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Drip Irrigation (drip + irrigation)
Selected AbstractsRecharge, upflux and water table response for shallow water table conditions in southwest FloridaHYDROLOGICAL PROCESSES, Issue 9 2006Fouad H. Jaber Abstract A disproportionate increase or decrease in water table in response to minor water input or drainage is observed in shallow water table conditions inside drainage lysimeters. This increase happens because the capillary fringe of the shallow water table reaches up to or near the surface (Wieringermeer effect). The correlations between water table level changes and rainfall, seepage irrigation, drip irrigation, and drainage were analysed. Correlations with rainfall, seepage irrigation, and drainage were high (R2 ranged from 0·46 to 0·97). Drip irrigation had low correlations due to the low rates of application (R2 ranged from 0·26 to 0·44). Conventional methods of calculating recharge, such as multiplying the specific yield with the water table fluctuations, cannot be used for Wieringermeer effect situations. A method using water balance data and soil moisture at different depths in the lysimeters was developed to estimate recharge and upflux. The recharge results were used to develop the apparent specific yield Sya, which could be used to calculate consequent recharge events from water table fluctuation data. Combining the water table fluctuation relationships developed with the Sya value will allow the prediction of recharge from rainfall and irrigation events without the need for soil moisture equipment. Copyright © 2005 John Wiley & Sons, Ltd. [source] Effects of irrigation with treated municipal wastewater on soil properties in arid and semi-arid regions,IRRIGATION AND DRAINAGE, Issue 5 2009Sayyed Hassan Tabatabaei eaux usées; méthode d'irrigation; transports de soluté; zone aride Abstract The use of municipal wastewater for irrigation needs special management. This is due to the environmental and health hazards. In this study, secondary treated municipal wastewater was used in five irrigation treatments. These treatments were as follows: furrow irrigation with normal water (FN), drip irrigation with wastewater (DI), subsurface drip irrigation in 15,cm depth with wastewater (SDI15), subsurface drip irrigation in 30,cm depth with wastewater (SDI30), and furrow irrigation with wastewater (FW). The results showed that the application of DI and SDI sand filters causes a decrease in wastewater index pollution, including 50.1% BOD5, 98.9% total count, 97.6% total coliform, 93.2% faecal coliform, 57.1% nematode, 81% total nitrogen, 52% N-NO3, 84% N-NH4 and 44% total suspended solids. In addition, the application of the SDI system causes a decrease in the moisture content of the soil surface, which decreases total coliform and faecal coliform on the soil surface. The average values for these parameters show no significant difference (5% level) between SDI treatments and FN. The results of this research also show that in the case of SDI with its minimal leaching, prevalence contamination (such as N-NO3) was minimized as a result of the usage of wastewater at depth and in groundwater. Moreover, in SDI treatments, the maximum EC and SAR leaching are observed at 60,cm depth, whereas in the FW this leaching is observed deeper than 90,cm. Copyright © 2008 John Wiley & Sons, Ltd. L'utilisation des eaux usées municipales pour l'irrigation nécessite une gestion spéciale afin d'éviter les risques pour la santé et l'environnement. Dans cette étude des eaux usées municipales de l'usine d'Ispahan avec traitement secondaire ont été utilisées dans cinq traitements d'irrigation. Ces traitements étaient les suivants: irrigation à la raie avec de l'eau normale (FN), l'irrigation au goutte-à-goutte avec des eaux usées (DI), irrigation en sub-surface à 15,cm de profondeur avec des eaux usées (SDI15), idem à 30,cm (SDI30), et irrigation à la raie avec des eaux usées (FW). Les résultats de cette recherche montrent que l'utilisation de filtres à sable dans DI et SDI a provoqué une diminution des index de pollution des eaux usées: 50,1% de la DBO5, 98,9% de la quantité totale, 97,6% des coliformes totaux, 93,2% des coliformes fécaux, 57,1% des nématodes, 81% de l'azote total, 52% de N-NO3, 84% de N-NH4 et 44% des matières en suspension. En outre l'application de SDI a entraîné une diminution de l'humidité de la surface du sol, ce qui a diminué les coliformes totaux et de coliformes fécaux en surface. Les valeurs moyennes pour ces paramètres n'ont révélé aucune différence significative (seuil 