the control. Mushrooms were aseptically sampled from the production beds for enumerating bacterial counts. Total aerobic bacterial populations were determined by standard microbiological plating procedures. Mushroom whiteness (L -value) and color (delta E) after harvest and postharvest storage were measured using a Minolta chromameter. Harvested mushrooms were separated by treatment and weighed to record yield. Mushrooms irrigated with water (control) had 7.3 log colony-forming units (CFU) of aerobic bacterial populations per gram of fresh mushroom tissue. Compared with the control, irrigation with 0.75% hydrogen peroxide and 0.3% calcium chloride reduced the bacterial populations on fresh mushrooms by 87% (6.4 log CFU/g). Irrigation with hydrogen peroxide and calcium chloride significantly enhanced mushroom whiteness after harvest as well as after 6 d of postharvest storage at 12 °C. The irrigation treatments did not have a significant effect on crop yields; hence, the addition of hydrogen peroxide and calcium chloride to irrigation water was demonstrated to have good potential as a practical strategy to reduce bacterial populations and to improve the quality of fresh mushrooms. [source] Irrigation and Society in the Peruvian Desert.JOURNAL OF LATIN AMERICAN & CARIBBEAN ANTHROPOLOGY, Issue 1 2004The Puquios of Nasca No abstract is available for this article. [source] INFILTRATION OF WASTEWATER AND SIMULATED RAINWATER AS AFFECTED BY POLYACRYLAMIDE,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 4 2002Duane T. Gardiner ABSTRACT: Irrigation reduces infiltration rates for subsequent irrigations or rains, thus decreasing the efficiency of water use and impacting watersheds in agricultural areas. Reduced infiltration causes greater runoff with its accompanying erosion, pollution, and sedimentation. Small rates of polyacrylamide (PAM) improve infiltration and reduce erosion on irrigated fields. The effects of PAM on infiltration of rainwater, the longevity of the effects of various rates of PAM, and the effects of repeated or intermittent PAM applications are not understood. This study measured the effects of four PAM application rates (0, 10, 25, and 40 ppm) on the subsequent infiltration of wastewater or simulated rainwater for seven weeks following the initial treatments. Also, effects of repeated and intermittent PAM applications on infiltration were determined. Hydraulic conductivity was determined for each soil column using the falling head method. Two soil types from the coastal plain of south Texas were tested , a soil high in clay (Victoria) and a sandy loam (Willacy). Effects of PAM rates were significant, but effects of water type were not (P > 0.05). Benefits from single PAM applications disappeared within two weeks. Water enriched with PAM is so viscous and infiltrates so slowly that applying PAM in every irrigation event may not be feasible. However, repeating PAM applications every two weeks maintained high infiltration rates on the alternate weeks. This intermittent application of PAM may be a practical approach for improving infiltration rates on irrigated lands. [source] The effects of irrigation, nitrogen fertilizer and grain size on Hagberg falling number, specific weight and blackpoint of winter wheatJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2004Matthew P Clarke Abstract The effects of irrigation and nitrogen (N) fertilizer on Hagberg falling number (HFN), specific weight (SW) and blackpoint (BP) of winter wheat (Triticum aestivum L) were investigated. Mains water (+50 and +100 mm month,1, containing 44 mg NO3, litre,1 and 28 mg SO42, litre,1) was applied with trickle irrigation during winter (17 January,17 March), spring (21 March,20 May) or summer (24 May,23 July). In 1999/2000 these treatments were factorially combined with three N levels (0, 200, 400 kg N ha,1), applied to cv Hereward. In 2000/01 the 400 kg N ha,1 treatment was replaced with cv Malacca given 200 kg N ha,1. Irrigation increased grain yield, mostly by increasing grain numbers when applied in winter and spring, and by increasing mean grain weight when applied in summer. Nitrogen increased grain numbers and SW, and reduced BP in both years. Nitrogen increased HFN in 1999/2000 and reduced HFN in 2000/01. Effects of irrigation on HFN, SW and BP were smaller and inconsistent over year and nitrogen level. Irrigation interacted with N on mean grain weight: negatively for winter and spring irrigation, and positively for summer irrigation. Ten variables derived from digital image analysis of harvested grain were included with mean grain weight in a principal components analysis. The first principal component (,size') was negatively related to HFN (in two years) and BP (one year), and positively related to SW (two years). Treatment effects on dimensions of harvested grain could not explain all of the effects on HFN, BP and SW but the results were consistent with the hypothesis that water and nutrient availability, even when they were affected early in the season, could influence final grain quality if they influenced grain numbers and size. Copyright © 2004 Society of Chemical Industry [source] Composition and organoleptic characteristics of oil from Arbequina olive (Olea europaea L) trees under deficit irrigationJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2002J Tovar Abstract This study evaluated the effects of different regulated deficit irrigation (RDI) strategies applied to olive (Arbequina