Electronic apex locator: A comprehensive literature review — Part II: Effect of different clinical and technical conditions on electronic apex locator′s accuracy

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Hamid Razavian

2014-01-01

Full Text Available Introduction: To investigate the effects of different clinical and technical conditions on the accuracy of electronic apex locators (EALs. Materials and Methods: "Tooth apex," "dental instrument," "odontometry," "electronic medical," and "electronic apex locator" were searched as primary identifiers via Medline/PubMed, Cochrane library, and Scopus data base up to 30 July 2013. Original articles that fulfilled the inclusion criteria were selected and reviewed. Results: Out of 402 relevant studies, 183 were selected based on the inclusion criteria. In this part, 75 studies are presented. Pulp vitality conditions and root resorption, types of files and irrigating materials do not affect an EAL′s accuracy; however, the file size and foramen diameter can affect its accuracy. Conclusions: Various clinical conditions such as the file size and foramen diameter may affect EALs′ accuracy. However, more randomized clinical trials are needed for definitive conclusion.

Variation in energy sorghum hybrid TX08001 biomass composition and lignin chemistry during development under irrigated and non-irrigated field conditions

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Olson, Sara N.; Ritter, Kimberley B.; Herb, Dustin W.; Karlen, Steven D.; Lu, Fachuang; Ralph, John; Rooney, William L.; Mullet, John E.

2018-01-01

This study was conducted to document the extent and basis of compositional variation of shoot biomass of the energy Sorghum bicolor hybrid TX08001 during development under field conditions. TX08001 is capable of accumulating ~40 Mg/ha of dry biomass under good growing conditions and this genotype allocates ~80% of its shoot biomass to stems. After 150 days of growth TX08001 stems had a fresh/dry weight ratio of ~3:1 and soluble biomass accounted for ~30% of stem biomass. A panel of diverse energy sorghum genotypes varied ~6-fold in the ratio of stem structural to soluble biomass after 150 days of growth. Near-infrared spectroscopic analysis (NIRS) showed that TX08001 leaves accumulated higher levels of protein, water extractives and ash compared to stems, which have higher sugar, cellulose, and lignin contents. TX08001 stem sucrose content varied during development, whereas the composition of TX08001 stem cell walls, which consisted of ~45–49% cellulose, ~27–30% xylan, and ~15–18% lignin, remained constant after 90 days post emergence until the end of the growing season (180 days). TX08001 and Della stem syringyl (S)/guaiacyl (G) (0.53–0.58) and ferulic acid (FA)/para-coumaric acid (pCA) ratios were similar whereas ratios of pCA/(S+G) differed between these genotypes. Additionally, an analysis of irrigated versus non-irrigated TX08001 revealed that non-irrigated hybrids exhibited a 50% reduction in total cell wall biomass, an ~2-fold increase in stem sugars, and an ~25% increase in water extractives relative to irrigated hybrids. This study provides a baseline of information to help guide further optimization of energy sorghum composition for various end-uses. PMID:29684037

Soils and irrigation of three areas in the Lower Tana Region, Kenya : a comparative study of soil conditions and irrigation suitability

NARCIS (Netherlands)

Muchena, F.N.

1987-01-01

The soils and soil conditions of three areas situated in different physiographic positions in the Lower Tana Region of Kenya were investigated in respect of their suitability for irrigated agriculture. The soils vary widely in both physical and chemical properties. Most of the soils have an

Alternate furrow irrigation of four fresh-market tomato cultivars under semi-arid condition of Ethiopia – Part II: Physiological response

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Ashinie Bogale

2016-11-01

Full Text Available Understanding the variation in physiological response to deficit irrigation together with better knowledge on physiological characteristics of different genotypes that contribute to drought adaptation mechanisms would be helpful in transferring different irrigation technologies to farmers. A field experiment was carried to investigate the physiological response of four tomato cultivars (Fetan, Chali, Cochoro and ARP Tomato d2 to moderate water deficit induced by alternate furrow irrigation (AFI and deficit irrigation (DI under semi-arid condition of Ethiopia during 2013 and 2014. The study also aimed at identifying physiological attributes to the fruit yield of tomato under different deficit irrigation techniques. A factorial combination of irrigation treatments and cultivar were arranged in a complete randomized design with three replicates. Results showed that stomatal conductance (g_s was significantly reduced while photosynthetic performance measured as chlorophyll fluorescence (Fv’/Fm’, relative water content (RWC and leaf ash content remained unaffected under deficit irrigations. Significant differences among cultivars were found for water use efficiency (WUE, g_s, chlorophyll content (Chl_SPAD, normal difference vegetation index (NDVI, leaf ash content and fruit growth rate. However, cultivar differences in WUE were more accounted for by the regulation of g_s, therefore, g_s could be useful for breeders for screening large numbers of genotypes with higher WUE under deficit irrigation condition. The study result also demonstrated that cultivar with traits that contribute to achieve higher yields under deficit irrigation strategies has the potential to increase WUE.

Utility of the end-of-season nitrate test for nitrogen sufficiency of irrigated maize under Mediterranean semi-arid conditions

Energy Technology Data Exchange (ETDEWEB)

Isla, R.; Salmeron, M.; Cavero, J.; Yagüe, M.R.; Quilez, D.

2015-07-01

Calibration of decision tools to improve N fertilizer management is critical to increase its adoption by maize (Zea mays L.) growers. The objective of this study was to establish nitrate and total nitrogen concentrations in the basal maize stalks (BMS) at harvest to separate maize fields among three N availability categories (N-deficient, N-optimum, and N-excess) under Mediterranean irrigated semiarid conditions. We analysed data from 26 irrigated maize trials conducted between 2001 and 2012. Trials included treatments receiving different N fertilizer rates and sources (mineral and organic), irrigation systems (flood, sprinkler) and soil types. The critical nitrate concentration in BMS to identify N-deficient plots (CNCL) is affected by the irrigation system. The CNCL was lower under sprinkler irrigation (708 mg NO{sub 3}{sup -}–N/kg) than under flood irrigation (2205 mg NO{sub 3}{sup -}–N/kg), and the later presented a higher degree of uncertainty compared to sprinkler irrigated systems. The results showed the difficulty to identify the N-deficient plots with the BMS test and the higher sensibility of nitrate-N than total-N concentration in BMS to separate N-deficient from N-optimal plots. Under sprinkler irrigation, nitrate in BMS>1500 mg NO{sub 3}{sup -}–N/kg had a 85% probability of having received an excess of N. Considering economic net returns to N fertilization, the range of nitrate concentration in BMS that maximized profit under sprinkler-irrigated conditions was established between 1100 and 1700 mg NO3-–N/kg. Results suggest that BMS test can be useful in detecting plots with an excess of N but considering irrigation efficiency is crucial for stablishing successful CNC thresholds. (Author)

Apical negative pressure irrigation versus syringe irrigation: a systematic review of cleaning and disinfection of the root canal system.

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Konstantinidi, E; Psimma, Z; Chávez de Paz, L E; Boutsioukis, C

2017-11-01

The aim of this study was to systematically review and critically analyse the published data on the treatment outcome (primary outcome) and on the cleaning and disinfection of root canals (secondary outcomes) achieved by negative pressure irrigation as compared to syringe irrigation. An electronic search was conducted in EMBASE, LILACS, PubMed, SciELO, Scopus and Web of Knowledge using both free-text keywords and controlled vocabulary. Additional studies were sought through hand searching of endodontic journals and of the relevant chapters of endodontic textbooks. No language restriction was imposed. The retrieved studies were screened by two reviewers according to predefined criteria. Included studies were critically appraised and the extracted data were arranged in tables. The electronic search and hand search retrieved 489 titles. One clinical study and 14 in vitro studies were finally included in the review; none of these studies assessed treatment outcome, four studies assessed the antimicrobial effect, seven studies evaluated the removal of pulp tissue remnants, and four studies investigated the removal of hard tissue debris or both hard tissue debris and pulp tissue remnants. Poor standardization and description of the protocols was evident. Inconclusive results were reported about the cleaning and disinfection accomplished by the two irrigation methods. Negative pressure irrigation was more effective under certain conditions when compared to suboptimal syringe irrigation; however, the variability of the protocols hindered quantitative synthesis. There is insufficient evidence to claim general superiority of any one of these methods. The level of the available evidence is low, and the conclusions should be interpreted with caution. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Potato yield and yield structure depending on irrigation

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Milić Stanko

2010-01-01

Full Text Available In the agroclimatic conditions of the Vojvodina Province, the application of an economic water regime and modern technology is necessary for stable and intensive potato production. A two-year experiment on calcareous chernozem was carried out to determine how irrigation and different pre-irrigation soil moisture affect potato yield and distribution of tuber fraction in the potato yield. The block-design trial had four replicates and was adapted for sprinkler irrigation conditions. It included four treatments: irrigation with pre-irrigation moisture levels of 60 % of field water capacity (FC, irrigation with pre-irrigation moisture levels of 70 % (FC, irrigation with pre-irrigation moisture levels of 80% (FC, and a non-irrigated control treatment. Irrigation significantly increased the yield of potato, which increased from 37.27 % to 75.86 %. Under irrigation, the percentage of small fractions decreased in favour of the 55 mm one, or fractions above the 45-55 mm range. On average, irrigated treatments produced significantly more tubers than the conditions of natural water supply. .

Performance of Er:YAG laser ablation of hard bone under different irrigation water cooling conditions

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Beltrán Bernal, Lina M.; Shayeganrad, Gholamreza; Kosa, Gabor; Zelechowski, Marek; Rauter, Georg; Friederich, Niklaus; Cattin, Philippe C.; Zam, Azhar

2018-02-01

The biological applicability of the Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser in surgical processes is so far limited to hard dental tissues. Using the Er:YAG laser for bone ablation is being studied since it has shown good performance for ablating dental hard tissues at the wavelength 2.94 μm, which coincides with the absorption peak of water, one of the main components of hard tissue, like teeth and bone. To obtain a decent performance of the laser in the cutting process, we aim at examining the influence of sequenced water jet irrigation on both, the ablation rate and the prevention of carbonization while performing laser ablation of bone with fixed laser parameters. An Er:YAG laser at 2.94 μm wavelength, 940 mJ energy per pulse, 400 μs pulse width, and 10 Hz repetition rate is used for the ablation of a porcine femur bone under different pulsed water jet irrigation conditions. We used micro-computed tomography (micro-CT) scans to determine the geometry of the ablated areas. In addition, scanning electron microscopy (SEM) is used for qualitative observations for the presence of carbonization and micro-fractures on the ablated surfaces. We evaluate the performance of the laser ablation process for the different water jet conditions in terms of the ablation rate, quantified by the ablated volume per second and the ablation efficiency, calculated as the ablated volume per pulse energy. We provide an optimized system for laser ablation which delivers the appropriate amount of water to the bone and consequently, the bone is ablated in the most efficient way possible without carbonization.

AUTOMATED IRRIGATION SYSTEM CONSTITUTED OF ELECTRONIC ELEMENTS, MOBILE DEVICE AND THE CONSTRUCTION OF SPRINKLER

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Alma Delia González

2017-12-01

Full Text Available This document presents the development of an automated irrigation system, which consisted of a sprinkler that has a range of 16 meters in diameter using only sprinklers per one hectare of land, water pump, hose, water containers, electro valves, relays, electronic components such as humidity and temperature sensor, ultrasonic sensor, LCD screen, microcontroller (Arduino Mega, for communication a bluetooth module and a mobile device (Android. The agile methodology used was Extreme XP Programming, following its 4 phases, planning, design, development and testing. With this an automated irrigation system was used that was developed to monitor temperature, humidity and to generate a saving in the water thanks to the census of the container of the same, as well as the reduction of maintenance costs, this can be activated or deactivated by the user regardless of the conditions. The system complies with the characteristics of a utility model, because these models are all those objects, tools, appliances or tools that, as a result of a change in their layout, configuration, structure or form, present a different function with respect to the parts that integrate it or advantages in terms of its usefulness and thanks to the search carried out in IMPI. In the study of the state of the art the search was made in the data bases of Mexico in SIGA (Information System of the Gazette of the Industrial Property and internationally in Thomson, the results showed that there were similar sy

Assessment of Irrigation Water Quality and Suitability for Irrigation in ...

African Journals Online (AJOL)

A number of factors like geology, soil, effluents, sewage disposal and other environmental conditions in which the water stays or moves and interacts are among the factors that affect the quality of irrigation water. This study was conducted to determine the quality and suitability of different water sources for irrigation purpose ...

Effects of deficit drip-irrigation scheduling regimes with saline water on pepper yield, water productivity and soil salinity under arid conditions of Tunisia

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Kamel Nagaz

2012-12-01

Full Text Available A two-year study was carried out in order to assess the effects of different irrigation scheduling regimes with saline water on soil salinity, yield and water productivity of pepper under actual commercial-farming conditions in the arid region of Tunisia. Pepper was grown on a sandy soil and drip-irrigated with water having an ECi of 3.6 dS/m. Irrigation treatments consisted in water replacements of accumulated ETc at levels of 100% (FI, full irrigation, 80% (DI-80, 60% (DI-60, when the readily available water in the control treatment (FI is depleted, deficit irrigation during ripening stage (FI-MDI60 and farmer method corresponding to irrigation practices implemented by the local farmers (FM. Results on pepper yield and soil salinity are globally consistent between the two-year experiments and shows significant difference between irrigation regimes. Higher soil salinity was maintained over the two seasons, 2008 and 2009, with DI-60 and FM treatments than FI. FI-MDI60 and DI-80 treatments resulted also in low ECe values. Highest yields for both years were obtained under FI (22.3 and 24.4 t/ha although we didn’t find significant differences with the regulated deficit irrigation treatment (FI-DI60. However, the DI-80 and DI-60 treatments caused significant reductions in pepper yields through a reduction in fruits number/m² and average fruit weight in comparison with FI treatment. The FM increased soil salinity and caused significant reductions in yield with 14 to 43%, 12 to 39% more irrigation water use than FI, FI-MDI60 and DI-80 treatments, respectively, in 2008 and 2009. Yields for all irrigation treatments were higher in the second year compared to the first year. Water productivity (WP values reflected this difference and varied between 2.31 and 5.49 kg/m3. The WP was found to vary significantly among treatments, where the highest and the lowest values were observed for DI-60 treatment and FM, respectively. FI treatment provides

Study on Dragons head (Lallemantia iberica L. Landraces Under Supplementary Irrigation and Rainfed Conditions

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Manouchehr Farzi

2016-06-01

Full Text Available Lallemantia iberica is an annual, herbaceous and drought tolerant plant in the mint family, Lamiaceae, which is cultivated for its seeds. Diversity of 12 dragons head landraces were studied for phenotypic and genotypic variations using agro-morphological traits and some drought tolerance indices. Field study was conducted in the spring of 2013 as a randomized complete block design with three replicates in Maragheh. Results of analysis of variance showed that there was significant difference among the studied landraces for all agro-morphological traits under study between the experimental sites. Combined analysis for grain yield showed that there were significant differences between the experimental sites. The average grain yields were in the range of 730 to 1380 kg.ha-1 under complementary irrigated condition and from 360 to 680 kg.ha-1 under rainfed conditions. Kalibar and Nazarlo landraces for all parameters were highly drought tolerant. Cluster analysis grouped these populations into three distinct clusters. The results also indicated that plant height and days to flowering under complementary irrigation and main branches under rainfed conditions exhibited highest correlations with seed yields.

Comparative evaluation of accuracy of two electronic apex locators in the presence of various irrigants: An in vitro study

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Saru Jain

2012-01-01

Full Text Available Context: The establishment of appropriate working length is one of the most critical steps in endodontic therapy. Electronic apex locators have been introduced to determine the working length. The development of electronic apex locators has helped make the assessment of the working length more accurate and predictable, along with reduction in treatment time and radiation dose. Objectives: The aim of this study was to compare the efficacy of electronic apex locators after cleansing and shaping of the root canals and whether there was any alteration in accuracy when used in the presence of irrigants. Materials and Methods: Seventy extracted human permanent molars with mature apices were selected. Equal number of maxillary and mandibular permanent molars (35 each were sectioned at the cemento-enamel junction. Access opening was done and only the mesiobuccal root canal was studied for the purpose of standardization. Electronic working length measurements were taken before and after preparation of the mesiobuccal canal with Root ZX and ProPex II using various irrigants. Statistical Analysis Used: The data were statistically analyzed using a paired t-test at 0.05 level of significance. Results: P-values for actual and final canal lengths for Root ZX employing NaoCl(0.001, CHX(0.006, LA(0.020 and for ProPex II was (0.001 respectively. When the data were compared, results were statistically significant (P < 0.05. Conclusion: Within the limitations of this study Root ZX can be considered to be an accurate electronic apex locator and CHX as irrigant matched more precisely with the actual canal length measurements.

Effect of addition of organic materials and irrigation conditions on soil quality in olive groves in the region of Messinia, Greece.

Science.gov (United States)

Kavvadias, Victor; Papadopoulou, Maria; Vavoulidou, Evangelia; Theocharopoulos, Sideris; Repas, Spiros; Koubouris, Georgos; Psaras, Georgios

2017-04-01

Intensive cultivation practices are associated to soil degradation mainly due to low soil organic matter content. The application of organic materials to land is a common practice in sustainable agriculture in the last years. However, its implementation in olive groves under different irrigation regimes has not been systematically tested under the prevailing Mediterranean conditions. The aim of this work was to study the effect of alternative carbon input techniques (i.e. wood shredded, pruning residues, returning of olive mill wastes the field with compost) and irrigation conditions (irrigated and rainfed olive orchards) on spatial distribution of soil chemical (pH, EC, total organic carbon, total nitrogen, inorganic nitrogen, humic and fulvic acids, available P, and exchangeable K) and microbial properties (soil basal microbial respiration and microbial biomass carbon) in two soil depths (0-10 cm and 10-40 cm). The study took place in the region of Messinia, South western Peloponnese, Greece during three year soil campaigns. Forty soil plots of olive groves were selected (20 rainfed and 20 irrigated) and carbon input practices were applied on the half of the irrigated and rainfed soil parcels (10 rainfed and 10 irrigated), while the remaining ones were used as controls. The results showed significant changes of chemical and biological properties of soil in olive orchards due to carbon treatments. However, these changes were depended on irrigation conditions. Microbial parameters appeared to be reliable indicators of changes in soil management. Proper management of alternative soil carbon inputs in olive orchards can positively affect soil fertility.

Short communication. Effect of deficit irrigation on curly lettuce grown under semiarid conditions

Energy Technology Data Exchange (ETDEWEB)

Kuslu, Y.; Dursun, A.; Sahin, U.; Kiziloglu, F. M.; Turan, M.

2008-07-01

Field experiments were conducted to characterize the effects of deficit irrigation on curly lettuce (Lactuca sativa var. Crispa cv. Bohemia) evapotranspiration, water use efficiency, marketable yield, yield components and mineral contents. The experiments were performed under semiarid climatic conditions in Erzurum province (east of Turkey) in the summer periods of 2005 and 2006. Irrigation water levels were selected to be 100% of usable soil water in full irrigation treatment (control) (T-100) and 80%, 60%, 40% and 20% of usable soil water in deficit irrigation treatments (T-80, T-60, T-40 and T- 20, respectively). Average seasonal evapotranspiration was 232 mm in T-100 and 121 mm in T-20. Average marketable yield was 39.49 Mg ha{sup -}1 in T-100 and 14.57 Mg ha{sup -}1 in T-20. A linear relationship (y=0.23x-13.97; R{sup 2}0.94) was found between seasonal evapotranspiration (x) and marketable plant yield (y). According to the regression equation, the yield response factor (k{sub y}) was found to be 1.39, and the coefficient of determination 0.91. Average water use efficiency was 168.88 kg ha{sup -}1 mm{sup -}1 in T-100 and 117.39 kg ha{sup -}1 mm{sup -}1 in T-20. The lowest plant length, width, steam diameter, leaf number, macro and micro element content values were obtained for T-20 in both years. (Author) 21 refs.

INFLUENCE OF DIFFERENT SOURCES OF WATER FOR IRRIGATION ON PEPPER (Capsicum annuum L. YIELD IN GLASSHOUSE CONDITIONS

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Jasna Šoštarić

2002-06-01

Full Text Available The aim of this paper was to determine the influence of different sources of water used for irrigation on the yield of pepper hybrids Cecil F1 and Bianca F1 in the early glasshouse production for the period 1998 - 2000 in the controlled glasshouse conditions in «D.G. – PROMET», Magadenovac, Croatia. Lagoon water and well water were two main sources of water used for irrigation in this experiment. Drip irrigation system was applied for pepper production. In comparison to lagoon water, chemical analyses of well water have shown increased values of the following elements: EC, sodium, potassium, calcium, chlorine, magnesium, bicarbonate, sulphate, iron and boron. Temperature of well water was lower than the allowed minimum and therefore had direct influence on the yield decrease. Consequently, areas which have been irrigated by well water have had problems with accumulation of slime and blocking of sprinklers, disturbed soil structure, fruit deformation and decreased crop yield. Statistical data analysis was conducted by the method of covariation three factorial trial (ABC with three repetitions for each treatment. The trial showed absolute difference regarding water efficiency of irrigation water from two sources, which has also been statistically determined (P<0,05. Furthermore, statistically justified difference in the average weight of the fruit of each investigated pepper hybrid (P<0,05 has been proven. Codependence of «water for irrigation» (A and «pepper hybrid» (B, i.e. (AB is statistically significant as well, and justified at the P<0,05 limit. This means that both pepper hybrids (Cecil F1 i Bianca F1 reacted differently to lagoon water and well water. Factor «year» (C has not proven to be statistically justified, and therefore does not have any significant influence on the crop yield due to controlled conditions in the glasshouse.

Varietal improvement of irrigated rice under minimal water conditions

International Nuclear Information System (INIS)

Abdul Rahim Harun; Marziah Mahmood; Sobri Hussein

2010-01-01

Varietal improvement of irrigated rice under minimal water condition is a research project under Program Research of Sustainable Production of High Yielding Irrigated Rice under Minimal Water Input (IRPA- 01-01-03-0000/ PR0068/ 0504). Several agencies were involved in this project such as Malaysian Nuclear Agency (MNA), Malaysian Agricultural Research and Development Institute (MARDI), Universiti Putra Malaysia (UPM) and Ministry of Agriculture (MOA). The project started in early 2004 with approved IRPA fund of RM 275,000.00 for 3 years. The main objective of the project is to generate superior genotypes for minimal water requirement through induced mutation techniques. A cultivated rice Oryza sativa cv MR219 treated with gamma radiation at 300 and 400 Gray were used in the experiment. Two hundred gm M2 seeds from each dose were screened under minimal water stress in greenhouse at Mardi Seberang Perai. Five hundred panicles with good filled grains were selected for paddy field screening with simulate precise water stress regime. Thirty eight potential lines with required adaptive traits were selected in M3. After several series of selection, 12 promising mutant line were observed tolerance to minimal water stress where two promising mutant lines designated as MR219-4 and MR219-9 were selected for further testing under several stress environments. (author)

Identification of Water Usage Efficiency for Corn(Zea mays L.Lines Irrigated with Drip Irrigation Under Green House Conditions asPer Plant Water Stress Index Evaluations

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Ali Beyhan UÇAK

2017-02-01

Full Text Available The present study was conducted as a greenhouse study under Çukurova conditions during the years2011-2012. Two different dent corn lines (5A2-B and 22K were used as the plant material of the experiments. Crop water stress index (CWSI values determined through leaf canopy temperature measurements performed ahead of irrigations were used to find outwater use efficiencies. Experiments were conducted in randomized blocks-split plots experimental design with three replications. Drip irrigation was used for irrigations and two different irrigation programs were created as of I100(supplying 100% of depleted water in every seven days and I75(applying 75% of depleted water. The amount of irrigation water applied for in the interaction of I100irrigation and corn lines (5A2-B and22K in the first and second year were respectively varied between 253.0-274.0and between 238.0-261.0mm, seasonal plant water consumptions varied between 294.0-305.0and between 284.6-302.6 mm, kernel yields varied between 2950.0-2990.0 and between 3130.0-3186.0kgha-1. With regard to (in the interaction irrigation treatments xcorn lines, the lowest and the highest CWSI values were observed in the interaction full irrigation (I100 and of the line 22K as 0.22 and in deficit irrigation treatment (I75 of the line 5A2-B as 0.41in the first year; in full irrigation treatment (I100 of the line 22K as 0.20 and in deficit irrigation treatment (I75 of the line 5A2-B as 0.36. The greatest and the lowest chlorophyll contents (in the interaction irrigation treatments x corn lines were respectively observed in I100treatment of the line 22K as 58.3 spad and in I75treatment of the line 5A2-Bas 50.9 spad in the first year; in I100treatment of the line 22K as 59.1 SPAD and in I75treatment of the line 5A2-B as 55.1 spad. While the effects of irrigation treatments on average dry matter contents of the lines were not found to be significant, significant differences were observed in water use efficiency

Characteristics and influencing factors of crop coefficient for drip-irrigated cotton under plastic mulch conditions in arid environment

DEFF Research Database (Denmark)

Ai, Zhipin; Yang, Yonghui; Wang, Qinxue

2017-01-01

agronomy practice such as plastic mulching and drip irrigation in arid environments. This study calculated and analyzed Kc of a drip-irrigated and plastic-mulched cotton field in Aksu Oasis of the arid Tarim River Basin, China, and its relationships with several crop-, soil- and management variables......-mulched condition already published, the Kc of mulched cotton for the entire growth season decreased by 16 to 39%. The largest reductions in Kc due to plastic mulch were found in the initial and developmental growth stage. Kc could be calculated by a third-degree polynomial model in relation to RGD, which...... significantly increased Kc, i.e., 29% on average, partly due to arid advection. This study provided up-to-date and detailed information on cotton crop coefficient under plastic mulching and drip irrigation conditions in arid environment, and it is useful for improved management of agricultural water resources....

Optimization of Water Allocation between Different Crops in Water Stress Conditions in Qazvin Irrigation Network

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Mehdi Mohammad khani

2017-06-01

Full Text Available Introduction: Evaluations show the necessity of using optimization models in order to determine optimal allocation of water in different water conditions. Its use can be proposed according to developed model abilities in this study in order to optimize water productivity and provide sustainable management and development of water resources over irrigation and drainage networks. Basic needs of the earth growing population and limitation of water and soil resources remindnecessity of optimal use of resources. World’s more than 280 million hectare lands are covered by irrigation networks (Khalkhali et al., 2006. The efficiency of most projects is between 30-50 percent and studies show that performance of most irrigation and drainage networks is not desirable and they have not achieved their aims. Hirich et al. (2014 Used deficit irrigation to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season 2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of a crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of the full irrigation during the vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity. Moghaddasi et al. (2010 worked examines and compares this approach with that based on the optimization method to manage agricultural water demand during drought to minimize damage. The results show that the optimization method resulted in 42% more income for the agricultural sector using the

The Effect of Initial Irrigation Conditions on Heap Leaching Efficiency

Science.gov (United States)

Briseño Arellano, A. D.; Milczarek, M.; Yao, M.; Brusseau, M. L. L.

2017-12-01

Heap leaching is an unsaturated flow metal recovery process, in which mined ore is irrigated with a lixiviant to dissolve metal contained in the ore. The metal is then extracted from solution. Large scale operations involve stacking ore to depths of 6 to 18 meters on pads that may be hundreds of hectares in area. Heterogeneities within the stacked ore can lead to uneven wetting and the formation of preferential flow pathways, which reduces solution contact and lowers metal recovery. Furthermore, mineral dissolution can cause alteration of the porous media structure and loss of ore permeability. Many mine operators believe that slow initial irrigation rates help minimize permeability loss and increase metal recovery rates. However, this phenomenon has not been studied in detail. Experiments were conducted to investigate the effect of varying initial irrigation rates on leach ore stability. These were conducted with large columns (1.5 m high, 0.5 m in diameter) packed with crushed ore samples that are known to have permeability constraints. The columns were highly instrumented to assess potential changes in material properties both spatially and temporally. Water content was measured with three different methods: capacitance soil moisture sensors placed at 20-cm intervals; a neutron probe to periodically log every 30 cm from four different directions; and electrical resistivity sensors to create a 2-dimensional tomography profile of water content over time. Tensiometers were paired with the soil moisture sensors to measure matric suction and characterize moisture retention characteristics. A non-reactive tracer was used to characterize advective-dispersive transport under unsaturated conditions. A dye solution was introduced at the end of each experiment to map preferential pathways. Continuous monitoring of settling at the surface assisted in measuring consolidation and loss in permeability.

Effect of complementary irrigation on yield components and alternate bearing of a traditional olive orchard in semi-arid conditions

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Enrico M. Lodolini

2016-06-01

Full Text Available Traditional olive orchards are usually not irrigated in the Mediterranean basin, but at those latitudes, the yearly rainfall is frequently insufficient to support equilibrated vegetative growth and high fruit and oil production. This three-year field study investigated the effect of complementary irrigation on olive tree vegetative growth, fruit and oil yield during a biennial alternate bearing cycle in a traditional grove under semi-arid conditions. Adult olive trees (Olea europaea L. cv. Nabali Baladi were subjected to complementary irrigation in 2011 and 2012 ('on' and 'off' years, respectively with 6, 10, 15 or 20 m3 of water per tree per season, which corresponded to 14.2%, 23.8%, 35.7% and 47.6% of the whole seasonal evapotranspiration (42 m3 of water per year, respectively. Rain-fed trees were used as control. In 2013, no complementary irrigation was supplied, and any residual effects on the yield components were determined. Results showed that none of the irrigation regimes affected vegetative growth, or olive fruit size (mesocarp and endocarp, as fresh and dry weights. The fruit and oil yield per tree increased compared to the rain-fed conditions only when the threshold of 15 m3 was exceeded, thus inducing a higher crop load compared to the rain-fed control during the 'off' and even further during the 'on' year. No residual effects were registered in 2013. The study showed that complementary irrigation of at least 35% of the seasonal water requirement can produce remarkable positive effects on fruit yield especially during 'on' bearing years.

Evaluation of Yield and Yield Components of Black Cumin (Nigella sativa L. under different Plant Density and Limited Irrigation Condition

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Sh Rezvan Beidokhti

2012-10-01

Full Text Available Research on crop response to deficit irrigation is important to reduce agriculture water use in areas where water is limited resource. Using drought resistant landraces with irrigation scheduling based on phenological stages in semi-arid and arid regions may provide an opportunity to optimize irrigation efficiency and water savings in these regions. In order to evaluate of yield and yield components of black cumin under different plant density and limited irrigation condition an experiment was conducted in Research Farm of Islamic Azad University of Damghan during growing season of 2007-2008. The experimental treatments were arranged in split plots based on a complete randomized block design with three replications. The limited irrigation (based on phenological stages treatments were included: cutting irrigation at blooming (folded flowers, cutting irrigation at flowering stage, cutting irrigation at seed formation and normal weekly irrigation (control were allocated to the main plots and different plant density: 100, 150, 200 and 250 plant per square meter (m2 were allocated to sub plots. The results showed that the effect of limited irrigation, plant density and their interaction on plant height, number of follicle, follicle weight, number of seed, 1000 seed weight, seed yield, biological yield and harvest index Black Cumin. The highest yield and yield components was obtained in normal irrigation (control and 200 plant density and the lowest yield were obtained when irrigation cut at the blooming stage and 250 plant density. There was a significant correlation between seed yield and number (r=0.90, 1000 seed weight (r=0.95 and biological yield (r=0.97. Optimum plant density of black cumin was decreased under limited irrigation treatments. Under normal (control and limited irrigation, optimum plant density was 200 and 150 plant per (m2 respectively.

Electronic signal conditioning

CERN Document Server

NEWBY, BRUCE

1994-01-01

At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

Effect of complementary irrigation on yield components and alternate bearing of a traditional olive orchard in semi-arid conditions

Energy Technology Data Exchange (ETDEWEB)

Lodolini, E.M.; Polverigiani, S.; Ali, S.; Mutawea, M.; Qutub, M.; Pierini, F.; Neri, D.

2016-11-01

Traditional olive orchards are usually not irrigated in the Mediterranean basin, but at those latitudes, the yearly rainfall is frequently insufficient to support equilibrated vegetative growth and high fruit and oil production. This three-year field study investigated the effect of complementary irrigation on olive tree vegetative growth, fruit and oil yield during a biennial alternate bearing cycle in a traditional grove under semi-arid conditions. Adult olive trees (Olea europaea L. cv. Nabali Baladi) were subjected to complementary irrigation in 2011 and 2012 ('on' and 'off' years, respectively) with 6, 10, 15 or 20 m3 of water per tree per season, which corresponded to 14.2%, 23.8%, 35.7% and 47.6% of the whole seasonal evapotranspiration (42 m3 of water per year), respectively. Rain-fed trees were used as control. In 2013, no complementary irrigation was supplied, and any residual effects on the yield components were determined. Results showed that none of the irrigation regimes affected vegetative growth, or olive fruit size (mesocarp and endocarp), as fresh and dry weights. The fruit and oil yield per tree increased compared to the rain-fed conditions only when the threshold of 15 m3 was exceeded, thus inducing a higher crop load compared to the rain-fed control during the 'off' and even further during the 'on' year. No residual effects were registered in 2013. The study showed that complementary irrigation of at least 35% of the seasonal water requirement can produce remarkable positive effects on fruit yield especially during 'on' bearing years. (Author)

Evaluation of drought tolerance and yield capacity of barley (hordeum vulgare) genotypes under irrigated and water-stressed conditions

International Nuclear Information System (INIS)

Khokhar, M.I.; Silva, J.A.T.D

2012-01-01

Twelve barley genotypes developed through different selection methods were evaluated under drought and irrigated conditions. The results of a correlation matrix revealed highly significant associations between Grain Yield (Yp) and Mean Productivity (MP), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP) and Yield Index (Yi) under irrigated conditions while the Mean Productivity (MP), Yield Stability Index (Yi), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP) and Yield Index (Yi) had a high response under stressed condition. Based on a principal component analysis, Geometric Mean Productivity (GMP), Mean Productivity (MP) and Stress Tolerance Index (STI) were considered to be the best parameters for selection of drought-tolerant genotypes. The 2-row barley genotypes B-07023 and B-07021 performed better in yield response under drought conditions and were more stable under stress conditions. Furthermore, drought stress reduced the yield of some genotypes while others were tolerant to drought, suggesting genetic variability in this material for drought tolerance. (author)

Agro-ecology and irrigation technology : comparative research on farmer-managed irrigation systems in the Mid-hills of Nepal

NARCIS (Netherlands)

Parajuli, U.N.

1999-01-01

Design and management of irrigation infrastructure in farmer managed irrigation systems (FMISs) are strongly influenced by social and agro-ecological conditions of an area. This thesis analyzes the elements of social and agro-ecological conditions in FMISs in the mid-hills of Nepal and

An intuitionistic fuzzy multi-objective non-linear programming model for sustainable irrigation water allocation under the combination of dry and wet conditions

Science.gov (United States)

Li, Mo; Fu, Qiang; Singh, Vijay P.; Ma, Mingwei; Liu, Xiao

2017-12-01

Water scarcity causes conflicts among natural resources, society and economy and reinforces the need for optimal allocation of irrigation water resources in a sustainable way. Uncertainties caused by natural conditions and human activities make optimal allocation more complex. An intuitionistic fuzzy multi-objective non-linear programming (IFMONLP) model for irrigation water allocation under the combination of dry and wet conditions is developed to help decision makers mitigate water scarcity. The model is capable of quantitatively solving multiple problems including crop yield increase, blue water saving, and water supply cost reduction to obtain a balanced water allocation scheme using a multi-objective non-linear programming technique. Moreover, it can deal with uncertainty as well as hesitation based on the introduction of intuitionistic fuzzy numbers. Consideration of the combination of dry and wet conditions for water availability and precipitation makes it possible to gain insights into the various irrigation water allocations, and joint probabilities based on copula functions provide decision makers an average standard for irrigation. A case study on optimally allocating both surface water and groundwater to different growth periods of rice in different subareas in Heping irrigation area, Qing'an County, northeast China shows the potential and applicability of the developed model. Results show that the crop yield increase target especially in tillering and elongation stages is a prevailing concern when more water is available, and trading schemes can mitigate water supply cost and save water with an increased grain output. Results also reveal that the water allocation schemes are sensitive to the variation of water availability and precipitation with uncertain characteristics. The IFMONLP model is applicable for most irrigation areas with limited water supplies to determine irrigation water strategies under a fuzzy environment.

Study on Replacement Probability of Organic with Chemical Fertilizers in Canola (Brassica napus under Two Deficit and Full Irrigation Conditions

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S. J. Azimzadeh

2017-03-01

fertilizer was scattered in plots and mixed completely with soil. After that in each plot, six rows with distance of 25 cm were designed and canola seeds were placed into the rows and were covered by 3 cm of soil. Through cultivation season and after harvesting the treatments of plant height, pod number per plant, seed number per pod, thousand kernel weight, seed yield and biological yield were recorded. Data were analyzed by MSTAT-C and mean comparison was performed using Duncan's multiple test range. Results and Discussion The highest seed yield was obtained in irrigation treatment and application of chemical fertilizer (1284 kg/h. In all of vermicompost treatments in full irrigation compared with deficit irrigation, seed yield was more but the trend of changes in seed yield was the same in both conditions. It means that seed yield increased with increasing vermicompost application from 7 to 11 t/h, but seed yield decreased with increasing vermicompost from 11 to 15 t/h. In treatment of manure application in both conditions of deficit and full irrigation, increasing the manure fertilizer, increased seed yield. Seed yield reaction in treatments of municipal waste compost in both conditions of full and deficit irrigation was the same as vermicompost. It means that increasing the application of municipal waste compost from 7 to 11 t/h, increased seed yield and increasing the application of municipal waste compost from 11 to 15 t/h, decreased seed yield. Biological yield reaction to fertilizer treatments was the same as seed yield. Overlay application of 50 t/h cow manure in deficit irrigation produced the most seed yield compared with all other fertilizer treatments including chemical fertilizer at the rate of 6%. This yield increment was due to higher pod number per plant and higher seed number per pod. In full irrigation, chemical fertilizer produced the most seed yield compared with all other fertilizer treatments. Conclusions Generally, it is concluded that canola in

Simulation of irrigation and nitrogen fertilization management of maize under edaphic conditions of south of Havana

International Nuclear Information System (INIS)

Lopez Seijas, Teresa; Cid, G.; Gonzalez, F.; Jorge, Y.; Chaterlan, Y.; Giralt, E.; Rodriguez, R.; Duennas, G.

1999-01-01

The main objective of this work is to validate the crop simulation model STICS for the soil and climate conditions of south of Havana, especially for the water and nitrogen balances on Maize crop on Ferralitic soil, For this purpose was used all the available information from field experiments carried out in the Experimental Stations of the Irrigation and Drainage and Soil Research Institutes, both on south of Havana, The comparison between the simulation and observed values showed a good fitness for the variables related to the crop water uptake, while for the soil water content when the root water uptake flux is minimum and the soil water redistribution flux is maximum wasn't good, The soil nitrogen balance was adjusted from the optimization of the parameters related to the mineralization velocity of soil organic nitrogen, Nevertheless is necessary to complete this study involving other climate conditions and water and nitrogen managements to define the optimum strategy for irrigation and fertilization of Maize crop on the studied conditions,

A review of mechanical move sprinkler irrigation control and automation technologies

Science.gov (United States)

Electronic sensors, equipment controls, and communication protocols have been developed to meet the growing interest in site-specific irrigation using center pivot and lateral move irrigation systems. Onboard and field-distributed sensors can collect data necessary for real-time irrigation manageme...

A multi-attribute preference model for optimal irrigated crop planning under water scarcity conditions

Energy Technology Data Exchange (ETDEWEB)

Montazar, A.; Snyder, R. L.

2012-11-01

Water resources sustainability has a key role in the existence and durability of irrigated farming systems and strongly depends on the crop planning. The decision process is complex due to a number of constraints and the desire to secure crop diversification and the involvement of affected various parameters. The objective of the present study was to develop a comprehensive multi-criteria model for selecting adequate cropping pattern in an irrigation district under water scarcity condition. Eleven and nine attribute decisions were considered in ranking the type of crop and determination of the percentage of crop cultivation area as an optimal irrigated crop planning system, respectively. The results indicate that the proposed multi-attribute preference approach can synthesize various sets of criteria in the preference elicitation of the crop type and cultivated area. The predictive validity analysis shows that the preferences acquired by the proposed model are evidently in reasonable accordance with those of the conjunctive water use model. Consequently, the model may be used to aggregate preferences in order to obtain a group decision, improve understanding of the choice problem, accommodate multiple objectives and increase transparency and credibility in decision making by actively involving relevant criteria in the crop planning. (Author) 27 refs.

Effectiveness of four different final irrigation activation techniques on smear layer removal in curved root canals : a scanning electron microscopy study.

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Puneet Ahuja

2014-02-01

Full Text Available The aim of this study was to assess the efficacy of apical negative pressure (ANP, manual dynamic agitation (MDA, passive ultrasonic irrigation (PUI and needle irrigation (NI as final irrigation activation techniques for smear layer removal in curved root canals.Mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. A glide path with #08-15 K files was established before cleaning and shaping with Mtwo rotary instruments (VDW, Munich, Germany up to size 35/0.04 taper. During instrumentation, 1 ml of 2.5% NaOCl was used at each change of file. Samples were divided into 4 equal groups (n=20 according to the final irrigation activation technique: group 1, apical negative pressure (ANP (EndoVac; group 2, manual dynamic agitation (MDA; group 3, passive ultrasonic irrigation (PUI; and group 4, needle irrigation (NI. Root canals were split longitudinally and subjected to scanning electron microscopy. The presence of smear layer at coronal, middle and apical levels was evaluated by superimposing 300-μm square grid over the obtained photomicrographs using a four-score scale with X1,000 magnification.Amongst all the groups tested, ANP showed the overall best smear layer removal efficacy (p < 0.05. Removal of smear layer was least effective with the NI technique.ANP (EndoVac system can be used as the final irrigation activation technique for effective smear layer removal in curved root canals.

Nitrogen replacement value of alfalfa to corn and wheat under irrigated Mediterranean conditions

OpenAIRE

Ballesta, A.; Lloveras, J.

2010-01-01

In crop rotations that include alfalfa (Medicago sativa L.), agronomic and environmental concerns mean that it is important to determine the N fertilizer contribution of this legume for subsequent crops in order to help to increase the sustainability of cropping systems. To determine the N fertilizer replacement value (FRV) of a 2-yr alfalfa crop on subsequent crops of corn (Zea mays L.) followed by wheat (Triticum aestivum L.) under irrigated Mediterranean conditions, two 4-yr rotations (alf...

Irrigation Depletions 1928-1989 : 1990 Level of Irrigation, Snake Yakima and Deschutes River Basins.

Energy Technology Data Exchange (ETDEWEB)

United States. Bonneville Power Administation; A.G. Crook Company

1993-07-01

The vast amount of irrigation in relation to the available water and extensive system of reservoirs located in the Snake River Basin above Brownlee reservoir precludes this area from using methods such as Blaney-Criddle for estimating irrigation depletions. Also the hydrology, irrigation growth patterns, and water supply problems are unique and complex. Therefore regulation studies were utilized to reflect the net effect on streamflow of the changes in irrigated acreage in terms of corresponding changes in storage regulation and in the amount of water depleted and diverted from and returned to the river system. The regulation study for 1990 conditions was conducted by the Idaho Department of Water Resources. The end product of the basin simulation is 61 years of regulated flows at various points in the river system that are based on 1990 conditions. Data used by the Idaho Department of Water Resources is presented in this section and includes natural gains to the river system and diversions from the river system based on a 1990 level of development and operation criteria. Additional information can be obtained for an Idaho Department of Water Resources Open-File Report ``Stream Flows in the Snake River Basin 1989 Conditions of Use and Management`` dated June 1991. Similar considerations apply to the Yakima and Deschutes river basins.

Effects of surface and subsurface drip irrigation regimes with saline water on yield and water use efficiency of potato in arid conditions of Tunisia

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Fathia El Mokh

2014-12-01

significant advantage on yield and WUE and reduces the soil salinity compared to the SDI in potato production under experimental conditions. The SSDI and FI100 irrigation techniques seem to optimize the use of saline water in potato production and to control soil salinity. Under situations of water shortage, adopting deficit irrigation treatment (DI60 could be an alternative for irrigation scheduling of spring and autumn potato under the arid conditions of southern Tunisia.

Environmental effects on proline accumulation and water potential in olive leaves (Olea europaea L. (cv Chemlali)) under saline water irrigated field conditions

Energy Technology Data Exchange (ETDEWEB)

Ben Ahmed, C.; Ben Rouina, B.; Boukhris, M.

2009-07-01

In arid regions in Tunisia suffering from limited water resources, the olive extension to irrigated lands has led to the urgent use of saline water, the most readily available water in the these areas. Nevertheless, the effects of salt stress on olive tree seem to be reinforced by environmental conditions. The issue of this paper is to determine how does the olive tree respond to environmental stress in the Mediterranean climate under saline water irrigated field conditions with respect to leaf proline concentrations and water Status. (Author)

Environmental effects on proline accumulation and water potential in olive leaves (Olea europaea L. CV Chemlali)) under saline water irrigated field conditions

International Nuclear Information System (INIS)

Ben Ahmed, C.; Ben Rouina, B.; Boukhris, M.

2009-01-01

In arid regions in Tunisia suffering from limited water resources, the olive extension to irrigated lands has led to the urgent use of saline water, the most readily available water in the these areas. Nevertheless, the effects of salt stress on olive tree seem to be reinforced by environmental conditions. The issue of this paper is to determine how does the olive tree respond to environmental stress in the Mediterranean climate under saline water irrigated field conditions with respect to leaf proline concentrations and water Status. (Author)

Downwind evolution of transpiration by two irrigated crops under conditions of local advection

Science.gov (United States)

McAneney, K. J.; Brunet, Y.; Itier, B.

1994-09-01

Previous measurements of water loss from small-dish evaporimeters mounted at the height of irrigated crops grown under conditions of extreme local advection in the Sudan are reexamined. From these evaporimeter measurements, it is possible to calculate fractional changes in the saturation deficit. Relationships between canopy conductance and saturation deficit are briefly reviewed and introduced into the Penman-Monteith equation to calculate transpiration rates as a function of distance downwind of the boundary between the upwind desert and the irrigated crop. In contradiction to most theoretical predictions, these new calculations show rates of transpiration to undergo only modest changes with increasing fetch. This occurs because of the feedback interaction between saturation deficit and stomatal conductance. This result is in good accord with a recent study suggesting that a dry-moist boundary transition may be best modelled as a simple step change in surface fluxes and further that the advective enhancement of evaporation may have been overestimated by many advection models. Larger effects are expected on dry matter yields because of the direct influence of saturation deficit on the yield-transpiration ratio.

Coordinated research project of the use of nuclear and related techniques in assessment of irrigation schedules of field crops to increase effective use of water in irrigation projects

International Nuclear Information System (INIS)

Anac, M.S.; Tuzel, I.H.; Anac, D.

1995-01-01

The study aimed at determining the followings; water consumptions. irrigation water requirements of new cotton variety N 84; specific growth stages of cotton which are less sensitive to stress so that the irrigation could be avoided without significant yield decrease; and interactions between deficit irrigation and nitrogen fertilizer use. The experiment was set up with 6 irrigation and three nitrogen fertilizer (0.60 , 120 kg.ha sup -1 ) treatments. The irrigation treatments employed single stress at vegetative, flowering and boll formation stages, in addition to full irrigation, continuous stress and the traditional practice. In stress conditions available soil water depleted to 75 - 80 %, whereas in normal irrigation the depletion was 40 % in 0.90 m. of root zone. In full irrigation treatment 8 irrigations were applied, whereas 3 or 4 irrigations were needed in continuous stress conditions. The number of irrigations were 6 or 7 for other stress treatments. Irrigation water applications varied form 424 to 751 mm. Seasonal ET were ranged between 659 and 899 mm. The highest monthly ET in august for all of the treatments. Daily ET were found to vary from 2.2 to 12.1 mm/day. The seed cotton yields, ky values and yield - N indices have indicated that the vegetative state was more sensitive to water stress. The stress at boll formation stage had slight effects on these parameters. Under limited water resource conditions, vegetative growth period of cotton should be given preference for irrigation, followed by flowering period. Omitting irrigation in boll formation period would result in 4.3 to 9.1 % water savings. Yield changes with respect to N rates showed that high N doses are accompanied by high yields. Nitrogen recoveries either from fertilizers or soil revealed high uptakes in full irrigation conditions. Nitrogen use efficiencies were also high in these conditions. Average of three years put forth that 19% of N in stress conditions and 29% in full irrigation were

Contribution to the improvement of irrigation management practices through water - deficit irrigation

International Nuclear Information System (INIS)

Bazza, M.