5%) entre les traitements SDI et FN. Les résultats de cette recherche ont également montré que avec SDI du fait d'une infiltration moindre, la contamination de prévalence (tels que le N-NO3) est minimisé du fait de l'utilisation des eaux usées en profondeur et des nappes phréatiques. En outre avec SDI les lessivages maximum de CE et de SAR ont été observées à 60,cm de profondeur alors qu'avec FW ce lessivage a été observé au-dessous de 90,cm. Copyright © 2008 John Wiley & Sons, Ltd. [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] Etude comparative de la disponibilité de l'eau en irrigation goutte à goutteIRRIGATION AND DRAINAGE, Issue 3 2001A.V. Ould Mohamed El-Hafedh goutteur; écartement; durée d'irrigation; fréquence d'arrosage Abstract Dans le but de déterminer la meilleure combinaison entre période et durée d'irrigation pour différents écartements inter-goutteurs, nous avons essayé d'analyser la disponibilité de l'eau au sein de la zone racinaire d'une culture de tomate irriguée à l'aide d'une rampe de goutteurs débitant chacun 4 l h,1. Trois écartements ont été étudiés à savoir 30, 50 et 70 cm. Lorsqu'on a pris une durée d'arrosage systématique de 4h30mn, nous avons observé à la fin des irrigations des teneurs en eau volumiques moyennes dépassant la capacité au champ pour les trois écartements. En effet, à l'examen de l'évolution des teneurs en eau au sein du bulbe, il est remarqué que la teneur en eau à la capacité au champ a été atteinte après 25 minutes, 50 minutes et deux heures respectivement pour 30, 50 et 70 cm. Mais l'humidification de toute la ligne de culture n'a été observée qu'après des temps respectifs d'une heure, deux heures et quatre heures (Ould Mohamed El-Hafedh et al., 2000). Les irrigations ont été reprises avec ces durées réduites (une heure, deux heures et quatre heures respectivement pour les écartements 30, 50 et 70 cm) en vue d'évaluer et comparer les consommations en eau de la culture sous les différents traitements. Dans le cas de l'irrigation d'une durée de 4h30mn, la période séparant deux arrosages successifs a été de cinq, quatre et trois jours respectivement pour les écartements 30, 50 et 70 cm. Pour les irrigations des durées réduites, on a constaté qu'il est impératif d'irriguer après trois jours pour les deux écartements 50 et 70 cm et après deux jours pour l'écartement 30 cm. En comparant les consommations en eau pour les durées réduites et la durée systématique de 4h30mn, on a observé une économie d'eau de l'ordre de 20, 15 et 5% respectivement pour 30, 50 et 70 cm d'écartement. D'autre part, la comparaison entre les durées réduites montre que la plus importante économie en eau a été réalisée avec 50 cm d'écartement. Copyright © 2001 John Wiley & Sons, Ltd. In order to determine the best combination between duration and frequency of drip irrigation for various inter-dripper spacing, we analysed the availability of water within the root zone of a tomato culture irrigated using lateral drippers each outputting 4 l h,1 discharge rate. Three spacings were studied, namely 30, 50 and 70 cm. Studying systematic irrigation duration of 4½ hours, we observed at the end of each irrigation average volumetric water contents exceeding the field capacity. Indeed, with the examination of the evolution of the water contents within the bulb, it is noticed that the water content at the field capacity was reached after 25 minutes, 50 minutes and 2 hours respectively for 30, 50 and 70 cm spacing. But the humidification of the whole culture line was observed only after the respective times of 1, 2 and 4 hours (Ould Mohamed El-Hafedh et al., 2000). The irrigations were taken again with these reduced durations (1, 2 and 4 hours for 30, 50 and 70 cm spacing respectively) in order to evaluate and compare water consumption of the culture under the various treatments. In case of systematic irrigation duration, the period separating two successive waterings was five, four and three days for 30, 50 and 70 cm spacing respectively. For the reduced irrigation durations, it is imperative to irrigate after three days for the 50 and 70 cm spacings and after two days for the 30 cm spacing. Comparing water consumption for the reduced durations and those of the systematic duration, we observed water savings of about 20, 15 and 5% respectively for 30, 50 and 70-cm spacing. The comparison between the reduced durations shows that the most significant water saving was obtained with the 50 cm spacing. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effects of Deficit Drip Irrigation Ratios on Cotton (Gossypium hirsutum L.) Yield and Fibre QualityJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2009H. Basal Abstract Increasing irrigation costs and declining water availability compel producers to adapt irrigation strategies for maximum crop yield and water use efficiency. A field trial was conducted to observe the effects of various drip irrigation ratios (IR-0, IR-25, IR-50, IR-75 and IR-100) on water use efficiency (WUE), the irrigation water use efficiency (IWUE), lint yield, yield components and fibre quality at two upland cotton varieties during 2004 and 2005. WUE was found to increase from 0.62 to 0.71 kg m,3 as the irrigation water applied was reduced from 100 % to 75 % of soil water depletion. Deficit irrigation of cotton with drip irrigation at 75 % treatment level (IR-75) did not decrease seed cotton yield and yield components during 2 years, with the exception of the number of bolls in 2005. Among fibre quality parameters, no significant differences in fibre length, fineness, uniformity index and elongation were detected between the 100 % and 75 % irrigation levels in 2005. The results revealed that irrigation of cotton with a drip irrigation method at 75 % level had significant benefits in terms of saved irrigation water without reducing yield, and high WUE indicated a definitive advantage of employing deficit irrigation under limited water supply conditions. [source] Effect of Irrigation Type on Inoculum Density of Macrophomina phaseolina in Melon Fields in ArizonaJOURNAL OF PHYTOPATHOLOGY, Issue 3 2004C. Nischwitz Abstract Charcoal rot, caused by Macrophomina phaseolina, has become increasingly problematic for melon growers using subsurface drip irrigation in Arizona; but has rarely been observed in fields with furrow irrigation. Since the relationship between increasing incidence of charcoal rot on melon and irrigation type is unknown, studies were initiated to determine the effects of edaphic factors on inoculum density. Soil samples were collected once from fields irrigated by subsurface drip, with and without plastic mulch, and by furrow at 10, 20 and 30 cm depths. Samples were analysed for percentage soil moisture, pH, salinity and inoculum density. Percentage soil moisture was significantly higher at 20 and 30 cm depths in the furrow-irrigated field compared with the drip-irrigated field with plastic mulch, but not in the field without plastic mulch. Average minimum and maximum temperatures and inoculum density were significantly lower at all three depths in the furrow-irrigated field compared with both types of drip irrigation. pH was significantly higher in the furrow-irrigated field compared with both types of drip irrigation at 20 and 30 cm depths but not at 10 cm depth. Differences in inoculum densities of M. phaseolina suggest that drip irrigation may contribute to higher disease incidences. [source] Effects of organic fertilisers and irrigation level on physical and chemical quality of industrial tomato fruit (cv. Nautilus)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2009Ramón Madrid Abstract BACKGROUND: The objective of this work was to study the influence of irrigation and organic fertilisation on quality attributes of tomato fruit (cv. Nautilus) grown for the canning industry. The assay was carried out during two consecutive years (2006 and 2007) in agricultural soil. Nine treatments resulting from the combination of three fertilisation types (sheep manure, a mixture of sheep manure and peat and an inorganic fertiliser (control)) with three levels of drip irrigation (3.30, 5.00 and 6.70 mm day,1) under black polyethylene mulch were applied (n = 3). RESULTS: For the chromatic attributes L*, H*, C* and S* the highest values corresponded to the treatments with organic matter. However, the a*/b* ratio and colour index value were higher for the control treatment. In all cases the estimated optimal ripening time was the same, and on this date a decline in the ratios was observed. The values of the physical properties increased with increasing irrigation, higher values always being obtained in the treatments with organic fertilisers. The highest production for all irrigation levels corresponded to the treatment with mixed sheep manure and peat fertiliser. CONCLUSION: Cultivation involving fertilisation with the manure/peat mixture and an irrigation level slightly above 5.00 mm day,1 can be recommended as optimal, since it gave the most satisfactory values with respect to the quality attributes of tomato fruit grown for the canning industry. Copyright © 2009 Society of Chemical Industry [source] | ||||||||||