cultivar) trees on the qualitative and quantitative parameters of the resulting oil during the maximum evaporative demand period for three consecutive crop seasons. Quality indices, fatty acid composition, pigments, colour, ,-tocopherol and phenolic contents, bitter index, oxidative stability and organoleptic properties of the oil were determined. Irrigation did not affect those parameters used as criteria for classifying olive oil in its commercial grades. Only polyphenol and o -diphenol contents and, consequently, the bitter index and oxidative stability were affected by the RDI strategy, with increasing values as the water applied decreased. Regulated deficit irrigation resulted in important savings in irrigation requirements without detriment to oil quality. © 2002 Society of Chemical Industry [source] Rationale and methods for compiling an atlas of desertification in ItalyLAND DEGRADATION AND DEVELOPMENT, Issue 3 2009E. A. C. Costantini Abstract This study presents the main results and the methodology used in the creation of the atlas of the risk of desertification in Italy. A desertified area was defined as an unproductive area for agricultural or forestry use, due to soil degradation processes. An area at risk of desertification was a tract of the earth's surface which is vulnerable or sensitive to the processes of desertification. In a vulnerable land, environmental characteristics are close to that of a desertified area, but some factors (e.g. vegetation cover or irrigation), successfully mitigate the desertification process. On the other hand, sensitive land is a surface where the process leading to desertification is active, although the land is not yet unproductive. The DPSIR (Driving force-Pressure-State-Impact-Response) framework has been adopted as a reference. Using the national soil information system and socio-economic layers, an atlas of indicators of desertification risks was created, which was organized into different soil degradation systems. 51.8 per cent of Italy was considered to be at potential risk of desertification. Some 21.3 per cent of Italy (41.1 per cent of the area at potential risk) featured land degradation phenomena. Specifically, 4.3 per cent of Italy is already unproductive; 4.7 per cent is sensitive and 12.3 per cent is vulnerable. In the territory at potential risk of desertification, unproductive lands, plus areas vulnerable or sensitive to soil erosion, are at least the 19 per cent. Areas affected by aridity also sum up to 19 per cent. Salt-affected soils in Italy are estimated to cover >1 million,ha. Irrigation can mitigate soil aridity and salinization, nevertheless, only about 15 per cent of the sensitive and vulnerable lands of southern Italy are actually equipped with irrigation networks. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Kuhls of Kangra: Community-Managed Irrigation in the Western HimalayaAMERICAN ANTHROPOLOGIST, Issue 4 2006NEERAJ VEDWAN The Kuhls of Kangra: Community-Managed Irrigation in the Western Himalaya.. J. Mark Baker. Seattle: University of Washington Press, 2005. 272 pp. [source] Water and Power in Highland Peru: The Cultural Politics of Irrigation and DevelopmentAMERICAN ETHNOLOGIST, Issue 2 2001Daniel W. Gade Water and Power in Highland Peru: The Cultural Politics of Irrigation and Development. Paul H. Gelles. New Brunswick, NJ: Rutgers University Press, 2000. xv. 233 pp., maps, photographs, diagrams, appendixes, notes, glossary, bibliography, index. [source] Radiographic Comparison of Three Methods for Nasal Saline Irrigation,THE LARYNGOSCOPE, Issue 8 2002David E. L. Olson MD Abstract Objective To compare intranasal distribution of saline solution delivered by three popular methods for nasal saline irrigation. Study Design Prospective, controlled comparison. Methods Eight healthy adult volunteers received nasal irrigation with 40 mL of isotonic, nonionic contrast material immediately before having coronal computed tomography to visualize distribution of solution in the paranasal sinuses. For each study subject, three methods of irrigation were used: irrigation using positive-pressure irrigation, irrigation using negative-pressure irrigation, and irrigation using a nebulizer. For each subject, three-dimensional computer reconstructions of the irrigated paranasal sinus airspaces were used to compare contrast solution volume and distribution achieved by the three methods. Results Of the three methods used, two methods, positive-pressure and negative-pressure irrigation, distributed contrast solution widely to ethmoid and maxillary sinuses, but distribution of contrast solution was more uniform using positive-pressure irrigation than using negative-pressure irrigation. The nebulization method distributed contrast solution poorly and resulted in a significantly lower volume of retained contrast solution (P <.05). Conclusion Judged solely on the basis of solution distribution in the nasal sinuses, nasal irrigation is effective when either positive-pressure or negative-pressure irrigation is used but is ineffective when a nebulizer is used. [source] Saline Irrigation in the Prevention of Otorrhea After Tympanostomy Tube PlacementTHE LARYNGOSCOPE, Issue 5 2001Rick D. Gross MD No abstract is available for this article. [source] Saline Irrigation in the Prevention of Otorrhea After Tympanostomy Tube Placement,THE LARYNGOSCOPE, Issue 2 2000Rick D. Gross MD Abstract Objectives: Comparison of intraoperative saline irrigation