1995-01-01

The study aimed at identifying irrigation management practices which could result in water savings through -water deficit irrigation. Two field experiments, one on wheat and the other on sugar beet, were conducted and consisted of refraining from supplying water during specific stages of the cycle so as to identy the period(s) during which water deficit would have a limited effect on crop production. In the case of wheat, high water deficit occurred during the early and during these stages was the most beneficial for the crop. However, one water application during the tillering stage allowed the yield to be lower only to that of the treatement with three irrigations. Irrigation during the stage of grain filling caused the kernel weight to be as high as under three irrigations. The lowest value corresponded to the treatement with one irrigation during grain filling and that under rainfed conditions. For sugar beet, when water stress was was applied early in the crop cycle, its effect could be almost entirely recovered with adequate watering during the rest of the growing season. On the opposite, good watering early in cycle, followed by a stress, resulted in the second lowest yield. Water deficit during the maturity stage had also a limited effect on yield. The most crucial periods for adequate watering were which correspond to late filiar development and root growth which coincided with the highest water requirements period. For the same amount of water savings through deficit irrigation, it was better to partition the stress throughout the cycle than during the critical stages of the crop. However, at the national level, it would have been more important to practice deficit irrigation and the irrigated area. For both crops, high yields as high as water - use efficiency values could have been obtained. 8 tabs; 5 refs ( Author )

Effect of Irrigation Regimes on Yield of Two Commercial Varieties of Pomegranate in the Climatic Condition in Yazd

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ali bafkar

2017-02-01

. At the beginning of each block a flow meter was installed to measure the amount of water distribution. All the operations, including pruning and combat weeds, fertilizing, leaching requirement, according to the research center for all three irrigation regimes in the garden was the same as usual conditions. Due to the salinity of irrigation water and soil salinity testing during the growing season only once and 25 percent, respectively water and soil physical and chemical properties of the test was run. Results and discussion: Analysis of variance and comparison of performance for the three treatments was shown in table (number of the table. In calculating the yield, weight per hectare garden products were considered. Analysis of variance showed that the yield of the different treatments in the water by five percent (p

Study of Irrigation Interval and Mulch Effects on Pomological Characteristics and Yield of Sevillana Cultivar in Field Condition

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rahmatollah gholami

2018-03-01

Full Text Available Introduction: Olive (Olea europaea L. is one of the drought tolerant ever green fruit trees. Olive is an economically important species of the Mediterranean area, so understanding the mechanisms by which olive plants face drought stress under environmental conditions is essential for the improvement of olive yield and oil quality. Olive is one of the fruit trees which become important in the Iranian fruit industry at the near future. Mulch is an optimizing strategy under which crops are allowed to sustain some degree of water deficit and yield reduction. Increasing crop water-use efficiency (WUE through water conservation in the soil is an important component of dry land farming. Mulching is among the water management practices for increasing WUE. Mulch is referred to as any material that is spread onto the surface of the soil for protection against solar radiation or evaporation. Different materials, such as wheat straw, rice straw, plastic film, grass, wood, and sand, are used as mulches. Materials and Methods: This experiment was conducted to study the effect of irrigation interval and mulch on Pomological characteristics and yield of 11-years old Sevillana olive cultivar. A factorial experiment was carried out in Dallaho Olive Research Station at Sarepole located in Kermanshah province. Field experiment based on randomized complete block design with three replications and two factors (irrigation interval and mulch were conducted in 2015. Each experiment unit consists of 4 trees and 108 trees were used. Irrigation treatments period for experiment were 3, 6 and 10 days interval and mulch treatments for experiment were polyethylene, organic materials and non-mulch (control. Geographical characters was longitude of 45˚, 51΄ E and latitude of 34˚, 30΄ N and the height of sea level 581m. The measured tree characteristics were: Fruit Weight, Pulp Fresh Weight, Pulp Dry Weight, Dry matter, Pulp/Pit ratio, Pit Length, Pit Diameter, Fruit Yield

Improving yield and water productivity of maize grown under deficit-irrigated in dry area conditions

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Mohamed H. Abd el-wahed

2015-10-01

Full Text Available Scarcity of water is the most severe constraint for development of maize in arid and semi-arid areas. Based on the actual crop need, the irrigation management has to be improved so that the water supply to the crop can be reduced while still achieving high yield. Therefore, the current study has been organized to evaluate the effects of deficit sprinkler irrigation (DSI and farmyard manure (FYM on Grain yield (GY and crop water productivity (CWP of corn, a 2-year experiment was conducted in arid region of Libya. The DSI treatments were (I100 = 100%, I85 = 85% or I70 = 70% of the crop evapotranspiration. FYM treatments were (0, 10 ton ha−1 spread either on the soil surface, incorporated with surface or subsurface layer (FYM10s, FYM10m or FYM10ss, respectively and 20 ton ha−1 spread as before (FYM20s, FYM20m or FYM20ss, respectively. Results indicated that the highest values of grain yield (GY were obtained from I100 treatment, while the lowest were observed in I70. FYM20ss enhanced GY than other FYM treatments in both seasons. The highest GY and CWP were recorded with I100 and received FYM20ss. It could be considered as a suitable under arid environmental conditions and similar regions, the treatment (I100 × FYM20ss is the most suitable for producing high GY and CWP. Under limited irrigation water, application of (I85 ×FYM20ss treatment was found to be favorable to save 15% of the applied irrigation water, at the time in which produced the same GY.

Are There Infinite Irrigation Trees?

Science.gov (United States)

Bernot, M.; Caselles, V.; Morel, J. M.

2006-08-01

In many natural or artificial flow systems, a fluid flow network succeeds in irrigating every point of a volume from a source. Examples are the blood vessels, the bronchial tree and many irrigation and draining systems. Such systems have raised recently a lot of interest and some attempts have been made to formalize their description, as a finite tree of tubes, and their scaling laws [25], [26]. In contrast, several mathematical models [5], [22], [10], propose an idealization of these irrigation trees, where a countable set of tubes irrigates any point of a volume with positive Lebesgue measure. There is no geometric obstruction to this infinitesimal model and general existence and structure theorems have been proved. As we show, there may instead be an energetic obstruction. Under Poiseuille law R(s) = s -2 for the resistance of tubes with section s, the dissipated power of a volume irrigating tree cannot be finite. In other terms, infinite irrigation trees seem to be impossible from the fluid mechanics viewpoint. This also implies that the usual principle analysis performed for the biological models needs not to impose a minimal size for the tubes of an irrigating tree; the existence of the minimal size can be proven from the only two obvious conditions for such irrigation trees, namely the Kirchhoff and Poiseuille laws.

Irrigation Water Management in Latin America

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Aureo S de Oliveira

2009-12-01

Full Text Available Latin American countries show a great potential for expanding their irrigated areas. Irrigation is important for strengthening local and regional economy and for enhancing food security. The present paper aimed at providing a brief review on key aspects of irrigation management in Latin America. Poor irrigation management can have great impact on crop production and on environment while good management reduces the waste of soil and water and help farmers maximizing their profits. It was found that additional research is needed to allow a better understanding of crop water requirements under Latin American conditions as well as to provide farmers with local derived information for irrigation scheduling. The advantages of deficit irrigation practices and the present and future opportunities with the application of remote sensing tools for water management were also considered. It is clear that due to the importance of irrigated agriculture, collaborative work among Latin American researchers and institutions is of paramount importance to face the challenges imposed by a growing population, environment degradation, and competition in the global market.

Preliminary Studies of the Performance of Quinoa (Chenopodium quinoa Willd.) Genotypes under Irrigated and Rainfed Conditions of Central Malawi.

Science.gov (United States)

Maliro, Moses F A; Guwela, Veronica F; Nyaika, Jacinta; Murphy, Kevin M

2017-01-01

The goal of sustainable intensification of agriculture in Malawi has led to the evaluation of innovative, regionally novel or under-utilized crop species. Quinoa ( Chenopodium quinoa Willd.) has the potential to provide a drought tolerant, nutritious alternative to maize. We evaluated 11 diverse varieties of quinoa for their yield and agronomic performance at two locations, Bunda and Bembeke, in Malawi. The varieties originated from Ecuador, Chile and Bolivia in South America; the United States and Canada in North America; and, Denmark in Europe, and were chosen based on their variation in morphological and agronomic traits, and their potential for adaptation to the climate of Malawi. Plant height, panicle length, days to maturity, harvest index, and seed yield were recorded for each variety under irrigation at Bunda and Bembeke, and under rainfed conditions at Bunda. Plant height was significantly influenced by both genotype and environment. There were also significant differences between the two locations for panicle length whereas genotype and genotype × environment (G × E) interaction were not significantly different. Differences were found for genotype and G × E interaction for harvest index. Notably, differences for genotype, environment and G × E were found for grain yield. Seed yield was higher at Bunda (237-3019 kg/ha) than Bembeke (62-692 kg/ha) under irrigated conditions. The highest yielding genotype at Bunda was Titicaca (3019 kg/ha) whereas Multi-Hued was the highest (692 kg/ha) at Bembeke. Strong positive correlations between seed yield and (1) plant height ( r = 0.74), (2) days to maturity ( r = 0.76), and (3) biomass ( r = 0.87) were found under irrigated conditions. The rainfed evaluations at Bunda revealed significant differences in seed yield, plant biomass, and seed size among the genotypes. The highest yielding genotype was Black Seeded (2050 kg/ha) followed by Multi-Hued (1603 kg/ha) and Bio-Bio (1446 kg/ha). Ecuadorian (257 kg/ha) was

Irrigation of steppe soils in the south of Russia: Problems and solutions (Analysis of Irrigation Practices in 1950-1990)

Science.gov (United States)

Minashina, N. G.

2009-07-01

Experience in irrigation of chernozems in the steppe zone of Russia for a period from 1950 to 1990 is analyzed. By the end of this period and in the subsequent years, the areas under irrigation reduced considerably, and the soil productivity worsened. This was caused by the improper design of irrigation systems, on the one hand, and by the low tolerance of chernozems toward increased moistening upon irrigation, on the other hand. The analysis of the factors and regimes of soil formation under irrigation conditions shows that irrigation-induced changes in the soil hydrology also lead to changes in the soil physicochemical, biochemical, and other properties. In particular, changes in the composition of exchangeable cations lead to the development of solonetzic process. In many areas, irrigation of chernozems was accompanied by the appearance of solonetzic, vertic, saline, and eroded soils. The development of soil degradation processes is described. In general, the deterioration of irrigated chernozems was related to the absence of adequate experience in irrigation of steppe soils, unskilled personnel, improper regime of irrigation, and excessively high rates of watering. In some cases, the poor quality of irrigation water resulted in the development of soil salinization and alkalization. To improve the situation, the training of personnel is necessary; the strategy of continuous irrigation should be replaced by the strategy of supplementary irrigation in the critical periods of crop development.

Biological degradation of chernozems under irrigation

Directory of Open Access Journals (Sweden)

Oksana Naydyonova

2014-12-01

Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

Effect of Timing and Amount of Irrigation Water on Bean Yield and Water Use Efficiency in Arid and Semi-arid Conditions

Directory of Open Access Journals (Sweden)

S.S. Nurbakhsh

2016-02-01

Full Text Available Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling is one of the most important factors in crop’s quality and quantity. The main objective of irrigation scheduling is to control crop’s water conditions in order to achieve its optimum yield level. So irrigation timing is the vital factor on which crop water stress and eventually yield's level are dependent upon. Moreover, irrigation timing is used in irrigation scheduling. The aim of this study was to evaluate the effect of irrigation time on water consumption, water use efficiency and yield of beans. Materials and Methods: In order to observe the effect of the amount and the time of the irrigation on water consumption, yields rate and water use efficiency, the current research was carried out at the University of Shahrekord during the summer of 2012. The experiment was done as a completely randomized design with 4 repetitions consisting of irrigation time and the amount of irrigation in 4 and 2 levels (at 6, 8, 14 and 18 and (deficit irrigation, full irrigation, respectively. Beans seeds were planted in 32 similar vases with a diameter of 45 cm and height of 60 cm, in each experiment. Treatments were begun after 37 days from planting. Treatments were irrigated when the average moisture in the root zone was equal to the lower border of readily available water of full irrigation. At the end of the experiments, plants were completely harvested. Then the plant’s height, number of branches, numbers of pods per plant, pod and seed weight were measured. Results and Discussion: Results showed that irrigating at different times during the day influenced water use efficiency, water consumption, seeds yield and number of pods in the bush. The water

Effect of climatic conditions and irrigation on sugarbeet production in the Vojvodina Province, Serbia and Montenegro

International Nuclear Information System (INIS)

Maksimovic, Livija; Dragovic, Svetimir

2004-01-01

The climatic conditions in the Vojvodina Province, the main agricultural region of Serbia and Montenegro, are generally favorable for crop production, but the rainfall during growing season is frequently too low or irregular to secure high and stable yields of agricultural crops including sugarbeet. In climatic conditions where there is an uneven amount and distribution of precipitation, as is the case with this region, sugarbeet yield performance is directly dependent on weather conditions. Sugarbeet yields vary not only from one year to another but also from one region to another within the single growing season. The average sugar beet water requirement for the period 1987-2002 was 586 mm, with fairly small variations by either the region or the year. About 10-20% of the total sugarbeet requirement for water comes from reserve soil water, while the rest is provided by rainfall and irrigation. The actual evapotranspiration is 392 mm on the average, ranging from 198 mm in dry years to 542 mm in rainy years. The average precipitation sum for the growing season at Rimski Sancevi site was 360 mm, with high annual variation - from 138 to 683 mm. The average water deficit relative to the sugar beet water requirement was 190 mm, ranging from 24 to 367 mm. The deficit was especially pronounced in July and August, when it ranged between 0 and 282 mm, averaging 146 mm, or 75% of the total requirement. Sugarbeet root yield is directly proportional to the amount of rainfall during growing season and the amount of available water spent for actual evapotranspiration. Relatively high yields have been obtained in years with high amounts of rainfall (from 500 to 650 mm) and favorable distribution of rainfall during growing season. High yields were also obtained in years with relatively low amounts of rainfall but moderately favorable or favorable distribution of rainfall. In the period 1990-1999, root yields in commercial production varied significantly, from the average of 22.7 t

Soil Suitability Classification of Tomas Irrigation Scheme for Irrigated ...

African Journals Online (AJOL)

The need for sustainable rice production in Nigeria cannot be over-emphasized. Since rice can be grown both under rain-fed and irrigated conditions, the need for soil suitability evaluation becomes very necessary in order for supply to meet up with demand. Six land qualities viz; climate, soil physical properties, drainage, ...

A Fuzzy analytical hierarchy process approach in irrigation networks maintenance

Science.gov (United States)

Riza Permana, Angga; Rintis Hadiani, Rr.; Syafi'i

2017-11-01

Ponorogo Regency has 440 Irrigation Area with a total area of 17,950 Ha. Due to the limited budget and lack of maintenance cause decreased function on the irrigation. The aim of this study is to make an appropriate system to determine the indices weighted of the rank prioritization criteria for irrigation network maintenance using a fuzzy-based methodology. The criteria that are used such as the physical condition of irrigation networks, area of service, estimated maintenance cost, and efficiency of irrigation water distribution. 26 experts in the field of water resources in the Dinas Pekerjaan Umum were asked to fill out the questionnaire, and the result will be used as a benchmark to determine the rank of irrigation network maintenance priority. The results demonstrate that the physical condition of irrigation networks criterion (W1) = 0,279 has the greatest impact on the assessment process. The area of service (W2) = 0,270, efficiency of irrigation water distribution (W4) = 0,249, and estimated maintenance cost (W3) = 0,202 criteria rank next in effectiveness, respectively. The proposed methodology deals with uncertainty and vague data using triangular fuzzy numbers, and, moreover, it provides a comprehensive decision-making technique to assess maintenance priority on irrigation network.

Ring Irrigation System (RIS) design through customer preference representation

OpenAIRE

Ridwan Infandra I.Z.; Rianmora Suchada; Werawatganon Siwat

2018-01-01

In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent ...

Column leaching experiments of a uranium ore by atomizing irrigation technique

International Nuclear Information System (INIS)

Zeng Yingying; Lei Zeyong; Chen Haihui

2007-01-01

Column leaching experiments ora uranium ore were made by atomizing irrigation technique. The leaching results are compared with the results obtained by spray irrigation and drip irrigation techniques respectively under the same conditions of column leaching experiments. The results show that the atomizing irrigation technique has more uniform solution distribution, higher leaching rate, shorter leaching period, and less ratio of liquid to solid. Consequently, the atomizing irrigation technique is suitable to the ore. (authors)

DEFICIT IRRIGATION TECHNIQUE FOR REDUCING WATER USE OF TOMATO UNDER POLYTUNNEL CONDITIONS

Directory of Open Access Journals (Sweden)

Sladjana SAVIC

2012-01-01

Full Text Available The aim of paper was to asses the use of regulated deficit irrigation (RDI for production of two tomato cultivars (Cedrico and Abellus in polytunnels in Serbia. RDI plants received 60% of the water that was applied to FI plants and significant saving of water for irrigation and increased in irrigation water use efficiency (IWUE were achieved. Yield data for Cedrico cultivar showed no differences between RDI and FI, while due to the bigger sensitivity to drought, yield of Abellus was reduced under RDI. In general, fruit quality (soluble solids, titrable acidity was sustained or improved in both cultivars under RDI. Economic analyses showed that due to the current low prices of water and electricity in Serbia, the profit increase of Cedrico, similarly to the previously trialed cultivar Amati, was not high under RDI comparing to FI. Reduction of yield and consequent profit for Abellus, indicated that for future commercial growing of tomato under RDI should be used drought resistant cultivars.

Defining Efficient Deficit Irrigation for Winegrape Cultivars Merlot and Cabernet Sauvignon under Semiarid Conditions

Science.gov (United States)

Efficient deficit irrigation balances enhanced berry attributes with acceptable reduction in yield. The present study relates pre and post-veraison midday leaf water potential with the growth and composition of east and west-facing berries. Two deficit irrigation treatments were applied over four g...

Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions.

Science.gov (United States)

Bowles, Timothy M; Barrios-Masias, Felipe H; Carlisle, Eli A; Cavagnaro, Timothy R; Jackson, Louise E

2016-10-01

Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Dealing with drought in irrigated agriculture through insurance schemes: an application to an irrigation district in Southern Spain

Energy Technology Data Exchange (ETDEWEB)

Ruiz, M.; Bielza, J.; Garrido, A.; Iglesias, A.

2015-07-01

Hydrological drought is expected to have an increasing impact on both crop and fruit yields in arid and semi-arid regions. Some existing crop insurance schemes provide coverage against water deficits in rain-fed agriculture. The Prevented Planting Program in the USA covers against drought for irrigated agriculture. However, drought insurance for irrigated agriculture is still a challenge for companies and institutions because of the complexity of the design and implementation of this type of insurance. Few studies have attempted to evaluate the risk of loss due to irrigation water scarcity using both stand-alone production functions and crop simulation models. This paper’s contributions are that it evaluates the suitability of AquaCrop for calculating drought insurance premiums for irrigated agriculture and that it discusses contract conditions and insurance design for hydrological drought risk coverage as part of a traditional insurance product, with on-field loss assessment in combination with a trigger index. This method was applied to an irrigation district in southern Spain. Our insurance premium calculation showed that it is feasible to apply this method provided that its data requirements are met, such as a large enough set of reliable small-scale yield and irrigation time series data, especially soil data, to calibrate AquaCrop. The choice of a trigger index should not be underestimated because it proved to have a decisive influence on insurance premiums and indemnities. Our discussion of the contract conditions shows that hydrological drought insurance must comply with a series of constraints in order to avoid moral hazard and basis risk. (Author)

Dealing with drought in irrigated agriculture through insurance schemes: an application to an irrigation district in Southern Spain

Directory of Open Access Journals (Sweden)

Jorge Ruiz

2015-12-01

Full Text Available Hydrological drought is expected to have an increasing impact on both crop and fruit yields in arid and semi-arid regions. Some existing crop insurance schemes provide coverage against water deficits in rain-fed agriculture. The Prevented Planting Program in the USA covers against drought for irrigated agriculture. However, drought insurance for irrigated agriculture is still a challenge for companies and institutions because of the complexity of the design and implementation of this type of insurance. Few studies have attempted to evaluate the risk of loss due to irrigation water scarcity using both stand-alone production functions and crop simulation models. This paper’s contributions are that it evaluates the suitability of AquaCrop for calculating drought insurance premiums for irrigated agriculture and that it discusses contract conditions and insurance design for hydrological drought risk coverage as part of a traditional insurance product, with on-field loss assessment in combination with a trigger index. This method was applied to an irrigation district in southern Spain. Our insurance premium calculation showed that it is feasible to apply this method provided that its data requirements are met, such as a large enough set of reliable small-scale yield and irrigation time series data, especially soil data, to calibrate AquaCrop. The choice of a trigger index should not be underestimated because it proved to have a decisive influence on insurance premiums and indemnities. Our discussion of the contract conditions shows that hydrological drought insurance must comply with a series of constraints in order to avoid moral hazard and basis risk.

The Impact of Regular and Periodic Irrigation on the Fertility and Productivity of an Ordinary Chernozem of the Azov Irrigation System

Science.gov (United States)

Shchedrin, V. N.

2016-02-01

The effect of regular and periodic irrigation on the fertility and productivity of an ordinary chernozem cultivated under different conditions within the same cereal-fodder crop rotation is discussed. The investigation object is located in the area of the Azov irrigation system on the second terrace of the Don River in Rostov oblast. Irrigation water for the system is taken from the Veselovsk water reservoir. Its salinity is 1.7-2.1 g/dm3, and the salt composition is sulfate-sodium. The field experiments were performed in 2006-2013 on three experimental plots. Two of them were regularly irrigated; the third plot was periodically irrigated with alternation of 2-year-long periods with and without irrigation. Our study proved that periodic irrigation could be applied in the chernozemic zone. This new irrigation mode contributes to the preservation of the natural soil-forming process and stops the development of unfavorable processes typical of the lands irrigated with water of inadequate quality. In eight years of cultivation of the ordinary chernozem with periodic irrigation, the soil humus content increased by 10% (from 3.80 to 4.15%), and the yield reached 66.0 t/ha of fodder units. This was 9% higher than the yield obtained upon regular irrigation without agroameliorative measures and 12% lower than the yield upon regular irrigation in combination with soil-protective measures. Our data suggest that periodic irrigation is promising for the chernozemic zone, because it ensures lower water loads and preservation of the irrigated chernozems.

The Effect of Irrigation and Nitrogen on Growth Attributes and Chlorophyll Content of Garlic in Line Source Sprinkler Irrigation System

Directory of Open Access Journals (Sweden)

rahim motalebifard

2017-02-01

Full Text Available Introduction: With 12 million tons production per year, garlic is the fourth important crop in world. In addition to its medical value, it has been used in food industry. The Hamedan province with 1900 ha cultivation area and 38 percent of production is one of the most important garlic area productions in Iran. Few studies on water use and management of garlic exist in the world. Garlic is very sensitive to water deficit especially in tubers initiation and ripening periods. The current research was done because of scarce research on garlic production under water deficit condition in Iran and importance of plant nutrition and nutrients especially nitrogen on garlic production under stressful conditions. Nitrogen is necessary and important element for increasing the yield and quality of garlic. Application of nitrogen increases the growth trend of garlic such as number of leaves, leaf length and plant body. Reports have shown that garlic has high nitrogen requirement, particularly in the early stages of growth. Materials and Methods: This study was conducted for evaluating the combined effects of nitrogen and irrigation on the yield and quality of garlic (Allium sativumL.. The study was performed as a split-block based on randomized complete blocks design with factors of irrigation at four levels (0-3(normal irrigation, 3-6 (slight water deficit, 6-9 (moderate water deficit and 9-12 (sever water deficit meters distance from main line source sprinkler system, nitrogen at four levels (0, 50,100 and 150 kg nitrogen per ha using three replications and line source sprinkler irrigation system. The total water of irrigation levels was measured by boxes that were fixed in meddle of each plot. The statistical analysis of results were performed using themethod described by Hanks (1980. The chlorophyll index was measured using the chlorophyll meter 502 (Minolta, Spain. The chlorophyll a and bwas measured by the method described by Arnon (1946 and Gross (1991

Assessing the changes of groundwater recharge / irrigation water use between SRI and traditional irrigation schemes in Central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

2015-04-01

To respond to agricultural water shortage impacted by climate change without affecting rice yield in the future, the application of water-saving irrigation, such as SRI methodology, is considered to be adopted in rice-cultivation in Taiwan. However, the flooded paddy fields could be considered as an important source of groundwater recharge in Central Taiwan. The water-saving benefit of this new methodology and its impact on the reducing of groundwater recharge should be integrally assessed in this area. The objective of this study was to evaluate the changes of groundwater recharge/ irrigation water use between the SRI and traditional irrigation schemes (continuous irrigation, rotational irrigation). An experimental paddy field located in the proximal area of the Choushui River alluvial fan (the largest groundwater pumping region in Taiwan) was chosen as the study area. The 3-D finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge process and amount under traditional irrigation schemes and SRI methodology. The use of effective rainfall was taken into account or not in different simulation scenarios for each irrigation scheme. The simulation results showed that there were no significant variations of infiltration rate in the use of effective rainfall or not, but the low soil moisture setting in deep soil layers resulted in higher infiltration rate. Taking the use of effective rainfall into account, the average infiltration rate for continuous irrigation, rotational irrigation, and SRI methodology in the first crop season of 2013 were 4.04 mm/day, 4.00 mm/day and 3.92 mm/day, respectively. The groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reducing 4% and 2% compared with continuous irrigation and rotational irrigation, respectively. The field irrigation requirement amount of SRI methodology was significantly

Reducing microbial contamination on wastewater-irrigated lettuce by cessation of irrigation before harvesting

DEFF Research Database (Denmark)

Keraita, Bernard; Konradsen, Flemming; Drechsel, Pay

2007-01-01

OBJECTIVE: To assess the effectiveness of cessation of irrigation before harvesting in reducing microbial contamination of lettuce irrigated with wastewater in urban vegetable farming in Ghana. METHODS: Assessment was done under actual field conditions with urban vegetable farmers in Ghana. Trials...... were arranged in completely randomized block design and done both in the dry and wet seasons. Seven hundred and twenty-six lettuce samples and 36 water samples were analysed for thermotolerant coliforms and helminth eggs. RESULTS: On average, 0.65 log units for indicator thermotolerant coliforms and 0.......4 helminth eggs per 100 g of lettuce were removed on each non-irrigated day from lettuce in the dry season. This corresponded to a daily loss of 1.4 tonnes/ha of fresh weight of lettuce. As an input for exposure analysis to make risk estimates, the decay coefficient, k, for thermotolerant coliforms was 0...

Trash-polluted irrigation: characteristics and impact on agriculture

Science.gov (United States)

Sulaeman, D.; Arif, SS; Sudarmadji

2018-04-01

Trash pollution has been a problem in sustainable water resources management. Trash pollutes not only rivers, lakes and seas, but also irrigation canals and rice fields. This study aimed to identify the characteristics of solid waste (type, time of occurrence and sources of trash) and its impact on agriculture. The study was conducted in four irrigation areas, namely Gamping, Merdiko, Nglaren and Karangploso in Bantul District, Yogyakarta Special Region. We applied the Irrigation Rapid Trash Assessment (IRTA) as our field survey instrument. The results showed that trash was found throughout irrigation canals and rice fields, and the occurrence was influenced by water flow, time and farmer activities. The irrigation was dominantly polluted by plastic trash (52.2%), biodegradable waste (17.91%) and miscellaneous trash (12.3%). The IRTA score showed that Gamping Irrigation Area was at marginal condition, bearing a high risk of disturbing the operation and maintenance of the irrigation canals as well as farmers’ health. Trash in irrigation also generated technical impact of the irrigation operation and maintenance, environmental quality, and social life. This research also offered environmental policy integration approach and water-garbage governance approach as an alternative solution to manage water resources and agriculture in a sustainable manner, under the pressure of increasing amount of trash.

Irrigation Requirement Estimation Using Vegetation Indices and Inverse Biophysical Modeling

Science.gov (United States)

Bounoua, Lahouari; Imhoff, Marc L.; Franks, Shannon

2010-01-01

We explore an inverse biophysical modeling process forced by satellite and climatological data to quantify irrigation requirements in semi-arid agricultural areas. We constrain the carbon and water cycles modeled under both equilibrium, balance between vegetation and climate, and non-equilibrium, water added through irrigation. We postulate that the degree to which irrigated dry lands vary from equilibrium climate conditions is related to the amount of irrigation. The amount of water required over and above precipitation is considered as an irrigation requirement. For July, results show that spray irrigation resulted in an additional amount of water of 1.3 mm per occurrence with a frequency of 24.6 hours. In contrast, the drip irrigation required only 0.6 mm every 45.6 hours or 46% of that simulated by the spray irrigation. The modeled estimates account for 87% of the total reported irrigation water use, when soil salinity is not important and 66% in saline lands.

Electron Conditioning of Technical Aluminium Surfaces

Energy Technology Data Exchange (ETDEWEB)

Le Pimpec, F

2004-09-02

The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (= 1.3, value of many pure elements [1]), the SEY of aluminium did not go lower than 1.8. In fact, it reincreases with continued electron exposure dose.

Evaluation of soil and water salinity for irrigation in North-eastern ...

African Journals Online (AJOL)

For sound land use and water management in irrigated area, knowledge of the chemical composition of soils, water, climate, drainage condition and irrigation methods before action are crucial for sustainability of irrigation projects. The study aimed to evaluate the physicochemical properties of soils and water for intended ...

Fluid regimens for colostomy irrigation: a systematic review.

Science.gov (United States)

Lizarondo, Lucylynn; Aye Gyi, Aye; Schultz, Tim

2008-09-01

Background  Various techniques for managing faecal evacuation have been proposed; however, colostomy irrigation is favoured as it leads to better patient outcomes. Alternative fluid regimens for colostomy irrigation have been suggested to achieve effective evacuation. Aim  The objective of this review was to summarise the best available evidence on the most effective fluid regimen for colostomy irrigation. Search strategy  Trials were identified by electronic searches of CINAHL, PubMed, MEDLINE, Current Contents, the Cochrane Library and EMBASE. Unpublished articles and references lists from included studies were also searched. Selection criteria  Randomised controlled trials and before-and-after studies investigating any fluid regimen for colostomy irrigation were eligible for inclusion. Outcomes measured included fluid inflow time, total wash-out time, haemodynamic changes during irrigation, cramps, leakage episodes, quality of life and level of satisfaction. Data collection and analysis  Trial selection, quality appraisal and data extraction were carried out independently by two reviewers. Differences in opinion were resolved by discussion. Main results  The systematic literature search strategy identified two cross-over trials that compared water with another fluid regimen. Owing to the differences in irrigating solutions used, the results were not pooled for analysis. Both the polyethylene glycol electrolyte solution and glyceryl trinitrate performed significantly better than water. Conclusion  There is some evidence to support the effectiveness of fluid regimens other than water, such as polyethylene glycol electrolyte and glyceryl trinitrate, for colostomy irrigation. Further well-designed clinical trials are required to establish solid evidence on the effectiveness of other irrigating solutions that might enhance colonic irrigation. © 2008 The Authors. Journal Compilation © Blackwell Publishing Asia Pty Ltd.

Bayesian Belief Networks Approach for Modeling Irrigation Behavior

Science.gov (United States)

Andriyas, S.; McKee, M.

2012-12-01

Canal operators need information to manage water deliveries to irrigators. Short-term irrigation demand forecasts can potentially valuable information for a canal operator who must manage an on-demand system. Such forecasts could be generated by using information about the decision-making processes of irrigators. Bayesian models of irrigation behavior can provide insight into the likely criteria which farmers use to make irrigation decisions. This paper develops a Bayesian belief network (BBN) to learn irrigation decision-making behavior of farmers and utilizes the resulting model to make forecasts of future irrigation decisions based on factor interaction and posterior probabilities. Models for studying irrigation behavior have been rarely explored in the past. The model discussed here was built from a combination of data about biotic, climatic, and edaphic conditions under which observed irrigation decisions were made. The paper includes a case study using data collected from the Canal B region of the Sevier River, near Delta, Utah. Alfalfa, barley and corn are the main crops of the location. The model has been tested with a portion of the data to affirm the model predictive capabilities. Irrigation rules were deduced in the process of learning and verified in the testing phase. It was found that most of the farmers used consistent rules throughout all years and across different types of crops. Soil moisture stress, which indicates the level of water available to the plant in the soil profile, was found to be one of the most significant likely driving forces for irrigation. Irrigations appeared to be triggered by a farmer's perception of soil stress, or by a perception of combined factors such as information about a neighbor irrigating or an apparent preference to irrigate on a weekend. Soil stress resulted in irrigation probabilities of 94.4% for alfalfa. With additional factors like weekend and irrigating when a neighbor irrigates, alfalfa irrigation

Hydrological drought index insurance for irrigation districts in Spain

Energy Technology Data Exchange (ETDEWEB)

Maestro, T.; Bielza, M.; Garrido, A.

2016-11-01

Hydrological droughts are a major risk for irrigated agriculture in many regions of the world. The aim of this article is to propose an insurance tool to help irrigators manage the risk of water scarcity in the framework of the Spanish Crop Insurance System (SCIS). Only the United States Insurance System provides this type of coverage, but has very restrictive conditions. To determine the type of insurance scheme that better fits with the SCIS and to the Spanish irrigated agriculture, an expert panel was held with the participation of all stakeholders involved in crop insurance. Following the expert panel conclusions, an hydrological drought index insurance (HDII) addressed to irrigation districts (ID) is proposed. It would compensate water deficits suffered in the whole ID. We detail the conditions that the ID should fulfill to be eligible for HDII. HDII is applied to the Bardenas Irrigation District V (ID-V) in Spain, and the hedging effectiveness of the instrument is analyzed comparing ID-V’s gross margins with and without the insurance contract. Results suggest that the proposed insurance scheme could provide an effective means of reducing farmers’ vulnerability to water shortages and there is no major impediment for it to be included as a new line in the SCIS. This type of insurance can be generalized to any ID fulfilling the conditions mentioned in this paper. (Author)

Condensation irrigation a system for desalination and irrigation

International Nuclear Information System (INIS)

Lindblom, J.; Nordell, B

2006-01-01

condensation irrigation is a system for both desalination and irrigation. The principles is that humidified air is let into an underground horizontal pipe system, where the air is cooled by the ground and humidity falls out as fresh water. The humidification could e.g. be achieved by evaporation of seawater in solar stills or any other heat source. By using drainage pipes for underground air transportation the water percolates into the soil, thereby irrigating the land. This study focuses on drinking water production, which means that humid air is led into plan pipes where the condensed water is collected at the pipe endings. Numerical simulations gave a study-state diurnal mean water production of 1.8 kg per meter of pipe over a 50 m pipe. Shorter pipes result in a greater mean production rate. Since the heat transfer of drainage pipes would be greater, current study indicates that condensation irrigation is a promising method for desalination and irrigation. Performed studies in condensation irrigation started at LTU in 2003. Current paper reports the initial theoretical work on the system.(Author)

Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

Science.gov (United States)

Mozo, Sandra; Llena, Carmen

2012-01-01

Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

Irrigation and Autocracy

DEFF Research Database (Denmark)

Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation pot...

Crop and Irrigation Management Systems under Greenhouse Conditions

Directory of Open Access Journals (Sweden)

Pedro García-Caparrós

2018-01-01

Full Text Available Plants of Ruscus aculeatus, known as “butcher’s broom”, Maytenus senegalensis, known as “confetti tree”, and Juncus acutus, known as “spiny rush” were grown in pots with a mixture of sphagnum peat-moss and Perlite in order to determine the effect and evolution over time of three water use systems on plant growth, water saving and nutrient uptake. These were an open system (irrigated with standard nutrient solution and two closed systems (blended-water (drainage water blended with water of low electrical conductivity (EC and sequential reuse of drainage (sequential-reuse water, over a period of 8 weeks. Irrigation with blended- and sequential-reuse-water increased the biomass of all three species at the end of the experiment, compared to the open system. Overall, sequential-reuse-water treatment maximised biomass production. The application of blended- and sequential-reuse-water allowed savings of 17% of water in comparison to the open system. Regarding Cl, NO3− and H2PO4− loads, there was a removal of 5%, 32% and 32%; respectively in the blended-water treatment and 15%, 17% and 17% in the sequential-reuse water treatment compared to the open system. For the cation loads (Na+, K+, Ca2+ and Mg2+ in these water treatments there was a removal of 10%, 32%, 7% and 18% respectively in the blended-water treatment, and 17%, 22%, 17% and 18% respectively in the sequential-reuse treatment, compared to the open system.

Assesing the suitability of water for irrigation theoretical and practical approach

International Nuclear Information System (INIS)

Hannan, A.; Javad, M.A.; Arif, M.; Rashid, A.

2006-01-01

Forced by the surface water shortage and prevalent drought like conditions in the country the farmers have started exploiting groundwater resource. On the other hand, seventy percent of the groundwater being marginal to unfit is a threat to the sustainability of irrigated agriculture. The judicious groundwater exploitation and application has also become imperative in context of ever increasing demographic pressure on soil, crop and water resources. Different classes of irrigation waters established by various research scientists / organizations within the country or abroad are not ultimate under all conditions but these serve as general guidelines. In some cases brackish water requires only minor modification under existing irrigation and ogronomic practices, while in most of the cases it requires major changes regarding type of crops grown, method of water application and the use of soil and water amendments. Therefore, before recommending water for irrigation. Soil characteristics, water management practices, drainage condition of the filed and climatic events must be taken into account as waters generally classified unsuitable for irrigation can be used successfully to grow crops without long term hazardous consequences to crops or soils. This can be attempted simply with the use of improved farming and management practices. Use of brackish water for irrigation may increase the resource base for irrigated agriculture in Pakistan. This article reviews various water classification schemes, salinity-crop yield interrelation with detailed discussion on brackish water application and associated problems. The article also covers a number of management options so as to mitigate the problem and sustain food security in the country. (author)

Automated Irrigation System for Greenhouse Monitoring

Science.gov (United States)

Sivagami, A.; Hareeshvare, U.; Maheshwar, S.; Venkatachalapathy, V. S. K.

2018-06-01

The continuous requirement for the food needs the rapid improvement in food production technology. The economy of food production is mainly dependent on agriculture and the weather conditions, which are isotropic and thus we are not able to utilize the whole agricultural resources. The main reason is the deficiency of rainfall and paucity in land reservoir water. The continuous withdrawal water from the ground reduces the water level resulting in most of the land to come under the arid. In the field of cultivation, use of appropriate method of irrigation plays a vital role. Drip irrigation is a renowned methodology which is very economical and proficient. When the conventional drip irrigation system is followed, the farmer has to tag along the irrigation timetable, which is different for diverse crops. The current work makes the drip irrigation system an automated one, thereby the farmer doesn't want to follow any timetable since the sensor senses the soil moisture content and based on it supplies the water. Moreover the practice of economical sensors and the simple circuitry makes this project as an inexpensive product, which can be bought even by an underprivileged farmer. The current project is best suited for places where water is limited and has to be used in limited quantity.

Automated Irrigation System for Greenhouse Monitoring

Science.gov (United States)

Sivagami, A.; Hareeshvare, U.; Maheshwar, S.; Venkatachalapathy, V. S. K.

2018-03-01

The continuous requirement for the food needs the rapid improvement in food production technology. The economy of food production is mainly dependent on agriculture and the weather conditions, which are isotropic and thus we are not able to utilize the whole agricultural resources. The main reason is the deficiency of rainfall and paucity in land reservoir water. The continuous withdrawal water from the ground reduces the water level resulting in most of the land to come under the arid. In the field of cultivation, use of appropriate method of irrigation plays a vital role. Drip irrigation is a renowned methodology which is very economical and proficient. When the conventional drip irrigation system is followed, the farmer has to tag along the irrigation timetable, which is different for diverse crops. The current work makes the drip irrigation system an automated one, thereby the farmer doesn't want to follow any timetable since the sensor senses the soil moisture content and based on it supplies the water. Moreover the practice of economical sensors and the simple circuitry makes this project as an inexpensive product, which can be bought even by an underprivileged farmer. The current project is best suited for places where water is limited and has to be used in limited quantity.

Prospective controlled trial comparing colostomy irrigation with "spontaneous-action" method.

Science.gov (United States)

Williams, N S; Johnston, D

1980-07-12

Thirty randomly selected patients with permanent colostomies entered a prospective controlled trial comparing colostomy irrigation with spontaneous action. Each patient was interviewed and examined before irrigation was begun and again after the technique had been used for three months. Each then reverted to spontaneous action for a further three months and was then reassessed. Eight patients abandoned irrigation and 22 (73%) adhered to the protocol. Irrigation caused no mishaps or complications. The mean time spent managing the stoma was 45 +/- SEM 9 min/24 hours during spontaneous action and 53 +/- 9 min/24 hours during irrigation. This difference was not significant. The numbers of bowel actions weekly were 13 +/ SEM 2 during spontaneous action and 6 +/- 1 during irrigation (p Irrigation reduced odour and flatus in 20 patients and enabled 12 out of 18 to stop using drugs and seven to discard their appliance. Irrigation also improved the social life of 18 patients and the working conditions of eight out of 14. These finding show that some patients may not be suitable for irrigation but that for many it is better than the conventional British method of colostomy management. With modern apparatus the technique is safe.

Correlation Coefficient, Path Analysis and Drought Tolerance Indices for Different Wheat Cultivars under Deficit Irrigation Conditions of Isfahan Region

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H. R Salemi

2017-06-01

Full Text Available Introduction Water crisis as a main factor of agronomy limitation exists in all over the arid and semiarid regions such as Isfahan province which is located in the central part of the Zayandehrud River Basin. This study aimed to use path analysis and indices of drought to evaluate the correlation coefficients between main physiological parameter (grain yield with yield components and water use efficiency of winter wheat under three water conditions. Materials and Methods The experiment was carried out in Kaboutar Abad Agricultural Research Station, Isfahan in the central region of Iran (32º 31’N, 51º 51’E is located at the altitude of 1545 m above the sea level with a split plot in a randomized complete block design (RCBD with three replications in three cropping seasons on irrigated wheat cultivars. The treatments were included three levels of irrigation (60%FI, 80%FI and full irrigation as main plots and six wheat cultivars (Pishtaz, Shiraz, Sepahan, Marvdasht, Mahdavi and BC-Roshan as sub plots. Grain yield, straw and stubble, biological yield, harvest index (H.I., productivity degree (P.D., water use efficiency (WUE, plant height, grain number per spike, spike number per m2 and TGW were determined. Winter wheat cultivars were sown at the beginning of November and harvested in mid-June of the following year. The seed rate was 400 seed m-2, with a row spacing of 0.75 m. The first irrigation was by furrow method, implemented one day after seeding. Seeds emergence was observed about 5 days later. The N application was 250, 200 and 300 kgha-1 of N (urea at 46% N for each year divided into installments (10 days before planting, 30 days after planting, and every 30 days until the last irrigation. The P2O5 (phosphate ammonium and super-phosphate triple application to soil was 200, 100 and 50 kg ha-1 during the 3 years, respectively. At this stage, cultivation was done to mix the fertilizers with top soil manually. Pests and weeds were

Energy savings potential from energy-conserving irrigation systems

Energy Technology Data Exchange (ETDEWEB)

Wilfert, G.L.; Patton, W.P.; Harrer, B.J.; Clark, M.A.

1982-11-01

This report systematically compares, within a consistent framework, the technical and economic characteristics of energy-conserving irrigation systems with those of conventional irrigation systems and to determine total energy savings. Levelized annual costs of owning and operating both energy-conserving and conventional irrigation systems have been developed and compared for all 17 states to account for the differences in energy costs and irrigation conditions in each state. Market penetration of energy-conserving systems is assessed for those systems having lower levelized annual costs than conventional systems performing the same function. Annual energy savings were computed by matching the energy savings per system with an assumed maximum market penetration of 100 percent in those markets where the levelized annual costs of energy-conserving systems are lower than the levelized annual costs of conventional systems.

Effect of Zinc and Salicylic acid Foliar Application on Quantitative and Qualititative Characteristics of Soybean under Deficit Irrigation Conditions

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Z Zarei

2017-03-01

Full Text Available Introduction Soybean (Glycine max (L. Merrill is a leguminous annual crop belonging to the Fabaceae family, that because an important source of food containing 20 to 28 grain oil percent and high protein is the most important oilseed of worldwide interest. Recently, cultivation of this plant is considered as a valuable oil plant in crop rotation. Drought, salinity, heat and freezing are environmental conditions that cause adverse effects on the growth of plants. Water deficit more than other stresses limits the growth of crops. Yield of soybean decreased due to drought stress. The consumption of fertilizers increases the quality of crops. According to the findings of Yasari and Vahedi (2012 use of Zn in soil and foliar application has an increasing effect on the percentage and the amount of oil and protein in soybean product. The role of salicylic acid (SA is reducing the effects of environmental stresses. It appears that water stress impairs plants and zinc alleviates water stress injuries. Thus, the purpose of this study was to evaluate the effect of water stress, zinc and salicylic acid foliar application on oil and grain protein percentage and their relation with oil and protein yield of soybean. Materials and Methods This study was carried out in the agricultural garden of Lorestan-Iran, in 2013. The meteorological data of the region are representing in Table 2. The soil was clay-loam texture (Table 1. The experiment was performed using Split factorial in a randomized complete block design with four replications. In this study, main factor was two levels of irrigation regimes: after 60 (optimum irrigation and 120 mm (stress evaporation from evaporation pan class A and subplot were considered combination of zinc foliar application (Zero and 1 L/ha, in two levels and salicylic acid (0, 0.5 and 1 mM. All statistical analyses were carried out using SAS software and the correlation was done using MSTAT-C program. Results and Discussion In the

ROOT CANAL IRRIGANTS AND IRRIGATION TECHNIQUES: A REVIEW

OpenAIRE

Aniketh; Mohamed; Geeta; Nandakishore; Gourav Kumar; Patrick Timothy; Jayson Mathew; Sahle Abdul

2015-01-01

Root canal irrigation is not much emphasised in endodontic therapy. Most articles discussed are on root canal shaping and obturation not much emphasis is given for irrigation. There are many irrigation solutions which are introduced into market. The primary objective of root canal therapy is the ret ention of the pulpless or pulpally involved tooth with its associated periapical tissues in a healthy state. Achievement of this objective requires that the pulpal spaces and con...

Evaluation of Tomato Yield and Quality under Deficit Irrigation conditions and Simultaneous Application of Superabsorbent Polymer, Shading and Mulches

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Maryam Bostani

2017-12-01

% probability level. Results and Discussion Analysis of variances revealed that effects of irrigation intervals, treatments and their interactions were highly significant on total yield, potential yield, marketable yield, blossom end rotten fruits yield, sunburned fruits yield, cracked fruits yield, average weight of fruits and number of main and lateral branches. Also, effects of treatments on number of days to 50 percent flowering, plant height and fruit wall thickness and effects of irrigation intervals on fruit shape index were significant at 5 percent of probability level. Results showed that increasing irrigation intervals decreased yield and its important components and increased blossom end rot, and cracked fruits. Increasing irrigation intervals from 3 to 9 days decreased 50 percent of total and marketable yield and quadrupled percentage of blossom end rotten fruits. Although shading improved total and marketable yield, but recording the highest number of days to 50 percent flowering for plants grown under shade of Saran® clothes, proved that shading delays harvesting of tomato. The maximum of total and potential yields produced by superabsorbent + shading + mulch treatment and the highest percentage of marketable fruits recorded for superabsorbent, mulches and shading + mulch, respectively. Application of shading clothes alone or along with mulches or superabsorbent minimized the percentage of sunburned fruits. The biggest fruits produced by treatments in which mulches were participated. Increasing irrigation intervals to six and nine days extremely decreased percentage of marketable and blossom rotten fruits, while increased cracked fruits. Conclusion Generally, for short irrigation intervals, superabsorbent + shading + mulch compound treatment and for extreme water deficit conditions and irrigation intervals more than six days adding superabsorbent A200 (10 g.plant-1, mixing into 30 cm depth of soil is recommended to improve yield and quality of tomato crop.

Ring Irrigation System (RIS design through customer preference representation

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Ridwan Infandra I.Z.

2018-01-01

Full Text Available In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent days, analyzing water used or water permeation automatically through the soil moisture has been raised as the interesting topic. Proposed in this research is the ring irrigation system (RIS which is introduced as an alternative channel for emitters that drip water directly onto the soil at the plant’s root zone where the soil conditions before and after watering can be quickly detected by the sensors. This RIS can be used for the potted plant, green house, or other small farm fields. Product design and development (PDD is applied in this research for assisting the designer to understand and create the RIS prototype properly according to the customer’s requirements where the suggested functions obtained will be added and tested.

Colostomy irrigation: results of 25 cases with particular reference to quality of life.

Science.gov (United States)

Karadağ, Ayişe; Menteş, B Bülent; Ayaz, Sultan

2005-04-01

The aim of this study was to document our results with colostomy irrigation with particular emphasis on the possible contribution of irrigation on quality of life. Colostomy irrigation is a useful method of achieving faecal continence in selected conditions, and may improve quality of life. When successful, irrigation offers a regular, predictable elimination pattern and only a small covering is needed for security between irrigations. The digestive disease quality of life questionnaire-15 (DDQ-15) and Short Form-36 were used to analyse quality of life before and 12 months after stomatherapy in a series of 25 irrigating patients with permanent end colostomies. During the same time period, 10 similar patients with left-end colostomies who also received counselling but did not consent to colostomy irrigation were also analysed for comparison. Colostomy irrigation was found to be effective for achieving faecal continence in selected patients with end colostomies with no complications or significant side-effects, The digestive disease quality of life questionnaire-15 score improved significantly in both groups after stomatherapy (P colostomy irrigation can be a useful method of achieving faecal continence in selected conditions, it is safe, and it may help improve many aspects of quality of life. Colostomy irrigation is free from complications and significant side-effects, and it may serve as a useful adjunct to conventional stomatherapy. Therefore, the enterostomal therapy nurse should assess the appropriateness of routine irrigation as a method of stoma management for patients with left-end colostomy.

Effect of different levels of nitrogen fertilizer on yield and quality of sugar beet Beta vulgaris irrigated with saline groundwater (fertigation and surface irrigation) and grown under saline conditions

International Nuclear Information System (INIS)

Janat, M.

2009-07-01

In a field experiment Sugar beet Beta vulgaris was grown as a spring crop during the growing seasons of 2004 and 2006, in salt affected soil, previously planted with sesbania and barley (2005 and 2003) to evaluate the response of sugar beet to two irrigation methods, (drip fertigation and surface irrigation), different levels of nitrogen fertilizer and its effect on yield and quality. Different rates of nitrogen fertilizers (0, 50, 100, 150 and 200 kg N/ ha) as urea (46% N) were injected for drip irrigation or broadcasted for the surface-irrigated treatments in four equally split applications. The 15 N labelled urea was applied to sub-plots of 1.0 m 2 in each experimental unit in a manner similar to that of unlabeled urea. Irrigation scheduling was carried out using the direct method of neutron scattering technique. Sugar beet was irrigated when soil moisture in the upper 25 cm was 80% of the field capacity (FC) and such practice continued until the six leaf stage. From the latter stage until harvest, sugar beet was irrigated when soil moisture in the upper 50 cm reached 80% of the FC. The amount of irrigation water applied, electrical conductivity of the soil paste, dry matter and fresh roots yield, total nitrogen uptake and N derived from fertilizer were also determined. Furthermore, Nitrogen use as well as water use-efficiencies for dry matter and roots yield were also calculated. Results revealed that sugar beets and dry matter yield increased with increasing N input up to 100-150 kg N/ha which was indicated by the higher dry matter yield, and sugar beet yield. Sugar percentage was also increased relative to the average percentage recorded in Syria. Crop water use efficiencies, for both the drip-fertigated and surface-irrigated treatments were increased in most cases with increasing rate of nitrogen fertilizer. During the course of this study, small increases in soil salinity under both irrigation methods were observed. Higher increases in soil salinity was

Appraising options to reduce shallow groundwater tables and enhance flow conditions over regional scales in an irrigated alluvial aquifer system

Science.gov (United States)

Morway, Eric D.; Gates, Timothy K.; Niswonger, Richard G.

2013-01-01

Some of the world’s key agricultural production systems face big challenges to both water quantity and quality due to shallow groundwater that results from long-term intensive irrigation, namely waterlogging and salinity, water losses, and environmental problems. This paper focuses on water quantity issues, presenting finite-difference groundwater models developed to describe shallow water table levels, non-beneficial groundwater consumptive use, and return flows to streams across two regions within an irrigated alluvial river valley in southeastern Colorado, USA. The models are calibrated and applied to simulate current baseline conditions in the alluvial aquifer system and to examine actions for potentially improving these conditions. The models provide a detailed description of regional-scale subsurface unsaturated and saturated flow processes, thereby enabling detailed spatiotemporal description of groundwater levels, recharge to infiltration ratios, partitioning of ET originating from the unsaturated and saturated zones, and groundwater flows, among other variables. Hybrid automated and manual calibration of the models is achieved using extensive observations of groundwater hydraulic head, groundwater return flow to streams, aquifer stratigraphy, canal seepage, total evapotranspiration, the portion of evapotranspiration supplied by upflux from the shallow water table, and irrigation flows. Baseline results from the two regional-scale models are compared to model predictions under variations of four alternative management schemes: (1) reduced seepage from earthen canals, (2) reduced irrigation applications, (3) rotational lease fallowing (irrigation water leased to municipalities, resulting in temporary dry-up of fields), and (4) combinations of these. The potential for increasing the average water table depth by up to 1.1 and 0.7 m in the two respective modeled regions, thereby reducing the threat of waterlogging and lowering non-beneficial consumptive use

Analysis of Irrigation Water Quality at Kadawa Irrigation Project for Improved Productivity

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AR Sanda

2014-09-01

Full Text Available In the face of water scarcity and the several negative consequences, such as water wastage, flooding, water logging, soil losses and production losses, conserving the finite amount of fresh water is a must. The quality of irrigation water must therefore be ascertained. The chemical quality of three sources of irrigation water from canal and drainage water, namely drainage water, fresh irrigation water from canal, and drainage/irrigation water mixture, were analyzed from Kadawa irrigation Project for year 2013 and 2014 cropping seasons, with the view to evaluating the potential risks associated with their use in irrigation and hence their suitability or otherwise for irrigation purposes. The analysis revealed that the use of drainage water alone for irrigation may result in problems associated with salinity, while a blend of drainage/irrigation water in the ratio of 1:1 is a viable means of water conservation and a good means of crop production. DOI: http://dx.doi.org/10.3126/ije.v3i3.11082 International Journal of Environment Vol.3(3 2014: 235-240

AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

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Leszek Łabędzki

2016-05-01

Full Text Available The paper is a review of the so far used in Poland methods and criteria for assessing the needs of irrigation for planning purposes, the assessment because of the agroclimatic conditions and taking into account the soil water retention. Irrigation needs of the most are determined taking into account crop water deficits. This is the factor that is characterized by a shortage of precipitation in relation to the water requirements of crops. Some methods use only the meteorological parameters that determine the state of the atmosphere-soil-plant system, and some also take into account soil water retention and its availability for plants.

Effect of Limited Drip Irrigation Regime on Yield and Yield Components of Sesame under Mediterranean Conditions

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Panayiota PAPASTYLIANOU

2017-05-01

Full Text Available Sesame is one of the most important oilseed crops in the world. Irrigation is of great importance to sesame production due to its positive effect on growth parameters. Although sesame has good drought tolerance compared with many other crops, it is particularly susceptible to drought damage during the seedling, flowering and seed filling stages and this can lead to yield loss. The aim of this study was to determine the response of sesame landraces to different irrigation applications during the 2015 growing season. The experiment was set up as a split plot design with three replicates, four main plots (irrigation treatments, designated as 100%, 75% 50% and 0 of the daily crop evapotranspiration and two sub-plots (sesame landraces, Limnos and Evros. Different characteristics such as plant height, number of seeds per capsule, and number of capsules per plant, seed yield, 1000-seed weight and % capsules without seeds, were recorded. The results indicated that all traits except 1000-seed weight were significantly affected by irrigation regimes. Plant height, shattering losses and number of capsules per plant decreased with increasing water shortage. Seed yield and number of seeds per capsule were less affected by irrigation level and showed higher values in the 50% of the daily crop evapotranspiration treatment. Limnos produced higher seed yield and number of seeds per capsule under all irrigation regimes. Evros showed higher plant height and shattering losses than Limnos. The results of this study suggest that sesame landraces can use water efficiently, are locally adapted and associated with traditional farming systems.

Performance evaluation of a center pivot variable rate irrigation system

Science.gov (United States)

Variable Rate Irrigation (VRI) for center pivots offers potential to match specific application rates to non-uniform soil conditions along the length of the lateral. The benefit of such systems is influenced by the areal extent of these variations and the smallest scale to which the irrigation syste...

Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

Science.gov (United States)

Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

2015-12-01

Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

Experimental study of faecal continence and colostomy irrigation.

Science.gov (United States)

O'Bichere, A; Sibbons, P; Doré, C; Green, C; Phillips, R K

2000-07-01

Colostomy irrigation is a useful method of achieving faecal continence in selected conditions, but remains largely underutilized because it is time consuming. This study investigated the effect of modifying irrigation technique (route, infusion regimen and pharmacological manipulation) on colonic emptying time in a porcine model. An end-colostomy and caecostomy were fashioned in six pigs. Twenty markers were introduced into the caecum immediately before colonic irrigation. Irrigation route (antegrade or retrograde), infusion regimen (tap water, polyethylene glycol (PEG), 1.5 per cent glycine) and pharmacological agent (glyceryl trinitrate (GTN) 0.25 mg/kg, diltiazem 3.9 mg/kg, bisacodyl 0.25 mg/kg) were assigned to each animal at random. Colonic transit was assessed by quantifying cumulative expelled markers (CEM) and stool every hour for 12 h. Mean CEM at 6 h for bisacodyl, GTN and diltiazem were 18.17, 12.17 and zero respectively; all pairwise differences in means were significant (P irrigation. PEG and glycine enhance emptying similar to bisacodyl and GTN solution. These findings show promise for improved faecal continence by colostomy irrigation and may justify construction of a Malone conduit at the time of colostomy in selected patients who wish to irrigate. Presented in part to the British Society of Gastroenterology in Glasgow, UK, March 1999, and published in abstract form as Gut 1999; 44(Suppl 1): A135

Phenotypic Responses of Twenty Diverse Proso Millet (Panicum miliaceum L. Accessions to Irrigation

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Cedric Habiyaremye

2017-03-01

Full Text Available To date, little research has been conducted on the phenotypic responses of proso millet to drought and deficit irrigation treatments in the dryland wheat-based cropping systems of the Palouse bioregion of the U.S. The objectives of this study were to evaluate critical agronomic traits of proso millet, including emergence, plant height, days to heading, days to maturity, and grain yield, with and without supplemental irrigation. Twenty diverse proso millet accessions, originating from Bulgaria, Czechoslovakia, Morocco, the former Soviet Union, Turkey, and the United States, were grown in irrigated and non-irrigated treatments under organic conditions in Pullman, WA, from 2012 to 2014. Irrigation was shown to significantly improve emergence and increase plant height at stem extension and to hasten ripening of all the varieties, whereas heading date was not affected by irrigation in two of the three years tested. Irrigation resulted in higher mean seed yield across all varieties, with ‘GR 665’ and ‘Earlybird’ performing best under irrigation. Seed yield was highest in ‘GR 658’ and ‘Minsum’ in the non-irrigated treatment, suggesting the importance of identification and utilization of varieties adapted to low rainfall conditions. The highest yielding varieties in irrigated systems are unlikely be the highest yielding in dryland systems. Our results suggest that millet has potential as a regionally novel crop for inclusion in traditional dryland cropping rotations in the Palouse ecosystem, thereby contributing to increased cropping system diversity.

Research advances on thereasonable water resources allocation in irrigation district

DEFF Research Database (Denmark)

Xuebin, Qi; Zhongdong, Huang; Dongmei, Qiao

2015-01-01

The rational allocation of water resources for irrigation is important to improve the efficiency in utilization of water resources and ensuring food security, but also effective control measures need to be in place for the sustainable utilization of water resources in an irrigation area. The prog......The rational allocation of water resources for irrigation is important to improve the efficiency in utilization of water resources and ensuring food security, but also effective control measures need to be in place for the sustainable utilization of water resources in an irrigation area...... mechanism of water resources is not perfect, the model for optimal water resources allocation is not practical, and the basic conditions for optimal allocation of water resources is relatively weak. In order to solve those problems in water resources allocation practice, six important as?pects must...... in irrigation districts, studying the water resources control technology in irrigation districts by hydrology ecological system, studying the technologies of real?time risk dispatching and intelligent management in irrigation districts, and finally studying the technology of cou?pling optimal allocation...

Root canal irrigants

OpenAIRE

Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

2010-01-01

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

Effects of Supplemental Irrigation on Yield and Growth Indices of Three

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M. Parsa

2012-04-01

Full Text Available In order to investigate the effects of different irrigation regimes on yield and growth indices of three chickpea cultivars, an experiment was conducted during the 2007 growing season at Mashhad (Iran. Six irrigation regimes including I1; full irrigation, I2; irrigation at branching, I3; irrigation at flowering, I4; irrigation at pod formation, I5; irrigation at seed filling stage and I6; dry farming without irrigation (main factors. Three Kabuli chickpea cultivars ILC482, Jam, Karaj 12-60-31 (sub factors in a spilt block experiment based on randomized block design with three replications. There were significant differences between supplemental irrigation levels on grain yield. The results showed that grain yield in supplemental irrigation at flowering stage was more than to supplemental irrigation at branching, podding and seed filling stages (respectively 3.3, 3.1 and 23%. Within the three cultivars, grain yield, biological yield and harvest index were highest and lowest in ILC482 and Karaj 12-60-31 cultivars respectively. The results showed that supplemental irrigation at flowering stage increased dry matter, leaf area index, crop growth rate, relative growth rate and net assimilation rate. The results showed that flowering stage in chickpea cultivars was sensitive to drought stress so, ILC482 cultivar also showed more tolerance to water stress condition.

Electron Conditioning of Technical Aluminium Surfaces: Effect on the Secondary Electron Yield

Energy Technology Data Exchange (ETDEWEB)

Le Pimpec, F.

2004-12-13

The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (< 1.3, value of many pure elements [1] ), the SEY of aluminium did not go lower than 1.8. In fact, it reincreases with continued electron exposure dose.

FEATURES OF MINERAL NUTRITION FOR TOMATO PLANTS WITH DRIP IRRIGATION SYSTEM IN OPEN FIELD CONDITION

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P. M. Akhmetova

2017-01-01

Full Text Available Dagestan is the largest region with irrigation system of agriculture in Russia. Irrigated lands provide 70% of total plant production. The field cultivation is carried on arable land in plain region of the republic. The drip irrigation as an ecologically safe technology for watering is regarded as major means for vegetable production farming. This approach maintains the propitious level of water and air in the soil without surface and deep drainage of irrigating water. These irrigated lands are expected to be used first of all for valuable and profitable crops such as tomato that is a leading crop in Dagestan. The experimental work was carried out at OOO ‘Dagagrocomplex’, Aleksandro-Nevskoye, in Tarumovskiy region. The aim of the study was to determinate the optimal dose of mineral fertilizers and the way of their application to improve the productivity without quality loss. The complex analysis of the technology for tomato production under drip irrigation through nontransplanting culture showed its high efficiency, because volume and quality of yield directly depended on soil moisture and precise supporting of mineral nutrition rates. The maximal yield of tomato fruits, 88.7-94.5 t/ha was observed with once mineral fertilizer application at a dose of N180P135K60 with soil humidity 70-80% (field moisture capacity, and also at the dose of N180P135K60 with basic application of N100 in nutrition rate. The result of the study showed that the optimization of two factors, namely soil water rate and mineral nutrition, enabled to produce additionally 39.2 t/ha. It was shown the tight connection between yielding and its quality; when yielding 95 t/ha, the increased contents of dry matter to 7.01%, sugar to 3.8% vitamin C to 18.46% were noticed. The high quality of produced output was supported by pre-watering threshold of moisture at 75-80% (field moisture capacity, when once fertilizer application at a dose of N180P135K60. 

NUTRIENT CONTENT IN SUNFLOWERS IRRIGATED WITH OIL EXPLORATION WATER

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ADERVAN FERNANDES SOUSA

2016-01-01

Full Text Available Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil - produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW, reverse osmosis - treated produced water (OPW, or ground water (GW. At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis - treated produced water in agriculture. However, more long - term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.

Irrigation and nitrogen level affect lettuce yield in greenhouse ...

African Journals Online (AJOL)

This study was conducted to investigate the effect of different irrigation and nitrogen levels on lettuce yield characteristics in greenhouse condition from December 2006 to March 2007. Irrigation levels of 100% of total class A pan (S1), 80% of total class A pan (S2), 60% of total class A pan (S3) and nitrogen levels of 0 kg ...

Sweet sorghum performance under irrigated conditions in northwest China : Biomass and its partitioning in inbred and hybrid cultivars at two nitrogen levels

NARCIS (Netherlands)

Fan, F.; Spiertz, J.H.J.; Han, L.P.; Liu, Z.X.; Xie, G.H.

2013-01-01

Effects of cultivar choice and nitrogen supply on biomass yield and dry matter partitioning of sweet sorghum [Sorghum bicolor (L.) Moench] were studied under irrigated conditions in the arid temperate climate of north-west China. Two hybrid cultivars, Zaoshu-1 (ZS 1) and Chuntian-2 (CT 2), and two

Response of potato to drip and gun irrigation systems

DEFF Research Database (Denmark)

Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

2015-01-01

The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

Arsenic transport in irrigation water across rice-field soils in Bangladesh

International Nuclear Information System (INIS)

Polizzotto, Matthew L.; Lineberger, Ethan M.; Matteson, Audrey R.; Neumann, Rebecca B.; Badruzzaman, A. Borhan M.; Ashraf Ali, M.

2013-01-01

Experiments were conducted to analyze processes impacting arsenic transport in irrigation water flowing over bare rice-field soils in Bangladesh. Dissolved concentrations of As, Fe, P, and Si varied over space and time, according to whether irrigation water was flowing or static. Initially, under flowing conditions, arsenic concentrations in irrigation water were below well-water levels and showed little spatial variability across fields. As flowing-water levels rose, arsenic concentrations were elevated at field inlets and decreased with distance across fields, but under subsequent static conditions, concentrations dropped and were less variable. Laboratory experiments revealed that over half of the initial well-water arsenic was removed from solution by oxidative interaction with other water-column components. Introduction of small quantities of soil further decreased arsenic concentrations in solution. At higher soil-solution ratios, however, soil contributed arsenic to solution via abiotic and biotic desorption. Collectively, these results suggest careful design is required for land-based arsenic-removal schemes. -- Highlights: •We analyzed the processes impacting arsenic transport in flowing irrigation water. •Arsenic in Bangladesh rice-field irrigation water varied over space and time. •Arsenic was correlated with Fe, P, and Si in flowing and static water. •Oxidation, adsorption and desorption reactions controlled arsenic concentrations. •Land-based arsenic removal from water will be impacted by hydraulic conditions. -- Arsenic concentrations in flowing and static irrigation water in Bangladesh varied over space and time, suggesting careful design is required for land-based pre-treatment schemes that aim to remove As from solution

Hygienic-sanitary conditions of vegetables and irrigation water from kitchen gardens in the municipality of Campinas, SP

Directory of Open Access Journals (Sweden)

Simões Marise

2001-01-01

Full Text Available We examined samples of irrigation water and vegetables from kitchen gardens in Campinas, Brazil. The bacterial analysis condemned 22.3% of the vegetable samples, and the parasitological examination condemned 14.5%. The criteria established by the Brazilian legislation condemned 11.8% of the irrigation water samples. Parasites were significantly more frequent in vegetables in the rainy season, while excessive fecal coliforms were more frequent in the dry season. A proper monitoring of the irrigation water supply is important to avoid the contamination of vegetables.

Water and solute balances as a basis for sustainable irrigation agriculture

Science.gov (United States)

Pla-Sentís, Ildefonso

2015-04-01

The growing development of irrigated agriculture is necessary for the sustainable production of the food required by the increasing World's population. Such development is limited by the increasing scarcity and low quality of the available water resources and by the competitive use of the water for other purposes. There are also increasing problems of contamination of surface and ground waters to be used for other purposes by the drainage effluents of irrigated lands. Irrigation and drainage may cause drastic changes in the regime and balance of water and solutes (salts, sodium, contaminants) in the soil profile, resulting in problems of water supply to crops and problems of salinization, sodification and contamination of soils and ground waters. This is affected by climate, crops, soils, ground water depth, irrigation and groundwater composition, and by irrigation and drainage management. In order to predict and prevent such problems for a sustainable irrigated agriculture and increased efficiency in water use, under each particular set of conditions, there have to be considered both the hydrological, physical and chemical processes determining such water and solute balances in the soil profile. In this contribution there are proposed the new versions of two modeling approaches (SOMORE and SALSODIMAR) to predict those balances and to guide irrigation water use and management, integrating the different factors involved in such processes. Examples of their application under Mediterranean and tropical climate conditions are also presented.

Coil irrigation in sugar cane (Saccharum officinarum

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Jesús Sánchez Gutiérrez

2016-01-01

Full Text Available This study was made at the Basic Seed Bank of the Local Sugar Cane Research Station for the Mideastern Cuba, based in Camaguey, on brown carbonate soil, between 2013 and 12014. Coil irrigation was applied to meet the water requirements for the crop, according to the edafoclimatic conditions and the different phenological phases it has. The Savo method was used to determine useful rain water. Adjustment and complementation of the irrigation program was based on indicators that characterize the exploitation scheme. The machine´s working parameters were determined to meet the water needs, and increase crop´s overall yields. The evaluations and results achieved have contributed to new proposals for management and operation of coil irrigation, and they are important to increase its efficiency.

Evaluation of endothelial mucin layer thickness after phacoemulsification with next generation ophthalmic irrigating solution.

Science.gov (United States)

Ghate, Deepta A; Holley, Glenn; Dollinger, Harli; Bullock, Joseph P; Markwardt, Kerry; Edelhauser, Henry F

2008-10-01

To evaluate human corneal endothelial mucin layer thickness and ultrastructure after phacoemulsification and irrigation-aspiration with either next generation ophthalmic irrigating solution (NGOIS) or BSS PLUS. Paired human corneas were mounted in an artificial anterior chamber, exposed to 3 minutes of continuous ultrasound (US) at 80% power using the Alcon SERIES 20000 LEGACY surgical system (n = 9) or to 2 minutes of pulsed US at 50% power, 50% of the time at 20 pps using the Alcon INFINITI Vision System (n = 5), and irrigated with 250 mL of either NGOIS or BSS PLUS. A control group of paired corneas did not undergo phacoemulsification or irrigation-aspiration (n = 5). Corneas were divided and fixed for mucin staining or transmission electron microscopy. Mucin layer thickness was measured on the transmission electron microscopy prints. The mucin layer thickness in the continuous phaco group was 0.77 +/- 0.02 microm (mean +/- SE) with NGOIS and 0.51 +/- 0.01 microm with BSS PLUS (t test, P INFINITI Vision System (pulsed US) and the LEGACY surgical system (continuous US).

Irrigation water policy analysis using a business simulation game

Science.gov (United States)

Buchholz, M.; Holst, G.; Musshoff, O.

2016-10-01

Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

Morphogenetic, structural and productive traits of buffel grass under different irrigation regimes

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Maria Janiele Ferreira Coutinho

2015-06-01

Full Text Available The water restriction conditions in the Brazilian semiarid region are one of the most limiting factors to the establishment and yield of forage grasses. This study aimed to evaluate the effect of different irrigation regimes on morphogenetic, structural and productive traits of buffel grass. Arandomized blocks design, with five treatments and six replications, was used. Treatments consisted of five irrigation regimes, corresponding to the intervals of 2, 4, 6, 8 and 10 days. The traits analyzed were: leaf emergence rate, phyllochron, leaf and stem elongation rate, leaf senescence rate, final leaf length, number of green leaves per tiller, number of tillers, stem height, leaf/stem ratio, leaf area index, dry mass of green leaf and stem, dry mass of green, dead and total forage, root dry mass, dry mass and green dry mass/dead dry mass ratio. The final leaf length and dead forage dry mass were not affected by the irrigation regimes. The leaf/stem ratio followed a quadratic model, maintaining the value of 0.51 up to the irrigation regime of four days. The other morphological, structural and productive traits decreased linearly with increasing irrigation frequencies. The irrigation intervals promoted reductions in the morphological, structural and productive parameters of buffel grass, when grown under greenhouse conditions. The irrigation regime of 2 days stands out as the least restrictive to the development of buffel grass.

Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

NARCIS (Netherlands)

Urrutia Cobo, N.

2006-01-01

Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands

Deficit irrigation and organic compost improve growth and yield of quinoa and pea

DEFF Research Database (Denmark)

Hirich, A.; Choukr-Allah, R.; Jacobsen, Sven-Erik

2014-01-01

Supplying organic matter under deficit irrigation conditions could be a practical solution to compensate the negative effect of water stress. For this purpose, studies in pea as a legume and quinoa as a new drought-tolerant crop were conducted in the south of Morocco between October 2011 and March...... significantly (P ≤ 0.05) increased seed yield by 18 and 11% under stress conditions and by 13 and 3% under full irrigation for quinoa and by 24 and 11% under full irrigation and by 41 and 25% under water-deficit irrigation for pea. It can be concluded that organic amendment improved significantly yield...... harvested yield was affected significantly (P seed yields (3.3 t ha-1 for quinoa and 5.6 t ha-1 for pea) were recorded under full irrigation and 10 t ha-1 of compost. Results indicated that organic amendment of 10 t ha-1 and 5 t ha-1...

Evaluating the impact of irrigation on surface water - groundwater interaction and stream temperature in an agricultural watershed.

Science.gov (United States)

Essaid, Hedeff I; Caldwell, Rodney R

2017-12-01

Changes in groundwater discharge to streams caused by irrigation practices can influence stream temperature. Observations along two currently flood-irrigated reaches in the 640-square-kilometer upper Smith River watershed, an important agricultural and recreational fishing area in west-central Montana, showed a downstream temperature decrease resulting from groundwater discharge to the stream. A watershed-scale coupled surface water and groundwater flow model was used to examine changes in streamflow, groundwater discharge to the stream and stream temperature resulting from irrigation practices. The upper Smith River watershed was used to develop the model framework including watershed climate, topography, hydrography, vegetation, soil properties and current irrigation practices. Model results were used to compare watershed streamflow, groundwater recharge, and groundwater discharge to the stream for three scenarios: natural, pre-irrigation conditions (PreIrr); current irrigation practices involving mainly stream diversion for flood and sprinkler irrigation (IrrCurrent); and a hypothetical scenario with only groundwater supplying sprinkler irrigation (IrrGW). Irrigation increased groundwater recharge relative to natural PreIrr conditions because not all applied water was removed by crop evapotranspiration. Groundwater storage and groundwater discharge to the stream increased relative to natural PreIrr conditions when the source of irrigation water was mainly stream diversion as in the IrrCurrent scenario. The hypothetical IrrGW scenario, in which groundwater withdrawals were the sole source of irrigation water, resulted in widespread lowering of the water table and associated decreases in groundwater storage and groundwater discharge to the stream. A mixing analysis using model predicted groundwater discharge along the reaches suggests that stream diversion and flood irrigation, represented in the IrrCurrent scenario, has led to cooling of stream temperatures

Effects of different irrigation regimes on vegetative growth, fruit yield ...

African Journals Online (AJOL)

This study was conducted during five growing seasons from 2004 to 2008 to investigate effects of different irrigation regimes on vegetative growth, fruit yield and quality of Salak apricot trees in semiarid climatic conditions. There were six irrigation treatments, five of which (S1, S2, S3, S4 and S5) were based on adjustment ...

Irrigation Training Manual. Planning, Design, Operation, and Management of Small-Scale Irrigation Systems [and] Irrigation Reference Manual. A Technical Reference to Be Used with the Peace Corps Irrigation Training Manual T0076 in the Selection, Planning, Design, Operation, and Management of Small-Scale Irrigation Systems.

Science.gov (United States)

Salazar, LeRoy; And Others

This resource for trainers involved in irrigated agriculture training for Peace Corps volunteers consists of two parts: irrigation training manual and irrigation reference manual. The complete course should fully prepare volunteers serving as irrigation, specialists to plan, implement, evaluate and manage small-scale irrigation projects in arid,…

Short-term effects of irrigation with treated domestic wastewater on microbiological activity of a Vertic xerofluvent soil under Mediterranean conditions.

Science.gov (United States)

Kayikcioglu, Huseyin Husnu

2012-07-15

Approximately 70% of the world water use, including all the water diverted from rivers and pumped from underground, is used for agricultural irrigation, so the reuse of treated domestic wastewater (TWW) for purposes such as agricultural and landscape irrigation reduces the amount of water that needs to be extracted from natural water sources as well as reducing discharge of wastewater to the environment. Thus, TWW is a valuable water source for recycling and reusing in arid and semi-arid regions which are frequently confronting water shortages. In this regard, this study was planned to reveal the short-term effects of advanced-TWW irrigation on microbial parameters of Vertic xerofluvent soil. For this purpose, certain parameters were measured in the study, including soil total organic carbon (C(org)), N-mineralization (N(min)), microbial biomass carbon (C(mic)), soil microbial quotient (C(mic)/C(org)) and the activities of the enzymes dehydrogenase (DHG), urease (UA), alkaline phosphatase (ALKPA), β-glucosidase (GLU) and aryl sulphatase (ArSA) in soils irrigated with TWW and fresh water (FW). All of the microbial parameters were negatively affected by TWW irrigation. Microbial parameters decreased by 10.1%-54.1% in comparison with the FW plots. This decrease especially in enzymatic activities of soil irrigated with TWW, presumably due to some heavy metals inhibited their activity associated with the soil types and the concentrations of heavy metals in wastewater. In contrast, C(mic)/C(org) was found higher in the plots irrigated with TWW at the end of the experiment. The addition of organic matter to soil by irrigation with TWW is cause for the increase in this ratio. The dose of irrigation should be modified to reduce the quantity and to increase the frequency of application to avoid the loss of aggregation and salt accumulation. TWW irrigation is a strategy with many benefits to agricultural land management; however, long-term studies should be implemented to

An optimization model to design and manage subsurface drip irrigation system for alfalfa

Science.gov (United States)

Kandelous, M.; Kamai, T.; Vrugt, J. A.; Simunek, J.; Hanson, B.; Hopmans, J. W.

2010-12-01

Subsurface drip irrigation (SDI) is one of the most efficient and cost-effective methods for watering alfalfa plants. Lateral installation depth and distance, emitter discharge, and irrigation time and frequency of SDI, in addition to soil and climatic conditions affect alfalfa’s root water uptake and yield. Here we use a multi-objective optimization approach to find optimal SDI strategies. Our approach uses the AMALGAM evolutionary search method, in combination with the HYDRUS-2D unsaturated flow model to maximize water uptake by alfalfa’s plant roots, and minimize loss of irrigation and drainage water to the atmosphere or groundwater. We use a variety of different objective functions to analyze SDI. These criteria include the lateral installation depth and distance, the lateral discharge, irrigation duration, and irrigation frequency. Our framework includes explicit recognition of the soil moisture status during the simulation period to make sure that the top soil is dry for harvesting during the growing season. Initial results show a wide spectrum of optimized SDI strategies for different root distributions, soil textures and climate conditions. The developed tool should be useful in helping farmers optimize their irrigation strategy and design.

The Effects of Two Different Deficit Irrigation Managements on the Root Length of Maize

Directory of Open Access Journals (Sweden)

M. Gheysari

2015-06-01

Full Text Available The response of root to water stress is one of the most important parameters for researchers. Study of growth and distribution of root under different irrigation managements helpsresearchersto a better understanding of soil water content, and the availability of water and nutrition in water stress condition. To investigate the effects of four levels of irrigation under two different deficit irrigation managements on the root length of maize, a study was conducted in 2009. Irrigation managements included fixed irrigation interval-variable irrigation depth (M1 and variable irrigation interval-fixed irrigation depth (M2. Maize plants were planted in 120 large 110-liter containers in a strip-plot design in a randomized complete block with three replications. Root data sampling was done after root washing in five growth stages. The results showed that the effect of irrigation levels on root length was significant (P

EFFICACY OF DIFFERENT ENDODONTIC IRRIGATION PROTOCOLS IN CALCIUM HYDROXIDE REMOVAL

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Elka N. Radeva

2016-10-01

Full Text Available Introduction: Calcium hydroxide is widely used in the field of endodontics as a temporary root canal filling. This medicament significantly increases pH and optimizes the treatment outcome. Its total removal before final obturation is very important. Otherwise it could affect the hermetic filling and respectively the endodontic success. Aim: To evaluate the most effective irrigation protocol of calcium hydroxide removal from root canals. Materials and methods: In this study 36 single root canal teeth were observed. They were randomly divided into three groups (n=10 each group according to the technique applied for calcium hydroxide removal - manual irrigation, irrigation and Revo-S rotary instrumentation; and passive ultrasonic irrigation, and a control group (n=6 – irrigation with distilled water only. After calcium hydroxide removals following the procedures above, teeth were separated longitudinally in a buccal-lingual direction and remnants of medicaments were observed in the apical, middle and coronal part of each tooth. Then all of the specimens were observed using scanning electron microscopy and evaluated by a specified scale. The results have undergone statistical analysis. Results: In the case of calcium hydroxide in the apex and in the middle with highest average is Revo-S, followed by Ultrasonic and irrigation. In the coronal part the highest average belongs to Revo-S, irrigation and Ultrasonic. In all groups the highest average is represented by control group. Conclusion: There is not a universal technique for removal of intracanal medicaments and applying more than one protocol is required.

[Influence of saltwater irrigation on the yield and quality of Cynodon dactylon under desert conditions].

Science.gov (United States)

Zhou, Ruilian; Dov, Paternak; Zhao, Halin

2002-08-01

Responses of six varieties (Suwannee, Coast cross, Tifton44, Tifton68, Tifton78 and Tifton85) of Cynodon dactylon to irrigation-water salinity were investigated in field by means of a double line source experimental design. The digestibility of the grass by goat was analyzed using the rumen gastric justice digestion method. The results showed that the six varieties grew well, and had a high yield of fresh grass when eletro-conductivity (Eci) Cynodon dactylon were not effected by saltwater irrigation.

Dwarf cashew growth irrigated with saline waters

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Hugo Orlando Carvallo Guerra

2009-12-01

Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

Production of mungbean under reclaimed sandy soil and irrigation levels using N-15 labeled

International Nuclear Information System (INIS)

Abdallah, A.A.G.; Thabet, E.M.A.

2000-01-01

Field experiment were performed at the Atomic Energy Authority, Experimental farm, Inshas, Egypt. During 1998 growing season. In tafla and sand mixture soil (1:7 Wt./Wt.). The treatments were laid out using a single line source sprinkler irrigation system which allows a gradual variation of irrigation from excess to little irrigation in which the calculated amount of irrigation water levels were 2241, 1562 and 1093 m 3 / feddan (W 1 , W 2 and W 3 ). The obtained results indicated that, there was a clear relationship between adequate amount of irrigation water and both total seed yield and total green pods/plot as well as there were significant increase in both characters due to irrigation W 1 and W 2 compared with W 3 . The results also indicated that W 2 irrigation level could be used in irrigation under the same conditions. Water use efficiency was significantly increased with middle irrigation level than with other two irrigation treatments. The result concerned fertilizer use efficiency using N 15 labeled fertilizers and total seed protein content were increased with decreasing irrigation level

Irrigation water consumption modelling of a soilless cucumber crop under specific greenhouse conditions in a humid tropical climate

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Galo Alberto Salcedo

Full Text Available ABSTRACT: The irrigation water consumption of a soilless cucumber crop under greenhouse conditions in a humid tropical climate has been evaluated in this paper in order to improve the irrigation water and fertilizers management in these specific conditions. For this purpose, a field experiment was conducted. Two trials were carried out during the years 2011 and 2014 in an experimental farm located in Vinces (Ecuador. In each trial, the complete growing cycle of a cucumber crop grown under a greenhouse was evaluated. Crop development was monitored and a good fit to a sigmoidal Gompertz type growth function was reported. The daily water uptake of the crop was measured and related to the most relevant indoor climate variables. Two different combination methods, namely the Penman-Monteith equation and the Baille equation, were applied. However, the results obtained with these combination methods were not satisfactory due to the poor correlation between the climatic variables, especially the incoming radiation, and the crop's water uptake (WU. On contrary, a good correlation was reported between the crop's water uptake and the leaf area index (LAI, especially in the initial crop stages. However, when the crop is fully developed, the WU stabilizes and becomes independent from the LAI. A preliminary model to simulate the water uptake of the crop was adjusted using the data obtained in the first experiment and then validated with the data of the second experiment.

Yellow berry, protein and agronomic characteristics in bread wheat under different conditions of nitrogen and irrigation in northwest mexico

International Nuclear Information System (INIS)

Felix, F.R.; Wong, B.R.; Chavez, P.I.T.; Alviles, A.; Salazar, S.M.; Martinez, M.E.R

2014-01-01

The aim of this research was to determine the effect of the amount of nitrogen fertilizer and number of irrigations on the YB disorder of wheat cultivar Tarachi, as well as its relationship with protein content, and the agronomic characteristics. The experiment was conducted in northwestern Mexico, during the fall-winter season, 2009-2010. Three levels of nitrogen (75, 150 or 250 kg ha-1) and three levels of irrigation (3, 4 or 5 irrigations) were studied. Increasing the nitrogen rate decreased the YB content, the thousand kernel weight and hectoliter weight; and increased the protein content and the number of grains per spike. The number of irrigations did not affect the number of grains per spike. However, increasing the number of irrigations increased the YB content, the thousand kernel weight and hectoliter weight; on the other hand, the protein content decreased. A negative correlation between protein content and percentage of YB was presented. It was concluded that the presence of the disorder YB in bread wheat, Tarachi, is due to a low nitrogen rate in the soil and an increase in number of irrigations. (author)

Assessing the groundwater recharge under various irrigation schemes in Central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Lin, Zih-Ciao; Tsai, Cheng-Bin

2014-05-01

The flooded paddy fields can be considered as a major source of groundwater recharge in Central Taiwan. The risk of rice production has increased notably due to climate change in this area. To respond to agricultural water shortage caused by climate change without affecting rice yield in the future, the application of water-saving irrigation is the substantial resolution. The System of Rice Intensification (SRI) was developed as a set of insights and practices used in growing irrigated rice. Based on the water-saving irrigation practice of SRI, impacts of the new methodology on the reducing of groundwater recharge were assessed in central Taiwan. The three-dimensional finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge under different irrigation schemes. According to local climatic and environmental characteristics associated with SRI methodology, the change of infiltration rate was evaluated and compared with the traditional irrigation schemes, including continuous irrigation and rotational irrigation scheme. The simulation results showed that the average infiltration rate in the rice growing season decreased when applying the SRI methodology, and the total groundwater recharge amount of SRI with a 5-day irrigation interval reduced 12% and 9% compared with continuous irrigation (6cm constant ponding water depth) and rotational scheme (5-day irrigation interval with 6 cm initial ponding water depth), respectively. The results could be used as basis for planning long-term adaptive water resource management strategies to climate change in Central Taiwan. Keywords: SRI, Irrigation schemes, Groundwater recharge, Infiltration

Optimal crop selection and water allocation under limited water supply in irrigation

Science.gov (United States)

Stange, Peter; Grießbach, Ulrike; Schütze, Niels

2015-04-01

Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.

Effect of low-cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

DEFF Research Database (Denmark)

Keraita, Bernard; Konradsen, Flemming; Drechsel, P.

2007-01-01

OBJECTIVE: To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water in urban farming in Ghana. METHODS: Trials on drip kits, furrow irrigation and watering...... cans were conducted with urban vegetable farmers. Trials were arranged in a completely randomised block design with each plot having all three irrigation methods tested. This was conducted in both dry and wet seasons. Three hundred and ninety-six lettuce, 72 soil, 15 poultry manure and 32 water samples...... were analysed for thermotolerant coliforms and helminth eggs. RESULTS: Lettuce irrigated with drip kits had the lowest levels of contamination, with, on average, 4 log units per 100 g, fewer thermotolerant coliforms than that irrigated with watering cans. However, drip kits often got clogged, required...

Apical extrusion of debris and irrigant using hand and rotary systems: A comparative study

Science.gov (United States)

Ghivari, Sheetal B; Kubasad, Girish C; Chandak, Manoj G; Akarte, NR

2011-01-01

Aim: To evaluate and compare the amount of debris and irrigant extruded quantitatively by using two hand and rotary nickel–titanium (Ni–Ti) instrumentation techniques. Materials and Methods: Eighty freshly extracted mandibular premolars having similar canal length and curvature were selected and mounted in a debris collection apparatus. After each instrument change, 1 ml of distilled water was used as an irrigant and the amount of irrigant extruded was measured using the Meyers and Montgomery method. After drying, the debris was weighed using an electronic microbalance to determine its weight. Statistical analysis used: The data was analyzed statistically to determine the mean difference between the groups. The mean weight of the dry debris and irrigant within the group and between the groups was calculated by the one-way ANOVA and multiple comparison (Dunnet D) test. Results: The step-back technique extruded a greater quantity of debris and irrigant in comparison to other hand and rotary Ni–Ti systems. Conclusions: All instrumentation techniques extrude debris and irrigant, it is prudent on the part of the clinician to select the instrumentation technique that extrudes the least amount of debris and irrigant, to prevent a flare-up phenomena. PMID:21814364

Efficacy of passive ultrasonic irrigation with natural irrigants (Morinda citrifolia juice, Aloe Vera and Propolis) in comparison with 1% sodium hypochlorite for removal of E. faecalis biofilm: an in vitro study.

Science.gov (United States)

Bhardwaj, Anuj; Velmurugan, Natanasabapathy; Ballal, Suma

2013-01-01

Present study evaluated the efficacy of natural derivative irrigants, Morinda citrifolia juice (MCJ), Aloe Vera and Propolis in comparison to 1% sodium hypochlorite with passive ultrasonic irrigation for removal of the intraradicular E. faecalis biofilms in extracted single rooted human permanent teeth. Biofilms of E. faecalis were grown on the prepared root canal walls of 60 standardized root halves which were longitudinally sectioned. These root halves were re-approximated and the samples were divided into five groups of twelve each. The groups were, Group A (1% NaOCl), Group B (MCJ), Group C (Aloe vera), Group D (Propolis) and Group E (Saline). These groups were treated with passive ultrasonic irrigation (PUI) along with the respective irrigants. The root halves were processed for scanning electron microscopy. Three images (X2.5), coronal, middle and apical, were taken for the twelve root halves in each of the five groups. The images were randomized and biofilm coverage assessed independently by three calibrated examiners, using a four-point scoring system. 1% NaOCl with passive ultrasonic irrigation (PUI) was effective in completely removing E. faecalis biofilm and was superior to the natural irrigants like MCJ, Aloe vera and Propolis tested in this study. 1% NaOCl used along with passive ultrasonic irrigation was effective in completely removing E. faecalis biofilm when compared to natural irrigants (MCJ, Aloe Vera and Propolis).

IRRIGATION USING SOLAR PUMP

OpenAIRE

Prof. Nitin P.Choudhary*1 & Ms. Komal Singne2

2017-01-01

In this report the described design of a PV and soil moisture sensor based automated irrigation system is introduced. This project aims to provide a human friendly, economical and automated water pumping system which eliminates the problems of over irrigation and helps in irrigation water optimization and manage it in accordance with the availability of water. Our project not only tries to modernize the irrigation practices and ensure the optimum yield by carefully fulfilling the requirements...

Rational use of water in trickle irrigation design.

Science.gov (United States)

Saad, J. C. C.; da Silva Junior, H. M.

2012-04-01

In trickle irrigation systems, the design is based on the pre-established emission uniformity (EU) which is the combined result of the equipment characteristics and its hydraulic configuration. However, this desired value of the EU may not be confirmed by the final project (in field conditions) and neither by the yield uniformity. However, the most important is to assure yield uniformity with rational use of water. The hypotheses of this research were: a) the EU of a trickle irrigation system at field conditions is equal to the emission uniformity pre-established in the design; b) EU has always the lowest value when compared with other indicators of uniformity; c) the discharge variation coefficient is not equal to production variation coefficient in the operational unit; d) the productivity variation coefficient is more dependent on water depth applied than the EU. This study aimed to evaluate the relationships among EU used in the irrigation system design, water depth applied and the final yield uniformity. The uniformity indicators evaluated were: EU, distribution uniformity (UD) and the index proposed by Barragan & Wu (2005). They were compared estimating the performance of a trickle irrigation system applied in a citrus orchard with dimensions of 400m x 600m. The design of the irrigation system was optimized by a Linear Programming model. The tree rows were leveled in the larger direction and the spacing adopted in the orchard was 7m x 4m. The manifold line was always operating on a slope condition. The sensitivity analysis involved different slopes, 0, 3, 6, 9 and 12%, and different values of emission uniformity, 60, 70, 75, 80, 85, 90 and 94%. The citrus yield uniformity was evaluated by the variation coefficient. The emission uniformity (EU) after design differed from the EU pre-established, more sharply in the initial values lower than 90%. Comparing the uniformity indexes, the EU always generated lower values when compared with the UD and with the index

Pricing Unmetered Irrigation Water under Asymmetric Information and Full Cost Recovery

Directory of Open Access Journals (Sweden)

Alban Lika

2016-12-01

Full Text Available The objective of this study is to define an efficient pricing scheme for irrigation water in conditions of unmetered water use. The study is based on a principal-agent model and identifies a menu of contracts, defined as a set of payments and share of irrigated area, able to provide incentives for an efficient use of the resource by maximizing social welfare. The model is applied in the case study of the Çukas region (Albania where irrigation water is not metered. The results demonstrate that using a menu of contracts makes it possible to define a second best solution that may improve the overall social welfare derived from irrigation water use compared with the existing pricing structure, though, in the specific case study, the improvement is small. Furthermore, the results also suggest that irrigation water pricing policy needs to take into account different farm types, and that appropriate contract-type pricing schemes have a potential role in providing incentives to farmers to make irrigation choices to the social optimum.

Improving efficiencies of irrigation and nitrogen uptake in wheat

International Nuclear Information System (INIS)

Bazza, M.

2000-01-01

Three years of field studies and lysimeter experiments on irrigated wheat had the objective of finding ways of managing irrigation and N fertilization to minimize losses and reduce contamination of groundwater. Applied N had significant positive effects on crop-water consumptive use. The highest N losses occurred during early growth. Irrigation had little effect on N loss when it was practiced efficiently. Under the prevailing conditions, it is recommended that no N be applied to wheat at planting, in order to limit N losses by leaching caused by the high precipitation that usually occurs during early development when crop-N requirements are small. No more than 120 kg N ha -1 should be applied in total to minimize groundwater pollution and maximize N-uptake efficiency and economic returns. Also, for economic and environmental reasons, irrigation should be limited to 80% of the total requirement and to depths of 40 to 60 mm. (author)

Effects of regulated deficit irrigation on physiology, yield and fruit quality in apricot trees under Mediterranean conditions

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Francisco Pérez-Sarmiento

2016-12-01

Full Text Available Scarce water resources mainly in arid and semi-arid areas have caused an increasing interest for applying irrigation protocols aiming to reduce water spends. The effects of regulated deficit irrigation (RDI on the performance of apricot trees (Prunus armeniaca L. cv. “Búlida” were assessed in Murcia (SE Spain, during three consecutive growing seasons (2008-2010. The hypothesis was that RDI would not restrict yield but increase fruit quality while saving water. Two irrigation treatments were established: i control, irrigated to fully satisfy crop water requirements (100% ETc and ii RDI, that reduced the amount of applied water to: a 40% of ETc at flowering and stage I of fruit growth; b 60% of ETc during the stage II of fruit growth and c 50% and 25% of ETc during the late postharvest period (from 60 days after harvest. Stem water potential, gas exchanges, trunk cross-sectional area (TCSA, fruit diameter, yield and fruit quality traits were determined. Vegetative growth was decreased by the use of RDI (12% less TCSA on average for the three years, whereas yield was unaffected. In addition, some qualitative characteristics of the fruits, such as the level of soluble solids, sweetness/acidity relation and fruit colour, were improved by the use of RDI. These results and average water savings of approximately 30%, lead us to conclude that RDI strategies are a possible solution for irrigation management in areas with water shortages, such as arid and semi-arid environments.

Effects of regulated deficit irrigation on physiology, yield and fruit quality in apricot trees under Mediterranean conditions

International Nuclear Information System (INIS)

Pérez-Sarmiento, F.; Mirás-Avalos, J.M.; Alcobendas, R.; Alarcón, J.J.; Mounzer, O.; Nicolas, E.

2016-01-01

Scarce water resources mainly in arid and semi-arid areas have caused an increasing interest for applying irrigation protocols aiming to reduce water spends. The effects of regulated deficit irrigation (RDI) on the performance of apricot trees (Prunus armeniaca L. cv. “Búlida”) were assessed in Murcia (SE Spain), during three consecutive growing seasons (2008-2010). The hypothesis was that RDI would not restrict yield but increase fruit quality while saving water. Two irrigation treatments were established: i) control, irrigated to fully satisfy crop water requirements (100% ETc) and ii) RDI, that reduced the amount of applied water to: a) 40% of ETc at flowering and stage I of fruit growth; b) 60% of ETc during the stage II of fruit growth and c) 50% and 25% of ETc during the late postharvest period (from 60 days after harvest). Stem water potential, gas exchanges, trunk cross-sectional area (TCSA), fruit diameter, yield and fruit quality traits were determined. Vegetative growth was decreased by the use of RDI (12% less TCSA on average for the three years), whereas yield was unaffected. In addition, some qualitative characteristics of the fruits, such as the level of soluble solids, sweetness/acidity relation and fruit colour, were improved by the use of RDI. These results and average water savings of approximately 30%, lead us to conclude that RDI strategies are a possible solution for irrigation management in areas with water shortages, such as arid and semi-arid environments.

Effects of regulated deficit irrigation on physiology, yield and fruit quality in apricot trees under Mediterranean conditions

Energy Technology Data Exchange (ETDEWEB)

Pérez-Sarmiento, F.; Mirás-Avalos, J.M.; Alcobendas, R.; Alarcón, J.J.; Mounzer, O.; Nicolas, E.