to otic drops in the prevention of postoperative otorrhea in children with middle ear effusion undergoing bilateral myringotomy with ventilation tubes. Study Design: This study was designed as a blinded, controlled, prospectively randomized trial. Methods: Study children were randomly assigned to receive either otic drops for 3 days postoperatively or saline irrigation of the middle ear space at the time of myringotomy. Only children with effusion present at the time of surgery were included. All children were evaluated for drainage 7 to 14 days postoperatively, and the degree of drainage was graded from 0 to 4. Results: Of the 84 patients entered into the study, 62 patients were eligible for data analysis (16 failed follow-up, 6 records were lost). Of the patients who completed the study, not all had bilateral effusions, resulting in 111 ears for inclusion in the study. Fifty-two ears underwent irrigation, and 10 were noted to have otorrhea (19.2%). Fifty-nine ears received otic drops, resulting in 21 ears with otorrhea (35.6%). Evaluating the degree of otorrhea with a five-point Leichert scale, the average score per ear was 0.42 for the saline irrigation group and 1.07 for the control group. The rate and degree of drainage were both statistically reduced in the saline irrigation group (P < .05). Conclusions: Using middle ear irrigation at the time of tympanostomy may be more effective than antibiotic drops in preventing postoperative otorrhea. [source] The impact of irrigation frequency on population density of thrips, Thrips tabaci Rom (Thripidae, Thysanoptera) and yield of onion in E1 Rahad, SudanANNALS OF APPLIED BIOLOGY, Issue 2 2001H O KANNAN Summary Vegetable farmers of the El Rahad Scheme (a newly developed scheme situated between latitude 13°31,,14°25, north and longitude 33°31,34°32, east) used to extend irrigation frequency for onion production as they believed it would hamper and suppress thrips incidence. Thrips, T. tabaci, is the only major insect pest of onion in the El Rahad Scheme and the influence of irrigation intervals on the population density of the pest and on onion yield was not quantified. Irrigation is a factor in the development of crop pests and the levels of the pest population are related to the commencement of irrigation. The effect of irrigation frequency on the development of onion thrips and yield was investigated and the response was found to be a significant increase in the population density of the pests from February to March with shorter irrigation frequency. A steady increase of thrips population was noted from February and March and a sharp decline was recorded in April during both the 1992/93 and 1993/94 seasons. At wider irrigation intervals, levels of the pest population were significantly less from February to March during both seasons. Total bulb yield and average bulb weight were significantly higher at shorter irrigation frequencies when compared with extended frequencies. The same pattern of results existed throughout the course of the experiment. [source] Does Allocation of Public Spending Matter in Poverty Reduction?ASIAN ECONOMIC JOURNAL, Issue 4 2008Evidence from Thailand H41; H53; H54 The present paper uses a panel dataset to estimate the marginal returns to different types of government expenditure on agricultural growth and rural poverty reduction in Thailand. The study finds that additional government spending on agricultural research provides the largest return in terms of agricultural productivity and has the second largest impact on rural poverty reduction. Increased investment in rural electrification has the largest poverty reduction impact, mainly through improved nonfarm employment. Rural education has the third largest impact on both productivity and poverty reduction. Irrigation has a positive impact on agricultural productivity, but regional variation is considerable. Government spending on rural roads has no significant impact on agricultural productivity and its poverty reduction impact ranks last among all investment alternatives considered. Additional investment in the Northeast Region has a greater impact on poverty reduction than in other regions. [source] Modelling hydroclimatic uncertainty and short-run irrigator decision making: the Goulburn system,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2009Marnie Griffith Australia has an incredibly variable and unpredictable hydroclimate, and while irrigation is designed to reduce risk, significant uncertainty remains in both seasonal water availability (,allocations') and irrigation crop water requirements. This paper explores the nature and impacts of seasonal hydroclimatic uncertainty on irrigator decision making and temporary water markets in the Goulburn system in northern Victoria. Irrigation and water trading plans are modelled for the three seasons of the irrigation year (spring, summer and autumn) via discrete stochastic programming, and contrasted against a perfect information base case. In water-scarce environments, hydroclimatic uncertainty is found to be costly, in terms of both the efficiency of irrigation decisions and the allocation of water via the water market. [source] Irrigation, poverty and inequality in rural China,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2005Qiuqiong Huang This paper examines the impact of irrigation on rural incomes, poverty and the income distribution in rural China. The relationship between irrigation and income