2016-07-01

Scarce water resources mainly in arid and semi-arid areas have caused an increasing interest for applying irrigation protocols aiming to reduce water spends. The effects of regulated deficit irrigation (RDI) on the performance of apricot trees (Prunus armeniaca L. cv. “Búlida”) were assessed in Murcia (SE Spain), during three consecutive growing seasons (2008-2010). The hypothesis was that RDI would not restrict yield but increase fruit quality while saving water. Two irrigation treatments were established: i) control, irrigated to fully satisfy crop water requirements (100% ETc) and ii) RDI, that reduced the amount of applied water to: a) 40% of ETc at flowering and stage I of fruit growth; b) 60% of ETc during the stage II of fruit growth and c) 50% and 25% of ETc during the late postharvest period (from 60 days after harvest). Stem water potential, gas exchanges, trunk cross-sectional area (TCSA), fruit diameter, yield and fruit quality traits were determined. Vegetative growth was decreased by the use of RDI (12% less TCSA on average for the three years), whereas yield was unaffected. In addition, some qualitative characteristics of the fruits, such as the level of soluble solids, sweetness/acidity relation and fruit colour, were improved by the use of RDI. These results and average water savings of approximately 30%, lead us to conclude that RDI strategies are a possible solution for irrigation management in areas with water shortages, such as arid and semi-arid environments.

Automation of irrigation systems to control irrigation applications and crop water use efficiency

Science.gov (United States)

Agricultural irrigation management to slow water withdrawals from non-replenishing quality water resources is a global endeavor and vital to sustaining irrigated agriculture and dependent rural economies. Research in site-specific irrigation management has shown that water use efficiency, and crop p...

Ghana - Agriculture - Irrigation

Data.gov (United States)

Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

Converting Surface Irrigation to Pressurized Irrigation Systems and its Effecton Yield of OrangeTrees (Case Study:North of Khouzestan

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M. Khorramian

2017-01-01

Full Text Available Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation efficiency with low-volume pressurized irrigation systems, citrus trees have adapted with these new irrigation systems. However limited information exists on the performance of mature orchards converted from border surface irrigation to pressurized irrigation systems. Therefore, the current research was conducted to evaluate the feasibility of converting surface irrigation to pressurized irrigation systems on mature citrus trees in climate conditions of North Khouzestan. Materials and Methods: This study was conducted during three years at Safiabad Agricultural Research Center to evaluate the yield of citrus trees and the quality of fruits for two Marss and Valencia varieties which grow 7 years previously with surface irrigation and converted to pressurized irrigation systems. The treatments consisted of six irrigation methods including Overhead sprinkle irrigation (OHSI, Under tree sprinkle irrigation(UTSI, Trickle irrigation(TI(six 8 L/h Netafim emitters, Microjet irrigation (MI(two 180 microjet were located under canopy near of the trunk at opposite sides of trunk,Bubbler irrigation(BI(a single located under the canopy of each treeandSurface irrigation(SI method.Soil texture was clay loam well drained without salinity(ECe=0.69ds m-1, with 1.25 percent organic carbon. The experimental design was completely randomized design. The trees were irrigated during spring and summer seasons. For calculating irrigation water depth in TI, MI and BI systems, daily evaporation from a class A evaporation pan of the Safiabad weather station (nearby the experimental field was collected, and evapotranspiration of the citrus trees was calculated applying a

APPLICATION OF DRIP IRRIGATION ON COTTON PLANT GROWTH (Gossypium sp.

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Syahruni Thamrin

2017-12-01

Full Text Available The condition of cotton planting in South Sulawesi is always constrained in the fulfillment of water. All plant growth stages are not optimal to increase production, so it is necessary to introduce good water management technology, such as through water supply with drip irrigation system. This study aims to analyze the strategy of irrigation management in cotton plants using drip irrigation system. Model of application by designing drip irrigation system and cotton planting on land prepared as demonstration plot. Observations were made in the germination phase and the vegetative phase of the early plants. Based on the result of drip irrigation design, the emitter droplet rate (EDR was 34.266 mm/hour with an operational time of 4.08 min/day. From the observation of cotton growth, it is known that germination time lasted from 6 to 13 days after planting, the average plant height reached 119.66 cm, with the number of leaves averaging 141.93 pieces and the number of bolls averaging 57.16 boll.

Differential Impact of Passive versus Active Irrigation on Urban Forests in Semiarid Regions

Science.gov (United States)

Luketich, A. M.; Papuga, S. A.; Crimmins, M.

2017-12-01

The network of trees within a city provides a variety of ecosystem services such as flood mitigation and reduced heat island effects. To maintain these `urban forests' in semiarid cities, the use of scarce water resources for irrigation is often necessary. Rainwater harvesting has been widely adopted in Tucson, AZ as a sustainable water source for trees, but the effects of passive water harvesting versus active irrigation on tree canopy productivity and microclimate is largely unquantified. We hypothesize that regardless of whether trees are passively or actively irrigated, deep soil moisture will be elevated compared to natural conditions; however, we expect that increased deep soil moisture conditions will be more frequent using active irrigation. Additionally, we hypothesize that similar to natural settings, urban trees will need access deep soil moisture for transpiration. Therefore, we expect that actively irrigated trees will have more periods of transpiration than passively irrigated trees and that this will result in elevated and sustained phenological activity. We also expect that this difference will translate to more ecosystem services for a longer portion of the year in actively irrigated urban forests. Here, we compare key ecohydrological indicators of passive and active irrigation systems at two sites in Tucson, AZ. Our measurements include soil moisture, transpiration, air temperature, soil temperature, below- and within- canopy temperatures, and canopy phenology. Our first year of results suggest there are differences in transpiration, canopy greening and microclimate between the two irrigation techniques and that the magnitude of these differences are highly seasonal. This research can help to improve understanding of the practices and function of green infrastructure in semiarid cities and inform models that attempt to aggregate the influence of these urban forests for understanding watershed management strategies.

Leaching of N-nitrosodimethylamine (NDMA) in turfgrass soils during wastewater irrigation.

Science.gov (United States)

Gan, J; Bondarenko, S; Ernst, F; Yang, W; Ries, S B; Sedlak, D L

2006-01-01

N-nitrosodimethylamine (NDMA) is a carcinogenic by-product of chlorination that is frequently found in municipal wastewater effluent. NDMA is miscible in water and negligibly adsorbed to soil, and therefore may pose a threat to ground water when treated wastewater is used for landscape irrigation. A field study was performed in the summer months under arid Southern California weather conditions to evaluate the leaching potential of NDMA in turfgrass soils during wastewater irrigation. Wastewater was used to irrigate multiple turfgrass plots at 110 to 160% evapotranspiration rate for about 4 mo, and leachate was continuously collected and analyzed for NDMA. The treated wastewater contained relatively high levels of NDMA (114-1820 ng L(-1); mean 930 ng L(-1)). NDMA was detected infrequently in the leachate regardless of the soil type or irrigation schedule. At a method detection limit of 2 ng L(-1), NDMA was only detected in 9 out of 400 leachate samples and when it was detected, the NDMA concentration was less than 5 ng L(-1). NDMA was relatively persistent in the turfgrass soils during laboratory incubation, indicating that mechanisms other than biotransformation, likely volatilization and/or plant uptake, contributed to the rapid dissipation. Under conditions typical of turfgrass irrigation with wastewater effluent it is unlikely that NDMA will contaminate ground water.

Infrastructure performance of irrigation canal to irrigation efficiency of irrigation area of Candi Limo in Mojokerto District

Science.gov (United States)

Kisnanto, S.; Hadiani, R. R. R.; Ikhsan, C.

2018-03-01

Performance is a measure of infrastructure success in delivering the benefits corresponding it’s design implementation. Debit efficiency is a comparison between outflow debit and inflow debit. Irrigation canal performance is part of the overall performance aspects of an irrigation area. The greater of the canal performance will be concluded that the canal is increasingly able to meet the planned benefits, need to be seen its comparison between the performance and debit efficiency of the canal. The existing problems in the field that the value of the performance of irrigation canals are not always comparable to the debit efficiency. This study was conducted to describe the relationship between the performance of the canal to the canal debit efficiency. The study was conducted at Candi Limo Irrigation Area in Mojokerto Disctrict under the authority of Pemerintahan Provinsi Jawa Timur. The primary canal and secondary canal are surveyed to obtain data. The physical condition of the primary and secondary canals into the material of this study also. Primary and secondary canal performance based on the physical condition in the field. Measurement inflow and outflow debit into the data for the calculation of the debit efficiency. The instrument used in this study such as the current meter for debit measurements in the field as a solution when there is a building measure in the field were damaged, also using the meter and the camera. Permen PU No.32 is used to determine the value of the performance of the canal, while the efficiency analysis to calculate a comparison value between outflow and inflow debit. The process of data running processing by performing the measurement and calculation of the performance of the canal, the canal debit efficiency value calculation, and display a graph of the relationship between the value of the performance with the debit efficiency in each canal. The expected results of this study that the performance value on the primary canal in the

Evaluation of the wettability of a resin-based sealer in contact with some herbal irrigants

Directory of Open Access Journals (Sweden)

Mohammadreza Nabavizade

2018-01-01

Conclusion: Under the experimental condition of this study, CC was able to increase dentin wettability and therefore may be regarded as a promising irrigant after careful evaluation of other properties of this irrigant.

Traditional Irrigation Management in Betmera-Hiwane, Ethiopia: The Main Peculiarities for the Persistence of Irrigation Practices

Institute of Scientific and Technical Information of China (English)

Solomon Habtu; Kitamura Yoshinobu

2006-01-01

Traditional irrigation, as part of the ancient agricultural practices in northern Ethiopia (Tigray), has persisted for long time since 500 B.C.,while many newly introduced irrigation projects have usually failed there. The main objective of this study is thus to investigate the peculiarities pertinent to irrigation management and those having contributed for the persistence of traditional irrigation practices for a long period of time. The experience gained from such areas can definitely help make irrigation management system of new irrigation schemes sustainable. Betmera-Hiwane, one of the ancient traditional irrigation areas in Tigray region, was selected for the field study. Direct observations through field visits accompanied by interviews to farmers, local officials, local knowledgeable individuals and higher officials were made. After analyzing the collected primary and secondary information, the main peculiarities that contributed to the persistence of traditional irrigation areas were identified, and they are: the presence of communally constructed local rules, locally designed hydraulic control structures, ownership feeling of the irrigators and accountability of water distributors to the irrigation management, the culture for mobilizing communal resources and the culture of self-initiating local water management strategies.

Development of fine and coarse roots of Thuja occidentalis 'Brabant' in non-irrigated and drip irrigated field plots

NARCIS (Netherlands)

Pronk, A.A.; Willigen, de P.; Heuvelink, E.; Challa, H.

2002-01-01

Aboveground dry mass, total root dry mass and root length density of the fine roots of Thuja occidentalis `Brabant' were determined under non- and drip-irrigated field conditions. Two-dimensional diffusion parameters for dynamic root growth were estimated based on dry mass production of the fine

Modernized Irrigation Technologies in West Africa

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Hakan Büyükcangaz

2017-12-01

Full Text Available Crop production in West Africa is mostly dependent upon rainfed agriculture. Irrigation is a vital need due to uneven distribution of rainfall and seasonality of water resources. However, management and sustainability of irrigation are under risk due to notably weak database, excessive cost, unappropriate soil or land use, environmental problems and extreme pessimism in some quarters since rainfed agriculture is seen as potentially able to support the present population. This paper focuses on modernized irrigation technologies and systems that utilize less water. Information about irrigation systems in Ghana and Liberia were gathered through: 1 Irrigation development authorities in both countries, by reviewing past literatures, online publications, reports and files about irrigation in West Africa, specifically Ghana and Liberia; 2 International Food Policy Research Institute (IFPRI; 3 Collation of information, reports and data from Ghana Irrigation Development Authority (GIDA and 4 International Water Management Institute (IWMI. The result shows that both countries have higher irrigation potential. However, the areas developed for irrigation is still a small portion as compare to the total land available for irrigation. On the other hand, as seen in the result, Liberia as compare to Ghana has even low level of irrigation development.

Irrigation in endodontic treatment.

Science.gov (United States)

Basrani, Bettina

2011-01-01

The primary endodontic treatment goal is to optimize root canal disinfection and to prevent reinfection. Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal system. In this review of the literature, various irrigants and the interactions between irrigants are discussed and new delivery systems are introduced.

The effect of irrigation time and type of irrigation fluid on cartilage surface friction.

Science.gov (United States)

Stärke, F; Awiszus, F; Lohmann, C H; Stärke, C

2018-01-01

It is known that fluid irrigation used during arthroscopic procedures causes a wash-out of lubricating substances from the articular cartilage surface and leads to increased friction. It was the goal of this study to investigate whether this effect depends on the time of irrigation and type of fluid used. Rabbit hind legs were used for the tests. The knees were dissected and the friction coefficient of the femoral cartilage measured against glass in a boundary lubrication state. To determine the influence of irrigation time and fluid, groups of 12 knees received either no irrigation (control), 15, 60 or 120min of irrigation with lactated Ringer's solution or 60min of irrigation with normal saline or a sorbitol/mannitol solution. The time of irrigation had a significant effect on the static and kinetic coefficient of friction (CoF), as had the type of fluid. Longer irrigation time with Ringer's solution was associated with increased friction coefficients (relative increase of the kinetic CoF compared to the control after 15, 60 and 120min: 16%, 76% and 88% respectively). The sorbitol/mannitol solution affected the static and kinetic CoF significantly less than either Ringer's or normal saline. The washout of lubricating glycoproteins from the cartilage surface and the associated increase of friction can be effectively influenced by controlling the time of irrigation and type of fluid used. The time of exposure to the irrigation fluid should be as short as possible and monosaccharide solutions might offer a benefit compared to salt solutions in terms of the resultant friction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carbon and water footprints of irrigated corn and non-irrigated wheat in Northeast Spain.

Science.gov (United States)

Abrahão, Raphael; Carvalho, Monica; Causapé, Jesús

2017-02-01

Irrigation increases yields and allows several crops to be produced in regions where it would be naturally impossible due to limited rainfall. However, irrigation can cause several negative environmental impacts, and it is important to understand these in depth for the correct application of mitigation measures. The life cycle assessment methodology was applied herein to compare the main irrigated and non-irrigated crops in Northeast Spain (corn and wheat, respectively), identifying those processes with greater contribution to environmental impacts (carbon and water footprint categories) and providing scientifically-sound information to facilitate government decisions. Due to concerns about climate change and water availability, the methods selected for evaluation of environmental impacts were IPCC 2013 GWP (carbon footprint) and water scarcity indicator (water footprint). The area studied, a 7.38-km 2 basin, was monitored for 12 years, including the period before, during, and after the implementation of irrigation. The functional unit, to which all material and energy flows were associated with, was the cultivation of 1 ha, throughout 1 year. The overall carbon footprint for irrigated corn was higher, but when considering the higher productivity achieved with irrigation, the emissions per kilogram of corn decrease and finally favor this irrigated crop. When considering the water footprint, the volumes of irrigation water applied were so high that productivity could not compensate for the negative impacts associated with water use in the case of corn. Nevertheless, consideration of productivities and gross incomes brings the results closer. Fertilizer use (carbon footprint) and irrigation water (water footprint) were the main contributors to the negative impacts detected.

Integrating Water Supply Constraints into Irrigated Agricultural Simulations of California

Science.gov (United States)

Winter, Jonathan M.; Young, Charles A.; Mehta, Vishal K.; Ruane, Alex C.; Azarderakhsh, Marzieh; Davitt, Aaron; McDonald, Kyle; Haden, Van R.; Rosenzweig, Cynthia E.

2017-01-01

Simulations of irrigated croplands generally lack key interactions between water demand from plants and water supply from irrigation systems. We coupled the Water Evaluation and Planning system (WEAP) and Decision Support System for Agrotechnology Transfer (DSSAT) to link regional water supplies and management with field-level water demand and crop growth. WEAP-DSSAT was deployed and evaluated over Yolo County in California for corn, rice, and wheat. WEAP-DSSAT is able to reproduce the results of DSSAT under well-watered conditions and reasonably simulate observed mean yields, but has difficulty capturing yield interannual variability. Constraining irrigation supply to surface water alone reduces yields for all three crops during the 1987-1992 drought. Corn yields are reduced proportionally with water allocation, rice yield reductions are more binary based on sufficient water for flooding, and wheat yields are least sensitive to irrigation constraints as winter wheat is grown during the wet season.

Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

NARCIS (Netherlands)

Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

2014-01-01

The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

Effect of Irrigation Intervals on Some Morphophysiological Traits of Basil (Ocimum basilicum L. Ecotypes

Directory of Open Access Journals (Sweden)

M Goldani

2012-10-01

Full Text Available In order to determine the effect of different irrigation intervals on some morphophysiological traits of basil (Ocimum basilicum L., an experiment was conducted as factorial based on randomized complete block design with three replications under greenhouse conditions during 2010. Treatments included five irrigation intervals with 4, 8, 12, 16 and 20 days intervals and two ecotypes of basil (green and purple. The results showed that by increasing irrigation interval plant height, spike number, spike weight and shoot dry weight between irrigation intervals decreased. Purple basil was more tolerant than basil green ecotype to drought stress. Interaction between irrigation intervals and ecotypes showed that the best treatment related to four days irrigation interval and purple basil ecotype. The effect of irrigation intervals on root area, root diameter mean, total length, root volume and dry weight of root was significant. In all irrigation intervals, purple basil had better performance compared to green ecotype. The results showed that by increasing in irrigation interval decreased root surface area, but increased total root length. It was concluded that increasing irrigation interval up to 12 days decreased shoot and root surface areas. Increasing irrigation interval decreased chlorophyll- a, b and increased prolin amino acid content of basil leaf.

Yield and quality responses of drip-irrigated spinach to different irrigation quantities in a semi-arid region with a high altitude

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Yasemin KUSLU

2016-09-01

Full Text Available The effect of different irrigation quantities on the growth, marketable yield, crop quality (antioxidant activity, mineral and total phenolic content and irrigation water use efficiency (IWUE of spinach grown in a semi-arid region of high altitude (1795 m a.s.l. was determined. Plants were irrigated with three different irrigation quantities which determined considering 100 (I1, 85 (I2 and 70% (I3 of the evaporation obtained from a Class A pan. Irrigation quantities in the I1, I2 and I3 treatments as two years average were 290, 264.3 and 238.6 mm, respectively. The I1 treatment provided the highest growth, marketable yield (28.06 t*ha-1 and IWUE (9.7 kg*m-3. However, mineral and total phenolic content and antioxidant activity in the leaves of spinach were significantly higher under lower water application conditions. The I2 treatment resulted with the highest antioxidant activity and content of N, K, Mg, Na, Fe, Cu and total phenolics. As a result of the study, I1 treatment in spinach production could be suitable for water sufficient regions due to higher yield and IWUE. However, I2 treatment may be more appropriate for water scarce semi-arid regions of high altitude for obtaining higher minerals and antioxidant activity.

How Patients Experience Antral Irrigation

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Karin Blomgren

2015-01-01

Full Text Available Background Antral irrigation earlier had an important role in the diagnosis and treatment of rhinosinusitis. Nowadays, it is often considered too unpleasant. However, the experience of patients of this procedure has been very seldom evaluated. Nor has the effect on pain in rhinosinusitis been evaluated. The aim of this study was to evaluate patients’ experience of discomfort and pain during antral irrigation. We also assessed facial pain caused by rhinosinusitis before the procedure and pain soon after the procedure. Methods Doctors and 121 patients completed their questionnaires independently after antral irrigation in a university clinic, in a private hospital, and at a communal health center. Results Patients experienced mild pain during antral irrigation (mean and median visual analog scale score: <3. Their experience of pain during antral irrigation was closely comparable to pain during dental calculus scaling. Facial pain assessed before antral irrigation decreased quickly after the procedure. Conclusions Antral irrigation was well tolerated as an outpatient procedure. The procedure seems to relieve facial pain caused by the disease quickly. The role of antral irrigation in the treatment of acute rhinosinusitis will need further investigation.

Modernisation Strategy for National Irrigation Systems in the Philippines: Balanac and Sta. Maria River Irrigation Systems

NARCIS (Netherlands)

Delos Reyes, M.L.F.

2017-01-01

This book examines the nature and impact of irrigation system rehabilitation on increasing the actual area irrigated by the publicly funded canal irrigation systems of the Philippines. It proposes a system diagnosis approach for the development of a more appropriate and climate-smart irrigation

Performances du goutte à goutte enterré pour l’irrigation de jeunes palmiers dattiers

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R. BOURZIZA

2017-03-01

Full Text Available In oasis areas, surface water resources are becoming increasingly scarce. Groundwater resources are often overexploited, and are of poor quality for their high salinity degree. Water conservation and economy have therefore become imperative for better oases durability. If localized irrigation is currently recommended in Morocco for saving water, its use in the sub-desert areas does not keep water safe from high evaporation rates. An alternative to this system would be the use of subsurface drip irrigation. This technique is defined as an application of water under soil surface through drippers, which discharge water at generally similar rates as the surface drip irrigation. As subsurface drip irrigation is a newly introduced technique in Morocco, a better understanding in local conditions of the infiltration process around a buried source, and its impact on plant growth is necessarily required. This study aims to contribute to improving the efficiency of water use by testing the performance of subsurface drip irrigation system, especially in areas where water is a limited resource. The objectives of this research are performance evaluation in arid conditions of the subsurface drip irrigation system for young date palms compared to the surface drip, as well as determining the appropriate method of flow measurement for a buried dripper. In this context, an experimental plot was installed on a farm in the region of Erfoud (Errachidia Province, Southeast Morocco to characterize the respective performances of surface and subsurface drip irrigation on young date palm. Flow measurement to calculate the uniformity of the application of water was done through two methods: a flow measurement of drippers above the surface and another one underground. The latter method has also helped us to estimate losses through evaporation for both irrigation techniques. In addition, in order to compare the effect of two irrigation modes, plants were identified at random

Proposed Fuzzy-NN Algorithm with LoRaCommunication Protocol for Clustered Irrigation Systems

Directory of Open Access Journals (Sweden)

Sotirios Kontogiannis

2017-11-01

Full Text Available Modern irrigation systems utilize sensors and actuators, interconnected together as a single entity. In such entities, A.I. algorithms are implemented, which are responsible for the irrigation process. In this paper, the authors present an irrigation Open Watering System (OWS architecture that spatially clusters the irrigation process into autonomous irrigation sections. Authors’ OWS implementation includes a Neuro-Fuzzy decision algorithm called FITRA, which originates from the Greek word for seed. In this paper, the FITRA algorithm is described in detail, as are experimentation results that indicate significant water conservations from the use of the FITRA algorithm. Furthermore, the authors propose a new communication protocol over LoRa radio as an alternative low-energy and long-range OWS clusters communication mechanism. The experimental scenarios confirm that the FITRA algorithm provides more efficient irrigation on clustered areas than existing non-clustered, time scheduled or threshold adaptive algorithms. This is due to the FITRA algorithm’s frequent monitoring of environmental conditions, fuzzy and neural network adaptation as well as adherence to past irrigation preferences.

Low cost satellite data for monthly irrigation performance monitoring: benchmarks from Nilo Coelho, Brazil

NARCIS (Netherlands)

Bastiaanssen, W.G.M.; Brito, R.A.L.; Bos, M.; Souza, R.A.; Cavalcanti, E.B.; Bakker, M.M.

2001-01-01

Irrigation performance indicators can help water managers to understand how an irrigation scheme operates under actual circumstances. The new contribution of remote sensing data is the opportunity to study the crop growing conditions at scales ranging from individual fields to scheme level. Public

Importance of rainfall and sprinkler irrigation in supporting sporulation, spread of inoculum in runoff-water, and new infections of Phytophthora ramorum under field conditions

Science.gov (United States)

Steve Tjosvold; David Chambers; Elizabeth. Fichtner

2010-01-01

If a nursery plant infected with Phytophthora ramorum is introduced in a non-infested area, then it is important to understand what environmental conditions could lead spread and infection of new hosts. Once an infected nursery plant is introduced in a nursery or landscape, moving water sources, such as from rain and irrigation events, could...

Irrigation efficiency and water-policy implications for river basin resilience

Science.gov (United States)

Scott, C. A.; Vicuña, S.; Blanco-Gutiérrez, I.; Meza, F.; Varela-Ortega, C.

2014-04-01

Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface water and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the efficiency paradox. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the scale paradox) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the sectoral paradox. This paper briefly considers three regional contexts with broadly similar climatic and water-resource conditions - central Chile, southwestern US, and south-central Spain - where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection.

Irrigation efficiency and water-policy implications for river-basin resilience

Science.gov (United States)

Scott, C. A.; Vicuña, S.; Blanco-Gutiérrez, I.; Meza, F.; Varela-Ortega, C.

2013-07-01

Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface- and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the efficiency paradox. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river-basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the scale paradox) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the sectoral paradox. This paper briefly examines policy frameworks in three regional contexts with broadly similar climatic and water-resource conditions - central Chile, southwestern US, and south-central Spain - where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection.

Study of the influence of stable cadmium on the transfer of zinc-65 in an ecosystem irrigated by submersion (irrigated rice field)

International Nuclear Information System (INIS)

Myttenaere, C.; Merlini, M.; Dabin, P.; Mousny, J.M.; Pozzi, G.; Bittel, R.

1975-01-01

Irrigation water contains varying amounts of stable cadmium from industrial disposal. The presence of this element is capable of modifying the transfer of and affecting the mechanisms of absorption of zinc-65, a radionuclide which is discharged into water by nuclear power stations. This type of interaction between a nuclear contaminant and a conventional contaminant was studied in a rice-field irrigated by submersion. This ecosystem was reproduced under controlled 'mini-rice-field' conditions: the water was enriched in stable zinc (1 ppm) and in stable cadmium (2,5x10 -3 ; 50x10 -3 ppm) so as to reproduce the actual conditions; the stable zinc was traced by means of zinc-65. Fish (20 Carassius auratus L.) were introduced into each compartment of the ecosystem. Samples of irrigation water and surface water were taken during cultivation, and at the end of cultivation the content of stable zinc, radioactive zinc and stable cadmium was determined in each component of the ecosystem. The results show the important influence of a conventional contaminant on the transfer of a radionuclide and justify the use of the term 'associate contaminant' to describe it. (author)

Irrigation water quality as indicator of sustainable rural development

Directory of Open Access Journals (Sweden)

Trajković Slaviša

2004-01-01

Full Text Available The sustainable rural development more and more depends on the efficient usage of water resources. Most often, at least in one part of the year, the rain is not sufficient for plant growth and rain plant production significantly depends on the yearly precipitation variation. The increase and stability of the agricultural production is possible in the irrigation conditions. The most part (around 70% of the global water resources is used for food production. Irrigation water quality indicator is used to show if the available water resources have the required quality for application in agriculture. Irrigation is characterised by the complex water-plant-soil relationship, and in that eco-system the man as the end user of the irrigated fields occupies a very important place. That explains the difficulties in producing one universal classification of irrigation water quality. The paper analyses numerous water quality classifications from the aspect of the applicability on the quantifying of this indicator. The adopted classification should possess understandable, qualified and internationally comparable indicator. Thus, local classifications (Neigebauer, Miljkovic cannot be used for this indicator. United Nation Food and Agricultural Organization (FAO and US Salinity Laboratory (USSL classifications are used for the evaluation of the irrigation water quality throughout the world. FAO classification gives the complex picture of the usability of the irrigation water from the point of its influence on the soil and the plants. However, the scope of the analyses is not often suited to the needs of that classification, which makes it difficult to apply. The conclusion is that the USSL (US Salinity Laboratory classification is best suited to this range of chemical water analyses. The evaluation of the irrigation water quality indicator in the Juzna Morava river basin, upstream from the Toplica river estuary is given in this paper. Based on the obtained

Year-Round Irrigation Schedule for a Tomato–Maize Rotation System in Reservoir-Based Irrigation Schemes in Ghana

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Ephraim Sekyi-Annan

2018-05-01

Full Text Available Improving irrigation management in semi-arid regions of Sub-Saharan Africa is crucial to respond to increasing variability in rainfall and overcome deficits in current irrigation schemes. In small-scale and medium-scale reservoir-based irrigation schemes in the Upper East region of Ghana, we explored options for improving the traditional, dry season irrigation practices and assessed the potential for supplemental irrigation in the rainy season. The AquaCrop model was used to (i assess current water management in the typical tomato-maize rotational system; (ii develop an improved irrigation schedule for dry season cultivation of tomato; and (iii determine the requirement for supplemental irrigation of maize in the rainy season under different climate scenarios. The improved irrigation schedule for dry season tomato cultivation would result in a water saving of 130–1325 mm compared to traditional irrigation practices, accompanied by approximately a 4–14% increase in tomato yield. The supplemental irrigation of maize would require 107–126 mm of water in periods of low rainfall and frequent dry spells, and 88–105 mm in periods of high rainfall and rare dry spells. Therefore, year-round irrigated crop production may be feasible, using water saved during dry season tomato cultivation for supplemental irrigation of maize in the rainy season.

Strategy of Irrigation Branch in Russia

Science.gov (United States)

Zeyliger, A.; Ermolaeva, O.

2012-04-01

At this moment, at the starting time of the program on restoration of a large irrigation in Russia till 2020, the scientific and technical community of irrigation branch does not have clear vision on how to promote a development of irrigated agriculture and without repeating of mistakes having a place in the past. In many respects absence of a vision is connected to serious backlog of a scientific and technical and informational and technological level of development of domestic irrigation branch from advanced one. Namely such level of development is necessary for the resolving of new problems in new conditions of managing, and also for adequate answers to new challenges from climate and degradation of ground & water resources, as well as a rigorous requirement from an environment. In such important situation for irrigation branch when it is necessary quickly generate a scientific and technical politics for the current decade for maintenance of translation of irrigated agriculture in the Russian Federation on a new highly effective level of development, in our opinion, it is required to carry out open discussion of needs and requirements as well as a research for a adequate solutions. From political point of view a framework organized in FP6 DESIRE 037046 project is an example of good practice that can serve as methodical approach how to organize and develop such processes. From technical point of view a technology of operational management of irrigation at large scale presents a prospective alternative to the current type of management based on planning. From point of view ICT operational management demands creation of a new platform for the professional environment of activity. This platform should allow to perceive processes in real time, at their partial predictability on signals of a straight line and a feedback, within the framework of variability of decision making scenarious, at high resolution and the big ex-awning of sensor controls and the gauges

Changes of soil organic matter and microbial activity in irrigated and non irrigated olive groves

Science.gov (United States)

Kavvadias, Victor; Papadopoulou, Maria; Theocharopoulos, Sideris; Vavoulidou, Evagelia; Doula, Maria; Reppas, Spiros

2014-05-01

The implementation of olive cultivation techniques in Greece has not been systematically tested under the prevailing Mediterranean conditions. A LIFE+ project was initiated (oLIVE-CLIMA; LIFE 11/ENV/000942) aiming to introduce new management practices in olive tree crops that lead to increased carbon dioxide uptake by plants as well as carbon sequestration from the atmosphere and reverse the trend of soil organic matter decline, erosion and desertification. This paper presents data on soil organic matter and microbial activity from a soil campaign in a pilot region in Greece, and particularly in the area of Chora, prefecture of Messinia, South west Peloponnese. The soil campaign took place during the period December 2012-February 2013. Twelve soil parcels of olive groves were selected (6 irrigated and 6 rainfed) and in each soil parcel six composite soil samples were taken from 0-10 cm depth at equal intervals along a straight line of the trunk of the tree to the middle of the distance from the nearest tree of the next tree series. The first three samples were under olive tree canopy. An additional composite sample was taken at depth of 10-40 cm. Soil samples were analyzed for soil physicochemical and biological properties. In this study results for total organic carbon (TOC), soil basal microbial respiration (BR), microbial biomass C (MB-C) from the region of Messinia, are presented. Organic matter was determined by dichromate oxidation. The microbial activity was measured by the amount of CO2 evolution, while microbial biomass C was determined by substrate-induced respiration, after the addition of glucose. The results showed considerable differences in TOC, BR and MB-C associated with the sampling position and soil depth. The higher TOC, BR and MB-C values, in most cases, were determined in samples taken from points under the canopy, but not close to the tree trunk compared to the sampling points outside the canopy. This indicates the positive effect of

Growth, Yield and WUE of Drip and Sprinkler Irrigated Okra Grown On Sandy Soil Under Semi-Arid Conditions in Southeast Ghana

DEFF Research Database (Denmark)

Plauborg, Finn

Vegetable production systems at the Keta sand spit, Southeast Ghana, are typically managed with excessive amounts of irrigation water and fertilizers on sandy soils with low inherent water and nutrient retention capacities. The shallow groundwater which is the primary irrigation water resource...... is prone to salinization from the Keta lagoon, the Atlantic Ocean and brackish water underneath (Kortatsi and Agyeku, 1999). To ensure the sustainability of vegetable production at the Keta spit, introduction of water saving irrigation systems and improved irrigation management schemes are important. Thus......, the main aim of our study was to explore the water sa ving potential of drip irrigation in order to save the shallow groundwater from over exploitation. A two season study (minor dry season, 2011 and major dry season, 2012) were carried out to determine the okra crop response to the following treatments: 1...

A comprehensive guide for designing more efficient irrigation systems with respect to application control

Science.gov (United States)

Khaddam, Issam; Schuetze, Niels

2017-04-01

The worldwide water scarcity problems are expected to aggravate due to the increasing population and the need to produce more food. Irrigated agriculture is considered the highest consumer of fresh water resources with a rate exceeds 70% of global consumption. Consequently, an improvement in the efficiency of all irrigation methods, such as furrow or drip irrigation, becomes more necessary and urgent. Therefore, a more precise knowledge about soil water distribution in the root zone and the water balance components is required. For this purpose and as a part of the SAPHIR project (Saxonian Platform for high Performance Irrigation), a 2D simulation- based study was performed with virtual field conditions. The study investigates the most important design parameters of many irrigation systems, such as irrigation intensity and duration, and shows there influence on the water distribution efficiency. Furthermore, three main soil textures are used to test the impact of the soil hydraulic properties on irrigation effectiveness. A numerous number of irrigation scenarios of each irrigation system was simulated using HYDRUS 2D. Thereafter, the results were digitally calculated, compiled and made available online in the so called "Irrigation Atlases". The irrigation atlases provide graphical results of the soil moisture and pressure head distributions in the root zone. Moreover, they contain detailed information of the water balance for all simulated scenarios. The most studies evaluate the irrigation water demands on local, regional or global scales and for that an efficient water distribution is required. In this context, the irrigation atlases can serve as a valuable tool for the implementation of planned irrigation measures.

Analysis of the Economic and Welfare Impacts of Establishing Irrigation Water Market in Qazvin Province

Directory of Open Access Journals (Sweden)

2014-03-01

Full Text Available In this study economic and welfare impacts of establishing irrigation water market in Qazvin province as well as potentiality of irrigation water transfer under stress irrigation conditions in the cities of Qazvin province were analyzed. To achieve the above objectives, Positive Mathematical Programming model and State Wide Agricultural Production functions were used. To achieve applicable results, the production function with a constant elasticity of substitution and cost function with an exponential form were included into the Positive Mathematical Programming model was imported. The study data for the year 2011-2012 was collected by asking the relevant offices in each city of Qazvin province. The proposed model was solved in six successive stages using the GAMS software. After solving the model, amount changes in the area of irrigated crops, farmer's gross profit and labor surplus under the two conditions of “existence of water market” and “lack of water market “at the regional level were calculated. The results showed that establishing irrigation water market increases total irrigated lands for 1/2 percent, total farmer’s gross profit for 1/86 percent and total labor force employed in agriculture for 1/8 percent in the province. Ultimately, considering the supportive and constructive role of regional water markets, it is recommended to provide necessary conditions and tools to establish an optimal use of such a mechanism associated with the type of market in Qazvin province.

Irrigation water sources and irrigation application methods used by U.S. plant nursery producers

Science.gov (United States)

Paudel, Krishna P.; Pandit, Mahesh; Hinson, Roger

2016-02-01

We examine irrigation water sources and irrigation methods used by U.S. nursery plant producers using nested multinomial fractional regression models. We use data collected from the National Nursery Survey (2009) to identify effects of different firm and sales characteristics on the fraction of water sources and irrigation methods used. We find that regions, sales of plants types, farm income, and farm age have significant roles in what water source is used. Given the fraction of alternative water sources used, results indicated that use of computer, annual sales, region, and the number of IPM practices adopted play an important role in the choice of irrigation method. Based on the findings from this study, government can provide subsidies to nursery producers in water deficit regions to adopt drip irrigation method or use recycled water or combination of both. Additionally, encouraging farmers to adopt IPM may enhance the use of drip irrigation and recycled water in nursery plant production.

Hygienic-sanitary conditions of vegetables and irrigation water from kitchen gardens in the municipality of Campinas, SP

OpenAIRE

Simões,Marise; Pisani,Beatriz; Marques,Eneida Gonçalves Lemes; Prandi,Maria Angela Garnica; Martini,Maria Helena; Chiarini,Paulo Flávio Teixeira; Antunes,José Leopoldo Ferreira; Nogueira,Ana Paula

2001-01-01

We examined samples of irrigation water and vegetables from kitchen gardens in Campinas, Brazil. The bacterial analysis condemned 22.3% of the vegetable samples, and the parasitological examination condemned 14.5%. The criteria established by the Brazilian legislation condemned 11.8% of the irrigation water samples. Parasites were significantly more frequent in vegetables in the rainy season, while excessive fecal coliforms were more frequent in the dry season. A proper monitoring of the irri...

Wireless sensor networks for irrigation management

Science.gov (United States)

Sustaining an adequate food supply for the world's population will require advancements in irrigation technology and improved irrigation management. Site-specific irrigation and automatic irrigation scheduling are examples of strategies to deal with declining arable land and limited fresh water reso...

Scintigraphic assessment of colostomy irrigation.

Science.gov (United States)

Christensen, P.; Olsen, N.; Krogh, K.; Laurberg, S.

2002-09-01

OBJECTIVE: This study aims to evaluate colonic transport following colostomy irrigation with a new scintigraphic technique. MATERIALS AND METHODS: To label the bowel contents 19 patients (11 uncomplicated colostomy irrigation, 8 complicated colostomy irrigation) took 111In-labelled polystyrene pellets one and two days before investigation. 99mTc-DTPA was mixed with the irrigation fluid to assess its extent within the bowel. Scintigraphy was performed before and after a standardized washout procedure. The colon was divided into three segments 1: the caecum andascending colon; 2: the transverse colon; 3: the descending and sigmoid colon. Assuming ordered evacuation of the colon, the contribution of each colonic segment to the total evacuation was expressed as a percentage of the original segmental counts. These were added to reach a total defaecation score (range: 0-300). RESULTS: In uncomplicated colostomy irrigation, the median defaecation score was 235 (range: 145-289) corresponding to complete evacuation of the descending and transverse colon and 35% evacuation of the caecum/ascending colon. In complicated colostomy irrigation it was possible to distinguish specific emptying patterns. The retained irrigation fluid reached the caecum in all but one patient. CONCLUSION: Scintigraphy can be used to evaluate colonic emptying following colostomy irrigation.

Modeling irrigation behavior in groundwater systems

Science.gov (United States)

Foster, Timothy; Brozović, Nicholas; Butler, Adrian P.

2014-08-01

Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas High Plains region of the United States we predict optimal irrigation strategies under variable levels of groundwater supply, and assess the limits of existing models for predicting land and groundwater use decisions by farmers. Our results show that irrigation behavior exhibits complex nonlinear responses to changes in groundwater availability. Declining well yields induce large reductions in the optimal size of irrigated area and irrigation use as constraints on instantaneous application rates limit the ability to maintain sufficient soil moisture to avoid negative impacts on crop yield. We demonstrate that this important behavioral response to limited groundwater availability is not captured by existing modeling approaches, which therefore may be unreliable predictors of irrigation demand, agricultural profitability, and resilience to climate change and aquifer depletion.

Using deficit irrigation with treated wastewater to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa

Directory of Open Access Journals (Sweden)

Abdelaziz HIRICH

2014-07-01

Full Text Available Several experiments were conducted in the south of Morocco (IAV-CHA, Agadir during two seasons 2010 and 2011 in order to evaluate the effect of deficit irrigation with treated wastewater on several crops (quinoa, sweet corn, faba bean and chickpeas. During the first season (2010 three crops were tested, quinoa, chickpeas and sweet corn applying 6 deficit irrigation treatments during all crop stages alternating 100% of full irrigation as non-stress condition and 50% of full irrigation as water deficit condition applied during vegetative growth, flowering and grain filling stage. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season (2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of full irrigation during vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity.

Effect of irrigation on heavy metals content of wastewater irrigated ...

African Journals Online (AJOL)

There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy ...

A coupled agronomic-economic model to consider allocation of brackish irrigation water

Science.gov (United States)

Ben-Gal, Alon; Weikard, Hans-Peter; Shah, Syed Hamid Hussain; van der Zee, Sjoerd E. A. T. M.

2013-05-01

In arid and semiarid regions, irrigation water is scarce and often contains high concentrations of salts. To reduce negative effects on crop yields, the irrigated amounts must include water for leaching and therefore exceed evapotranspiration. The leachate (drainage) water returns to water sources such as rivers or groundwater aquifers and increases their level of salinity and the leaching requirement for irrigation water of any sequential user. We develop a conceptual sequential (upstream-downstream) model of irrigation that predicts crop yields and water consumption and tracks the water flow and level of salinity along a river dependent on irrigation management decisions. The model incorporates an agro-physical model of plant response to environmental conditions including feedbacks. For a system with limited water resources, the model examines the impacts of water scarcity, salinity and technically inefficient application on yields for specific crop, soil, and climate conditions. Moving beyond the formulation of a conceptual frame, we apply the model to the irrigation of Capsicum annum on Arava Sandy Loam soil. We show for this case how water application could be distributed between upstream and downstream plots or farms. We identify those situations where it is beneficial to trade water from upstream to downstream farms (assuming that the upstream farm holds the water rights). We find that water trade will improve efficiency except when loss levels are low. We compute the marginal value of water, i.e., the price water would command on a market, for different levels of water scarcity, salinity and levels of water loss.

An assessment of colostomy irrigation.

Science.gov (United States)

Laucks, S S; Mazier, W P; Milsom, J W; Buffin, S E; Anderson, J M; Warwick, M K; Surrell, J A

1988-04-01

One hundred patients with permanent sigmoid colostomies were surveyed to determine their satisfaction and success with the "irrigation" technique of colostomy management. Most patients who irrigate their colostomies achieve continence. Odors and skin irritation are minimized. The irrigation method is economical, time efficient, and allows a reasonably liberal diet. It avoids bulky appliances and is safe. In appropriately selected patients, the irrigation technique is the method of choice for management of an end-sigmoid colostomy.

Irrigation and Autocracy

DEFF Research Database (Denmark)

Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

2017-01-01

. We argue that the effect has historical origins: irrigation allowed landed elites in arid areas to monopolize water and arable land. This made elites more powerful and better able to oppose democratization. Consistent with this conjecture, we show that irrigation dependence predicts land inequality...

Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture.

Science.gov (United States)

Bair, Daniel A; Popova, Ina E; Tate, Kenneth W; Parikh, Sanjai J

2017-09-02

The transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

STUDY ON MICROBIAL COMMUNITIES AND SOIL ORGANIC MATTER IN IRRIGATED AND NON-IRRIGATED VERTISOL FROM BOIANU

Directory of Open Access Journals (Sweden)

Sorina Dumitru

2012-12-01

Full Text Available Irrigation, when administered correctly, confers the producers the possibility to overcome drought effects and obtain higher yields, supplementing the quality of food for animals or human consumers. In the mean time, soil erosion, pathogens attack and nutrients or pesticides spreading can be prevented by an adequate management of irrigation water. As a consequence, soil microbial community structure, composition and activities, as well as the organic matter quality can be different from those in non-irrigated soil. Research have been carried out in order to assess changes in bacterial and fungal communities and activity in irrigated Vertisol from Boianu, as compared with non-irrigated. The paper presents the results concerning the taxonomical composition of bacterial and fungalmicroflora in the horizons of the two soil profiles, as well as the level of CO2 released by microorganisms. Chromatographic aspects of humus fractions were used to characterize the organic matter in irrigated and nonirrigated soil. Increased moisture and lowered temperature in Ap horizon of irrigated soil increased bacterial counts(18 x106 viable cells x g-1 dry soil and their metabolic activity expressed by carbon dioxide released (46.838mg CO2 x g-1 dry soil comparatively with non- irrigated soil. Fungal microflora was more abundant after 25-50cm under irrigation. Species diversity slightly increased under irrigation in both upper and lower part of soil profile. In irrigated soil, associations of species belonging to bacterial genera Pseudomonas and Bacillus were dominant in surface and white actinomycetes in the depth. Fungal consortia of Penicillium, Aspergillus and Fusarium dominated in both soil profiles.Irrigation induced changes in the quantity and quality of soil organic matter, as well as in the aspect of their migration pattern, as revealed on circular chromatograms.

Estimated Colorado Golf Course Irrigation Water Use, 2005

Science.gov (United States)

Ivahnenko, Tamara

2009-01-01

Golf course irrigation water-use data were collected as part of the U.S. Geological Survey National Water Use Program's 2005 compilation to provide baseline information, as no golf course irrigation water-use data (separate from crop irrigation) have been reported in previous compilations. A Web-based survey, designed by the U.S. Geological Survey, in cooperation with the Rocky Mountain Golf Course Superintendents Association (RMGCSA), was electronically distributed by the association to the 237 members in Colorado. Forty-three percent of the members returned the survey, and additional source water information was collected by telephone for all but 20 of the 245 association member and non-member Colorado golf courses. For golf courses where no data were collected at all, an average 'per hole' coefficient, based on returned surveys from that same county, were applied. In counties where no data were collected at all, a State average 'per hole' value of 13.2 acre-feet was used as the coefficient. In 2005, Colorado had 243 turf golf courses (there are 2 sand courses in the State) that had an estimated 2.27 acre-feet per irrigated course acre, and 65 percent of the source water for these courses was surface water. Ground water, potable water (public supply), and reclaimed wastewater, either partially or wholly, were source waters for the remaining courses. Fifty-three of the 64 counties in Colorado have at least one golf course, with the greatest number of courses in Jefferson (23 courses), Arapahoe (22 courses), and El Paso Counties (20 courses). In 2005, an estimated 5,647.8 acre-feet in Jefferson County, 5,402 acre-feet in Arapahoe County, and 4,473.3 acre-feet in El Paso County were used to irrigate the turf grass.

Estimation of Maize photosynthesis Efficiency Under Deficit Irrigation and Mulch

International Nuclear Information System (INIS)

Al-Hadithi, S.

2004-01-01

This research aims at estimating maize photosynthesis efficiency under deficit irrigation and soil mulching. A split-split plot design experiment was conducted with three replicates during the fall season 2000 and spring season 2001 at the experimental Station of Soil Dept./ Iraq Atomic Energy Commission. The main plots were assigned to full and deficit irrigation treatments: (C) control. The deficit irrigation treatment included the omission of one irrigation at establishment (S1, 15 days), vegetation (S2, 35 days), flowering (S3, 40 days) and yield formation (S4, 30 days) stages. The sub-plots were allocated for the two varieties, Synthetic 5012 (V1) and Haybrid 2052 (V2). The sub-sub-plots were assigned to mulch (M1) with wheat straw and no mulch (M0). Results showed that the deficit irrigation did not affect photosynthesis efficiency in both seasons, which ranged between 1.90 to 2.15% in fall season and between 1.18 and 1.45% in spring season. The hybrid variety was superior 9.39 and 9.15% over synthetic variety in fall and spring seasons, respectively. Deficit irrigation, varieties and mulch had no significant effects on harvest index in both seasons. This indicates that the two varieties were stable in their partitioning efficiency of nutrient matter between plant organ and grains under the condition of this experiment. (Author) 21 refs., 3 figs., 6 tabs

Irrigation offsets wheat yield reductions from warming temperatures

Science.gov (United States)

Tack, Jesse; Barkley, Andrew; Hendricks, Nathan

2017-11-01

Temperature increases due to climate change are expected to cause substantial reductions in global wheat yields. However, uncertainty remains regarding the potential role for irrigation as an adaptation strategy to offset heat impacts. Here we utilize over 7000 observations spanning eleven Kansas field-trial locations, 180 varieties, and 29 years to show that irrigation significantly reduces the negative impact of warming temperatures on winter wheat yields. Dryland wheat yields are estimated to decrease about eight percent for every one-degree Celsius increase in temperature, yet irrigation completely offsets this negative impact in our sample. As in previous studies, we find that important interactions exist between heat stress and precipitation for dryland production. Here, uniquely, we observe both dryland and irrigated trials side-by-side at the same locations and find that precipitation does not provide the same reduction in heat stress as irrigation. This is likely to be because the timing, intensity, and volume of water applications influence wheat yields, so the ability to irrigate—rather than relying on rainfall alone—has a stronger influence on heat stress. We find evidence of extensive differences of water-deficit stress impacts across varieties. This provides some evidence of the potential for adapting to hotter and drier climate conditions using optimal variety selection. Overall, our results highlight the critical role of water management for future global food security. Water scarcity not only reduces crop yields through water-deficit stress, but also amplifies the negative effects of warming temperatures.