is examined using descriptive statistics and multivariate analysis. A simulation approach is used to explore the impact of irrigation on poverty incidence. To uncover the effect of irrigation on the income distribution, inequality is decomposed by source of income, by group according to access to irrigation and by estimated income flows as a result of specific household characteristics. The results show that irrigation increases income and reduces poverty and inequality. [source] Modification of Vegetative Phenology in a Tropical Semi-deciduous Forest by Abnormal Drought and Rain,BIOTROPICA, Issue 1 2002R. Borchert ABSTRACT The control of vegetative phenology in tropical trees is not well understood. In dry forest trees, leaf abscission may be enhanced by advanced leaf age, increasing water stress, or declining photoperiod. Normally, it is impossible to dissect the effects of each of these variables because most leaves are shed during the early dry season when day length is near its minimum and leaves are relatively old. The 1997 El-Niño Southern Oscillation caused a ten-week long, severe abnormal drought from June to August in the semi-deciduous forests of Guanacaste, Costa Rica. We monitored the effect of this drought on phenology and water status of trees with young leaves and compared modifications of phenology in trees of different functional types with the pattern observed during the regular dry season. Although deciduous trees at dry sites were severely water stressed (,stem < -7MPa) and their mesic leaves remained wilted for more than two months, these and all other trees retained all leaves during the abnormal drought. Many trees exchanged leaves three to four months earlier than normal during the wet period after the abnormal drought and shed leaves again during the regular dry season. Irrigation and an exceptional 70 mm rainfall during the mid-dry season 1998/1999 caused bud break and flushing in all leafless trees except dormant stem succulents. The complex interactions between leaf age and water stress, the principal determinants of leaf abscission, were found to vary widely among trees of different functional types. [source] A Multicenter Comparison of Tap Water versus Sterile Saline for Wound IrrigationACADEMIC EMERGENCY MEDICINE, Issue 5 2007Ronald M. Moscati MD ObjectivesTo compare wound infection rates for irrigation with tap water versus sterile saline before closure of wounds in the emergency department. MethodsThe study was a multicenter, prospective, randomized trial conducted at two Level 1 urban hospitals and a suburban community hospital. Subjects were a convenience sample of adults presenting with acute simple lacerations requiring sutures or staples. Subjects were randomized to irrigation in a sink with tap water or with normal saline using a sterile syringe. Wounds were closed in the standard fashion. Subjects were asked to return to the emergency department for suture removal. Those who did not return were contacted by telephone. Wounds were considered infected if there was early removal of sutures or staples, if there was irrigation and drainage of the wound, or if the subject needed to be placed on antibiotics. Equivalence of the groups was met if there was less than a doubling of the infection rate. ResultsA total of 715 subjects were enrolled in the study. Follow-up data were obtained on 634 (88%) of enrolled subjects. Twelve (4%) of the 300 subjects in the tap water group had wound infections, compared with 11 (3.3%) of the 334 subjects in the saline group. The relative risk was 1.21 (95% confidence interval = 0.5 to 2.7). ConclusionsEquivalent rates of wound infection were found using either irrigant. The results of this multicenter trial evaluating tap water as an irrigant agree with those from previous single institution trials. [source] The proto-oncogene BCL6 promotes survival of olfactory sensory neuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 6 2010Joji M. Otaki Abstract For the mammalian olfactory epithelium to continually detect odorant, neuronal survival, apoptosis, and regeneration must be coordinated. Here, we showed that the proto-oncogene BCL6, which encodes a transcriptional repressor required for lymphocyte terminal differentiation, contributes to the survival of olfactory sensory neurons (OSNs). In the olfactory epithelia of the BCL6 null mutant mice, many OSNs were positive for both OMP and GAP43. The epithelium was relatively thinner, showing many apoptotic signals. These characters were phenotypically similar to those of the wild-type mice treated with nasal lectin irrigation, which acutely induces apoptosis of OSNs. Odorant receptors were expressed normally in the epithelia of the mutant mice, and their overall expression profile based on DNA microarray analyses was roughly similar to that of the apoptosis-induced olfactory epithelia of the wild-type mice. Experimental increase of BCL6 together with green fluorescent protein in OSNs using adenovirus-mediated gene transfer made the epifluorescence last longer than the control fluorescence without exogenous BCL6 after the nasal lectin irrigation, indicating that BCL6 made the infected neurons survive longer. We conclude that BCL6 plays an active role in the survival of OSNs as an anti-apoptotic factor and confers immature OSNs enough time to fully differentiate into mature ones. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 424-435, 2010 [source] | ||||||||||||||||||||||||||||