Conditions for formation of electron pairs in a metal

Energy Technology Data Exchange (ETDEWEB)

Shekhtman, A.Z., E-mail: shekhtmanalexander@gmail.com

2015-04-15

Highlights: • A new approach has been developed for consideration of electron pairing in metals. • Binding energy of a single pair induced by electron-phonon interaction is very small. • A new mechanism for electron pairing in metals has been considered. • Conditions for feasibility of the mechanism give conditions for electron pairing. • The mechanism gives wide opportunities to study new conditions for electron pairing. - Abstract: In an isotropic model of the electron system of metal that is presented by the Fröhlich’s initial Hamiltonian, in the approximation of a weak electron–phonon interaction at T = 0, first time, we show that the ground state of the system is the state with pairing correlations of electrons (the pair correlations of occupied electron states). In contrast to the BCS approach, the initial point in our approach is not electron pairing but is the maximum reduction of the energy of the considered system due to virtual processes of the electron–phonon interaction and to the exchange effect for the indirect electron–electron interaction (which is induced by certain phonon modes separately from others). In contrast to the BCS approach, we take into account the portion of the energy of the electron system that is connected with the above exchange effect. In the BCS approach, the corresponding portion is missed, and its role is prescribed to the portion that does not relate to the electron pairing. We show that expectation values of the above Hamiltonian for different wave functions for two interacting electrons above the Fermi sea of the non-interacting system (with interaction between the electrons that is induced by different phonon modes separately from others) are minimum for a certain structure of these functions and simultaneously for phonon modes that can induce the transitions of the interacting electrons between electron states in which they are (without violation of the Pauli exclusion principle and at everything else

Novel approach to evaluate the dynamic variation of wind drift and evaporation losses under moving irrigation systems

Science.gov (United States)

Sayed-Hossein Sadeghi; Troy R. Peters; Mohammad Z. Amini; Sparkle L. Malone; Hank W. Loescher

2015-01-01

The increased need for water and food security requires the development of new approaches to save water through irrigation management strategies, particularly for center pivot irrigation. To do so entails monitoring of the dynamic variation in wind drift and evaporation losses (WDELs) of irrigation systems under different weather conditions and for relatively long time...

Therapeutic effect of intraductal irrigation of the salivary gland: A technical report

Energy Technology Data Exchange (ETDEWEB)

Lee, Chena [Dept. of Oral and Maxillofacial Radiology, Yonsei University College of Dentistry, Seoul (Korea, Republic of); Kim, Jo Eun; Huh, Kyoung Hoe; Yi, Won Jin; Lee, Sam Sun; Choi, Soon Chul [Dept. of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

2017-06-15

Obstructive and inflammatory disease often occurs in the major salivary glands, and no predictive treatment has yet been developed for this condition. The aim of this report was to introduce an intraductal irrigation procedure and to illustrate its application to practical patient cases. Two patients complaining of pain and swelling in the parotid gland during meals who underwent sialography were diagnosed as having sialodochitis with sialadenitis. Intraductal irrigation was then performed on the parotid gland on the side of the complaint. The irrigation procedure was conducted in the same manner as the sialography procedure, except that saline was used as the filling solution. Symptom severity was evaluated with a numerical rating scale (NRS) at the initial visit and a month after the irrigation. The initial NRS value of patient 1 was 10. The value decreased to 6 and then to 0 after 2 irrigation procedures. The NRS value of patient 2 regarding the symptoms involving the left parotid gland decreased from 4-5 to 1 after 4 irrigation procedures performed at 1-month intervals. Intraductal irrigation of the salivary gland may be a simple, safe, and effective treatment option for patients with obstructive and inflammatory disease of the salivary gland that is capable of resolving their symptoms.

Therapeutic effect of intraductal irrigation of the salivary gland: A technical report.

Science.gov (United States)

Lee, Chena; Kim, Jo-Eun; Huh, Kyoung-Hoe; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul

2017-06-01

Obstructive and inflammatory disease often occurs in the major salivary glands, and no predictive treatment has yet been developed for this condition. The aim of this report was to introduce an intraductal irrigation procedure and to illustrate its application to practical patient cases. Two patients complaining of pain and swelling in the parotid gland during meals who underwent sialography were diagnosed as having sialodochitis with sialadenitis. Intraductal irrigation was then performed on the parotid gland on the side of the complaint. The irrigation procedure was conducted in the same manner as the sialography procedure, except that saline was used as the filling solution. Symptom severity was evaluated with a numerical rating scale (NRS) at the initial visit and a month after the irrigation. The initial NRS value of patient 1 was 10. The value decreased to 6 and then to 0 after 2 irrigation procedures. The NRS value of patient 2 regarding the symptoms involving the left parotid gland decreased from 4-5 to 1 after 4 irrigation procedures performed at 1-month intervals. Intraductal irrigation of the salivary gland may be a simple, safe, and effective treatment option for patients with obstructive and inflammatory disease of the salivary gland that is capable of resolving their symptoms.

WHEAT CULTIVARS: RESPONSE TO IRRIGATION AND SOWING DATES

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Klar A.E.

1996-01-01

Full Text Available This study was carried out in an Alfisol-Oxisol transition sandy-clay texture, using six wheat cultivars (Triticum aestivum, L.: two tall and tolerant to soil aluminium toxicity (BH-1146, and IAC-18, and four semi-dwarf cultivars - Anahuac, IAC-162, IAC-24, and IAC-60 - of which only the first two are sensitive to soil aluminium toxicity. Two minimum soil water potentials (ys levels were used: 1. watered, when Ys reached about -0.05 MPa; 2. dry, when the water potential reached around -1.5 MPa. Two sowing dates, 05/22/92 and 06/11/92, were used. The results showed that Anahuac and IAC-60 are the most indicated cultivars for the studied region; when irrigated all cultivars presented similar yield level under no irrigation conditions; the irrigation was not sufficient to avoid yield differences between the two growing seasons; differences in rainfall were important for the crop in the dry treatment for both seasons.

Methods to estimate irrigated reference crop evapotranspiration - a review.

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Kumar, R; Jat, M K; Shankar, V

2012-01-01

Efficient water management of crops requires accurate irrigation scheduling which, in turn, requires the accurate measurement of crop water requirement. Irrigation is applied to replenish depleted moisture for optimum plant growth. Reference evapotranspiration plays an important role for the determination of water requirements for crops and irrigation scheduling. Various models/approaches varying from empirical to physically base distributed are available for the estimation of reference evapotranspiration. Mathematical models are useful tools to estimate the evapotranspiration and water requirement of crops, which is essential information required to design or choose best water management practices. In this paper the most commonly used models/approaches, which are suitable for the estimation of daily water requirement for agricultural crops grown in different agro-climatic regions, are reviewed. Further, an effort has been made to compare the accuracy of various widely used methods under different climatic conditions.

Opportunities for woody crop production using treated wastewater in Egypt. II. Irrigation strategies.

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Evett, Steven R; Zalesny, Ronald S; Kandil, Nabil F; Stanturf, John A; Soriano, Chris

2011-01-01

An Egyptian national program targets annual reuse of 2.4 billion m3 of treated wastewater (TWW) to irrigate 84,000 ha of manmade forests in areas close to treatment plants and in the desert. To evaluate the feasibility of such afforestation efforts, we describe information about TWW irrigation strategies based on (1) water use of different tree species, (2) weather conditions in different climate zones of Egypt, (3) soil types and available irrigation systems, and (4) the requirement to avoid deep percolation losses that could lead to groundwater contamination. We conclude that drip irrigation systems are preferred, that they should in most cases use multiple emitters per tree in order to increase wetted area and decrease depth of water penetration, that deep rooting should be encouraged, and that in most situations irrigation system automation is desirable to achieve several small irrigations per day in order to avoid deep percolation losses. We describe directed research necessary to fill knowledge gaps about depth of rooting of different species in sandy Egyptian soils and environments, tree crop coefficients needed for rational irrigation scheduling, and depth of water penetration under different irrigation system designs. A companion paper addresses recommendations for afforestation strategies (see Zalesny et al. 2011, this issue).

Heavy metal accumulation imparts structural differences in fragrant Rosa species irrigated with marginal quality water.

Science.gov (United States)

Ahsan, Muhammad; Younis, Adnan; Jaskani, Muhammad Jafar; Tufail, Aasma; Riaz, Atif; Schwinghamer, Timothy; Tariq, Usman; Nawaz, Fahim

2018-09-15

Wastewater is an alternative to traditional sources of renewable irrigation water in agriculture, particularly in water-scarce regions. However, the possible risks due to heavy metals accumulation in plant tissues are often overlooked by producers. The present study aimed to identify heavy metals-induced structural modifications to roots of scented Rosa species that were irrigated with water of marginal quality. The chemical and mineral contents from the experimental irrigation canal water (control) and treated wastewater were below the limits recommended by the Pakistan Environmental Protection Agency (Pak-EPA) for medicinal plants. The experimentally untreated wastewater contained electrical conductivity (EC), chemical oxygen demand (COD), biological oxygen demand (BOD), and heavy metals (Co, Cu, Cd, Pb) that were above the recommended limits. The responses by wastewater-treated Rosa species (Rosa damascena, R. bourboniana, R. Gruss-an-Teplitz, and R. centifolia) were evaluated. The experimental data revealed that treated wastewater significantly increased the thickness of collenchyma (cortex and pith) and parenchyma tissues (vascular bundle, xylem, and phloem) of R. Gruss-an-Teplitz. Root dermal tissues (epidermis) of R. bourboniana also responded to treated wastewater. R. damascena and R. centifolia were the least affected species, under the experimental irrigation conditions. Collenchyma and dermal tissues were thicker in R. damascena and R. Gruss-an-Teplitz under untreated wastewater conditions. In parenchyma tissues, vascular bundles were thicker in R. damascena in untreated wastewater conditions, while the xylem and phloem of R. Gruss-an-Teplitz were thicker where treated wastewater was applied. In tissues other than the vascular bundle, the differences in anatomical metrics due to the experimental irrigation treatments were greater during the second year of the experiment than in the first year. The contents of metals other than chromium in the roots and

Infiltration into cropped soils: effect of rain and sodium adsorption ratio-impacted irrigation water.

Science.gov (United States)

Suarez, Donald L; Wood, James D; Lesch, Scott M

2008-01-01

The sodium adsorption ratio (SAR) and salinity criteria for water suitability for irrigation have been developed for conditions where irrigation water is the only water source. It is not clear that these criteria are applicable to environments where there is a combination of rain and irrigation during the growing season. The interaction of rainfall with irrigation water is expected to result in increased sodicity hazard because of the low electrical conductivity of rain. In this study we examined the effects of irrigation waters of SAR 2, 4, 6, 8, and 10 mmol(1/2) L(-1/2) and electrical conductivities of 1 and 2 dS m(-1) on the infiltration rate of two soils with alternating cycles of rain (simulated with a rainfall sprinkler) and irrigation water, separated by drying cycles. The infiltration rate of surface samples from two soils, Kobase silty clay (fine, smectitic, frigid, Torrertic Haplustept) and Glendive very fine sandy loam (coarse-loamy, mixed superactive, calcareous, frigid Aridic Ustifluvent) were evaluated under alfalfa (Medicago sativa) cropped conditions for over 140 d and under full canopy cover. Reductions in infiltration were observed for both soils for SAR above 2, and the reductions became more severe with increasing SAR. Saturated hydraulic conductivity measurements taken from undisturbed cores at the end of the experiment were highly variable, suggesting that in situ infiltration measurements may be preferred when evaluating SAR effects.

Behavior of durum wheat genotypes under normal irrigation and ...

African Journals Online (AJOL)

Behavior of durum wheat genotypes under normal irrigation and drought stress conditions in the greenhouse. ... African Journal of Biotechnology ... Genotypes were grouped in cluster analysis (using Ward's method) based on Yp, Ys and ...

Approaches and challenges of soil water monitoring in an irrigated vineyard

Science.gov (United States)

Nolz, Reinhard; Loiskandl, Willibald

2016-04-01

Monitoring of water content is an approved method to quantify certain components of the soil water balance, for example as basis for hydrological studies and soil water management. Temporal soil water data also allow controlling water status by means of demand-oriented irrigation. Regarding spatial variability of water content due to soil characteristics, plant water uptake and other non-uniformities, it is a great challenge to select a location that is most likely representing soil water status of a larger area (e.g. an irrigated field). Although such an approach might not satisfy the requirements of precision farming - which becomes more and more related to industrial agriculture - it can help improving water use efficiency of small-scale farming. In this regard, specific conditions can be found in typical vineyards in the eastern part of Austria, where grapes are grown for high quality wine production. Generally, the local dry-subhumid climate supports grape development. However, irrigation is temporarily essential in order to guarantee stable yields and high quality. As the local winegrowers traditionally control irrigation based on their experience, there is a potential to improve irrigation management by means of soil water data. In order to gain experience with regard to irrigation management, soil water status was determined in a small vineyard in Austria (47°48'16'' N, 17°01'57'' E, 118 m elevation). The vineyard was equipped with a subsurface drip irrigation system and access tubes for measuring water content in soil profiles. The latter was measured using a portable device as well as permanently installed multi-sensor capacitance probes. Soil samples were taken at chosen dates and gravimetrically analyzed in the laboratory. Water content data were analyzed using simple statistical procedures and the temporal stability concept. Soil water content was interpreted considering different environmental conditions, including rainfall and irrigation periods

Effect of different drip irrigation regimes on yield and oil quality of sunflower

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Semih Metin SEZEN

2016-06-01

Full Text Available This study examines the effects of different irrigation regimes on yield, yield components, oil yield and quality and water use of sunflower (Oleko variety irrigated with a drip system under field conditions in 2010 and 2011 growing seasons at the Alata Horticultural Research Institute, Tarsus Soil and Water Resources area in the Mediterranean region of Turkey. Irrigation regimes consisted of three irrigation intervals (A1:= 25 mm; A2:= 50 mm; A3: = 75 mm of cumulative pan evaporation and six irrigation levels (I1=0.50, I2=0.75, I3=1.00 and I4=1.25. In addition, I5=PRD75 and I6=PRD50 treatments were considered. They received 75 and 50% of the full irrigation (I3 treatment from alternative laterals, respectively. Also, rainfed treatment is a control plot in the experiment. Maximum and minimum yields were obtained from the A2I4 and rainfed treatments, respectively in all experimental years. As the irrigation level value decreased the total yields in each irrigation interval also decreased. Seasonal irrigation amounts in the treatments varied from 199 mm to 563 mm in the experimental years. Seasonal evapotranspiration values in the treatments varied from 243 mm to 611 mm in the experimental years. Both irrigation amounts and irrigation frequencies had significantly effects on oil content of sunflower. The saturated (palmitic and stearic acid and unsaturated (oleic and linoleic acid fatty acid contents were significantly affected by water stress. In conclusion, A2I4 irrigation regime is recommended for sunflower production in the Mediterranean region in order to attain higher yields with improved quality. In case of water shortage, A2I13 irrigation regime is recommended to increase sunflower yield and quality.

Evolution of Grain Yield and its Components Relationships in Bread Wheat Genotypes under Full Irrigation and Terminal Water Stress Conditions Using Multivariate Statistical Analysis

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S Mohammadi

2014-07-01

Full Text Available To study relationships between effective traits on wheat grain yield, the varieties Zarrin and Alvand, and some promising lines i.e. C-81-4, C-81-10, C-81-14 and C-82-12 were investigated at three sowing dates including 10 October, 1 November and 21 November. The experiment was carried out using strip plot in RCBD with three replications under two different water conditions including full-irrigation and terminal water stress at Miyandoab Agricultural Research Station in 2005-06 and 2006-07 cropping seasons. The results showed that under both full irrigation and terminal water stress conditions, grain yield had positive and significant correlation with days to heading, days to maturity, plant height, number of spikes/m2 and 1000 grain weight. Stepwise regression analysis revealed that 83 percent of yield variation under non-stressed conditions could be determined by days to maturity and number of spikes/m2 (R2 = 83% whereas these traits explained 87% of yield variation under stress conditions (R2= 87%. Path analysis indicated that number of spikes/m2 and days to maturity had the greatest positive direct and indirect effect on grain yield, under both conditions. The results of factor analysis under non-stressed condition showed that three factors explained 77% of total variation; these factors were called grain yield components, grain characteristics and plant phonology. Under non-stressed condition two factors (that were called grain yield and phenology, and plant morphology explained 88% of total variation. Cluster analysis through ward method, classified days to maturity and number of spikes/m2 in the same cluster where the grain yield was put under both conditions. It was concluded that under different sowing dates, selection based on days to maturity and number spikes/m2 could indirectly led to higher yield under both normal and water stress conditions.

Effect of drip irrigation on yield, evapotranspiration and water use efficiency of sweet basil (Ocimum basilicum L.

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Pejić Borivoj

2017-01-01

Full Text Available The experiments showing the effect of drip irrigation on yield, evapotranspiration and water productivity of sweet basil (Ocimum basilicum L. were conducted at the experimental field of the Alternative Crops Department, Institute of Field and Vegetable Crops, Novi Sad. Irrigation was scheduled on the basis of the water balance method. Daily evapotranspiration (ETd was computed from the reference evapotranspiration (ETo and crop coefficient (kc in May, June, July and August of 0.5, 0.6, 1.1 and 1.0, respectively. ETo was calculated using Hargreaves equation. The irrigation depth was restricted to the soil depth of 0.3 m. In other words, irrigation started when readily available water in the soil layer of 0.3 m was completely depleted by plants. The irrigation rate was 30 mm (30 l m-2 while the amount of water added by irrigation during the season was 140 mm. Basil sensitivity to water stress was determined using a yield response factor (Ky. According to the results, the yield of fresh herb of basil under irrigation (32.015 t ha-1 was higher by 9% compared to non-irrigated, control variant (29.364 t ha-1. Worthy of note, basil essential oil yield was significantly affected by irrigation (35.329/28.766 kg ha-1. The content of essential oil was significantly higher in irrigated (6.45 g kg-1 than in non-irrigated variant (5.33 g kg-1 in the first harvest, while no significant difference between irrigated and non-irrigated variants was obtained in the second harvest (6.83 and 6.62 g kg-1 , respectively. Water used on evapotranspiration in irrigation conditions (ETm was 431 mm and 270 mm in non-irrigated, control variant (ETa. The values of irrigation water use efficiency (Iwue and evapotranspiration water use efficiency (ETwue were 1.89 kg m-3 and 1.65 kg m-3 respectively. Ky value (0.22 exhibits all essential characteristics of climate conditions of 2016 rainy year. These preliminary results could be used as a good platform for basil growers in the

Optimization of irrigation water in stone fruit and table grapes

Science.gov (United States)

de la Rosa, Jose Mª; Castillo, Cristina; Temnani, Abdel; Pérez-Pastor, Alejandro

2017-04-01

In water scarcity areas, it must be highlighted that the maximum productions of the crops do not necessarily imply maximum profitability. Therefore, during the last years a special interest in the development of deficit irrigation strategies based on significant reductions of the seasonal ET without affecting production or quality has been observed. The strategies of regulated deficit irrigation (RDI) are based on the reduction of water supply during non critical periods, the covering of water needs during critical periods and maximizing, at the same time, the production by unit of applied water. The main objective of this experiment was to implement, demonstrate and disseminate a sustainable irrigation strategy based on deficit irrigation to promote its large scale acceptance and use in woody crops in Mediterranean agroecosystems, characterized by water scarcity, without affecting the quality standards demanded by exportation markets. Five demonstration plots were established in representative crops of the irrigating community of Campotejar (Murcia, Spain): i) Peach trees, cv. catherina in the "Periquitos" farm; ii) Apricot trees, cv. "Red Carlet" in "La Hoya del Fenazar" farm; iii) Nectarine trees, cv. Viowhite in "Agrícola Don Fernando" farm; iv) Table grape, cv "Crimson Seedless" in "La Hornera" farm; and v) Paraguayan cv. carioca in "The Hornera" farm. In each demonstration plot, at least two irrigation treatments were established: i) Control (CTL), irrigated to ensure non-limiting water conditions (120% of crop evapotranspiration) and ii) Regulated deficit irrigation (RDI) irrigated as CTL during critical periods and decreasing irrigation in non-critical periods. The plant water status indicators evaluated were midday stem water potential and Trunk Diameter Fluctuation derived indices: maximum daily shrinkage (MDS) and trunk daily growth rate (TGR); vegetative growth of the different crops from trunk diameter and pruning dry weight, fruit growth and fruit

Local land-atmosphere feedbacks limit irrigation demand

Science.gov (United States)

Decker, Mark; Ma, Shaoxiu; Pitman, Andy

2017-05-01

Irrigation is known to influence regional climate but most studies forecast and simulate irrigation with offline (i.e. land only) models. Using south eastern Australia as a test bed, we demonstrate that irrigation demand is fundamentally different between land only and land-atmosphere simulations. While irrigation only has a small impact on maximum temperature, the semi-arid environment experiences near surface moistening in coupled simulations over the irrigated regions, a feedback that is prevented in offline simulations. In land only simulations that neglect the local feedbacks, the simulated irrigation demand is 25% higher and the standard deviation of the mean irrigation rate is 60% smaller. These local-scale irrigation-driven feedbacks are not resolved in coarse-resolution climate models implying that use of these tools will overestimate irrigation demand. Future studies of irrigation demand must therefore account for the local land-atmosphere interactions by using coupled frameworks, at a spatial resolution that captures the key feedbacks.

Point irrigation for locality Buchel in the north desert Gobi in Mongolia

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Pavel Spitz

2009-01-01

Full Text Available The design of point irrigation, created by Filip et al. (2007, was worked up as the bilateral projekt in the frame of abroad developing cooperation between the Czech Republic and Mongolia „Rehabilitation of plant production in semiarid territories of northern Gobi”. The period of project realization are years 2006–2009. The responsible institution for the project is Ministery of Agriculture of the Czech Republic and with the realization of the project was encharged Mendel University of Agriculture and Forestry in Brno. The task was work irrigation design for experimental plants and vegetables on the choosen land in Gobi desert in Mongolia. To disposition was underground water source – bore with capacity about 2 l / s and temperature about 10 °C, electric power and land about area cca 1 ha. The condition was use simple irrigation equipment. The fundamental limitation was im­pos­si­bi­li­ty using technically more complex and more sophisticated equipment e.g. drip irrigation. The map was not to the disposition, only a judgment of slope 0,2 % in flat terrain. The technical design of surface and subsurface point irrigation are introduced, shortly described are hydrotechnical basis used to created and described the original PC program HYBOZAM (hydraulics of point irrigation for Mongolia developed in table editor of Microsoft Excel for pipe dimensions of point irrigation design. Part of the program is also evaluation of the irrigation uniformity from outflows on irrigation line.

Soil salinisation and irrigation management of date palms in a Saharan environment.

Science.gov (United States)

Haj-Amor, Zied; Ibrahimi, Mohamed-Khaled; Feki, Nissma; Lhomme, Jean-Paul; Bouri, Salem

2016-08-01

The continuance of agricultural production in regions of the world with chronic water shortages depends upon understanding how soil salinity is impacted by irrigation practises such as water salinity, irrigation frequency and amount of irrigation. A two-year field study was conducted in a Saharan oasis of Tunisia (Lazala Oasis) to determine how the soil electrical conductivity was affected by irrigation of date palms with high saline water. The study area lacked a saline shallow water table. Field results indicate that, under current irrigation practises, soil electrical conductivity can build up to levels which exceed the salt tolerance of date palm trees. The effects of irrigation practises on the soil electrical conductivity were also evaluated using model simulations (HYDRUS-1D) of various irrigation regimes with different frequencies, different amounts of added water and different water salinities. The comparison between the simulated and observed results demonstrated that the model gave an acceptable estimation of water and salt dynamics in the soil profile, as indicated by the small values of root mean square error (RMSE) and the high values of the Nash-Sutcliffe model efficiency coefficient (NSE). The simulations demonstrated that, under field conditions without saline shallow groundwater, saline irrigation water can be used to maintain soil electrical conductivity and soil water content at safe levels (soil electrical conductivity soil water content >0.04 cm(3) cm(-3)) if frequent irrigations with small amounts of water (90 % of the evapotranspiration requirements) were applied throughout the year.

Yield response of cotton, maize, soybean, sugar beet, sunflower and wheat to deficit irrigation

International Nuclear Information System (INIS)

Kirda, C.; Kanber, R.; Tulucu, K.

1995-01-01

Results of several field experiments on deficit irrigation programmes in Turkey are discussed. Deficit irrigation of sugar beet with water stress imposed (i e.,irrigation omitted)during ripening,stage saved nearly 22 % water, yet with no significant yield decrease. An experiment, conducted in Turkey Region, the European part of Turkey,and aimed at studying water production functions of sunflower(i e,yield vs water consumption), revealed that water stress imposed at either head forming or seed filling stags influence yield the least , and 40 % savings of irrigation water supply , compared with traditional practices in the region, can be achieved without significant yield reduction. Water stress imposed at vegetative and flowering stages of maize hindered the yield most significantly. The results showed that deficit irrigation can be a feasible option under limited supply of irrigation if stress occurs during yield formation stage. A four year field experiments aiming at developing deficit irrigation strategies for soybean showed that soybean was at the most sensitive to water stress during flowering and pod filling stages, and irrigation during these stages would ensure high yields. Results of experiments on cotton showed that irrigations omitted during yield formation stage did not significantly hinder the yield. Similarly wheat give good yield response if irrigated at booting,heading and milking stages, depending on w heather conditions. In areas where rainfall at planting is limited, supplementary irrigation during this period can ensure good establishment of wheat crop. 1 tab; 9 figs; 59 refs (Author)

Digging, Damming or Diverting? Small-Scale Irrigation in the Blue Nile Basin, Ethiopia

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Irit Eguavoen

2012-10-01

Full Text Available The diversity of small-scale irrigation in the Ethiopian Blue Nile basin comprises small dams, wells, ponds and river diversion. The diversity of irrigation infrastructure is partly a consequence of the topographic heterogeneity of the Fogera plains. Despite similar social-political conditions and the same administrative framework, irrigation facilities are established, used and managed differently, ranging from informal arrangements of households and 'water fathers' to water user associations, as well as from open access to irrigation schedules. Fogera belongs to Ethiopian landscapes that will soon transform as a consequence of large dams and huge irrigation schemes. Property rights to land and water are negotiated among a variety of old and new actors. This study, based on ethnographic, hydrological and survey data, synthesises four case studies to analyse the current state of small-scale irrigation. It argues that all water storage options have not only certain comparative advantages but also social constraints, and supports a policy of extending water storage 'systems' that combine and build on complementarities of different storage types instead of fully replacing diversity by large dams.

Effect of Irrigation with Reclaimed Water on Fruit Characteristics and Photosynthesis of Olive Trees under Two Irrigation Systems

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N. Ashrafi

2016-02-01

Full Text Available Introduction: Olive (Olea europaea L. trees are mainly cultivated in the Mediterranean area and are grown for their oil or processed as table olives. Despite the fact that olive is known to be resistant to drought conditions due to its anatomical, physiological, and biochemical adaptations to drought stress, reports indicate that the olive can be adversely affected by drought stress, which has a negative effect on the growth of olive trees. In the absence of adequate supplies of water, the demand for water can be met by using improved irrigation methods or by using reclaimed water (RW. Reports have shown that recycled water has been used successfully for irrigating olive orchards with no negative effects on plant growth.Attention has been paid to reclaimed water as one of the most significant available water resources used in agriculture around large cities in arid and semi-arid regions. On the other hand, irrigation efficiency is low and does not meet the demands of farmers.In order to investigate the possibility of irrigating olive orchards with subsurface leakage irrigation (SLI in application of reclaimed water, an experiment was carried out with the aim of investigating the effect of reclaimed water on photosynthetic indices and morphological properties of olive fruit. Materials and Methods: Research was conducted using a split-plot experimental design with two factors (irrigation system and water quality on the campus of Isfahan University of Technology in Isfahan, Iran, on a sandy-clay soil with a pH of 7.5 and electrical conductivity (EC of 2.48 dSm-1.PVC leaky tubes were used for the SLI system. The SLI system was installed 40 cm from the crown of each tree at a depth of 30 - 40 cm.At the end of the experiment fruit yield, weight per fruit, volume, length and firmness were calculated. A portable gas exchange system (Li-6400., LICOR, Lincoln, NE, USA was used to measure the net rate photosynthesis (A, the internal partial pressure CO2

BIOMETRIC PARAMETERS OF FIELD GROWN SESAME INFLUENCED BY ARBUSCULAR MYCORRHIZAL INOCULATION, ROCK PHOSPHATE FERTILIZATION AND IRRIGATION

Directory of Open Access Journals (Sweden)

V.S. Harikumar

2017-08-01

Full Text Available The aim of the study was to assess the effect of inoculation with arbuscular mycorrhizal fungi (AMF and rock phosphate (RP fertilization on biometric parameters and mycorrhizal colonization of field grown sesame under rainfed and irrigated conditions. Inoculation of AMF Funneliformis dimorphicus improved the biometric parameters of the crop such as leaf area (LA, leaf area index (LAI, specific leaf weight (SLW, net assimilation rate (NAR, oil index (OI as well as mycorrhizal colonization (%F in roots. Mycorrhizal inoculation however, did not give any positive response on harvest index (HI. LA, LAI and OI and %F showed a general increment in treatments of no added P (P0, while the other parameters such as SLW and NAR were improved by the application of RP at half the recommended dose (P50. HI did not respond to RP fertilization. Most of the parameters (LA, LAI, NAR, %F showed higher values under rainfed condition than irrigated condition whereas, SLW, HI and OI improved significantly under irrigated condition. Results indicated that the inoculation of AMF to field grown sesame can compensate for 50% of the recommended P fertilizer under a need based irrigation schedule, without affecting the biometric parameters.

Simulated Effects of Seasonal Ground-Water Pumpage for Irrigation on Hydrologic Conditions in the Lower Apalachicola-Chattahoochee-Flint River Basin, Southwestern Georgia and Parts of Alabama and Florida, 1999-2002

Science.gov (United States)

Jones, L. Elliott; Torak, Lynn J.

2006-01-01

To determine the effects of seasonal ground-water pumpage for irrigation, a finite-element ground-water flow model was developed for the Upper Floridan aquifer in the lower Flint River Basin area, including adjacent parts of the Chattahoochee and Apalachicola River Basins. The model simulates withdrawal from the aquifer at 3,280 irrigation, municipal, and industrial wells; stream-aquifer flow between the aquifer and 36 area streams; leakage to and from the overlying upper semiconfining unit; regional ground-water flow at the lateral boundaries of the model; and water-table recharge in areas where the aquifer is at or near land surface. Steady-state calibration to drought conditions of October 1999 indicated that the model could adequately simulate measured groundwater levels at 275 well locations and streamflow gains and losses along 53 reaches of area streams. A transient simulation having 12 monthly stress periods from March 2001 to February 2002 incorporated time-varying stress from irrigation pumpage, stream and lake stage, head in the overlying upper semiconfining unit, and infiltration rates. Analysis of simulated water budgets of the Upper Floridan aquifer provides estimates of the source of water pumped for irrigation. During October 1999, an estimated 127 million gallons per day (Mgal/d) of irrigation pumpage from the Upper Floridan aquifer in the model area were simulated to be derived from changes in: stream-aquifer flux (about 56 Mgal/d, or 44 percent); leakage to or from the upper semiconfining unit (about 49 Mgal/d, or 39 percent); regional flow (about 18 Mgal/d, or 14 percent); leakage to or from Lakes Seminole and Blackshear (about 2.7 Mgal/d, or 2 percent); and flux at the Upper Floridan aquifer updip boundary (about 1.8 Mgal/d, or 1 percent). During the 2001 growing season (May-August), estimated irrigation pumpage ranged from about 310 to 830 Mgal/ d, about 79 percent of the 12-month total. During the growing season, irrigation pumpage was

Irrigation management of sigmoid colostomy.

Science.gov (United States)

Jao, S W; Beart, R W; Wendorf, L J; Ilstrup, D M

1985-08-01

Questionnaires were sent to 270 patients who had undergone abdominoperineal resection and sigmoid colostomy at the Mayo Clinic, Rochester, Minn, during the ten years from 1972 to 1982; 223 patients returned their questionnaires with evaluable data. Sixty percent of the patients were continent with irrigation, and 22% were incontinent with irrigation. Eighteen percent had discontinued irrigation for various reasons. The proportion continent was higher in women, younger patients, and previously constipated patients. A poorly constructed colostomy may cause acute angle, parastoma hernia, stomal prolapse, or stenosis and thus be the cause of failure of irrigation.

Evaluation of the oil Produced from lettuce crop cultivated under three irrigation conditions

Directory of Open Access Journals (Sweden)

Hassan El-Mallah, M.

2012-10-01

Full Text Available Three oil lettuce seed samples (lactuca Sativa LS10, LS20, LS30 were cultivated under three irrigation conditions (well, normal and water deficient conditions, after 10, 20 and 30 days respectively to evaluate their oils and to see to what extent the oil lettuce plant resists draught conditions. The oils extracted from the three seed samples were evaluated by determining eight lipid profiles using HPLC in conjunction with capillary GLC. Lettuce seed oils are characterized by high contents of linoleic and oleic acids. Of the triacyl glycerols determined, those containing linoleyl and oleyl acyles are the major ones. The whole sterol profiles include β-sitosterol (as major component followed by 7-stigmasterol, campesterol and 5-stigmasterol, which were found in all the lettuce seed oil samples but with slight differences. Furthermore, sterol patterns of the free and acylated sterols, free and acylated sterylglycosides were determined. It was found that LS30 oil has the highest tocopherol content and α-tocopherol is the only constituent in all the lettuce seed oil samples. On the other hand, the 2-position in the lettuce seed oil samples is mainly acylated by unsaturated fatty acids (98.6% namely, oleic and linoleic acids. According to these results, it can be concluded that irrigation conditions do not affect the lipid constituents of the oil and the oil lettuce plant resists draught and its lipid profiles are in agreement with those of conventional vegetable oils.

Tres muestras de semillas de lechuga (Lactuca Sativa LS10, LS20, LS30 se cultivaron bajo tres condiciones de riego (bien regado, normal y con deficiencia de agua, después de 10, 20 y 30 días, respectivamente para evaluar sus aceites y ver hasta qué punto el aceite de la planta de lechuga resiste las condiciones de riego. Los aceites extraídos de las tres muestras de semillas se evaluó mediante la determinación de ocho perfiles de lípidos usando cromatograf

Mapping irrigated lands at 250-m scale by merging MODIS data and National Agricultural Statistics

Science.gov (United States)

Pervez, Md Shahriar; Brown, Jesslyn F.

2010-01-01

Accurate geospatial information on the extent of irrigated land improves our understanding of agricultural water use, local land surface processes, conservation or depletion of water resources, and components of the hydrologic budget. We have developed a method in a geospatial modeling framework that assimilates irrigation statistics with remotely sensed parameters describing vegetation growth conditions in areas with agricultural land cover to spatially identify irrigated lands at 250-m cell size across the conterminous United States for 2002. The geospatial model result, known as the Moderate Resolution Imaging Spectroradiometer (MODIS) Irrigated Agriculture Dataset (MIrAD-US), identified irrigated lands with reasonable accuracy in California and semiarid Great Plains states with overall accuracies of 92% and 75% and kappa statistics of 0.75 and 0.51, respectively. A quantitative accuracy assessment of MIrAD-US for the eastern region has not yet been conducted, and qualitative assessment shows that model improvements are needed for the humid eastern regions where the distinction in annual peak NDVI between irrigated and non-irrigated crops is minimal and county sizes are relatively small. This modeling approach enables consistent mapping of irrigated lands based upon USDA irrigation statistics and should lead to better understanding of spatial trends in irrigated lands across the conterminous United States. An improved version of the model with revised datasets is planned and will employ 2007 USDA irrigation statistics.

Preferential flow, nitrogen transformations and 15N balance under urine-affected areas of irrigated and non-irrigated clover-based pastures

Science.gov (United States)

Pakro, Naser; Dillon, Peter

1995-12-01

Urine-affected areas can lead to considerable losses of N by leaching, ammonia volatilisation and denitrification from dairy pastures in the southeast of South Australia. Potable groundwater supplies are considered to have become contaminated by nitrate as a result of leaching from these leguminous pastures. Dairy cow urine, labelled with 15N urea, was applied to micro-plots and mini-lysimeters installed in two adjacent irrigated (white clover-rye grass) and non-irrigated (subterranean clover-annual grasses) paddocks of a dairy farm on four occasions representing different seasonal conditions. These experiments allowed measurement of nitrogen transformations, recovery of 15N in the pasture and soil, and leaching below various depths. Gaseous losses were calculated from the nitrogen balance. The results of the four experiments showed that within a day of urine application up to 40% of the applied urinary-N was leached below a depth of 150 mm as a result of macropore flow in the irrigated paddock, and up to 24% in the non-irrigated one. After application to the irrigated paddock 17% of the urinary-N moved immediately below 300 mm but only 2% below the 450-mm depth. The urinary-N remaining in the soil was converted from urea to ammonium within a day regardless of season. Within the first 7 days of application six times more nitrate was produced in summer than in winter. This has obvious implications for leaching potential. Leaching of 15N from the top 150 mm of soil, following urine applications in all seasons, was between 41% and 62% of the applied 15N in the irrigated paddock and 25-51% in the non-irrigated paddock. However, leaching losses measured at depths of 300 or 450 mm were smaller by a factor of 2-4. The leaching loss of 15N applied in spring in both paddocks was 41% below 150 mm and 12% below 450 mm. Recovery of 15N from the soil-plant system in the 450-nm deep lysimeters was ˜60% of that applied. Estimated ammonia was ˜9% of applied 15N with no paddock

Moisture ingress into electronics enclosures under isothermal conditions

DEFF Research Database (Denmark)

Staliulionis, Zygimantas; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

2016-01-01

loads are still not understood well by design engineers, therefore this field has become one of the bottlenecks in the electronics system design. The objective of this paper is to model moisture ingress into an electronics enclosure under isothermal conditions. The moisture diffusion model is based......The number of electronics used in outdoor environment is constantly growing. The humidity causes about 19 % of all electronics failures and, especially, moisture increases these problems due to the ongoing process of miniaturization and lower power consumption of electronic components. Moisture...

Irrigation water management: Basic principles and applications

OpenAIRE

Ella, Victor B.

2007-01-01

This presentation defines the term, irrigation, as well as explains the common methods of irrigation in attempt to define the fundamental principles needed to wisely design an irrigation system. It outlines a typical drip irrigation set-up, and discusses management of an irrigation system, including water volume application suggestions. LTRA-5 (Agroforestry and Sustainable Vegetable Production)

Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

NARCIS (Netherlands)

Kissawike, K.

2008-01-01

This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to
understand how irrigation and agricultural technologies have interacted with local
society to transform production, paying particular attention to gender relations and
changes for women farmers. The

Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

2016-04-01

The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

Where Does the Irrigation Water Go? An Estimate of the Contribution of Irrigation to Precipitation Using MERRA

Science.gov (United States)

Wei, Jiangfeng; Dirmeyer, Paul A.; Wisser, Dominik; Bosilovich, Michael G.; Mocko, David M.

2013-01-01

Irrigation is an important human activity that may impact local and regional climate, but current climate model simulations and data assimilation systems generally do not explicitly include it. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) shows more irrigation signal in surface evapotranspiration (ET) than the Modern-Era Retrospective Analysis for Research and Applications (MERRA) because ERA-Interim adjusts soil moisture according to the observed surface temperature and humidity while MERRA has no explicit consideration of irrigation at the surface. But, when compared with the results from a hydrological model with detailed considerations of agriculture, the ET from both reanalyses show large deficiencies in capturing the impact of irrigation. Here, a back-trajectory method is used to estimate the contribution of irrigation to precipitation over local and surrounding regions, using MERRA with observation-based corrections and added irrigation-caused ET increase from the hydrological model. Results show substantial contributions of irrigation to precipitation over heavily irrigated regions in Asia, but the precipitation increase is much less than the ET increase over most areas, indicating that irrigation could lead to water deficits over these regions. For the same increase in ET, precipitation increases are larger over wetter areas where convection is more easily triggered, but the percentage increase in precipitation is similar for different areas. There are substantial regional differences in the patterns of irrigation impact, but, for all the studied regions, the highest percentage contribution to precipitation is over local land.

Estimating irrigation water use in the humid eastern United States

Science.gov (United States)

Levin, Sara B.; Zarriello, Phillip J.

2013-01-01

Accurate accounting of irrigation water use is an important part of the U.S. Geological Survey National Water-Use Information Program and the WaterSMART initiative to help maintain sustainable water resources in the Nation. Irrigation water use in the humid eastern United States is not well characterized because of inadequate reporting and wide variability associated with climate, soils, crops, and farming practices. To better understand irrigation water use in the eastern United States, two types of predictive models were developed and compared by using metered irrigation water-use data for corn, cotton, peanut, and soybean crops in Georgia and turf farms in Rhode Island. Reliable metered irrigation data were limited to these areas. The first predictive model that was developed uses logistic regression to predict the occurrence of irrigation on the basis of antecedent climate conditions. Logistic regression equations were developed for corn, cotton, peanut, and soybean crops by using weekly irrigation water-use data from 36 metered sites in Georgia in 2009 and 2010 and turf farms in Rhode Island from 2000 to 2004. For the weeks when irrigation was predicted to take place, the irrigation water-use volume was estimated by multiplying the average metered irrigation application rate by the irrigated acreage for a given crop. The second predictive model that was developed is a crop-water-demand model that uses a daily soil water balance to estimate the water needs of a crop on a given day based on climate, soil, and plant properties. Crop-water-demand models were developed independently of reported irrigation water-use practices and relied on knowledge of plant properties that are available in the literature. Both modeling approaches require accurate accounting of irrigated area and crop type to estimate total irrigation water use. Water-use estimates from both modeling methods were compared to the metered irrigation data from Rhode Island and Georgia that were used to

Effective colostomy irrigation.

Science.gov (United States)

Mazier, W P; Dignan, R D; Capehart, R J; Smith, B G

1976-06-01

The ultimate goal of the cone method of colostomy irrigation is to return patients with colostomies to their former role in society with confidence in themselves to the extent that having a colostomy is not considered a handicap. The results have generally been excellent. We believe all patients with stomas should be afforded the opportunity to attempt colostomy irrigation.

Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis

Science.gov (United States)

Borzini, Letizia; Condò, Roberta; De Dominicis, Paolo; Casaglia, Adriano; Cerroni, Loredana

2016-01-01

Background: There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues. Objectives: To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis. Method: Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”. Results: Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro. Conclusion: Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space. PMID:28217184

Use of infrared thermometer technique in irrigation scheduling of pomegranate (Punica granatum L. plant

Directory of Open Access Journals (Sweden)

Begüm TEKELİOĞLU

2017-06-01

Full Text Available The main objectives of this study are to assess crop water stress index (CWSI and to determine irrigation schedule of pomegranate using infrared thermometer technique. Treatments with three replications were irrigated every three and six days intervals, as much as 0.50 (S1, 0.75 (S2, 1.00 (S3, and 1.25 (S4 of Class A pan evaporation. Additionally, an unirrigated plot was also formed. The equations obtained for non-water stress baseline is Tc-Ta=0.645VPD-4.338. The equation of full water stressed upper baseline obtained from data taken from branches of pomegranate plant cut in different days is given by Tc-Ta= 0.0489VPD+2.8734. According to the results obtained, it is concluded that infrared thermometer can be used for irrigation scheduling of the pomegranate plants in Antalya conditions. When using this technique in Antalya conditions, it is suggested to keep the seasonal mean CWSI value approximately 0.12 and the index value of 0.40 can be used to start the irrigation. Additionally, it is suggested that the amount of irrigation can be determined as much as the amount of evaporation measured until the index value reaches 0.40.

Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

NARCIS (Netherlands)

Kooij, van der S.

2016-01-01

Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems (FMIS). Thinking along

Farmers’ willingness to pay for surface water in the West Mitidja irrigated perimeter, northern Algeria

International Nuclear Information System (INIS)

Azzi, M.; Calatrava, J.; Bedrani, S.

2018-01-01

Algeria is among the most water-stressed countries in the world. Because of its climatic conditions, irrigation is essential for agricultural production. Water prices paid by farmers in public irrigation districts are very low and do not cover the operation and maintenance (O&M) costs of the irrigated perimeters, thus leading to the deterioration of these infrastructures. The objective of this paper is to analyse whether farmer’s in the West Mitidja irrigation district in northern Algeria would be willing to pay more for surface water in order to maintain the water supply service in its current conditions. We estimated farmers’ willingness to pay (WTP) for water using data from a dichotomous choice contingent valuation survey to 112 randomly selected farmers. Farmers’ responses were modelled using logistic regression techniques. We also analysed which technical, structural, social and economic characteristics of farms and farmers explain the differences in WTP. Our results showed that nearly 80% of the surveyed farmers are willing to pay an extra price for irrigation water. The average WTP was 64% greater than the price currently paid by farmers, suggesting some scope for improving the financial resources of the Mitidja irrigated perimeter, but insufficient to cover all O&M costs. Some of the key identified factors that affect WTP for surface water relate to farm ownership, access to groundwater resources, cropping patterns, farmers’ agricultural training and risk exposure.

Scheduling of Irrigation and Leaching Requirements

Directory of Open Access Journals (Sweden)

Amer Hassan Al-haddad

2015-03-01

Full Text Available Iraq depends mainly on Tigris and Euphrates Rivers to provide high percentage of agricultural water use for thousands years. At last years, Iraq is suffering from shortage in water resources due to global climate changes and unfair water politics of the neighboring countries, which affected the future of agriculture plans for irrigation, added to that the lack of developed systems of water management in the irrigation projects and improper allocation of irrigation water, which reduces water use efficiency and lead to losing irrigation water and decreasing in agricultural yield. This study aims at studying the usability of irrigation and leaching scheduling within the irrigating projects and putting a complete annual or seasonal irrigation program as a solution for the scarcity of irrigation water, the increase of irrigation efficiency, lessening the salinity in the projects and preparing an integral irrigation calendar through field measurements of soil physical properties and chemical for project selected and compared to the results of the irrigation scheduling and leaching with what is proposed by the designers. The process is accomplished by using a computer program which was designed by Water Resources Department at the University of Baghdad, with some modification to generalize it and made it applicable to various climatic zone and different soil types. Study area represented by large project located at the Tigris River, and this project was (Al-Amara irrigation project. Sufficient samples of project's soil were collected so as to identify soil physical and chemical properties and the salinity of soil and water as well as identifying the agrarian cycles virtually applied to this project. Finally, a comparison was conducted between the calculated water quantities and the suggested ones by the designers. The research results showed that using this kind of scheduling (previously prepared irrigation and leaching scheduling with its properties

Irrigation and nitrogen level affect lettuce yield in greenhouse ...

African Journals Online (AJOL)

STORAGESEVER

2008-12-17

Dec 17, 2008 ... and it achieves very high irrigation efficiency and uses. *Corresponding ... serious harmful effect on lettuce growing (Table 1). During the ... Seeds were sown in a seed bed under greenhouse conditions on. October 20th in ...

Effect of irrigation frequency and application levels of sulphur ...

African Journals Online (AJOL)

Administrator

2011-09-21

Sep 21, 2011 ... both years of experimentation, application of two irrigations significantly increased the India ... marginal lands with poor fertility under rainfed conditions. ... and 40 kg K20 ha-1 as muriate of potash was applied to each plot.

Irrigation Analysis Based on Long-Term Weather Data

Directory of Open Access Journals (Sweden)

James R. Mahan

2016-08-01

Full Text Available Irrigation management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET using weather data. In 1994, an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. Though producers used the ET-network, by 2010 public access was discontinued. Why did producers allow a valuable irrigation-management tool to be eliminated? Our objective was to analyze the effect of declining well capacities on the usefulness of cotton ET (ETc for irrigation. Thirty years (1975–2004 of daily ETc data were used to compare irrigation demand vs. irrigation responses at four locations, analyzed for multiple years and range of well capacities for three irrigation-intervals. Results indicated that when well capacities declined to the point that over-irrigation was not possible, the lower well capacities reduced the value of ETc in terms of the number of irrigations and total amount of water applied. At well capacities <1514 L·min−1 the fraction of irrigations for which ETc information was used to determine the irrigation amount was <35% across years and irrigation intervals. The value of an ETc-based irrigation may fall into disuse when irrigation-water supplies decline.

EFFECTS OF IRRIGATION WATER QUALITY (DIFFERENT SALINITY LEVELS AND BORON CONCENTRATIONS ON MORPHOLOGICAL CHARACTERISTICS OF GRAFTED AND NON-GRAFTED EGGPLANTS

Directory of Open Access Journals (Sweden)

İsmail Taş

2016-07-01

Full Text Available High yield cultivars with quite high resistance against pests and diseases, irrigation water salinity and deficit irrigation conditions are significant in plant production activities. Researches have been conducted also to improve the resistance of available cultivars. Since 1990s, researchers have tried to use low quality irrigation waters just because of deficit water resources and current trends in global warming and climate change. The basic target in all these researches is to reduce production costs and to improve quality and yields. Availability of low quality irrigation waters is a basic component of sustainable agricultural production. The present study was conducted in 40 liter pots under greenhouse conditions. Grafted and non-grafted eggplant seedlings were planted into these pots. Then, plants were irrigated with irrigations waters with different salinity levels (0.25, 1, 1.5, 2, 4, 6, 10 and 15 dS/m and boron concentrations (0, 1, 2, 4, 8, 16, 32 and 64 ppm. In this way, effects of different irrigation water qualities on plant morphological characteristics were investigated.

Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, S.H.; Andersen, Mathias Neumann; Lærke, Poul Erik

2011-01-01

Nitrogen (N) uptake (kg ha-1) of field-grown potatoes was measured in 4.32 m2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

NARCIS (Netherlands)

Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

2012-01-01

Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system,

Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

NARCIS (Netherlands)

Paudel, K.

2010-01-01

Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

Yield, nitrogen uptake and nitrogen use efficiency by tomato, pepper, cucumber, melon and eggplant as affected by nitrogen rates applied with drip-irrigation under greenhouse conditions

International Nuclear Information System (INIS)

Halitligil, M.B.; Akin, A.I.; Kislal, H.; Ozturk, A.; Deviren, A.

2002-01-01

A number of experiments were conducted to investigate the influence of different N rates applied through drip irrigation on the growth and N uptake by tomato, pepper, cucumber, melon and eggplant under greenhouse conditions. It was found that, for tomato, the % NUE was significantly increased by applying the N fertilizer through fertigation (53.9%) as compared to the soil application (34.0%) at 100 mg N/L. In general, any further increase of N fertilizer did not have an improving effect on the tomato yield. With pepper, the % NUE was significantly increased by applying the N fertilizer in the irrigation water (49.2%) as compared to the soil application (33.9%) at the same N level (140 mg N/L), being the optimum N rate under our greenhouse conditions. At a fertilization level of 100 mg N/L with fertigation, the % NUE was significantly increased as compared to the soil application. With respectively cucumber, melon and eggplant; the % NUE with fertigation was 63.4, 21.4 and 50.8%, while with soil application it was 34,0 11.0 and 18.8%. (author)

Balancing lake ecological condition and agriculture irrigation needs in the Mississippi Alluvial Valley

Science.gov (United States)

Miranda, Leandro E.; Omer, A.R.; Killgore, K.J.

2017-01-01

The Mississippi Alluvial Valley includes hundreds of floodplain lakes that support unique fish assemblages and high biodiversity. Irrigation practices in the valley have lowered the water table, increasing the cost of pumping water, and necessitating the use of floodplain lakes as a source of water for irrigation. This development has prompted the need to regulate water withdrawals to protect aquatic resources, but it is unknown how much water can be withdrawn from lakes before ecological integrity is compromised. To estimate withdrawal limits, we examined descriptors of lake water quality (i.e., total nitrogen, total phosphorus, turbidity, Secchi visibility, chlorophyll-a) and fish assemblages (species richness, diversity, composition) relative to maximum depth in 59 floodplain lakes. Change-point regression analysis was applied to identify critical depths at which the relationships between depth and lake descriptors exhibited a rapid shift in slope, suggesting possible thresholds. All our water quality and fish assemblage descriptors showed rapid changes relative to depth near 1.2–2.0 m maximum depth. This threshold span may help inform regulatory decisions about water withdrawal limits. Alternatives to explain the triggers of the observed threshold span are considered.

Smart Irrigation From Soil Moisture Forecast Using Satellite And Hydro -Meteorological Modelling

Science.gov (United States)

Corbari, Chiara; Mancini, Marco; Ravazzani, Giovanni; Ceppi, Alessandro; Salerno, Raffaele; Sobrino, Josè

2017-04-01

Increased water demand and climate change impacts have recently enhanced the need to improve water resources management, even in those areas which traditionally have an abundant supply of water. The highest consumption of water is devoted to irrigation for agricultural production, and so it is in this area that efforts have to be focused to study possible interventions. The SIM project funded by EU in the framework of the WaterWorks2014 - Water Joint Programming Initiative aims at developing an operational tool for real-time forecast of crops irrigation water requirements to support parsimonious water management and to optimize irrigation scheduling providing real-time and forecasted soil moisture behavior at high spatial and temporal resolutions with forecast horizons from few up to thirty days. This study discusses advances in coupling satellite driven soil water balance model and meteorological forecast as support for precision irrigation use comparing different case studies in Italy, in the Netherlands, in China and Spain, characterized by different climatic conditions, water availability, crop types and irrigation techniques and water distribution rules. Herein, the applications in two operative farms in vegetables production in the South of Italy where semi-arid climatic conditions holds, two maize fields in Northern Italy in a more water reach environment with flood irrigation will be presented. This system combines state of the art mathematical models and new technologies for environmental monitoring, merging ground observed data with Earth observations. Discussion on the methodology approach is presented, comparing for a reanalysis periods the forecast system outputs with observed soil moisture and crop water needs proving the reliability of the forecasting system and its benefits. The real-time visualization of the implemented system is also presented through web-dashboards.

Newer Root Canal Irrigants in Horizon: A Review

Directory of Open Access Journals (Sweden)

Sushma Jaju

2011-01-01

Full Text Available Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

Remote Sensing of Irrigated Agriculture: Opportunities and Challenges

Directory of Open Access Journals (Sweden)

Chelsea Cervantes

2010-09-01

Full Text Available Over the last several decades, remote sensing has emerged as an effective tool to monitor irrigated lands over a variety of climatic conditions and locations. The objective of this review, which summarizes the methods and the results of existing remote sensing studies, is to synthesize principle findings and assess the state of the art. We take a taxonomic approach to group studies based on location, scale, inputs, and methods, in an effort to categorize different approaches within a logical framework. We seek to evaluate the ability of remote sensing to provide synoptic and timely coverage of irrigated lands in several spectral regions. We also investigate the value of archived data that enable comparison of images through time. This overview of the studies to date indicates that remote sensing-based monitoring of irrigation is at an intermediate stage of development at local scales. For instance, there is overwhelming consensus on the efficacy of vegetation indices in identifying irrigated fields. Also, single date imagery, acquired at peak growing season, may suffice to identify irrigated lands, although to multi-date image data are necessary for improved classification and to distinguish different crop types. At local scales, the mapping of irrigated lands with remote sensing is also strongly affected by the timing of image acquisition and the number of images used. At the regional and global scales, on the other hand, remote sensing has not been fully operational, as methods that work in one place and time are not necessarily transferable to other locations and periods. Thus, at larger scales, more work is required to indentify the best spectral indices, best time periods, and best classification methods under different climatological and cultural environments. Existing studies at regional scales also establish the fact that both remote sensing and national statistical approaches require further refinement with a substantial investment of

Declining Groundwater Levels in North India: Understanding Sources of Irrigation Inefficiency

Science.gov (United States)

O'Keeffe, J.; Buytaert, W.; Mijic, A.; Brozovic, N.

2014-12-01

Over the last half century, the green revolution has transformed India from a famine-prone, drought-susceptible country, into the world's third largest grain producer and one of the most intensely irrigated regions on the planet. This is in no small part due to the country's vast water resources along with an increase in tubewells and more advanced abstraction methods. While agricultural intensification has had undeniable benefits, it has, and continues to have a significant impact on water resources. Unless solutions which take into consideration the ever evolving socio-economic, hydrological and climatic conditions are found, India's agricultural future looks bleak.This research examines the irrigation behaviour of farmers, using data collected during field work in the State of Uttar Pradesh within the Ganges Basin of North India. Significant differences in farmer behaviour and irrigation practices are highlighted, not only between State districts but between individual farmers. This includes the volume of irrigation water applied and the price paid, as well as differences in the yields of crops produced. Analyses of results suggest that this is due to a number of factors, particularly the source of irrigation water. Study areas which had access to cheaper, but crucially less reliable, canal water were found to invest in more efficient water saving technologies in order to reduce the overall cost of irrigation during periods where less expensive canal water is not available. As a result, overall water use and irrigation cost is lower and yields are higher despite very similar climatic conditions. While cheap canal water is not an option for all farmers, the results show that the introduction of more efficient water saving technologies, despite the significant capital expenditure is a viable option for many farmers and costs can be recovered in a relatively short space of time. In addition, the reduction of declining water levels mean that water is abstracted from

Unsaturated flow dynamics during irrigation with wastewater: field and modelling study

Science.gov (United States)

Martinez-Hernandez, V.; de Miguel, A.; Meffe, R.; Leal, M.; González-Naranjo, V.; de Bustamante, I.

2012-04-01

To deal with water scarcity combined with a growing water demand, the reuse of wastewater effluents of wastewater treatment plants (WWTP) for industrial and agricultural purposes is considered as a technically and economically feasible solution. In agriculture, irrigation with wastewater emerges as a sustainable practice that should be considered in such scenarios. Water infiltration, soil moisture storage and evapotranspiration occurring in the unsaturated zone are fundamental processes that play an important role in soil water balance. An accurate estimation of unsaturated flow dynamics (during and after irrigation) is essential to improve wastewater management (i.e. estimating groundwater recharge or maximizing irrigation efficiency) and to avoid possible soil and groundwater affections (i.e. predicting contaminant transport). The study site is located in the Experimental Plant of Carrión de los Céspedes (Seville, Spain). Here, treated wastewater is irrigated over the soil to enhance plants growth. To obtain physical characteristics of the soil (granulometry, bulk density and water retention curve), soil samples were collected at different depths. A drain gauge passive capillary lysimeter was installed to determine the volume of water draining from the vadose zone. Volumetric water content of the soil was monitored by measuring the dielectric constant using capacitance/frequency domain technology. Three soil moisture probes were located at different depths (20, 50 and 70 cm below the ground surface) to control the variation of the volumetric water content during infiltration. The main aim of this study is to understand water flow dynamics through the unsaturated zone during irrigation by using the finite element model Hydrus-1D. The experimental conditions were simulated by a 90 cm long, one dimensional solution domain. Specific climatic conditions, wastewater irrigation rates and physical properties of the soil were introduced in the model as input parameters

[Irrigants and intracanal medicaments in endodontics].

Science.gov (United States)

Zehnder, Matthias; Lehnert, Birgit; Schönenberger, Kathrin; Waltimo, Tuomas

2003-01-01

Modern, biologic root canal therapy should be performed with suitable irrigating solutions and intracanal medicaments. The goal of endodontic treatment is to free the treated tooth from infection and prevent reinfection as thoroughly as possible by means which do not put the organism at risk. In this review of the literature, an evidence-based concept for irrigation and medication of root canal systems is presented. Irrigants and medicaments are discussed with respect to their antimicrobial, tissue-dissolving and endotoxin-decontaminating capacity in relation to their systemic toxicity. Recent findings pertaining to interactions of root canal medicaments and irrigating solutions and their impact on a sound irrigating and medicating concept are discussed.

Irrigation in dose assessments models

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

2004-05-01

SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

Irrigation in dose assessments models

International Nuclear Information System (INIS)

Bergstroem, Ulla; Barkefors, Catarina

2004-05-01

SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

Sediment Transport Model for a Surface Irrigation System

Directory of Open Access Journals (Sweden)

Damodhara R. Mailapalli

2013-01-01

Full Text Available Controlling irrigation-induced soil erosion is one of the important issues of irrigation management and surface water impairment. Irrigation models are useful in managing the irrigation and the associated ill effects on agricultural environment. In this paper, a physically based surface irrigation model was developed to predict sediment transport in irrigated furrows by integrating an irrigation hydraulic model with a quasi-steady state sediment transport model to predict sediment load in furrow irrigation. The irrigation hydraulic model simulates flow in a furrow irrigation system using the analytically solved zero-inertial overland flow equations and 1D-Green-Ampt, 2D-Fok, and Kostiakov-Lewis infiltration equations. Performance of the sediment transport model was evaluated for bare and cropped furrow fields. The results indicated that the sediment transport model can predict the initial sediment rate adequately, but the simulated sediment rate was less accurate for the later part of the irrigation event. Sensitivity analysis of the parameters of the sediment module showed that the soil erodibility coefficient was the most influential parameter for determining sediment load in furrow irrigation. The developed modeling tool can be used as a water management tool for mitigating sediment loss from the surface irrigated fields.

Mapping irrigated areas in Afghanistan over the past decade using MODIS NDVI

Science.gov (United States)

Pervez, Md Shahriar; Budde, Michael; Rowland, James

2014-01-01

the severe drought conditions in those years, whereas 2009, 2012 and 2013 registered the largest irrigated area (~ 2.5 million hectares) due to record snowpack and snowmelt in the region. The model holds promise the ability to provide near-real-time (by the end of the growing seasons) estimates of irrigated area, which are beneficial for food security monitoring as well as subsequent decision making for the country. While the model is developed for Afghanistan, it can be adopted with appropriate adjustments in the derived threshold values to map irrigated areas elsewhere.

Evaluation model development for sprinkler irrigation uniformity ...

African Journals Online (AJOL)

use

Sprinkle and trickle irrigation. The. Blackburn Press, New Jersey, USA. Li JS, Rao MJ (1999). Evaluation method of sprinkler irrigation nonuniformity. Trans. CSAE. 15(4): 78-82. Lin Z, Merkley GP (2011). Relationships between common irrigation application uniformity indicators. Irrig Sci. Online First™, 27 January. 2011.

Survey the Effects of Partial Root Zone Deficit Irrigation and Deficit Irrigation on Quantitative, Qualitative and Water Use Efficiency of Pomegranate

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mohammad saeed tadaion

2017-12-01

Full Text Available Introduction: One of the latest efficient methods on increment of water use efficiency that confirmed by many scientists all over the world is deficit and alternative partial root zone deficit irrigation. In this experiment the effect of deficit and alternative partial root zone deficit irrigation on fruit yield, quality and water use efficiency of pomegranate (Punicagranatum (L. cv. Zarde-anar were investigatedin Arsenjan semi-arid region. Materials and Methods: The experiment was carried out in a constant plots and randomized complete block design (RCBD with four replicationsin five years.Treatmentswere 1- full flood irrigation (100 percent crop water requirement (T1 2- flood irrigation with 100 percent crop water requirement as alternate partial root-zone irrigation(every irrigation conducted on one side of tree (T2 3- flood irrigation with 50 percent crop water requirement as regular deficit irrigation (T3 4- full two-side drip irrigation(with regard to crop water requirement (eight drippers with twolit/hour flow by two different individual networks (T4 5- alternate partial root-zone drip irrigation with 100 percent crop water requirement (T5 6- regular deficit drip irrigation with 50 percent crop water requirement (T6 in every irrigation period. Each experimental treatment includes four trees and 96 similar twelve years old trees overall. Cultivation practice was conducted similarly on all of the trees. Results and Discussion: Results showed that the highest yield and water use efficiency based on statistical analysis belong to both PRD treatments i.e. alternate partial root-zone drip irrigation with 100 percent crop water requirement and alternate partial root-zone flood irrigation with 100 percent crop water requirement, respectively, that both of them decreased water requirement for irrigation up to 35 and 50 percent in comparison tocontrol. Application of partial root drying irrigation on both traditional flood irrigation and drip

Climate forcing and desert malaria: the effect of irrigation.

Science.gov (United States)

Baeza, Andres; Bouma, Menno J; Dobson, Andy P; Dhiman, Ramesh; Srivastava, Harish C; Pascual, Mercedes

2011-07-14

in the actual risk of disease. This implies that irrigation can lead to more endemic conditions for malaria, creating the potential for unexpectedly large epidemics in response to excess rainfall if these climatic events coincide with a relaxation of control over time. The implications of our findings for control policies of epidemic malaria in arid regions are discussed.

Evaluation of 14 winter bread wheat genotypes in normal irrigation ...

African Journals Online (AJOL)

Evaluation of 14 winter bread wheat genotypes in normal irrigation and stress conditions after anthesis stage. ... African Journal of Biotechnology ... Using biplot graphic method, comparison of indices amounts and mean rating of indices for ...

The Swedish study of Irrigation-fluid temperature in the evacuation of Chronic subdural hematoma (SIC!)

DEFF Research Database (Denmark)

Bartley, Andreas; Jakola, Asgeir S; Bartek, Jiri

2017-01-01

BACKGROUND: Chronic subdural hematoma (cSDH) is one of the most common conditions encountered in neurosurgical practice. Recurrence, observed in 5-30% of patients, is a major clinical problem. The temperature of the irrigation fluid used during evacuation of the hematoma might theoretically...... and health-related quality of life. DISCUSSION: Irrigation-fluid temperature might influence recurrence rates in the evacuation of chronic subdural hematomas. We present a study protocol for a multicenter randomized controlled trial investigating our hypothesis that irrigation fluid at body temperature...

Irrigation as an Historical Climate Forcing

Science.gov (United States)

Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

2014-01-01

Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

Root canal debris removal using different irrigating needles: An SEM study

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Sheetal Ghivari

2011-01-01

Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

Comparison of winter wheat yield sensitivity to climate variables under irrigated and rain-fed conditions

Science.gov (United States)

Xiao, Dengpan; Shen, Yanjun; Zhang, He; Moiwo, Juana P.; Qi, Yongqing; Wang, Rende; Pei, Hongwei; Zhang, Yucui; Shen, Huitao

2016-09-01

Crop simulation models provide alternative, less time-consuming, and cost-effective means of determining the sensitivity of crop yield to climate change. In this study, two dynamic mechanistic models, CERES (Crop Environment Resource Synthesis) and APSIM (Agricultural Production Systems Simulator), were used to simulate the yield of wheat ( Triticum aestivum L.) under well irrigated (CFG) and rain-fed (YY) conditions in relation to different climate variables in the North China Plain (NCP). The study tested winter wheat yield sensitivity to different levels of temperature, radiation, precipitation, and atmospheric carbon dioxide (CO2) concentration under CFG and YY conditions at Luancheng Agro-ecosystem Experimental Stations in the NCP. The results from the CERES and APSIM wheat crop models were largely consistent and suggested that changes in climate variables influenced wheat grain yield in the NCP. There was also significant variation in the sensitivity of winter wheat yield to climate variables under different water (CFG and YY) conditions. While a temperature increase of 2°C was the threshold beyond which temperature negatively influenced wheat yield under CFG, a temperature rise exceeding 1°C decreased winter wheat grain yield under YY. A decrease in solar radiation decreased wheat grain yield under both CFG and YY conditions. Although the sensitivity of winter wheat yield to precipitation was small under the CFG, yield decreased significantly with decreasing precipitation under the rainfed YY treatment. The results also suggest that wheat yield under CFG linearly increased by ≈3.5% per 60 ppm (parts per million) increase in CO2 concentration from 380 to 560 ppm, and yield under YY increased linearly by ≈7.0% for the same increase in CO2 concentration.

Irrigation of pistachios : strategies to confront water scarcity

NARCIS (Netherlands)

Pérez-López, David; Memmi, Houssem; Gijón-López, Maria del Carmen; Moreno, Marta Maria; Couceiro, José Francisco; Centeno, Ana; Martín-Palomo, Maria J.; Corell, Mireia; Noguera-Artiaga, Luis; Galindo Egea, Alejandro; Torrecillas, Arturo; Moriana, Alfonso; Tejero, Ivan Francisco Garcia; Zuazo, Victor Hugo Duran

2017-01-01

Pistachio trees are capable to be profitable under rain-fed conditions. They also have a good response to low amounts of irrigation water, so are a great candidate to be considered for water-scarcity scenarios. The pistachio tree has a singular way of alternate bearing, losing a percentage of its

Effect of Er:YAG laser-activated irrigation solution on Enterococcus Faecalis biofilm in an ex-vivo root canal model.

Science.gov (United States)

Sahar-Helft, Sharonit; Stabholtz, Adam; Moshonov, Joshua; Gutkin, Vitaly; Redenski, Idan; Steinberg, Doron

2013-07-01

Abstract Objective: The purpose of this study was to evaluate mineral content and surface morphology of root canals coated with Enterococcus faecalis biofilm after treatment with several endodontic irrigation solutions, with and without Er:YAG laser-activated irrigation (LAI). LAI has been introduced as a powerful method for root canal irrigation resulting in smear-layer removal from the root canal wall. Distal and palatal roots from 60 freshly extracted human molars were used in this study. The coronal of each tooth was removed. Roots were split longitudinally and placed in an ultrasonic bath to remove the smear layer, creating conditions for the formation of E. faecalis biofilm. After incubation, the two halves were reassembled in impression material to simulate clinical conditions. Specimens were divided into two main groups: roots rinsed with irrigation solutions and roots subjected to laser irradiation combined with irrigation solutions. Solutions tested were 2% chlorhexidine and 17% ethylenediaminetetraacetic acid (EDTA) and saline. Surface morphology: 17% EDTA irrigant solution combined with Er:YAG laser showed the best results for removing bacteria from the root canal walls. Chemical analysis: all samples treated with combined laser irradiation and irrigation solution had low surface levels of Ca compared with samples treated with irrigation alone. The Ca/P ratio was highest in the laser-EDTA group. Overall, mineral changes caused by laser with irrigation solutions were minimal, and statistically nonsignificant. In vitro irrigation solutions, combined with Er:YAG laser irradiation, were effective in removing E. faecalis biofilm from root canal walls. Irrigation solutions without laser irradiation were less effective, leaving a layer of biofilm on the dentin surface.

Estimate of uptake and translocation of emerging organic contaminants from irrigation water concentration in lettuce grown under controlled conditions.

Science.gov (United States)

Hurtado, Carlos; Domínguez, Carmen; Pérez-Babace, Lorea; Cañameras, Núria; Comas, Jordi; Bayona, Josep M

2016-03-15

The widespread distribution of emerging organic contaminants (EOCs) in the water cycle can lead to their incorporation in irrigated crops, posing a potential risk for human consumption. To gain further insight into the processes controlling the uptake of organic microcontaminants, Batavia lettuce (Lactuca sativa) grown under controlled conditions was watered with EOCs (e.g., non-steroidal anti-inflammatories, sulfonamides, β-blockers, phenolic estrogens, anticonvulsants, stimulants, polycyclic musks, biocides) at different concentrations (0-40μgL(-1)). Linear correlations were obtained between the EOC concentrations in the roots and leaves and the watering concentrations for most of the contaminants investigated. However, large differences were found in the root concentration factors ( [Formula: see text] =0.27-733) and leaf translocation concentration factors ( [Formula: see text] =0-3) depending on the persistence of the target contaminants in the rhizosphere and the specific physicochemical properties of each one. With the obtained dataset, a simple predictive model based on a linear regression and the root bioconcentration and translocation factors can be used to estimate the concentration of the target EOCs in leaves based on the dose supplied in the irrigation water or the soil concentration. Finally, enantiomeric fractionation of racemic ibuprofen from the initial spiking mixture suggests that biodegradation mainly occurs in the rhizosphere. Copyright © 2015 Elsevier B.V. All rights reserved.

Colostomy irrigation: are we offering it enough?

Science.gov (United States)

Woodhouse, Fran

This article discusses the use of irrigation for suitable colostomists and reasons why it can have a very positive effect on lifestyle. While it is evidence-based it also includes anecdotal tips from patients who irrigate. The suitability of patients to irrigate and ways to 'get started' with irrigation are discussed.

A scintigraphic study of colostomy irrigation

Energy Technology Data Exchange (ETDEWEB)

Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige (Nara Medical Univ., Kashihara (Japan))

1991-09-01

Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with {sup 99m}Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author).

A scintigraphic study of colostomy irrigation

International Nuclear Information System (INIS)

Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige

1991-01-01

Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with 99m Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author)

Economic assessment at farm level of the implementation of deficit irrigation for quinoa production in the Southern Bolivian Altiplano

Directory of Open Access Journals (Sweden)

J. Cusicanqui

2013-10-01

Full Text Available In the Southern Bolivian Altiplano recent research has suggested to introduce deficit irrigation as a strategy to boost quinoa yields and to stabilize it at 2.0 ton ha-1. In this study we carried out an economic assessment of the implementation of deficit irrigation at farm level using a hydro-economic model for simulating profit for quinoa production. As input of the model we worked with previously developed farms typology (livestock, quinoa and subsistence farms, simulated quinoa production with and without irrigation using AquaCrop model, and calculated yield response functions for four different climate scenarios (wet, normal, dry and very dry years. Results from the hydro-economic model demonstrate that maximum profit is achieved with less applied irrigated water than for maximum yield, and irrigated quinoa earned more profit than rainfed production for all farms types and climate scenarios. As expected, the benefits of irrigation under dry and very dry climate conditions were higher than those under normal and wet years, and benefits among farms types were higher for quinoa farms. In fact, profit of irrigated quinoa might be stabilized at around BOB 6500 ha-1 (about USD 920 compared with the huge differences found for rainfed conditions for all climate scenarios. Interestingly, the economic water productivity, expressed in terms of economic return for amount of applied irrigated water (BOB mm-1, reached the highest values with intermediate and low level of water availability schemes of deficit irrigation for all climate scenarios.

Selection of the optimum condition for electron capture detector operation

International Nuclear Information System (INIS)

Lasa, J.; Korus, A.

1974-01-01

A method of determination of the optimal work conditions for the electron capture detector is presented in the paper. Physical phenomena which occur in the detector, as well as the energetic dependence of the electron attachment process are taken into consideration. The influence of the kind of carrier gas, temperature, and the parameters of the supplied voltage in both direct and pulse methods on average values of electron energy is described. Dependence of the sensitivity of the electron capture detector on the carrier gas and the polarizing voltage is illustrated for the Model DNW-300 electron capture detector produced in Poland. Practical indications for selecting optimal conditions of electron capture detector operation are given at the end of the paper. (author)

Moderate irrigation intervals facilitate establishment of two desert shrubs in the Taklimakan Desert Highway Shelterbelt in China.

Science.gov (United States)

Li, Congjuan; Shi, Xiang; Mohamad, Osama Abdalla; Gao, Jie; Xu, Xinwen; Xie, Yijun

2017-01-01

Water influences various physiological and ecological processes of plants in different ecosystems, especially in desert ecosystems. The purpose of this study is to investigate the response of physiological and morphological acclimation of two shrubs Haloxylon ammodendron and Calligonum mongolicunl to variations in irrigation intervals. The irrigation frequency was set as 1-, 2-, 4-, 8- and 12-week intervals respectively from March to October during 2012-2014 to investigate the response of physiological and morphological acclimation of two desert shrubs Haloxylon ammodendron and Calligonum mongolicunl to variations in the irrigation system. The irrigation interval significantly affected the individual-scale carbon acquisition and biomass allocation pattern of both species. Under good water conditions (1- and 2-week intervals), carbon assimilation was significantly higher than other treatments; while, under water shortage conditions (8- and 12-week intervals), there was much defoliation; and under moderate irrigation intervals (4 weeks), the assimilative organs grew gently with almost no defoliation occurring. Both studied species maintained similar ecophysiologically adaptive strategies, while C. mongolicunl was more sensitive to drought stress because of its shallow root system and preferential belowground allocation of resources. A moderate irrigation interval of 4 weeks was a suitable pattern for both plants since it not only saved water but also met the water demands of the plants.

Farmers’ willingness to pay for surface water in the West Mitidja irrigated perimeter, northern Algeria

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Malika Azzi

2018-04-01

Full Text Available Algeria is among the most water-stressed countries in the world. Because of its climatic conditions, irrigation is essential for agricultural production. Water prices paid by farmers in public irrigation districts are very low and do not cover the operation and maintenance (O&M costs of the irrigated perimeters, thus leading to the deterioration of these infrastructures. The objective of this paper is to analyse whether farmer’s in the West Mitidja irrigation district in northern Algeria would be willing to pay more for surface water in order to maintain the water supply service in its current conditions. We estimated farmers’ willingness to pay (WTP for water using data from a dichotomous choice contingent valuation survey to 112 randomly selected farmers. Farmers’ responses were modelled using logistic regression techniques. We also analysed which technical, structural, social and economic characteristics of farms and farmers explain the differences in WTP. Our results showed that nearly 80% of the surveyed farmers are willing to pay an extra price for irrigation water. The average WTP was 64% greater than the price currently paid by farmers, suggesting some scope for improving the financial resources of the Mitidja irrigated perimeter, but insufficient to cover all O&M costs. Some of the key identified factors that affect WTP for surface water relate to farm ownership, access to groundwater resources, cropping patterns, farmers’ agricultural training and risk exposure.

Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal.

Science.gov (United States)

Çapar, İsmail Davut; Aydinbelge, Hale Ari

2014-01-01

The purpose of the present study is to evaluate smear layer generation and residual debris after using self-adjusting file (SAF) or rotary instrumentation and to compare the debris and smear layer removal efficacy of the SAF cleaning/shaping irrigation system against final agitation techniques. One hundred and eight maxillary lateral incisor teeth were randomly divided into nine experimental groups (n = 12), and root canals were prepared using ProTaper Universal rotary files, with the exception of the SAF instrumentation group. During instrumentation, root canals were irrigated with a total of 16 mL of 5% NaOCl. For final irrigation, rotary-instrumented groups were irrigated with 10 mL of 17% EDTA and 10 mL of 5% NaOCl using different irrigation agitation regimens (syringe irrigation with needles, NaviTip FX, manual dynamic irrigation, CanalBrush, EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and SAF irrigation). In the SAF instrumentation group, root canals were instrumented for 4 min at a rate of 4 mL/min with 5% NaOCl and received a final flush with same as syringe irrigation with needles. The surface of the root dentin was observed using a scanning electron microscope. The SAF instrumentation group generated less smear layer and yielded cleaner canals compared to rotary instrumentation. The EndoActivator, EndoVac, PUI, and SAF irrigation groups increased the efficacy of irrigating solutions on the smear layer and debris removal. The SAF instrumentation yielded cleaner canal walls when compared to rotary instrumentation. None of the techniques completely removed the smear layer from the root canal walls. © 2014 Wiley Periodicals, Inc.

Impacts of irrigation regimes with saline water on carrot productivity and soil salinity

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Kamel Nagaz

2012-01-01

Full Text Available A three-year study was conducted to evaluate the effects of different irrigation regimes with saline water on soil salinity, yield and water productivity of carrot as a fall-winter crop under actual commercial-farming conditions in the arid region of Tunisia. Carrot was grown on a sandy soil and surface-irrigated with a water having an ECi of 3.6 dS/m. For the three years, a complete randomized block design with four replicates was used to evaluate five irrigation regimes. Four irrigation methods were based on the use of soil water balance (SWB to estimate irrigation amounts and timing while the fifth consisted of using traditional farmers practices. SWB methods consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI-100, 80% (DI-80 and 60% (DI-60. FI-100 was considered as full irrigation while DI-80 and DI-60 were considered as deficit irrigation regimes. Regulated deficit irrigation regime where 40% reduction is applied only during ripening stage (FI-DI60 was also used. Farmer method (Farmer consisted in giving fixed amounts of water (25 mm every 7 days from planting till harvest. Results on carrot production and soil salinization are globally consistent between the three-year experiments and shows significant difference between irrigation regimes. Higher soil salinity in the root zone is observed at harvest under DI-60 (3.1, 3.4, 3.9 dS/m, respectively, for the three years and farmer irrigation (3.3, 3.6, 3.9 dS/m treatments compared to FI-100 treatment (2.3, 2.6 and 3.1 dS/m. Relatively low ECe values were also observed under FI-DI60 and DI-80 treatments with respectively (2.7, 3, 3.5 dS/m and (2.5, 2.9, 3.3 dS/m. ECe values under the different irrigation treatments were generally lower than or equal to the EC of irrigation water used. Rainfall received during fall and/or winter periods (57, 26 and 29 mm, respectively, during the three years contributed probably to leaching soluble

Impacts of Irrigation on the Heat Fluxes and Near-Surface Temperature in an Inland Irrigation Area of Northern China

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Li Jiang

2014-03-01

Full Text Available Irrigated agriculture has the potential to alter regional to global climate significantly. We investigate how irrigation will affect regional climate in the future in an inland irrigation area of northern China, focusing on its effects on heat fluxes and near-surface temperature. Using the Weather Research and Forecasting (WRF model, we compare simulations among three land cover scenarios: the control scenario (CON, the irrigation scenario (IRR, and the irrigated cropland expansion scenario (ICE. Our results show that the surface energy budgets and temperature are sensitive to changes in the extent and spatial pattern of irrigated land. Conversion to irrigated agriculture at the contemporary scale leads to an increase in annual mean latent heat fluxes of 12.10 W m−2, a decrease in annual mean sensible heat fluxes of 8.85 W m−2, and a decrease in annual mean temperature of 1.3 °C across the study region. Further expansion of irrigated land increases annual mean latent heat fluxes by 18.08 W m−2, decreases annual mean sensible heat fluxes by 12.31 W m−2, and decreases annual mean temperature by 1.7 °C. Our simulated effects of irrigation show that changes in land use management such as irrigation can be an important component of climate change and need to be considered together with greenhouse forcing in climate change assessments.

Agriculture Irrigation and Water Use

OpenAIRE

Bajwa, Rajinder S.; Crosswhite, William M.; Hostetler, John E.; Wright, Olivia W.; United States Department of Agriculture, Economic Research Service

1992-01-01

The 17 Western States, plus Arkansas, Florida, and Louisiana, account for 91 percent of all U.S. irrigated acreage, with the Western States alone contributing over 85 percent. This report integrates data on the distribution, characteristics, uses, and management of water resources from a wide variety of data sources. The report includes charts and tables on water use in irrigation; farm data comparing selected characteristics of irrigated and nonirrigated farms; and data on water applicatio...

Online decision support system for surface irrigation management

Science.gov (United States)

Wang, Wenchao; Cui, Yuanlai

2017-04-01

Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

Colonic irrigation for defecation disorders after dynamic graciloplasty.

Science.gov (United States)

Koch, Sacha M; Uludağ, Ozenç; El Naggar, Kadri; van Gemert, Wim G; Baeten, Cor G

2008-02-01

Dynamic graciloplasty (DGP) improves anal continence and quality of life for most patients. However, in some patients, DGP fails and fecal incontinence is unsolved or only partially improved. Constipation is also a significant problem after DGP, occurring in 13-90%. Colonic irrigation can be considered as an additional or salvage treatment for defecation disorders after unsuccessful or partially successful DGP. In this study, the effectiveness of colonic irrigation for the treatment of persistent fecal incontinence and/or constipation after DGP is investigated. Patients with defecation disorders after DGP visiting the outpatient clinic of the University Hospital Maastricht were selected for colonic irrigation as additional therapy or salvage therapy in the period between January 1999 and June 2003. The Biotrol(R) Irrimatic pump or the irrigation bag was used for colonic irrigation. Relevant physical and medical history was collected. The patients were asked to fill out a detailed questionnaire about colonic irrigation. Forty-six patients were included in the study with a mean age of 59.3 +/- 12.4 years (80% female). On average, the patients started the irrigation 21.39 +/- 38.77 months after the DGP. Eight patients started irrigation before the DGP. Fifty-two percent of the patients used the irrigation as additional therapy for fecal incontinence, 24% for constipation, and 24% for both. Irrigation was usually performed in the morning. The mean frequency of irrigation was 0.90 +/- 0.40 times per day. The mean amount of water used for the irrigation was 2.27 +/- 1.75 l with a mean duration of 39 +/- 23 min. Four patients performed antegrade irrigation through a colostomy or appendicostomy, with good results. Overall, 81% of the patients were satisfied with the irrigation. Thirty-seven percent of the patients with fecal incontinence reached (pseudo-)continence, and in 30% of the patients, the constipation completely resolved. Side effects of the irrigation were

Ruling by canal: Governance and system-level design characteristics of large scale irrigation infrastructure in India and Uzbekistan

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Peter Mollinga

2016-06-01

Full Text Available This paper explores the relationship between governance regime and large-scale irrigation system design by investigating three cases: 1 protective irrigation design in post-independent South India; 2 canal irrigation system design in Khorezm Province, Uzbekistan, as implemented in the USSR period, and 3 canal design by the Madras Irrigation and Canal Company, as part of an experiment to do canal irrigation development in colonial India on commercial terms in the 1850s-1860s. The mutual shaping of irrigation infrastructure design characteristics on the one hand and management requirements and conditions on the other has been documented primarily at lower, within-system levels of the irrigation systems, notably at the level of division structures. Taking a 'social construction of technology' perspective, the paper analyses the relationship between technological structures and management and governance arrangements at irrigation system level. The paper finds qualitative differences in the infrastructural configuration of the three irrigation systems expressing and facilitating particular forms of governance and rule, differences that matter for management and use, and their effects and impacts.

Bridging Mediterranean cultures in the IYS: A documentary exhibition on irrigation techniques in water scarcity conditions

Science.gov (United States)

Barontini, Stefano; Louki, Amina; Ben Slima, Zied; Ezzahra Ghaouch, Fatima; Labaran, Raisa; Raffelli, Giulia; Peli, Marco; Vitale, Nicola

2015-04-01

Brescia, an industrial city in Northern Italy, is now experiencing a crucial change in its traditional structure. In recent years in fact it has been elected as living and working seat by many foreigners and it is now one of the cities with the greatest percentage of migrants in the Country. This is an important challenge for the city and an opportunity to merge, compare and integrate different cultures to build its future. In this context some students of different Courses (engineering and medicine), belonging both to the Arabian and local community, met together and with researchers in the study team 'Al-B¯i r¯u n¯i , for culture, science and society'. The team aims at organising cultural events in which, starting from the figure of the Persian scientist Ab¯u Raih. ¯a n Al-B¯i r¯u n¯i (about 973, 1051), the contribution of the Arabian and Islamic culture to the development of the European one in the middle ages is investigated. Moving from the initial idea of the study team Al-B¯i r¯u n¯i and from the suggestions of the World Soil Day 2014 and of the International Year of Soils 2015, we built a documentary exhibition entitled 'Irrigation techniques in water scarcity conditions'. The exhibition, which stresses the importance of the irrigation techniques for the soil conservation, is focused on the idea of disseminating two main concepts, i.e. (1) the technological continuity of some water supply systems in countries, around the Mediterranean Sea, affected by similar conditions of water availability, and (2) the possibility of building environments where, due to severe or extreme climatic conditions, the sustainability is reached when the man lives in equilibrium with the nature. The exhibition, which is written in Italian and will move around in the city during all 2015, consists of about twenty posters organized into three main chapters, corresponding to three main classes of water supply systems which are common in most of the countries surrounding

Effects of irrigation levels on interactions among Lygus hesperus (Hemiptera: Miridae), insecticides, and predators in cotton.

Science.gov (United States)

Asiimwe, Peter; Naranjo, Steven E; Ellsworth, Peter C

2014-04-01

Variation in plant quality and natural enemy abundance plays an important role in insect population dynamics. In manipulative field studies, we evaluated the impact of varying irrigation levels and insecticide type on densities of Lygus hesperus Knight and the arthropod predator community in cotton. Three watering levels were established via irrigations timed according to three levels of percent soil water depletion (SWD): 20, 40, or 60, where 40% SWD is considered standard grower practice, 60% represents a deficit condition likely to impose plant productivity losses, and 20% represents surplus conditions with likely consequences on excessive vegetative plant production. The two key L. hesperus insecticides used were the broad-spectrum insecticide acephate and the selective insecticide flonicamid, along with an untreated check. We hypothesized that densities of L. hesperus and its associated predators would be elevated at higher irrigation levels and that insecticides would differentially impact L. hesperus and predator dynamics depending on their selectivity. L. hesperus were more abundant at the higher irrigation level (20% SWD) but the predator densities were unaffected by irrigation levels. Both L. hesperus and its predators were affected by the selectivity of the insecticide with highest L. hesperus densities and lowest predator abundance where the broad spectrum insecticide (acephate) was used. There were no direct interactions between irrigation level and insecticides, indicating that insecticide effects on L. hesperus and its predators were not influenced by the irrigation levels used here. The implications of these findings on the overall ecology of insect-plant dynamics and yield in cotton are discussed.

21 CFR 876.5895 - Ostomy irrigator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ostomy irrigator. 876.5895 Section 876.5895 Food... DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5895 Ostomy irrigator. (a) Identification. An ostomy irrigator is a device that consists of a container for fluid, tubing with a cone-shaped...

SPOT-Based Sub-Field Level Monitoring of Vegetation Cover Dynamics: A Case of Irrigated Croplands

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Olena Dubovyk

2015-05-01

Full Text Available Acquiring multi-temporal spatial information on vegetation condition at scales appropriate for site-specific agricultural management is often complicated by the need for meticulous field measurements. Understanding spatial/temporal crop cover heterogeneity within irrigated croplands may support sustainable land use, specifically in areas affected by land degradation due to secondary soil salinization. This study demonstrates the use of multi-temporal, high spatial resolution (10 m SPOT-4/5 image data in an integrated change vector analysis and spectral mixture analysis (CVA-SMA procedure. This procedure was implemented with the principal objective of mapping sub-field vegetation cover dynamics in irrigated lowland areas within the lowerlands of the Amu Darya River. CVA intensity and direction were calculated separately for the periods of 1998–2006 and 2006–2010. Cumulative change intensity and the overall directional trend were also derived for the entire observation period of 1998–2010. Results show that most of the vector changes were observed between 1998 and 2006; persistent conditions were seen within the study region during the 2006–2010 period. A decreasing vegetation cover trend was identified within 38% of arable land. Areas of decreasing vegetation cover were located principally in the irrigation system periphery where deficient water supply and low soil quality lead to substandard crop development. During the 2006–2010 timeframe, degraded crop cover conditions persisted in 37% of arable land. Vegetation cover increased in 25% of the arable land where irrigation water supply was adequate. This high sub-field crop performance spatial heterogeneity clearly indicates that current land management practices are inefficient. Such information can provide the basis for implementing and adapting irrigation applications and salt leaching techniques to site-specific conditions and thereby make a significant contribution to sustainable

Irrigation Requirement Estimation using MODIS Vegetation Indices and Inverse Biophysical Modeling; A Case Study for Oran, Algeria

Science.gov (United States)

Bounoua, L.; Imhoff, M.L.; Franks, S.

2008-01-01

Human demand for food influences the water cycle through diversion and extraction of fresh water needed to support agriculture. Future population growth and economic development alone will substantially increase water demand and much of it for agricultural uses. For many semi-arid lands, socio-economic shifts are likely to exacerbate changes in climate as a driver of future water supply and demand. For these areas in particular, where the balance between water supply and demand is fragile, variations in regional climate can have potentially predictable effect on agricultural production. Satellite data and biophysically-based models provide a powerful method to quantify the interactions between local climate, plant growth and water resource requirements. In irrigated agricultural lands, satellite observations indicate high vegetation density while the precipitation amount indicates otherwise. This inconsistency between the observed precipitation and the observed canopy leaf density triggers the possibility that the observed high leaf density is due to an alternate source of water, irrigation. We explore an inverse process approach using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), climatological data, and the NASA's Simple Biosphere model, SiB2, to quantitatively assess water demand in a semi-arid agricultural land by constraining the carbon and water cycles modeled under both equilibrium (balance between vegetation and prevailing local climate) and nonequilibrium (water added through irrigation) conditions. We postulate that the degree to which irrigated lands vary from equilibrium conditions is related to the amount of irrigation water used. We added water using two distribution methods: The first method adds water on top of the canopy and is a proxy for the traditional spray irrigation. The second method allows water to be applied directly into the soil layer and serves as proxy for drip irrigation. Our approach indicates that over

Comparison of traditional and ET-based irrigation scheduling of surface-irrigated cotton in the arid southwestern USA

Science.gov (United States)

The use of irrigation scheduling tools to produce cotton under-surface irrigation in the arid southwesternUSA is minimal. In the State of Arizona, where traditional irrigation scheduling is the norm, producersuse an average of 1460 mm annually to grow a cotton crop. The purpose of this paper was to ...

Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

International Nuclear Information System (INIS)

Antonijevic, Djordje; Milovanovic, Petar; Brajkovic, Denis; Ilic, Dragan; Hahn, Michael; Amling, Michael; Rakocevic, Zlatko; Djuric, Marija; Busse, Björn

2015-01-01

Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

Energy Technology Data Exchange (ETDEWEB)

Antonijevic, Djordje; Milovanovic, Petar [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Brajkovic, Denis [Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac (Serbia); Ilic, Dragan [Department of Restorative Medicine, School of Dental Medicine, University of Belgrade, Belgrade (Serbia); Hahn, Michael; Amling, Michael [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany); Rakocevic, Zlatko [Laboratory for Atomic Physics, Institute for Nuclear Science “Vinca”, University of Belgrade, Belgrade (Serbia); Djuric, Marija [Laboratory for Anthropology, Institute for Anatomy, Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Busse, Björn, E-mail: b.busse@uke.uni-hamburg.de [Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Lottestr. 55A, 22529 Hamburg (Germany)

2015-11-15

Graphical abstract: - Highlights: • Different irrigation solutions and disinfectants were used for treatment of root canal dentine and gutta-percha points. • Materials surface characteristics were assessed using quantitative backscattered electron imaging, reference point indentation, and contact angle analyzer. • The most significant differences in mineralization, indentation, and adhesive outcomes were observed after ethylenediaminetetraacetic acid treatment. • Irrigation solutions confer to superior sealing ability of endodontic filling materials. • Micromechanical characteristics of dentine after irrigation are considerable reduced. - Abstract: The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples’ microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

75 FR 43958 - Turlock Irrigation District and Modesto Irrigation District; Notice of Application for Amendment...

Science.gov (United States)

2010-07-27

... to the Turlock Irrigation District's Tuolumne Substation; (2) 23-mile-long, 69-kV Don Pedro-Hawkins Line extending from the Don Pedro switchyard to the Turlock Irrigation District's Hawkins Substation...

Impact of climate change on irrigation management for olive orchards at southern Spain

Science.gov (United States)

Lorite, Ignacio; Gabaldón-Leal, Clara; Santos, Cristina; Belaj, Angjelina; de la Rosa, Raul; Leon, Lorenzo; Ruiz-Ramos, Margarita

2017-04-01

The irrigation management for olive orchards under future weather conditions requires the development of advanced tools for considering specific physiological and phenological components affected by the foreseen changes in climate and atmospheric [CO2]. In this study a new simulation model named AdaptaOlive has been considered to develop controlled deficit irrigation and full irrigation scheduling for the traditional olive orchards located in Andalusia region (southern Spain) under the projected climate generated by an ensemble of 11 climate models from the ENSEMBLES European project corresponding to the SRES A1B scenario. Irrigation requirements, irrigation water productivity (IWP) and net margin (NM) were evaluated for three periods (baseline, near future and far future) and three irrigation strategies (rainfed, RF, controlled deficit irrigation, CDI, and full irrigation, FI). For irrigation requirements, a very limited average increase for far future compared with baseline period was found (2.6 and 1.3%, for CDI and FI, respectively). Equally, when IWP was analyzed, significant increases were identified for both irrigation strategies (77.4 and 72.2%, for CDI and FI, respectively) due to the high simulated increase in yield. Finally, when net margin was analyzed, the irrigation water cost had a key significance. For low water costs FI provided higher net margin values than for CDI. However, for high water costs (expected in the future due to the foreseen reduction in rainfall and the increase of the competence for the available water resources), net margin is reduced significantly, generating a very elevated number of years with negative net margin. All the described results are affected by a high level of uncertainty as the projections from the ensemble of 11 climate models show large spread. Thus, for a representative location within Andalusia region as Baeza, a reduction of irrigation requirements under full irrigation strategy was found for the ensemble mean

Measuring Transpiration to Regulate Winter Irrigation Rates

Energy Technology Data Exchange (ETDEWEB)

Samuelson, Lisa [Auburn University

2006-11-08

Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

The influence of the forerunner plant and the irrigation on some quality indicators of the wheat plant (Triticum aestivum L. in their growth conditions on the acid soils in the North-Western Romania

Directory of Open Access Journals (Sweden)

Ileana ARDELEAN

2010-05-01

Full Text Available The paper sustains the importance of the forerunner plant concerning the quality of the wheat (Triticum aestivum L. and is based on the research carried out during 2006-2008 on a long term trial placed on the brown luvic (acid soils from Oradea in 1990. In non-irrigating and irrigating conditions as well the smallest protein, wet gluten and dry gluten values were obtained in wheat mono-crop; the values increased in the forerunner plant, wheat-maize and the biggest values were registered in the forerunner plant, wheat-maize-soybean.

Management of poor quality irrigation water

International Nuclear Information System (INIS)

Change, M.H.; Leghari, A.M.; Sipio, Q.A.

2000-01-01

The effect of poor quality drainage effluent on moderately saline sodic, medium textured soil at different growth stages of wheat and cotton is reported. The irrigation treatments were: I) All canal irrigations, II) one irrigation of 75 mm with saline drainage effluent (EC = 3 dS m1) after four weeks sowing of the crop, III) one irrigation of 75 mm with saline drainage effluent after seven weeks sowing of the crop, and IV) one irrigation of 75 mm with saline drainage effluent after ten weeks sowing of the crop. The treatments receiving saline water gave significant decrease in crop yields as compared to canal irrigation treatment. The higher yield of wheat and seed cotton was recorded T1 followed by T2, T3 and T4. The trend of produce was T1< T2< T3< T4 respectively. Electrical conductivity of the soil (Ece) in T1 was decreased and in other three treatments was increased, whereas, pH decreased in T1 and T2. The SAR of soil decreased in all the treatments as compared with initial values. Treatment receiving an irrigation with saline water after four weeks of sowing (T2) was better in reducing soil salinity as compared to treatments receiving such water after 7 or 10 weeks os sowing. Poor quality water (EC = 3 d Sm/sup -1/) can be managed for irrigation after four weeks of swing of crops provided certain soil and water management practices like good seed bed preparation and proper drainage measures are adopted. (author)

Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

Science.gov (United States)

Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

2013-01-01

Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

Alfalfa Water Use and Yield under Different Sprinkler Irrigation Regimes in North Arid Regions of China

Directory of Open Access Journals (Sweden)

Yan Li

2017-08-01

Full Text Available Alfalfa (Medicago sativa is one of the major crops grown in Northern China in recent years, however, the current serious water shortage conditions present a challenge to the growth of this crop, especially if efficient use of water is considered in forage production for sustainability. This study aimed to evaluate alfalfa productivity and water use efficiency (WUE under different sprinkler irrigation levels. This experiment was conducted at Shiyanghe Experimental Station for Water-Saving in Agriculture and Ecology of China Agricultural University in Wuwei, Gansu, China, over a period of two years. There were three irrigation treatments: A1: 100% measured evapotranspiration (ETc of alfalfa; A2: irrigation amount was 66% of A1; A3: irrigation amount was 33% of A1; and a control of A4: no irrigation during the growing season. A randomized block design with three replications were applied. The results showed that the ETc and forage yield of alfalfa decreased, while WUE and crude protein (CP increased with the decreasing irrigation amounts. The seasonal average ETc and yield ranged from 412 mm to 809 mm and from 11,577 to 18,636 kg/ha, respectively, under different irrigation levels. The highest yields were obtained from the first growth period in all treatments in both years, due to the winter irrigation and the longest growth period. Alfalfa grown under lesser irrigation treatment conditions had higher variability in ETc and yield, mainly due to the variability in the amount of rainfall during the growth period. The seasonal average WUE of treatments ranged from 22.78 to 26.84 kg/(mm·ha, and the highest WUE was obtained at the first growth period, regardless of treatments. Seasonal average CP content ranged from 18.99% to 22.99%. A significant linear relationship was found between yield and ETc or irrigation amount, and the fitting results varied between growth periods and years. The present results also implied that winter irrigation provided the

Effect of Dust Deposition on Yield and Yield Components of Chickpea (Cicer arietinum L. under Rain Fed and Supplemental Irrigation Conditions in Kermanshah

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hamze felegari

2017-10-01

of poding stage and Washing at the end of vegetative and poding stages. Experiment was a randomized complete block design with three replications. The Analysis of variance using SAS softwares was performed for studied parameters. The means were compared using Duncan test at level of 0.05 probabilities. Results and Discussion Dust particles deposited on chickpea leaves resulted in the reduction of the total dry matter and seed yield. Interaction of supplemental irrigation and dust deposition on biological yield, seed yield, harvest index, number of seeds per plant, number of pods per plant and number of lateral branches were significant. The highest biological and seed yield were obtained due to the interaction of Supplemental irrigation and Control (no dust deposition with 341 and 144 g.m-2, respectively. Zia-Khan et al., (2015 reported the mean reduction of yield in the dusted treatment was about 28%, indicating that the stress conditions in this experiment were relatively severe. Chaurasi et al (2013 reported a decrease in dry matter of groundnut planted in the vicinity of a cement factory, and an increasing rate of groundnut dry matter accumulation was observed while the distance of farm and factory increased.. By cleaning the dust particles of the leaves at the end of growth and poding stages, carbon assimilation and finally grain yield slightly increased. This findings are also according to Zia-khan et al., 2014. Chouhan & Joshi (2010 reported that the growth of wheat at 0.5km distance from a Cement industry was lesser than to plants farther from the cement industry. Armbrust, (1986 Reported a decrease in dry matter accumulation after three days of dust application. Conclusions According to the results of this experiment, the drought stress and the dust deposition on leaf surfaces, cause a reduction in light absorption of leaves, reduction stomata conductance, photosynthesis and transpiration and increase leaf temperature. The results of this study show that

Soil salinity assessment through satellite thermography for different irrigated and rainfed crops

Science.gov (United States)

Ivushkin, Konstantin; Bartholomeus, Harm; Bregt, Arnold K.; Pulatov, Alim; Bui, Elisabeth N.; Wilford, John

2018-06-01

The use of canopy thermography is an innovative approach for salinity stress detection in plants. But its applicability for landscape scale studies using satellite sensors is still not well investigated. The aim of this research is to test the satellite thermography soil salinity assessment approach on a study area with different crops, grown both in irrigated and rainfed conditions, to evaluate whether the approach has general applicability. Four study areas in four different states of Australia were selected to give broad representation of different crops cultivated under irrigated and rainfed conditions. The soil salinity map was prepared by the staff of Geoscience Australia and CSIRO Land and Water and it is based on thorough soil sampling together with environmental modelling. Remote sensing data was captured by the Landsat 5 TM satellite. In the analysis we used vegetation indices and brightness temperature as an indicator for canopy temperature. Applying analysis of variance and time series we have investigated the applicability of satellite remote sensing of canopy temperature as an approach of soil salinity assessment for different crops grown under irrigated and rainfed conditions. We concluded that in all cases average canopy temperatures were significantly correlated with soil salinity of the area. This relation is valid for all investigated crops, grown both irrigated and rainfed. Nevertheless, crop type does influence the strength of the relations. In our case cotton shows only minor temperature difference compared to other vegetation classes. The strongest relations between canopy temperature and soil salinity were observed at the moment of a maximum green biomass of the crops which is thus considered to be the best time for application of the approach.

Uncertainties in modelling the climate impact of irrigation

Science.gov (United States)

de Vrese, Philipp; Hagemann, Stefan

2017-11-01

Irrigation-based agriculture constitutes an essential factor for food security as well as fresh water resources and has a distinct impact on regional and global climate. Many issues related to irrigation's climate impact are addressed in studies that apply a wide range of models. These involve substantial uncertainties related to differences in the model's structure and its parametrizations on the one hand and the need for simplifying assumptions for the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In order to estimate possible uncertainties with regard to the model's more general structure, we compared the climate impact of irrigation between three simulations that use different schemes for the land-surface-atmosphere coupling. Here, it can be shown that the choice of coupling scheme does not only affect the magnitude of possible impacts but even their direction. For example, when using a scheme that does not explicitly resolve spatial subgrid scale heterogeneity at the surface, irrigation reduces the atmospheric water content, even in heavily irrigated regions. Contrarily, in simulations that use a coupling scheme that resolves heterogeneity at the surface or even within the lowest layers of the atmosphere, irrigation increases the average atmospheric specific humidity. A second experiment targeted possible uncertainties related to the representation of irrigation characteristics. Here, in four simulations the irrigation effectiveness (controlled by the target soil moisture and the non-vegetated fraction of the grid box that receives irrigation) and the timing of delivery were varied. The second experiment shows that uncertainties related to the modelled irrigation characteristics, especially the irrigation effectiveness, are also substantial. In general the impact of irrigation on the state of the land

Comparison of positive-pressure, passive ultrasonic, and laser-activated irrigations on smear-layer removal from the root canal surface.

Science.gov (United States)

Sahar-Helft, Sharonit; Sarp, Ayşe Sena Kabaş; Stabholtz, Adam; Gutkin, Vitaly; Redenski, Idan; Steinberg, Doron

2015-03-01

The purpose of this study was to compare the efficacy of three irrigation techniques for smear-layer removal with 17% EDTA. Cleaning and shaping the root canal system during endodontic treatment produces a smear layer and hard tissue debris. Three irrigation techniques were tested for solution infiltration of this layer: positive-pressure irrigation, passive ultrasonic irrigation, and laser-activated irrigation. Sixty extracted teeth were divided into six equal groups; 17% EDTA was used for 60 sec irrigation of five of the groups. The groups were as follows: Group 1, treated only with ProTaper™ F3 Ni-Ti files; Group 2, positive-pressure irrigation, with a syringe; Group 3, passive ultrasonic irrigation, inserted 1 mm short of the working length; Group 4, passive ultrasonic irrigation, inserted in the upper coronal third of the root; Group 5, Er:YAG laser-activated irrigation, inserted 1 mm short of the working length; and Group 6, Er:YAG laser-activated irrigation, inserted in the upper coronal third of the root. Scanning electron microscopy showed that the smear layer is removed most efficiently using laser-activated irrigation at low energy with 17% EDTA, inserted either at the working length or only in the coronal upper third of the root. Amounts of Ca, P, and O were not significantly different on all treated dentin surfaces. Smear-layer removal was most effective when the root canals were irrigated using Er:YAG laser at low energy with 17% EDTA solution. Interestingly, removal of the smear layer along the entire canal was similar when the laser was inserted in the upper coronal third and at 1 mm short of the working length of the root canal. This effect was not observed with the ultrasonic and positive-pressure techniques.

Application of electron beam technology in improving sewage water ...

African Journals Online (AJOL)

user

irradiation sewage water can find its application either in agriculture for irrigation or in industry sector for cooling ... The water samples were collected from sewage water treatment .... to be irrigated, soil conditions and the irrigation system.

Simulation of Crop Growth and Water-Saving Irrigation Scenarios for Lettuce: A Monsoon-Climate Case Study in Kampong Chhnang, Cambodia

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Pinnara Ket

2018-05-01

Full Text Available Setting up water-saving irrigation strategies is a major challenge farmers face, in order to adapt to climate change and to improve water-use efficiency in crop productions. Currently, the production of vegetables, such as lettuce, poses a greater challenge in managing effective water irrigation, due to their sensitivity to water shortage. Crop growth models, such as AquaCrop, play an important role in exploring and providing effective irrigation strategies under various environmental conditions. The objectives of this study were (i to parameterise the AquaCrop model for lettuce (Lactuca sativa var. crispa L. using data from farmers’ fields in Cambodia, and (ii to assess the impact of two distinct full and deficit irrigation scenarios in silico, using AquaCrop, under two contrasting soil types in the Cambodian climate. Field observations of biomass and canopy cover during the growing season of 2017 were used to adjust the crop growth parameters of the model. The results confirmed the ability of AquaCrop to correctly simulate lettuce growth. The irrigation scenario analysis suggested that deficit irrigation is a “silver bullet” water saving strategy that can save 20–60% of water compared to full irrigation scenarios in the conditions of this study.

Evaluation of Modern Irrigation Techniques with Brackish Water

OpenAIRE

Aboulila, Tarek Selim

2012-01-01

Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. Furthermore, by using drip irrigation simultaneously with brackish irrigation water, some of the water stress due to shortage of fresh water resources can be managed. The objective of the current study was to investigate the infl...

HEAVY METALS AND MICRONUTRIENTS IN THE SOIL AND GRAPEVINE UNDER DIFFERENT IRRIGATION STRATEGIES

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Vanessa de Souza Oliveira

2015-02-01

Full Text Available Soils under natural conditions have heavy metals in variable concentrations and there may be an increase in these elements as a result of the agricultural practices adopted. Transport of heavy metals in soil mainly occurs in forms dissolved in the soil solution or associated with solid particles, water being their main means of transport. In this context, the aim of this study was to evaluate the heavy metal and micronutrient content in the soil and in the grapevine plant and fruit under different irrigation strategies. The experiment was carried out in Petrolina, PE, Brazil. The treatments consisted of three irrigation strategies: full irrigation (FI, regulated deficit irrigation (RDI, and deficit irrigation (DI. During the period of grape maturation, soil samples were collected at the depths of 0-10, 10-20, 20-40, 40-60, and 60-80 cm. In addition, leaves were collected at the time of ripening of the bunches, and berries were collected at harvest. Thus, the heavy metal and micronutrient contents were determined in the soil, leaves, and berries. The heavy metal and micronutrient contents in the soil showed a stochastic pattern in relation to the different irrigation strategies. The different irrigation strategies did not affect the heavy metal and micronutrient contents in the vine leaves, and they were below the contents considered toxic to the plant. In contrast, the greater availability of water in the FI treatment favored a greater Cu content in the grape, which may be a risk to vines, causing instability and turbidity. Thus, adoption of deficit irrigation is recommended so as to avoid compromising the stability of tropical wines of the Brazilian Northeast.

Actual and potential salt-related soil degradation in an irrigated rice scheme in the Sahelian zone of Mauritania

NARCIS (Netherlands)

Asten, van P.J.A.; Barbi'ro, L.; Wopereis, M.C.S.; Maeght, J.L.; Zee, van der S.E.A.T.M.

2003-01-01

Salt-related soil degradation due to irrigation activities is considered a major threat to the sustainability of rice cropping under semi-arid conditions in West Africa. Rice productivity problems related to soil salinity, alkalinity and topographic position were observed in an irrigated rice scheme

Effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin

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Flávia Emi Razera BALDASSO

2017-05-01

Full Text Available Abstract This study aimed to evaluate the effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin. Sixty root canals from mandibular incisors were instrumented and randomly divided into six groups (n = 10 according to the irrigant used: QMiX, 17% EDTA, 10% citric acid (CA, 1% peracetic acid (PA, 2.5% NaOCl (solution control, and distilled water (negative control. The chelating solutions were used to irrigate the canal followed by 2.5% NaOCl as a final flush. After the irrigation protocols, all specimens were rinsed with 10 mL of distilled water to remove any residue of the chemical solutions. Before and after the final irrigation protocols, dentin microhardness was measured with a Knoop indenter. Three indentations were made at 100 µm and 500 µm from the root canal lumen. Afterwards, the specimens were prepared for scanning electron microscopic analysis and the amount of dentin erosion was examined. Wilcoxon and Kruskal-Wallis tests were used to analyze the results with a significance level set at 5%. At 100 µm, all protocols significantly reduced dentin microhardness (p < .05, while at 500 µm, this effect was detected only in the EDTA and QMiX groups (p < .05. CA was the irrigant that caused more extensive erosion in dentinal tubules, followed by PA and EDTA. QMiX opened dentinal tubules, but did not cause dentin erosion. Results suggest that QMiX and 17% EDTA reduced dentin microhardness at a greater depth. Additionally, QMiX did not cause dentin erosion.

Optimization of modern irrigation for biosaline agriculture

International Nuclear Information System (INIS)

Shahid, S.A.; Hasbini, B.

2007-01-01

Supplementation water is a must to offset the water requirement to produce profitable crops in most arid and semiarid zones, where fresh water resources are insufficient to meet the pressure of irrigated agriculture. This necessitates the use of poor quality water resources. These waters if not properly managed and used can cause serious soil related problems (salinity, sodicity, destruction of soil structure) in addition to decline in crop yields. Biosaline agriculture (using saline water on saline soils to grow salt-tolerant crops) becomes the only option for the farmer when both soil and water resources are saline and the water resource is scarce. In this regards key design considerations must be taken into account when irrigating with salty waters to optimize water uses and to reduce subsequent soil salinity development. Sprinkler irrigation systems are commonly used in irrigation of large-scale irrigational production systems. However they tend to concentrate salts on the leaves of plants. For this reason discharge and degree of overlap between consecutive sprinkler heads, are key design parameters when applying salty waters. Trickle irrigation is the most efficient system and is gaining importance in the GCC countries in the agriculture and landscape irrigation. The objective of this study was to optimize modern irrigation systems through development of design standards for drip (emitters spacing) and sprinkler irrigation systems (single head jet and overlapping) by applying saline water. The effect of emitter spacing (drip) and overlapping (sprinkler) were tested for the formation of salt contours in soil. The leaching ratio (LR) is the overall soil sanity within rhizosphere divided by the average irrigation water salinity. In this study LR is used to evaluate the effectiveness of irrigation systems in developing soil sanity. From the present investigations it is concluded that when using saline water for irrigation, the soil sanity development can be

Ancestral irrigation method by kanis in Bolivia

Science.gov (United States)

Roldán-Cañas, José; Chipana, René; Fátima Moreno-Pérez, María

2015-04-01

Irrigation in the Andean region is an ancient practice. For centuries, farmers were able to use the waters of rivers, lakes and springs to complement or supplement the scarce rainfall regime. The inter-Andean valleys of the Department of La Paz are the best areas for the study of traditional irrigation systems. This work has been carried out in the community of Jatichulaya located in te town of Charazani, 300 km from the city of La Paz, which lies 3250 meters above sea level. The annual rainfall ranges around 450 mm distributed mainly between the months of December to March. Therefore, water is needed to achieve adequate crop yields. The traditional irrigation system is done by the method of Kanis, consisting of a surface irrigation already developed by traditional Andean cultures of the country, in harmony with the ecological and productive characteristics of the area. Water enters the irrigation plot through a main channel (mama kani) from which the secondary channels (juchuy kanis) are derived. The fundamental characteristic of this irrigation is that these channels are open at the same time the water enters into the plot. The system works properly, adapting to the topography of the area. The irrigation method practiced in this community does not cause water erosion of soils because water management within the plot is based on the ancient knowledge of farmers following the contour lines. This practice allows good irrigation development and soil protection without causing any problems. However, it was evident a high use of labor in irrigation practice. Irrigation scheduling is done according to requests made by the irrigators in a given period. Delivering of water to the farmers is made by the so-called Water Agent (Agente de Aguas) or person in charge of the distribution of water. The Water Agent is elected annually and its functions include the maintenance and care of all system waterworks. The period between August and January is the highest water demand and

GSM BASED IRRIGATION CONTROL AND MONITORING SYSTEM

OpenAIRE

GODFREY A. MILLS; STEPHEN K. ARMOO; AGYEMAN K. ROCKSON; ROBERT A. SOWAH; MOSES A. ACQUAH

2013-01-01

Irrigated agriculture is one of the primary water consumers in most parts of the world. With developments in technology, efforts are being channeled into automation of irrigation systems to facilitate remote control of the irrigation system and optimize crop production and cost effectiveness. This paper describes an on-going work on GSM based irrigation monitoring and control systems. The objective of the work is to provide an approach that helps farmers to easily access, manage and regulate ...

Comparative efficiency of trickle and furrow irrigation

International Nuclear Information System (INIS)

Hanif, M.; Qureshi, R.H.; Sandhu, G.R.

1976-01-01

Comparison of furrow and trickle methods of irrigation to know their relative efficiency with respect to water applied and fertilizer used on tomatoes, cauliflower and lettuce as test crops using canal water, showed a significant saving of about 44 and 41 per cent respectively for irrigation water and fertilizer applied with trickle as compared to furrow irrigation. Trickle irrigated crops also showed a better response as regards the rate of survival, crop growth and time of maturity

Mitigating global warming potentials of methane and nitrous oxide gases from rice paddies under different irrigation regimes.

Science.gov (United States)

Ali, Muhammad Aslam; Hoque, M Anamul; Kim, Pil Joo

2013-04-01

A field experiment was conducted in Bangladesh Agricultural University Farm to investigate the mitigating effects of soil amendments such as calcium carbide, calcium silicate, phosphogypsum, and biochar with urea fertilizer on global warming potentials (GWPs) of methane (CH4) and nitrous oxide (N2O) gases during rice cultivation under continuous and intermittent irrigations. Among the amendments phosphogypsum and silicate fertilizer, being potential source of electron acceptors, decreased maximum level of seasonal CH4 flux by 25-27 % and 32-38 % in continuous and intermittent irrigations, respectively. Biochar and calcium carbide amendments, acting as nitrification inhibitors, decreased N2O emissions by 36-40 % and 26-30 % under continuous and intermittent irrigations, respectively. The total GWP of CH4 and N2O gases were decreased by 7-27 % and 6-34 % with calcium carbide, phosphogypsum, and silicate fertilizer amendments under continuous and intermittent irrigations, respectively. However, biochar amendments increased overall GWP of CH4 and N2O gases.

EVALUATION OF RADIONUCLIDE ACCUMULATION IN SOIL DUE TO LONG-TERM IRRIGATION

International Nuclear Information System (INIS)

De Wesley Wu

2006-01-01

Radionuclide accumulation in soil due to long-term irrigation is an important part of the model for predicting radiation dose in a long period of time. The model usually assumes an equilibrium condition in soil with a constant irrigation rate, so that radionuclide concentration in soil does not change with time and can be analytically solved. This method is currently being used for the dose assessment in the Yucca Mountain project, which requires evaluating radiation dose for a period of 10,000 years. There are several issues associated with the method: (1) time required for the equilibrium condition, (2) validity of constant irrigation rate, (3) agricultural land use for a long period of time, and (4) variation of a radionuclide concentration in water. These issues are evaluated using a numerical method with a simple model built in the GoldSim software. Some key radionuclides, Tc-99, Np-237, Pu-239, and Am-241 are selected as representative radionuclides. The results indicate that the equilibrium model is acceptable except for a radionuclide that requires long time to accumulate in soil and that its concentration in water changes dramatically with time (i.e. a sharp peak). Then the calculated dose for that radionuclide could be overestimated using the current equilibrium method

Analysis of water footprints of rainfed and irrigated crops in Sudan

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Shamseddin Musa Ahmed

2011-12-01

Full Text Available Water rather than land is the limiting factor for crop production in Sudan. This study attempts to use the water footprint (WFP and virtual water concepts to account for crops water consumption under the Sudanese rainfed and irrigated conditions. The general average of the green WFP of sorghum and millet were found to be about 7700 and 10700 m3 ton-1, respectively. According to experimental results at three different climates, in-situ rainwater harvesting techniques could reduce the WFP of rainfed sorghum by 56% on the average. The blue component (surface water shows the highest contribution to the total WFP of irrigated crops: 88% for cotton, 70% for sorghum, 68% for groundnut and 100% for wheat. However, the role of the green water (rainwater is not marginal since it largely influences the operation and maintenance (silt clearance of the gravity-fed irrigation system. Under normal conditions, the annual total virtual water demand of sorghum (the dominant food crop in Sudan is found to be 15 km3, of which 91% is green water. During a dry year, however, Sudan could experience a deficit of 2.3 km3 of water, necessitating the adoption of a wise food stocking-exporting policy.

Energy performance of sprinkler irrigated maize, wheat and sunflower in Vigia irrigation district

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Sandra; Rodrigues, Goncalo Caleia; Paredes, Paula; Pereira, Luis S. [Centro de Engenharia dos Biossistemas (CEER/ISA), Lisboa (Portugal)], E-mail: lspereira@isa.utl.pt

2008-07-01

The energy potential of a crop may be evaluated through life cycle assessment methodologies. These refer to the computation of the crop's energy balance and other related indicators, such as the energy ratio and the energetic efficiency, that may be used as to assess how a given irrigated crop may be used for production of biofuel. This study concerns sprinkler irrigated sunflower, wheat and maize crops using data relative to the campaign of 2007 in the Vigia Irrigation District, Alentejo. A model was developed and various scenarios were considered. The modelling results lead to the conclusion that the maize crop is the most efficient in producing energy and sunflower is the least one for all the alternative scenarios considered. (author)

Representing Farmer Irrigation Decisions in Northern India: Model Development from the Bottom Up.

Science.gov (United States)

O'Keeffe, J.; Buytaert, W.; Brozovic, N.; Mijic, A.

2017-12-01

The plains of northern India are among the most intensely populated and irrigated regions of the world. Sustaining water demand has been made possible by exploiting the vast and hugely productive aquifers underlying the Indo-Gangetic basin. However, an increasing demand from a growing population and highly variable socio-economic and environmental variables mean present resources may not be sustainable, resulting in water security becoming one of India's biggest challenges. Unless solutions which take into consideration the regions evolving anthropogenic and environmental conditions are found, the sustainability of India's water resources looks bleak. Understanding water user decisions and their potential outcome is important for development of suitable water resource management options. Computational models are commonly used to assist water use decision making, typically representing natural processes well. The inclusion of human decision making however, one of the dominant drivers of change, has lagged behind. Improved representation of irrigation water user behaviour within models provides more accurate, relevant information for irrigation management. This research conceptualizes and proceduralizes observed farmer irrigation practices, highlighting feedbacks between the environment and livelihood. It is developed using a bottom up approach, informed through field experience and stakeholder interaction in Uttar Pradesh, northern India. Real world insights are incorporated through collected information creating a realistic representation of field conditions, providing a useful tool for policy analysis and water management. The modelling framework is applied to four districts. Results suggest predicted future climate will have little direct impact on water resources, crop yields or farmer income. In addition, increased abstraction may be sustainable in some areas under carefully managed conditions. By simulating dynamic decision making, feedbacks and interactions

Scenario Studies on Effects of Soil Infiltration Rates, Land Slope, and Furrow Irrigation Characteristics on Furrow Irrigation-Induced Erosion.

Science.gov (United States)

Dibal, Jibrin M; Ramalan, A A; Mudiare, O J; Igbadun, H E

2014-01-01

Furrow irrigation proceeds under several soil-water-furrow hydraulics interaction dynamics. The soil erosion consequences from such interactions in furrow irrigation in Samaru had remained uncertain. A furrow irrigation-induced erosion (FIIE) model was used to simulate the potential severity of soil erosion in irrigated furrows due to interactive effects of infiltration rates, land slope, and some furrow irrigation characteristics under different scenarios. The furrow irrigation characteristics considered were furrow lengths, widths, and stream sizes. The model itself was developed using the dimensional analysis approach. The scenarios studied were the interactive effects of furrow lengths, furrow widths, and slopes steepness; infiltration rates and furrow lengths; and stream sizes, furrow lengths, and slopes steepness on potential furrow irrigation-induced erosion, respectively. The severity of FIIE was found to relate somewhat linearly with slope and stream size, and inversely with furrow lengths and furrow width. The worst soil erosion (378.05 t/ha/yr) was found as a result of the interactive effects of 0.65 m furrow width, 50 m furrow length, and 0.25% slope steepness; and the least soil erosion (0.013 t/ha/yr) was induced by the combined effects of 0.5 l/s, 200 m furrow length, and 0.05% slope steepness. Evidently considering longer furrows in furrow irrigation designs would be a better alternative of averting excessive FIIE.

Irrigation management in organic greenhouse

NARCIS (Netherlands)

Voogt, W.; Balendonck, J.; Berkelmans, R.; Enthoven, N.

2017-01-01

Irrigation in protected cultivation is essential due to the absence of natural precipitation. High evapotranspiration, due to higher temperature and prolonged cropping period, requires ample an adequate supply of water. The water supply in a greenhouse is solely carried out by irrigation and thus

[Optimal irrigation index for cotton drip irrigation under film mulching based on the evaporation from pan with constant water level].

Science.gov (United States)

Shen, Xiao-Jun; Zhang, Ji-Yang; Sun, Jing-Sheng; Gao, Yang; Li, Ming-Si; Liu, Hao; Yang, Gui-Sen

2013-11-01

A field experiment with two irrigation cycles and two irrigating water quotas at squaring stage and blossoming-boll forming stage was conducted in Urumqi of Xinjiang Autonomous Region, Northwest China in 2008-2009, aimed to explore the high-efficient irrigation index of cotton drip irrigation under film mulching. The effects of different water treatments on the seed yield, water consumption, and water use efficiency (WUE) of cotton were analyzed. In all treatments, there was a high correlation between the cotton water use and the evaporation from pan installed above the plant canopy. In high-yield cotton field (including the treatment T4 which had 10 days and 7 days of irrigation cycle with 30.0 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2008, and the treatment T1 having 7 days of irrigation cycle with 22.5 mm and 37.5 mm of irrigating water quota at squaring stage and blossoming-boll forming stage, respectively in 2009), the pan-crop coefficient (Kp) at seedling stage, squaring stage, blossoming-boll forming stage, and boll opening stage was 0.29-0.30, 0.52-0.53, 0.74-0.88, and 0.19-0.20, respectively. As compared with the other treatments, T4 had the highest seed cotton yield (5060 kg x hm(-2)) and the highest WUE (1.00 kg x m(-3)) in 2008, whereas T1 had the highest seed cotton yield (4467 kg x hm(-2)) and the highest WUE (0.99 kg x m(-3)) in 2009. The averaged cumulative pan evaporation in 7 days and 10 days at squaring stage was 40-50 mm and 60-70 mm, respectively, and that in 7 days at blossoming-boll forming stage was 40-50 mm. It was suggested that in Xinjiang cotton area, irrigating 45 mm water for seedling emergence, no irrigation both at seedling stage and at boll opening stage, and irrigation was started when the pan evaporation reached 45-65 mm and 45 mm at squaring stage and blossoming-boll stage, respectively, the irrigating water quota could be determined by multiplying cumulative

Effects of deficit irrigation on yield and yield components of ...

African Journals Online (AJOL)

Vegetable soybeans [Glycine max L (Merr.)] are very sensitive crops to environmental conditions during their growth stages, especially in term of water scarcity. Water scarcity is one of the major environmental factors influencing sustainable agricultural production in arid and semi-arid regions. Careful management irrigation ...

performance evaluation of sprinkler irrigation system at mambilla

African Journals Online (AJOL)

HOD

ratio (DPR), irrigation productivity (IP), labour requirements and water quality. Standard procedure was ... The exchangeable cations analysis of Kakara irrigation ... Keywords: Tea, irrigation System, Performance Evaluation. 1. INTRODUCTION.

Expanding the Annual Irrigation Maps (AIM) Product to the entire High Plains Aquifer (HPA): Addressing the Challenges of Cotton and Deficit-Irrigated Fields

Science.gov (United States)

Rapp, J. R.; Deines, J. M.; Kendall, A. D.; Hyndman, D. W.

2017-12-01

The High Plains Aquifer (HPA) is the most extensively irrigated aquifer in the continental United States and is the largest major aquifer in North America with an area of 500,000 km2. Increased demand for agricultural products has led to expanded irrigation extent, but brought with it declining groundwater levels that have made irrigation unsustainable in some locations. Understanding these irrigation dynamics and mapping irrigated areas through time are essential for future sustainable agricultural practices and hydrological modeling. Map products using remote sensing have only recently been able to track annual dynamics at relatively high spatial resolution (30 m) for a large portion of the northern HPA. However follow-on efforts to expand these maps to the entire HPA have met with difficulty due to the challenge of distinguishing irrigation in crop types that are commonly deficit- or partially-irrigated. Expanding these maps to the full HPA requires addressing unique features of partially irrigated fields and irrigated cotton, a major water user in the southern HPA. Working in Google Earth Engine, we used all available Landsat imagery to generate annual time series of vegetation indices. We combined this information with climate covariables, planting dates, and crop specific training data to algorithmically separate fully irrigated, partially irrigated, and non-irrigated field locations. The classification scheme was then applied to produce annual maps of irrigation across the entire HPA. The extensive use of ancillary data and the "greenness" time series for the algorithmic classification generally increased accuracy relative to previous efforts. High-accuracy, representative map products of irrigation extent capable of detecting crop type and irrigation intensity within aquifers will be an essential tool to monitor the sustainability of global aquifers and to provide a scientific bases for political and economic decisions affecting those aquifers.

Managing Water Resources for Environmentally Sustainable Irrigated Agriculture in Pakistan

OpenAIRE

Muhammad Afzal

1996-01-01

Pakistan’s agriculture is almost wholly dependent on irrigation and irrigated land supplies more than 90 percent of agricultural production. Irrigation is central to Pakistan’s economy. Massive investments in irrigation contributed to the development of one of the largest Indus Basin Irrigation System. Despite heavy budgetary inputs in irrigation system, it is facing shortage of resources and suffering from operational problems. The sustainability of irrigated agriculture is threatened due to...

Microbial quality of irrigation water used in leafy green production in Southern Brazil and its relationship with produce safety.

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Decol, Luana Tombini; Casarin, Letícia Sopeña; Hessel, Claudia Titze; Batista, Ana Carolina Fösch; Allende, Ana; Tondo, Eduardo César

2017-08-01

Irrigation water has been recognized as an important microbial risk factor for fruits and vegetables in many production areas, but there is still a lack of information about how the microbiological quality of different irrigation water sources and climatic conditions influence the safety of vegetables produced in Brazil. This study evaluated the distribution of generic E. coli and the prevalence of E. coli O157:H7 in two different water sources (ponds and streams bordering farmlands and urban areas) used for irrigation and on commercially produced lettuces in Southern Brazil. We also evaluated the effect of agricultural factors and meteorological conditions in the potential contamination of water and produce samples. A longitudinal study was conducted on four farms during a year (July 2014 to August 2015). The results showed generic E. coli prevalence of 84.8% and 38.3% in irrigation water samples and on lettuces, respectively, indicating irrigation water as an important source of contamination of lettuces. No significant differences were detected in the counts of E. coli between the two different surface water sources. The climatic conditions, particularly rainfall and environmental temperature, have influenced the high concentration of E. coli. The highest loads of E. coli in irrigation water and on lettuces were found during the warmest time of the year. E. coli O157:H7 was detected by qualitative polymerase chain reaction (qPCR) in 13 water samples but only 4 were confirmed by isolation in culture media. Copyright © 2017 Elsevier Ltd. All rights reserved.

Water Use and Crop Coefficients in Sprinkler Irrigated Rice

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Antonino Spanu

Full Text Available Field experiments were carried out during the years 2002, 2004, 2005 and 2006 to analyze water-soil-atmosphere interactions in sprinkler irrigated rice. The research was carried out in Sardinia (39º 59’ N; 8º 40’ E, at altitude 15 m. The cultivars used in the experiments, respectively in 2002 and in 2004-2005-2006, were Irat 212 and Eurosis. In each year cultivars were subjected to the same crop management. Irrigation was applied since the emergence with the sprinkler method, taking into account the loss of water from ‘Class A’ pan evaporation. Soil water content was monitored at 0.10 m intervals until 1.00-m depth using a ‘Diviner 2000’ (Sentek. In 2002 seven irrigation scheduling treatments were compared. In 2004, 2005, 2006 irrigation treatments provided for optimal soil water conditions during the growing season. In 2002 the results highlighted: 1 0-0.20 m depth was the most important layer for crop water uptake and the best correlated layer with rice rough yield; 2 the positive relationship between yield and water supply was significant until 6500 m3 ha-1 of water applied. Further seasonal irrigation volumes did not increase significantly yield. In 2004, 2005 and 2006 the analysis of the soil water balance at different crop phenological stages allowed to estimate crop coefficients (Kc using the Penman-Monteith equation and the ‘Class A’ pan evaporation (Kcev. Kc varied over the three-year period on average from 0.90 to 1.07 and 0.97, respectively for the emergence-end of tillering, end of tillering-heading and heading-maturing periods, while crop coefficients as a ratio between maximum crop evapotranspiration (ETc and Epan, Kcev ranged from 0.78 to 0.92 and 0.81 for the same time periods.

Humidity Buildup in Electronic Enclosures Exposed to Constant Conditions

DEFF Research Database (Denmark)

Conseil, Helene; Staliulionis, Zygimantas; Jellesen, Morten Stendahl

2017-01-01

Electronic components and devices are exposed to a wide variety of climatic conditions, therefore the protection of electronic devices from humidity is becoming a critical factor in the system design. The ingress of moisture into typical electronic enclosures has been studied with defined paramet....... The moisture buildup inside the enclosure has been simulated using an equivalent RC circuit consisting of variables like controlled resistors and capacitors to describe the diffusivity, permeability, and storage in polymers....

An improved delivery system for bladder irrigation.

Science.gov (United States)

Moslemi, Mohammad K; Rajaei, Mojtaba

2010-10-05

Occasionally, urologists may see patients requiring temporary bladder irrigation at hospitals without stocks of specialist irrigation apparatus. One option is to transfer the patient to a urology ward, but often there are outstanding medical issues that require continued specialist input. Here, we describe an improved system for delivering temporary bladder irrigation by utilizing readily available components and the novel modification of a sphygmomanometer blub. This option is good for bladder irrigation in patients with moderate or severe gross hematuria due to various causes. In this prospective study from March 2007 to April 2009, we used our new system in eligible cases. In this system, an irrigant bag with 1 L of normal saline was suspended 80 cm above the indwelled 3-way Foley catheter, and its drainage tube was inserted into the irrigant port of the catheter. To increase the flow rate of the irrigant system, we inserted a traditional sphygmomanometer bulb at the top of the irrigant bag. This closed system was used for continuous bladder irrigation (CBI) in patients who underwent open prostatectomy, transurethral resection of the prostate (TURP), or transurethral resection of the bladder (TURB). This high-pressure system is also used for irrigation during cystourethroscopy, internal urethrotomy, and transurethral lithotripsy. Our 831 eligible cases were divided into two groups: group 1 were endourologic cases and group 2 were open prostatectomy, TURP, and TURB cases. The maximum and average flow rates were evaluated. The efficacy of our new system was compared prospectively with the previous traditional system used in 545 cases. In group 1, we had clear vision at the time of endourologic procedures. The success rate of this system was 99.5%. In group 2, the incidence of clot retention decreased two fold in comparison to traditional gravity-dependent bladder flow system. These changes were statistically significant (P = 0.001). We did not observe any adverse

Irrigation effects on soil attributes and grapevine performance in a 'Godello' vineyard of NW Spain

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Fandiño, María; Trigo-Córdoba, Emiliano; Martínez, Emma M.; Bouzas-Cid, Yolanda; Rey, Benjamín J.; Cancela, Javier J.; Mirás-Avalos, Jose M.

2014-05-01

Irrigation systems are increasingly being used in Galician vineyards. However, a lack of information about irrigation management can cause a bad use of these systems and, consequently, reductions in berry quality and loss of water resources. In this context, experiences with Galician cultivars may provide useful information. A field experiment was carried out over two seasons (2012-2013) on Vitis vinifera (L.) cv. 'Godello' in order to assess the effects of irrigation on soil attributes, grapevine performance and berry composition. The field site was a commercial vineyard located in A Rúa (Ourense-NW Spain). Rain-fed vines (R) were compared with two irrigation systems: surface drip irrigation (DI) and subsurface drip irrigation (SDI). Physical and chemical characteristics of soil were analyzed after installing irrigation systems at the beginning of each season, in order to assess the effects that irrigation might have on soil attributes. Soil water content, leaf and stem water potentials and stomatal conductance were periodically measured over the two seasons. Yield components including number of clusters, yield per plant and cluster average weight were taken. Soluble solids, pH, total acidity and amino acids contents were measured on the grapes at harvest. Pruning weight was also recorded. Soil attributes did not significantly vary due to the irrigation treatments. Stem water potentials were significantly lower for R plants on certain dates through the season, whereas stomatal conductance was similar for the three treatments in 2013, while in 2012 SDI plants showed greater stomatal conductance values. SDI plants yielded more than those R due to both a greater number of clusters per plant and to heavier clusters. Pruning weight was significantly higher in SI plants. Berry composition was similar for the three treatments except for the amino acids content, which was higher under SDI conditions. These results may be helpful for a sustainable management of irrigation

Review of root canal irrigant delivery techniques and devices

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Yeon-Jee Yoo

2011-05-01

Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

Adaptive Effectiveness of Irrigated Area Expansion in Mitigating the Impacts of Climate Change on Crop Yields in Northern China

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Tianyi Zhang

2017-05-01

Full Text Available To improve adaptive capacity and further strengthen the role of irrigation in mitigating climate change impacts, the Chinese government has planned to expand irrigated areas by 4.4% by the 2030s. Examining the adaptive potential of irrigated area expansion under climate change is therefore critical. Here, we assess the effects of irrigated area expansion on crop yields based on county-level data during 1980–2011 in northern China and estimate climate impacts under irrigated area scenarios in the 2030s. Based on regression analysis, there is a statistically significant effect of irrigated area expansion on reducing negative climate impacts. More irrigated areas indicate less heat and drought impacts. Irrigated area expansion will alleviate yield reduction by 0.7–0.8% in the future but associated yield benefits will still not compensate for greater adverse climate impacts. Yields are estimated to decrease by 4.0–6.5% under future climate conditions when an additional 4.4% of irrigated area is established, and no fundamental yield increase with an even further 10% or 15% expansion of irrigated area is predicted. This finding suggests that expected adverse climate change risks in the 2030s cannot be mitigated by expanding irrigated areas. A combination of this and other adaptation programs is needed to guarantee grain production under more serious drought stresses in the future.

Irrigation management strategies to improve Water Use Efficiency of potatoes crop in Central Tunisia

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Ghazouani, Hiba; Provenzano, Giuseppe; Rallo, Giovanni; Mguidiche, Amel; Douh, Boutheina; Boujelben, Abdelhamid

2015-04-01

watering, with timing ranging between one and three hours in T1, and between about half-an-hour and one-hour and a-half, in T2. The validity of Hydrus-2D model was initially assessed based on the comparison between measured and estimated soil water content at different distances from the emitter (RMSE values were not higher than 0.036). Then, model simulations allowed to verify that it is possible to enhance irrigation water use efficiency by increasing the frequency of irrigation even maintaining limited water deficit conditions during the full development stage subsequent the crop tuberization. Experimental results, joined to model simulations can therefore provide useful guidelines for a more sustainable use of irrigation water in countries characterised by semi-arid environments and limited availability of water resources.

Size and stochasticity in irrigated social-ecological systems

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Puy, Arnald; Muneepeerakul, Rachata; Balbo, Andrea L.

2017-03-01

This paper presents a systematic study of the relation between the size of irrigation systems and the management of uncertainty. We specifically focus on studying, through a stylized theoretical model, how stochasticity in water availability and taxation interacts with the stochastic behavior of the population within irrigation systems. Our results indicate the existence of two key population thresholds for the sustainability of any irrigation system: or the critical population size required to keep the irrigation system operative, and N* or the population threshold at which the incentive to work inside the irrigation system equals the incentives to work elsewhere. Crossing irretrievably leads to system collapse. N* is the population level with a sub-optimal per capita payoff towards which irrigation systems tend to gravitate. When subjected to strong stochasticity in water availability or taxation, irrigation systems might suffer sharp population drops and irreversibly disintegrate into a system collapse, via a mechanism we dub ‘collapse trap’. Our conceptual study establishes the basis for further work aiming at appraising the dynamics between size and stochasticity in irrigation systems, whose understanding is key for devising mitigation and adaptation measures to ensure their sustainability in the face of increasing and inevitable uncertainty.

Assessing the Efficacy of the SWAT Auto-Irrigation Function to Simulate Irrigation, Evapotranspiration, and Crop Response to Management Strategies of the Texas High Plains

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Yong Chen

2017-07-01

Full Text Available In the semi-arid Texas High Plains, the underlying Ogallala Aquifer is experiencing continuing decline due to long-term pumping for irrigation with limited recharge. Accurate simulation of irrigation and other associated water balance components are critical for meaningful evaluation of the effects of irrigation management strategies. Modelers often employ auto-irrigation functions within models such as the Soil and Water Assessment Tool (SWAT. However, some studies have raised concerns as to whether the function is able to adequately simulate representative irrigation practices. In this study, observations of climate, irrigation, evapotranspiration (ET, leaf area index (LAI, and crop yield derived from an irrigated lysimeter field at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas were used to evaluate the efficacy of the SWAT auto-irrigation functions. Results indicated good agreement between simulated and observed daily ET during both model calibration (2001–2005 and validation (2006–2010 periods for the baseline scenario (Nash-Sutcliffe efficiency; NSE ≥ 0.80. The auto-irrigation scenarios resulted in reasonable ET simulations under all the thresholds of soil water deficit (SWD triggers as indicated by NSE values > 0.5. However, the auto-irrigation function did not adequately represent field practices, due to the continuation of irrigation after crop maturity and excessive irrigation when SWD triggers were less than the static irrigation amount.

Morphophysiology of guava under saline water irrigation and nitrogen fertilization

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Idelfonso L. Bezerra

Full Text Available ABSTRACT The aim of this study was to evaluate the growth of grafted guava cv. ‘Paluma’ subjected to different concentrations of salts in irrigation water and nitrogen (N fertilization. The plants were transplanted to 150 L lysimeters and under field conditions at the Science and Agri-food Technology Center of the Federal University of Campina Grande, in the municipality of Pombal - PB. The experiment was conducted in randomized block design in a 5 x 4 factorial scheme, with three replicates, and the treatments corresponded to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1 and four N doses (70, 100, 130 and 160% of the N dose recommended for the crop. The doses equivalent to 100% corresponded to 541.1 mg of N dm-3 of soil. Irrigation water salinity above 0.3 dS m-1 negatively affects the number of leaves, leaf area, stem diameter, dry phytomass of leaves, branches and shoots . A significant interaction between irrigation water salinity and N fertilization was observed only for the number of leaves and leaf area at 120 days after transplanting. N dose above 70% of the recommendation (378.7 mg N dm-3 soil did not mitigate the deleterious effects caused by salt stress on plant growth.

Evaluation of apical extrusion of debris and irrigant using two new reciprocating and one continuous rotation single file systems.

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Nayak, Gurudutt; Singh, Inderpreet; Shetty, Shashit; Dahiya, Surya

2014-05-01

Apical extrusion of debris and irrigants during cleaning and shaping of the root canal is one of the main causes of periapical inflammation and postoperative flare-ups. The purpose of this study was to quantitatively measure the amount of debris and irrigants extruded apically in single rooted canals using two reciprocating and one rotary single file nickel-titanium instrumentation systems. Sixty human mandibular premolars, randomly assigned to three groups (n = 20) were instrumented using two reciprocating (Reciproc and Wave One) and one rotary (One Shape) single-file nickel-titanium systems. Bidistilled water was used as irrigant with traditional needle irrigation delivery system. Eppendorf tubes were used as test apparatus for collection of debris and irrigant. The volume of extruded irrigant was collected and quantified via 0.1-mL increment measure supplied on the disposable plastic insulin syringe. The liquid inside the tubes was dried and the mean weight of debris was assessed using an electronic microbalance. The data were statistically analysed using Kruskal-Wallis nonparametric test and Mann Whitney U test with Bonferroni adjustment. P-values less than 0.05 were considered significant. The Reciproc file system produced significantly more debris compared with OneShape file system (P0.05). Extrusion of irrigant was statistically insignificant irrespective of the instrument or instrumentation technique used (P >0.05). Although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file systems.

Irrigation management in Mediterranean salt affected agriculture: how leaching operates

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Angela Libutti

2012-03-01

and relative drainage volumes according to a three steps procedure of covariance analysis. A simple, general and comprehensive leaching model is thus presented. Results showed that salt build up into the soil can be very rapid, generally occurring within a single irrigated summer crop cycle. Rainfalls of the autumn-winter period had a crucial role in the removal of salts brought into the soil by summer irrigation. This paper strongly emphasises that additional fresh water supply is of great importance to establish acceptable soil conditions. Two suitable periods for intentional leaching were identified.

Effect of Gibberellic Acid under Deficit Irrigation on Physicochemical and Shelf Life Attributes of Pomegranate Fruit (cv. Shahvar

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yahya selahvarzi

2017-02-01

Full Text Available Introduction: Pomegranate (Punica granatum L. belonging to the family Punicaceae, native to subtropical regions of Iran and adapted to arid or semi arid climates with mild winters. Pomegranate is fairly drought tolerant but requires regular irrigation to produce high yield and fruit weight. Large parts of Iran within the boundaries of central deserts (Dasht-e-kavir and Kavir-e-Loot have arid or semi-arid conditions which make them suitable for pomegranate production. However drought crisis and water resources restriction are very serious in these areas. Materials and Methods: This experiment was conducted on 7-year old pomegranate cv. Shahvar trees from 2013 to 2014 in Torbat-e-Heydarieh, Razavi Khorasan, Iran. Irrigation treatments and Gibberellic acid application were used in Completely Randomized Split-Plot Design with four replications. Irrigation treatments included [1-control: 100% of estimated crop evapotranspiration (Etc 2-Sustained deficit irrigation (SDI: watering was constantly used at 50%Etc, and 3-Regulated deficit irrigation (RDI: not watering was imposed until fruit set and then irrigation was applied same as control]. Foliar application of Gibberellic acid was done with two concentrations (0 and 150 ppm at early May and September. Precipitation and pan evaporation (Ep was recorded by weather station that located at 15 km distance from the studied orchard. Daily crop reference evapotranspiration (ETo was estimated by penman-monteith equation. Trees were drip-irrigated by two lateral lines parallel to the tree row and four emitters that each one delivers 4 liters per hour. Fruit weight and numbers, tree production (yield, peel, arils and juice percent and finally fruit cracking of each treatment were determined at ordinary harvest time in late of October. Some uniform and intact fruits per treatment transferred to cold storage (T= 5 ◦C, RH= 85-90%. After storage period the fruits transfered to shelf life condition (7 days at 20 �

Etude comparative de l'irrigation au goutte-à-goutte et à la raie sur une culture de pomme de terre de saison

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Boujelben, A.

2001-01-01

Full Text Available Comparative Study of the Drip and Furrow Irrigation on Seasonable Potato Crop. Under semi-arid climate conditions, use of furrow irrigation for potato is relatively low when compared to drip irrigation. An experimental trial was carried out at the Agricultural Research Station at Chott-Mariem located in the Center East of Tunisia. A drip irrigation system with three amounts (D, 0.75D and 0.5D was compared to blocked furrows (D on potato. The drip irrigation system (D = 210 mm produced best results for dry and fresh matter production in leaves and stems, and in tubers, percentage cover of soil and plant height. Lower amounts of water applied (0.75D and 0.5D with drip irrigation gives similar results to those obtained with furrow irrigation (D.

Sensing technologies for precision irrigation

CERN Document Server

Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

2014-01-01

This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

Intervention processes and irrigation institutions : sustainability of farmer managed irrigation systems in Nepal

OpenAIRE

Pant, D.R.

2000-01-01

With the support from various donors, His Majesty's Government of Nepal has implemented support programmes with a view to transform water availability, improve production, and increase the institutional capabilities of farmers to develop and sustain efficient, fair and reliable irrigation management practices in irrigation systems in Nepal. In this respect, this study aimed to understand the social, administrative and political processes involved in the social and institutional chang...

Untangling the effects of shallow groundwater and deficit irrigation on irrigation water productivity in arid region: New conceptual model.

Science.gov (United States)

Xue, Jingyuan; Huo, Zailin; Wang, Fengxin; Kang, Shaozhong; Huang, Guanhua

2018-04-01

Water scarcity and salt stress are two main limitations for agricultural production. Groundwater evapotranspiration (ET g ) with upward salt movement plays an important role in crop water use and water productivity in arid regions, and it can compensate the impact of deficit irrigation on crop production. Thus, comprehensive impacts of shallow groundwater and deficit irrigation on crop water use results in an improvement of irrigation water productivity (IWP). However, it is difficult to quantify the effects of groundwater and deficit irrigation on IWP. In this study, we built an IWP evaluation model coupled with a water and salt balance model and a crop yield estimation model. As a valuable tool of IWP simulation, the calibrated model was used to investigate the coupling response of sunflower IWP to irrigation water depths (IWDs), groundwater table depth (GTDs) and groundwater salinities (GSs). A total of 210 scenarios were run in which five irrigation water depths (IWDs) and seven groundwater table depths (GTDs) and six groundwater salinities (GSs) were used. Results indicate that increasing GS clearly increases the negative effect on a crop's actual evapotranspiration (ET a ) as salt accumulation in root zone. When GS is low (0.5-1g/L), increasing GTD produces more positive effect than negative effect. In regard to relatively high GS (2-5g/L), the negative effect of shallow-saline groundwater reaches a maximum at 2m GTD. Additionally, the salt concentration in the root zone maximizes its value at 2.0m GTD. In most cases, increasing GTD and GS reduces the benefits of irrigation water and IWP. The IWP increases with decreasing irrigation water. Overall, in arid regions, capillary rise of shallow groundwater can compensate for the lack of irrigation water and improve IWP. By improving irrigation schedules and taking advantages of shallow saline groundwater, we can obtain higher IWP. Copyright © 2017 Elsevier B.V. All rights reserved.

Using Irrigation Scheduling to Increase Water Productivity of Wheat-Maize Rotation under Climate Change Conditions Calendario de Riego para Aumentar la Productividad del Agua en Rotación Trigo-Maíz en Condiciones de Cambio Climático

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Gamal El Afandi

2010-09-01

Full Text Available Irrigation scheduling was used to increase water productivity of wheat (Triticum aestivum L.-maize (Zea mays L. rotation under two climate change scenarios. Three wheat varieties and two maize hybrids were planted at in a 2-yr field experiment. CropSyst model was calibrated and validated for the collected field data, then was used to assess the impact of two climate change scenarios (A2 and B2 and three adaptation strategies (early sowing changing, irrigation schedule and the interaction between them in the year of 2038s. The results revealed that A2 reduced yield more than B2 scenario for both crops. High yield reduction in wheat-maize rotation could be expected under climate change conditions, where wheat and maize yield will be reduced by an average of 41 and 56%, respectively. The most effective adaptation strategy for wheat was sowing 3 wk earlier and irrigation every 21 d, with irrigation water saving and no yield improvement under A2 scenario in both growing seasons. Whereas under B2 scenario yield improvement by 2% occurred with 3% saving in the applied irrigation water in the 1st growing season and in the 2nd growing season yield could improved by 8% with less than 1% increase in the applied irrigation water and higher water productivity. Changing irrigation schedule was an effective adaptation option for maize, where yield improvement could occur under both climate change scenarios in both growing seasons by up to 9% with less than 3% increase in the applied irrigation water and higher water productivity.

Salinity and cationic nature of irrigation water on castor bean cultivation

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Geovani S. de Lima

Full Text Available ABSTRACT This study aimed to evaluate the water relations, cell damage percentage and growth of the castor bean cv. ‘BRS Energia’ as a function of salinity and cationic nature of the water used in irrigation. The experiment was conducted in drainage lysimeters under greenhouse conditions in eutrophic Grey Argisol of sandy loam texture. Six combinations of water salinity and cations were studied (S1 - Control; S2 - Na+, S3 - Ca2+, S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+, in a randomized block design with four replicates. In the control (S1, plants were irrigated with 0.6 dS m-1 water, whereas the other treatments received 4.5 dS m-1 water, obtained by adding different salts, all in the chloride form. Higher relative water content in the leaf blade of plants irrigated with K+-salinized water associated with leaf succulence are indicative of tolerance of the castor bean cv. ‘BRS Energia’ to salinity. Saline stress negatively affected castor bean growth, regardless of cationic nature of water. Among the ions studied, ‘BRS Energia’ castor bean was more sensitive to the presence of sodium in the irrigation water, in terms of both water relations and leaf succulence.

Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, S.H.; Andersen, M.N.; Lærke, P.E.

2011-01-01

received 65% of FI after tuber bulking and lasted for six weeks until final harvest. Results showed that the irrigation treatments were not significantly different in terms of N uptake in the tubers, shoot, and whole crop. However, there was a statistical difference between the soil textures where plants...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

Moisture ingress into electronics enclosures under isothermal conditions

International Nuclear Information System (INIS)

Staliulionis, Ž.; Jabbari, M.; Hattel, J. H.

2016-01-01

The number of electronics used in outdoor environment is constantly growing. The humidity causes about 19 % of all electronics failures and, especially, moisture increases these problems due to the ongoing process of miniaturization and lower power consumption of electronic components. Moisture loads are still not understood well by design engineers, therefore this field has become one of the bottlenecks in the electronics system design. The objective of this paper is to model moisture ingress into an electronics enclosure under isothermal conditions. The moisture diffusion model is based on a 1D quasi-steady state (QSS) approximation for Fick’s second law. This QSS approach is also described with an electrical analogy which gives a fast tool in modelling of the moisture response. The same QSS method is applied to ambient water vapour variations. The obtained results are compared to an analytical solution and very good agreement is found.

Fruit yield and root system distribution of 'Tommy Atkins' mango under different irrigation regimes

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Marcelo R. dos Santos

2014-04-01

Full Text Available This study aimed to evaluate the fruit yield and the distribution of 'Tommy Atkins' mango root system under different irrigation regimes in the semiarid region of Bahia. The experimental design was completely randomized with five treatments and three replicates: 1 - Irrigation supplying 100% of ETc in phases I, II and III; 2 - Regulated deficit irrigation (RDI supplying 50% of ETc in phase I (beginning of flowering to early fruit growth; 3 - RDI supplying 50% ETc in phase II (start of expansion until the beginning of physiological maturity; 4 - RDI supplying 50% ETc in phase III (physiological mature fruits; 5 - No irrigation during all three phases. The regulated deficit irrigation supplying 50% of the ETc during phase I and II provided larger root length density of 'Tommy Atkins' mango. Regardless of management strategy, the roots were developed in all evaluated soil volume and the highest density is concentrated from 0.50 to 1.50 m distance from the trunk and in 0.20 to 0.90 m depth in the soil, that suggests this region to be the best place for fertilizer application as well for soil water sensor placement. The application of RDI during fruit set does not influence either root distribution or production. Root system and crop production is significantly reduced under no irrigation conditions.

Conjunctive use of groundwater and surface water for irrigated agriculture: Risk aversion

Science.gov (United States)

Bredehoeft, John D.; Young, Richard A.

1983-01-01

In examining the South Platte system in Colorado where surface water and groundwater are used conjunctively for irrigation, we find the actual installed well capacity is approximately sufficient to irrigate the entire area. This would appear to be an overinvestment in well capacity. In this paper we examine to what extent groundwater is being developed as insurance against periods of low streamflow. Using a simulation model which couples the hydrology of a conjunctive stream aquifer system to a behavioral-economic model which incorporates farmer behavior in such a system, we have investigated the economics of an area patterned after a reach of the South Platte Valley in Colorado. The results suggest that under current economic conditions the most reasonable groundwater pumping capacity is a total capacity capable of irrigating the available acreage with groundwater. Installing sufficient well capacity to irrigate all available acreage has two benefits: (1) this capacity maximizes the expected net benefits and (2) this capacity also minimizes the variation in annual income: it reduces the variance to essentially zero. As pumping capacity is installed in a conjunctive use system, the value of flow forecasts is diminished. Poor forecasts are compensated for by pumping groundwater.

Irrigation and avifaunal change in coastal Northwest Mexico: has irrigated habit attracted threatened migratory species?

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Grason, Emily; Navarro-Sigüenza, Adolfo G.

2015-01-01

Irrigation in desert ecosystems can either reduce or increase species diversity. Groundwater pumping often lowers water tables and reduces natural wetlands, whereas canal irrigation often creates mesic habitat, resulting in great increases in avian diversity from irrigation. Here we compare a dataset of potential natural vegetation to recent datasets from areal and satellite imagery to show that 60% of the land in the coastal plain of southern Sonora and northern Sinaloa lying below 200 m elevation has been converted by irrigation to more mesic habitats. We then use the record of bird specimens in the world’s museums from this same region of Mexico to examine the avian community before and after the development of extensive irrigation. In general these museum records show an increase in the abundance and diversity of breeding birds associated with mesic habitats. Although thorn forest birds have likely decreased in total numbers, most are common enough in the remaining thorn forest that collection records did not indicate their probable decline. Four migrants having most of their breeding ranges in the US or Canada, Yellow-billed Cuckoo, Cliff Swallow, Bell’s Vireo, and Orchard Oriole, apparently have increased dramatically as breeders in irrigated habitats of NW Mexico. Because these species have decreased or even largely disappeared as breeding birds in parts of the US or Canada, further research should assess whether their increases in new mesic habitats of NW Mexico are linked to their declines as breeding birds in Canada and the US For Bell’s Vireo recent specimens from Sinaloa suggest its new breeding population in NW Mexico may be composed partly of the endangered Least Bell’s Vireo. PMID:26312181

ASPECTS OF DRIP IRRIGATION ON SLOPES

Directory of Open Access Journals (Sweden)

Oprea Radu

2010-01-01

Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

Plant height and grain yield of soybean depending on the year, irrigation and variety

Directory of Open Access Journals (Sweden)

Daria Galić Šubašić

2017-01-01

Full Text Available Three-year field trials determined the influence of the year, irrigation treatment and varieties on plant height and grain yield of soybeans in the eastern Croatia conditions. All three investigated factors, as well as their interactions, with the exception of irrigation interactions and varieties that were significant at P=0.05, show a statistically significant influence (P=0.01 on the height of soybean plants. Soybean grain yields, as well as all their interactions, affect the significance level P=0.01. The obtained values of soybean grain yields during the study (mostly greater than 3000 kg ha-1 indicate the importance of selecting appropriate varieties and irrigation treatment in adapting soybean production to adverse weather effects of the year.

improving of irrigation management: a learning based approach

African Journals Online (AJOL)

p2333147

Irrigation farms are small businesses and like any other business, the managers or ... human factors and constraints that impact on the adoption of irrigation ... Informal interaction with other irrigation farmers and social networks played a ...

Impact of Potentially Contaminated River Water on Agricultural Irrigated Soils in an Equatorial Climate

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Juan M. Trujillo-González

2017-06-01

Full Text Available Globally, it is estimated that 20 million hectares of arable land are irrigated with water that contains residual contributions from domestic liquids. This potentially poses risks to public health and ecosystems, especially due to heavy metals, which are considered dangerous because of their potential toxicity and persistence in the environment. The Villavicencio region (Colombia is an equatorial area where rainfall (near 3000 mm/year and temperature (average 25.6 °C are high. Soil processes in tropical conditions are fast and react quickly to changing conditions. Soil properties from agricultural fields irrigated with river water polluted by a variety of sources were analysed and compared to non-irrigated control soils. In this study, no physico-chemical alterations were found that gave evidence of a change due to the constant use of river water that contained wastes. This fact may be associated with the climatic factors (temperature and precipitation, which contribute to fast degradation of organic matter and nutrient and contaminants (such as heavy metals leaching, or to dilution of wastes by the river.

Nutrition of Tithonia diversifolia and attributes of the soil fertilized with biofertilizer in irrigated system

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Matheus M. Reis

Full Text Available ABSTRACT The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1, combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil.

Saline water irrigation for crop production

Energy Technology Data Exchange (ETDEWEB)

Khan, A R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Singh, S S; Singh, S R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India)

2001-05-01

Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation.

Saline water irrigation for crop production

International Nuclear Information System (INIS)

Khan, A.R.; Singh, S.S.; Singh, S.R.

2001-05-01

Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation

Water distribution in an orchard irrigated by perforated distributors in stony ground

International Nuclear Information System (INIS)

Decroix, M.; Marcesse, J.; Normand, M.

1975-01-01

In the context of new irrigation techniques the Compagnie Nationale d'Amenagement du Bas-Rhone et du Languedoc (B.Rh.L.) has developed a process of localized irrigation by perforated distributors. Conditions were defined for the optimum use of this process, especially the distribution of water in the ground. The study was carried out in a peach orchard in stony ground. The neutronic method was used to measure the soil moisture content. Because of the heterogeneous stone size distribution it was necessary for the specific humidity determination to take into account the dry apparent density. This parameter was measured by gammametry [fr

Impact of irrigation intervals, nitrogen fertilizer levels and heritability on spineless performance in safflower genotypes

International Nuclear Information System (INIS)

Ragab, A.I.; Kassem, M.

2003-01-01

The present study was conducted to study the impact of irrigation intervals, nitrogen fertilizer levels on spineless percentages, meanwhile, heritability and genetic gain were determind for further selection for eight safflower genotype, during 1998/1999-1999/2000 seasons, at nuclear research center-inshas. Concerning irrigation intervals, results showed that spineless percentages of safflower genotypes were markedly increased with the increasing of irrigation intervals, this eans that increase of drought conditions leds to increase the spineless percentages in all the genotypes. Regarding nitrogen fertilizer levels, results exhibited that spineless percentages were increased with the increasing of nitrogen fertilizer levels for all the studied genotypes. Combined analysis of variance chowed highly significant effect for irrigation intervals, fertilizer levels, years and genotypes for spineles trait. The first order interaction, second order interaction and third order interaction were highly significant suggesting that spineless trait was affected the environmental factors

Integrated water-crop-soil-management system for evaluating the quality of irrigation water

International Nuclear Information System (INIS)

Pla-Sentis, I.

1983-01-01

The authors make use of an independent balance of the salts and ions present in the water available for irrigation, based on the residence times in the soil solution that are allowed by solubility limits and drainage conditions, to develop an efficient system for evaluating the quality of such water which combines the factors: water, crop, soil and management. The system is based on the principle that such quality depends not only on the concentration and composition of the salts dissolved in the water, but also on existing possibilities and limitations in using and managing it in respect of the soil and crops, with allowance for the crop's tolerance of salinity, drainage conditions and hydrological properties of the soils, climate and current or potential practices for the management of the irrigation. If this system is used to quantify approximately the time behaviour of the concentration and composition of the salts in the soil solution, it is possible not only to predict the effects on soil, crops and drainage water, but also to evaluate the various combinations of irrigation water, soil, crops and management and to select the most suitable. It is also useful for fairly accurately diagnosing current problems of salinity and for identifying alternatives and possibilities for reclamation. Examples of its use for these purposes in Venezuela are presented with particular reference to the diagnosis of the present and future development of ''salino-sodic'' and ''sodic'' soils by means of low-salt irrigation water spread over agricultural soils with very poor drainage in a sub-humid or semi-arid tropical climate. The authors also describe the use of radiation techniques for gaining an understanding of the relations between the factors making up the system and for improving the quantitative evaluations required to diagnose problems and to select the best management methods for the available irrigation water. (author)

Correlation Coefficient, Path Analysis and Drought Tolerance Indices for Wheat under Deficit Irrigation Conditions and Nitrogen Levels

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A. R Tavakoli

2012-07-01

Full Text Available In order to investigate the indices of drought tolerance, correlation coefficient and path analysis at deficit irrigation and nitrogen experiment, this experiment was conducted as split plot arranged in a randomized complete block design (RCBD with three replications during 2000-2003 for wheat at Maragheh agricultural research station of DARI. The treatments were included four levels of deficit irrigation (Rainfed, 100, 160 and 220mm of water use as main plots and five nitrogen rates (0, 30, 60, 90 and 120 kg.N.ha-1 as sub plots. Grain, straw and biological yield, harvest index, productivity degree, plant height, kernel number per spike, Spike number per square meter and TKW determined from the middle of each plot. There were positive significant correlations due to grain yield with all variables: harvest index (r = 0.969 , Productivity degree (r = 0.952 , straw yield (r = 0.904 , plant height (r = 0.904 , biological yield (r = 0.824 , Spike number per square meter (r = 0.817 , kernel number per spike (r = 0.773 and TKW (r = 0.612 respectively. Results of path analysis showed that increase in grain yield was due to increase spike number per square meter and kernel number per spike respectively. On based of indices of drought tolerance (Tolerance Index, Mean Productivity, Geometric Mean Productivity and Harmonic Mean, treatment of %66full irrigation combined with 90KgN.ha-1 was substantially increased water productivity.

Evaluation of the Effect of Different Irrigation Levels of Drip Irrigation (Tape on Yield and Yield Components of Corn

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mohammad karimi

2016-02-01

Full Text Available Introduction: One of the serious problems in the further development of maize cultivation is increasing irrigation efficiency. Using conventional irrigation causes a shortage of water resources to increase the acreage of the crop. With regard to the development of maize cultivation, agronomic and executable methods must be studied to reduce water consumption. Using drip irrigation system is most suitable for row crops. Hamedi et al. (2005 compared drip (tape and surface irrigation systems on yield of maize in different levels of water requirement and indicated that drip irrigation increases the amount of yield to 2015 kg/ha and water use efficiency to 3 time. Kohi et al. (2005 investigated the effects of deficit irrigation use of drip (tape irrigation on water use efficiency on maize in planting of one and two rows. The results showed that maximum water use efficiency related to crop density, water requirement and planting pattern 85000, 125% and two rows, respectively with 1.46 kg/m3. Jafari and Ashrafi (2011 studied the effects of irrigation levels, plant density and planting pattern in drip irrigation (tape on corn. The results showed that the amount of irrigation water and crop density on the level of 1% and their interactions and method of planting were significant at the 5 and 10% on water use efficiency, respectively. The yield was measured under different levels of irrigation, crop density and method of planting and the difference was significant on the level of 1%. Lamm et al. (1995 studied water requirement of maize in field with silt loam texture under sub drip irrigation and reported that water use reduced to 75%; but yield of maize remained at maximum amount of 12.5 t/ha. The objective of this study was to evaluate the drip (tape irrigation method for corn production practices in the Qazvin province in Iran. Materials and Methods: In this study, yield and yield components of corn (SC 704 were investigated under different levels of

Introduction: Panda or Hydra? The untold stories of drip irrigation

NARCIS (Netherlands)

Kuper, M.; Venot, J.P.; Zwarteveen, M.; Venot, J.P.; Kuper, M.; Zwarteveen, M.

2017-01-01

Irrigated areas in the world are witnessing a transformation from open canal systems to more ‘modern’ irrigation methods such as drip irrigation that convey water through closed pipe systems. Initially associated with hi-tech irrigated agriculture, drip irrigation is now being used by a wide range

[Ecological risks of reclaimed water irrigation: a review].

Science.gov (United States)

Chen, Wei-Ping; Zhang, Wei-Ling; Pan, Neng; Jiao, Wen-Tao

2012-12-01

Wastewater reclamation and reuse have become an important approach to alleviate the water crisis in China because of its social, economic and ecological benefits. The irrigation on urban green space and farmland is the primary utilization of reclaimed water, which has been practiced world widely. To understand the risk of reclaimed water irrigation, we summarized and reviewed the publications associated with typical pollutants in reclaimed water including salts, nitrogen, heavy metals, emerging pollutants and pathogens, systematically analyzed the ecological risk posed by reclaimed water irrigation regarding plant growth, groundwater quality and public health. Studies showed that salt and salt ions were the major risk sources of reclaimed water irrigation, spreading disease was another potential risk of using reclaimed water, and emerging pollutants was the hot topic in researches of ecological risk. Based on overseas experiences, risk control measures on reclaimed water irrigation in urban green space and farmland were proposed. Five recommendations were given to promote the safe use of reclaimed water irrigation including (1) strengthen long-term in situ monitoring, (2) promote the modeling studies, (3) build up the connections of reclaimed water quality, irrigation management and ecological risk, (4) evaluate the soil bearing capacity of reclaimed water irrigation, (5) and establish risk management system of reclaimed water reuse.

Ocean-Atmosphere Interactions Modulate Irrigation's Climate Impacts

Science.gov (United States)

Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa

2016-01-01

Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean- atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that ocean-atmosphere interaction does impact the magnitude of global-mean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the oceans, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and mid-latitudes in our simulations, approximately doubling the global-mean amplitude of surface temperature changes due to irrigation. The fractions of global area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with ocean-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern Ocean, and that attribution studies should include interactive oceans and need to consider LCLUC, including irrigation, as a truly global forcing that affects climate and the water cycle over ocean as well as land areas.

Mapping Irrigation Potential in the Upper East Region of Ghana

Science.gov (United States)

Akomeah, E.; Odai, S. N.; Annor, F. O.; Adjei, K. A.; Barry, B.

2009-04-01

The Upper East Region together with the other two regions in Northern Ghana (Upper West and Northern Region) is seen as the locus of perennial food deficit (GPRS, 2003). Despite, the provision of over 200 small scale dams and various mechanisms aimed at poverty alleviation, the region is still plagued with poverty and yearly food shortages. To achieve food security and alleviate poverty in the region however, modernization of agriculture through irrigation is deemed inevitable. While it is true that considerable potential still exists for future expansion of irrigation, it cannot be refuted that water is becoming scarcer in the regions where the need for irrigation is most important, hence mapping the irrigation potential of the region will be the first step toward ensuring sound planning and sustainability of the irrigation developments. In this study, an attempt has been made to map out the irrigation potential of the Upper East Region. The river basin approach was used in assessing the irrigation potential. The catchments drained by The White Volta river, Red volta river, River Sissili and River Kulpawn were considered in the assessment. The irrigation potential for the sub basins was computed by combining information on gross irrigation water requirements for the selected cash crops, area of soil suitable for irrigation and available water resources. The capacity of 80%, 70%, 60% and 50% time of exceedance flow of the available surface water resources in the respective sub basins was estimated. The area that can be irrigated with this flow was computed with selected cropping pattern. Combining the results of the potential irrigable areas and the land use map of the respective sub basins, an irrigation potential map has been generated showing potential sites in the upper east region that can be brought under irrigation. Keywords: Irrigation potential, irrigation water requirement, land evaluation, dependable flow

A Method for Precision Closed-Loop Irrigation Using a Modified PID Control Algorithm

Science.gov (United States)

Goodchild, Martin; Kühn, Karl; Jenkins, Malcolm; Burek, Kazimierz; Dutton, Andrew

2016-04-01

The benefits of closed-loop irrigation control have been demonstrated in grower trials which show the potential for improved crop yields and resource usage. Managing water use by controlling irrigation in response to soil moisture changes to meet crop water demands is a popular approach but requires knowledge of closed-loop control practice. In theory, to obtain precise closed-loop control of a system it is necessary to characterise every component in the control loop to derive the appropriate controller parameters, i.e. proportional, integral & derivative (PID) parameters in a classic PID controller. In practice this is often difficult to achieve. Empirical methods are employed to estimate the PID parameters by observing how the system performs under open-loop conditions. In this paper we present a modified PID controller, with a constrained integral function, that delivers excellent regulation of soil moisture by supplying the appropriate amount of water to meet the needs of the plant during the diurnal cycle. Furthermore, the modified PID controller responds quickly to changes in environmental conditions, including rainfall events which can result in: controller windup, under-watering and plant stress conditions. The experimental work successfully demonstrates the functionality of a constrained integral PID controller that delivers robust and precise irrigation control. Coir substrate strawberry growing trial data is also presented illustrating soil moisture control and the ability to match water deliver to solar radiation.

Irrigation ponds: Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

Institute of Scientific and Technical Information of China (English)

DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang

2009-01-01

Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

Irrigation ponds:Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

Institute of Scientific and Technical Information of China (English)

BROWN; Larry

2009-01-01

Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

The use of treated wastewater for chemlali olive tree irrigation: effects on soil properties, growth and oil quality

Energy Technology Data Exchange (ETDEWEB)

Ben Rouina, B.; Bedbabis, S.; Ben Ahmed, C.; Boukhris, M.

2009-07-01

Olive tree (Olea european L.) cultivation, the major tree crops in Mediterranean countries is being extended to irrigated lands. However, the limited water availability, the severe climatic conditions and the increased need for good water quality for urban and industrial sector uses are leading to the urgent use of less water qualities (brackish water and recycled wastewater) for olive tree irrigation. The aim of this work was to asses the effects of long term irrigation with treated waste water (TWW) on the soil chemical properties, on olive tree growth and on oil quality characteristics. (Author)

The use of treated wastewater for chemlali olive tree irrigation: effects on soil properties, growth and oil quality

International Nuclear Information System (INIS)

Ben Rouina, B.; Bedbabis, S.; Ben Ahmed, C.; Boukhris, M.

2009-01-01

Olive tree (Olea european L.) cultivation, the major tree crops in Mediterranean countries is being extended to irrigated lands. However, the limited water availability, the severe climatic conditions and the increased need for good water quality for urban and industrial sector uses are leading to the urgent use of less water qualities (brackish water and recycled wastewater) for olive tree irrigation. The aim of this work was to asses the effects of long term irrigation with treated waste water (TWW) on the soil chemical properties, on olive tree growth and on oil quality characteristics. (Author)

Evaluation of Different Rice Genotypes Tolerance to Saline Irrigation Water

Directory of Open Access Journals (Sweden)

S. Jafari Rad

2015-12-01

Full Text Available To study the responses of seven rice genotypes (Khazar, SA13, Deylam, Sange Joe, Sepidrud, 831 and T5 to different levels of irrigation water salinity, and determining grain yield based on tolerance indices, a CRD based factorial pot experiment with five levels of irrigation water salinity (1, 2, 4, 6 and 8 dSm-1 and three replications was carried out at Rice Research Institute of Iran in 2011. Indices such as SSI, TOL, MP, GMP, HM, STI, YI and YSI were calculated and their correlations with grain yield were estimated for both stress and non-stress conditions. Results indicated significant differences among genotypes and the indices within both conditions. Results also showed that STI and MP indices could be considered as the best indices to screen salt tolerant genotypes. Among the genotypes used in the experiment, T5 produced the highest yield in both non-stress (19.71 g/plant and stress (10.69 g/plant conditions, while the lowest yield in normal (11.84 g/plant and stressful (4.29 g/plant conditions was recorded for Deylam and Khazar, respectively. The highest and the lowest percentage of yield reduction were found in Khazar (69.49% and Sange Joe (31.48% in stressful conditions, respectively. Overall, genotypes T5, 831, Sepidrud and Sange Joe can probably be considered as superior high yielding genotypes in both saline and non-saline conditions for further research.

Sustainable irrigation in fruit trees

Directory of Open Access Journals (Sweden)

Cristos Xiloyannis

2010-09-01

Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

Sustainable irrigation in fruit trees

Directory of Open Access Journals (Sweden)

Cristos Xiloyannis

Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

Agriculture and natural resources in a changing world - the role of irrigation

Science.gov (United States)

Sauer, T.; Havlík, P.; Schneider, U. A.; Kindermann, G.; Obersteiner, M.

2009-04-01

Fertile land and fresh water constitute two of the most fundamental resources for food production. These resources are affected by environmental, political, economic, and technical developments. Regional impacts may transmit to the world through increased trade. With a global forest and agricultural sector model, we quantify the impacts of increased demand for food due to population growth and economic development on potential land and water use. In particular, we investigate producer adaptation regarding crop and irrigation choice, agricultural market adjustments, and changes in the values of land and water. Against the background of resource sustainability and food security topics, this study integrates the spatial and operational heterogeneity of irrigation management into a global land use model. It represents a first large scale assessment of agricultural water use under explicit consideration of alternative irrigation options in their particular biophysical, economic, and technical context, accounting for international trade, motivation-based farming, and quantified aggregated impacts on land scarcity, water scarcity, and food supply. The inclusion of technical and economic aspects of irrigation choice into an integrated land use modeling framework provides new insights into the interdisciplinary trade-offs between determinants of global land use change. Agricultural responses to population and economic growth include considerable increases in irrigated area and agricultural water use, but reductions in the average water intensity. Different irrigation systems are preferred under different exogenous biophysical and socioeconomic conditions. Negligence of these adaptations would bias the burden of development on land and water scarcity. Without technical progress in agriculture, predicted population and income levels for 2030 would require substantial price adjustments for land, water, and food to equilibrate supply and demand.

Balancing water scarcity and quality for sustainable irrigated agriculture

Science.gov (United States)

Assouline, Shmuel; Russo, David; Silber, Avner; Or, Dani

2015-05-01

The challenge of meeting the projected doubling of global demand for food by 2050 is monumental. It is further exacerbated by the limited prospects for land expansion and rapidly dwindling water resources. A promising strategy for increasing crop yields per unit land requires the expansion of irrigated agriculture and the harnessing of water sources previously considered "marginal" (saline, treated effluent, and desalinated water). Such an expansion, however, must carefully consider potential long-term risks on soil hydroecological functioning. The study provides critical analyses of use of marginal water and management approaches to map out potential risks. Long-term application of treated effluent (TE) for irrigation has shown adverse impacts on soil transport properties, and introduces certain health risks due to the persistent exposure of soil biota to anthropogenic compounds (e.g., promoting antibiotic resistance). The availability of desalinated water (DS) for irrigation expands management options and improves yields while reducing irrigation amounts and salt loading into the soil. Quantitative models are used to delineate trends associated with long-term use of TE and DS considering agricultural, hydrological, and environmental aspects. The primary challenges to the sustainability of agroecosystems lies with the hazards of saline and sodic conditions, and the unintended consequences on soil hydroecological functioning. Multidisciplinary approaches that combine new scientific knowhow with legislative, economic, and societal tools are required to ensure safe and sustainable use of water resources of different qualities. The new scientific knowhow should provide quantitative models for integrating key biophysical processes with ecological interactions at appropriate spatial and temporal scales.

Effect of different irrigation regimes on the quality attributes of mono varietal virgin olive oil from cv. Cobrancosa

Energy Technology Data Exchange (ETDEWEB)

Fernandes-Silva, A. A.; Gouveia, J. B.; Vasconcelos, P.; Ferreira, T. C.; Villalobos, F. J.

2013-05-01

The aim of this study was to assess the effect of different irrigation strategies in virgin olive oil (VOO) composition and quality of cv. Cobrancosa, integrated in a protected denomination of origin of Azeite de Tras-os-Montes in the Northeast of Portugal. Three irrigation treatments were applied: T2-full irrigation that received a seasonal water equivalent to 100% of estimated crop evapotranspiration (ETc), T1-continuous deficit irrigation (30% ETc) and T0- rainfed treatment. Data were collected from two consecutive crop years (2005-2006). Irrigation regimes had a minor effect on standard quality indices (free fatty acids, peroxide value, K{sub 2}32 and K{sub 2}70) of VOO and in fatty acid composition. Total polyphenols decreased up to treatment T2, and were strongly related to the water stress integral, suggesting that the effect of irrigation on this variable occurs along the crop season and not just during the oil accumulation phase. A strategy of continuous deficit irrigation with only 30% of maximum ETc may have an advantageous effect, as it increased oil yield to more than double that of rainfed conditions while VOO quality was similar. (Author) 49 refs.

Nutrient management and institutional cooperation as conditions for environmentally safe wastewater irrigation: the case of Hanoi, Vietnam

NARCIS (Netherlands)

Evers, J.G.; Huibers, F.P.; van Vliet, Bas J.M.; Dung, N.V.; Van, D.T.H.; Ragab, Ragab; Koo-Oshima, Sasha

2006-01-01

Hanoi is rapidly growing in population and in economic activities. Increasing volumes of domestic and industrial wastewater flows are discharged mostly untreated into the drainage system. At downstream level, these polluted, nutrient rich waters are used for irrigation. Nutrient concentrations in

Root Zone Sensors for Irrigation Management in Intensive Agriculture

Directory of Open Access Journals (Sweden)

Jochen Hemming

2009-04-01

Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

Directory of Open Access Journals (Sweden)

Haibing He

2014-01-01

Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

Irrigation Capability Evaluation of Illushi Floodplain, Edo State, Nigeria

Directory of Open Access Journals (Sweden)

A.S. Umweni

2014-06-01

Full Text Available Many irrigation projects, especially in the developing tropical regions, are embarked upon without any land capability assessment, resulting in avoidable and undesirable ecological consequences. The aim of this study is to assess the irrigation capability potentials of the soils of a rice growing Illushi/Ega community in Edo State of Nigeria. Soils of Illushi/Ega (200 ha were studied to establish their irrigation capabilities. Water samples were collected from the rivers within and near the sites at the proposed points of intake structures and analyzed for salinity (ECw, permeability (SAR and ion toxicity [Chlorine (Cl and Boron (B]. Gravity irrigation suitability assessment was carried out following the guidelines of the United States Bureau for Land Reclamation (USBR, 1953 and FAO (1979. Results showed that about 5.5 % of the land was non-irrigable, 11.5 % was marginally irrigable, 30.5% was moderately irrigable and 52.5 % highly irrigable.Thus about 83 % of the total land area was found to be irrigable. The results of analyses of irrigation water [ECw, SAR and Cl and B (ion toxicity problems in water sources were 0.1 – 0.7 dS m-1, 1.2 – 1.7, 0.6 – 1.8 cmol kg-1 and 0.5 – 0.7 mg kg-1] also show that there is no indication of salinity or ion toxicity problem.

Root-Zone Redox Dynamics - In Search for the Cause of Damage to Treated-Wastewater Irrigated Orchards in Clay Soils

Science.gov (United States)

Yalin, David; Shenker, Moshe; Schwartz, Amnon; Assouline, Shmuel; Tarchitzky, Jorge

2016-04-01

Treated wastewater (TW) has become a common source of water for agriculture. However recent findings raise concern regarding its use: a marked decrease (up to 40%) in yield appeared in orchards irrigated with TW compared with fresh water (FW) irrigated orchards. These detrimental effects appeared predominantly in orchards cultivated in clay soils. The association of the damage with clay soils rather than sandy soils led us to hypothesize that the damage is linked to soil aeration problems. We suspected that in clay soils, high sodium adsorption ratio (SAR) and high levels of organic material, both typical of TW, may jointly lead to an extreme decrease in soil oxygen levels, so as to shift soil reduction-oxidation (redox) state down to levels that are known to damage plants. Two-year continuous measurement of redox potential, pH, water tension, and oxygen were conducted in the root-zone (20-35 cm depth) of avocado trees planted in clay soil and irrigated with either TW or FW. Soil solution composition was sampled periodically in-situ and mineral composition was sampled in tree leaves and woody organs biannually. In dry periods the pe+pH values indicated oxic conditions (pe+pH>14), and the fluctuations in redox values were small in both TW and FW plots. Decreases in soil water tension following irrigation or rain were followed by drops in soil oxygen and pe+pH values. TW irrigated plots had significantly lower minimum pe+pH values compared with FW-irrigated plots, the most significant differences occurred during the irrigation season rather than the rain season. A linear correlation appeared between irrigation volume and reduction severity in TW-irrigated plots, but not in the FW plots, indicating a direct link to the irrigation regime in TW-irrigated plots. The minimum pe+pH values measured in the TW plots are indicative of suboxic conditions (9water tension and oxygen concentration levels. The consequences of our findings to plant health will be discussed, and

Effects of different irrigation regimes on vegetative growth, fruit yield ...

African Journals Online (AJOL)

ONOS

2010-09-06

Sep 6, 2010 ... This study was conducted during five growing seasons from 2004 to 2008 to investigate effects of different irrigation regimes on vegetative growth, fruit yield and quality of Salak apricot trees in semi- arid climatic conditions. ... is very important to know the critical stages of fruit development and the final ...

Effect of irrigation disruption and biological nitrogen on growth and ...

African Journals Online (AJOL)

In addition, the maximum (4.29 %) harvest index was obtained from irrigation disruption at third and second harvest with 9 L/ha of nitroxin application. In conclusion, lower amounts of nitrogen was needed to produced the optimal yield of seed in water deficit situation compared with non stress condition, while the nitrogen ...

Grower demand for sensor-controlled irrigation

Science.gov (United States)

Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

2015-01-01

Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

Evaluation of apical extrusion of debris and irrigant using two new reciprocating and one continuous rotation single file systems.

Directory of Open Access Journals (Sweden)

Gurudutt Nayak

2014-06-01

Full Text Available Apical extrusion of debris and irrigants during cleaning and shaping of the root canal is one of the main causes of periapical inflammation and postoperative flare-ups. The purpose of this study was to quantitatively measure the amount of debris and irrigants extruded apically in single rooted canals using two reciprocating and one rotary single file nickel-titanium instrumentation systems.Sixty human mandibular premolars, randomly assigned to three groups (n = 20 were instrumented using two reciprocating (Reciproc and Wave One and one rotary (One Shape single-file nickel-titanium systems. Bidistilled water was used as irrigant with traditional needle irrigation delivery system. Eppendorf tubes were used as test apparatus for collection of debris and irrigant. The volume of extruded irrigant was collected and quantified via 0.1-mL increment measure supplied on the disposable plastic insulin syringe. The liquid inside the tubes was dried and the mean weight of debris was assessed using an electronic microbalance. The data were statistically analysed using Kruskal-Wallis nonparametric test and Mann Whitney U test with Bonferroni adjustment. P-values less than 0.05 were considered significant.The Reciproc file system produced significantly more debris compared with OneShape file system (P0.05. Extrusion of irrigant was statistically insignificant irrespective of the instrument or instrumentation technique used (P >0.05.Although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file systems.

Environmental impacts of irrigated and rain-fed barley production in Iran using life cycle assessment (LCA)

Energy Technology Data Exchange (ETDEWEB)

Houshyar, E.

2017-07-01

Current intensive grain crops production is often associated with environmental burdens. However, very few studies deal with the environmental performance of both current and alternative systems of barley production. This study was undertaken to evaluate energy consumption and environmental impacts of irrigated and rain-fed barley production. Additionally, three alternative scenarios were examined for irrigated barley fields including conservation tillage and biomass utilization policies. The findings showed that around 25 GJ/ha energy is needed in order to produce 2300 kg/ha irrigated barley and 13 GJ/ha for 1100 kg/ha rain-fed barley. Life cycle assessment (LCA) results indicated that irrigated farms had more environmental impacts than rain-fed farms. Electricity generation and consumption had the highest effect on the abiotic depletion potential, human toxicity potential, freshwater and marine aquatic ecotoxicity potential. However, alternative scenarios revealed that using soil conservation tillage systems and biomass consumption vs. gas for electricity generation at power plants can significantly mitigate environmental impacts of irrigated barley production similar to the rain-fed conditions while higher yield is obtained.

Environmental impacts of irrigated and rain-fed barley production in Iran using life cycle assessment (LCA)

International Nuclear Information System (INIS)

Houshyar, E.

2017-01-01

Current intensive grain crops production is often associated with environmental burdens. However, very few studies deal with the environmental performance of both current and alternative systems of barley production. This study was undertaken to evaluate energy consumption and environmental impacts of irrigated and rain-fed barley production. Additionally, three alternative scenarios were examined for irrigated barley fields including conservation tillage and biomass utilization policies. The findings showed that around 25 GJ/ha energy is needed in order to produce 2300 kg/ha irrigated barley and 13 GJ/ha for 1100 kg/ha rain-fed barley. Life cycle assessment (LCA) results indicated that irrigated farms had more environmental impacts than rain-fed farms. Electricity generation and consumption had the highest effect on the abiotic depletion potential, human toxicity potential, freshwater and marine aquatic ecotoxicity potential. However, alternative scenarios revealed that using soil conservation tillage systems and biomass consumption vs. gas for electricity generation at power plants can significantly mitigate environmental impacts of irrigated barley production similar to the rain-fed conditions while higher yield is obtained.

[Effects of irrigation amount on morphological characteristics and water use of Jatropha curcas].

Science.gov (United States)

Yang, Qi-Liang; Zhang, Jing; Liu, Xiao-Gang; Liu, Yan-Wei; Yang, Ju-Rui

2014-05-01

Jatropha curcas is the most promising energy tree, and soil moisture is the key factor which affects the seedling quality and water use efficiency of J. curcas. With aims to evaluate the effect of different irrigation amount on growth, morphological characteristics and water use of J. curcas, a pot experiment was conducted with four irrigation amounts, i. e., W1:472.49 mm, W2: 228.79 mm, W3:154.18 mm and W4:106.93 mm, respectively. Compared with W1 treatment, the leaf area and stem cross-section area of base significantly decreased in W2, W3 and W4 treatments, but Huber value significantly increased, which could improve the efficiency of water transfer from root to shoot, thus enhance the capability of resistance to drought stress. Compared with W, treatment, the healthy index of J. curcas seedlings decreased slightly in W2 treatment but significantly decreased in W3 and W4 treatments. Hence, the irrigation amount from 228.79 to 472.49 mm was beneficial to increase the healthy index of J. curcas seedlings. Compared with W1 treatment, irrigation water was saved by 67.4% in W3 treatment, and the total dry mass and evapotranspiration significantly decreased by 17.4% and 68.6%, and the irrigation water use efficiency and total water use efficiency increased by 153.2% and 163.2%, respectively. In the condition of this study, the irrigation amount of 154.18 mm was beneficial to increase water use efficiency.

Drip Irrigation for Commercial Vegetable and Fruit Production

OpenAIRE

Maughn, Tiffany; Allen, Niel; Drost, Dan

2017-01-01

Drip irrigation is a highly efficient irrigation method well suited to many fruit and vegetable row crops. Drip tubing or tape discharges water to the soil through emitters positioned close to the plant. The drip tubing can be placed uncovered on the soil surface, under plastic mulch, buried in the soil, or suspended above the ground (e.g., on a trellis system). Water application rate is relatively low and irrigations are usually frequent. Properly designed and maintained drip-irrigation syst...

Practical salinity management for leachate irrigation to poplar trees.

Science.gov (United States)

Smesrud, Jason K; Duvendack, George D; Obereiner, James M; Jordahl, James L; Madison, Mark F

2012-01-01

Landfill leachate can be beneficially reused for irrigation of fiber crops with appropriate attention to nutrient and salinity management. The Riverbend Landfill in Western Oregon has been effectively practicing irrigation of landfill leachate to poplar trees since 1993. Over that time, the site has been adaptively managed to control salinity impacts to the tree crop while beneficially utilizing the applied water and nutrients during each growing season. Representative leachate irrigation water has ranged in concentration of total dissolved solids from 777 to 6,940 mg/L, chloride from 180 to 1,760 mg/L and boron from 3.2 to 7.3 mg/L. Annual leachate irrigation applications have also ranged between 102 and 812 mm/yr. Important conclusions from this site have included: 1) Appropriate tree clone selection and tree stand spacing, thinning, and harvest rotations are critical to maintaining a productive tree stand that is resilient and resistant to salt stress. The most effective combinations have included clones DN-34, OP-367, 184-411, 49-177, and 15-29 planted at spacing of 3.7-m x 1.8-m to 3.7-m x 3.7-m; 2) Leaf tissue boron levels are closely correlated to soil boron levels and can be managed with leaching. When leaf tissue boron levels exceed 200 to 250 mg/kg, signs of salt stress may emerge and should be monitored closely; 3) Salinity from leachate irrigation can be managed to sustain a healthy tree crop by controlling mass loading rates and providing appropriate irrigation blending if necessary. Providing freshwater irrigation following each leachate irrigation and targeting freshwater irrigation as 30 percent of total irrigation water applied has successfully controlled salt impacts to vegetation; and 4) Drip irrigation generally requires more careful attention to long-term soil salinity management than spray irrigation. Moving drip irrigation tubes periodically to prevent the formation of highly saline zones within the soil profile is important. In this paper, a

Computer-based irrigation scheduling for cotton crop

International Nuclear Information System (INIS)

Laghari, K.Q.; Memon, H.M.

2008-01-01

In this study a real time irrigation schedule for cotton crop has been tested using mehran model, a computer-based DDS (Decision Support System). The irrigation schedule was set on selected MAD (Management Allowable Depletion) and the current root depth position. The total 451 mm irrigation water applied to the crop field. The seasonal computed crop ET (Evapotranspiration) was estimated 421.32 mm and actual (ET/sub ca/) observed was 413 mm. The model over-estimated seasonal ET by only 1.94. WUE (Water Use Efficiency) for seed-cotton achieved 6.59 Kg (ha mm)/sup -1/. The statistical analysis (R/sup 2/=0.96, ARE%=2.00, T-1.17 and F=550.57) showed good performance of the model in simulated and observed ET values. The designed Mehran model is designed quite versatile for irrigation scheduling and can be successfully used as irrigation DSS tool for various crop types. (author)

Simple Myths and Basic Maths about Greening Irrigation

Science.gov (United States)

Dionisio Pérez-Blanco, C.; Gómez, C. Mario

2014-05-01

Managing water is a very complex societal issue that needs to involve legal, environmental, technological, financial and political considerations that are difficult to co-ordinate in an effective manner. This complexity and the lack of an agreed assessment framework have often implied that political decisions, largely driven by transaction costs (especially the bargaining costs required to come to an acceptable agreement with all the parties involved), have overshadowed and prevailed over other considerations. As a result, (financially) expensive solutions such as irrigation modernization programmes have been preferred to their inexpensive alternatives to save water, such as quotas or pricing policies. However, greening the economy is mostly about improving water governance and not only about putting the existing resource saving technical alternatives into practice. Focusing on the second and forgetting the first risks finishing with a highly efficient use of water services at the level of each individual user but with an unsustainable amount of water use for the entire economy. This might be happening already in many places with the modernization of irrigated agriculture, the world's largest water user and the one offering the most promising water saving opportunities. In spite of high expectations, costly modern irrigation techniques seem not to be contributing to reduce water scarcity and increase drought resiliency. In fact, according to the little evidence available, in some areas they are resulting in higher water use. Building on basic economic principles this study aims to show the conditions under which this apparently paradoxical outcome, known as the Jevons' Paradox, might appear. This basic model is expected to serve as guidance for assessing the actual outcomes of increasing irrigation efficiency and to discuss the changes in water governance that would be required for this to make a real contribution to sustainable water management.

{sup 137}Cs in irrigation water and its effect on paddy fields in Japan after the Fukushima nuclear accident

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, Natsuki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Obara, Hitomi [Oriental Consultants, Sumitomo Fudosan Nishi Shinjuku Bldg. No. 6, 3-12-1 Honmachi, Shibuya-ku, Tokyo 151-0071 (Japan); Ogasa, Marie; Miyazu, Susumu [Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Harada, Naoki [Institute of Science and Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan); Nonaka, Masanori [Graduate School for Management of Technology, Niigata University, 8050 Ikarashi 2-nocho, Nishi-ku, Niigata 950-2181 (Japan)

2014-05-01

There is concern that radiocesium deposited in the environment after the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 will migrate to paddy fields through hydrological pathways and cause serious and long-lasting damage to the agricultural activities. This study was conducted in the Towa region of Nihonmatsu in the northern part of Fukushima Prefecture, Japan, (1) to quantify {sup 137}Cs in stream water used to irrigate paddy fields by separating the dissolved and particulate components in water samples and then fractionating the particulate components bonded in different ways using a sequential extraction procedure, and (2) to determine the amounts of radiocesium newly added to paddy fields in irrigation water relative to the amounts of radiocesium already present in the fields from the deposition of atmospheric fallout immediately after the FDNPP accident. Three catchments were studied, and the {sup 137}Cs activity concentrations in stream water samples were 79–198 mBq L{sup −1} under stable runoff conditions and 702–13,400 Bq L{sup −1} under storm runoff conditions. The residual fraction (F4, considered to be non-bioavailable) was dominant, accounting for 59.5–82.6% of the total {sup 137}Cs activity under stable runoff conditions and 69.4–95.1% under storm runoff conditions. The {sup 137}Cs newly added to paddy fields in irrigation water only contributed 0.03–0.05% of the amount already present in the soil (201–348 kBq m{sup −2}). This indicates that the {sup 137}Cs inflow load in irrigation water is negligible compared with that already in the soil. However, the contribution from the potentially bioavailable fractions (F1 + F2 + F3) was one order of magnitude larger, accounting for 0.20–0.59%. The increase in the dissolved and soluble radiocesium fraction (F1) was especially large (3.0% to infinity), suggesting that radiocesium migration in irrigation water is increasing the accumulation of radiocesium in rice

[Continent colostomy and colon irrigation].

Science.gov (United States)

Kostov, D; Temelkov, T; Kiriazov, E; Ivanov, K; Ignatov, V; Kobakov, G

2000-01-01

The authors have studied a functional activity of a continent colostomy at 20 patients, undergone an abdomeno-perineal extirpation of rectum and carried out periodic colonirrigations, during a period of 6 months. A conus type, closed irrigating system has been used. The degree of an incontinency at patients has been compared before and after the beginning of the colonirrigations. The irrigating procedures have reduced spontaneous defications at patients during a week 28 times and have improved the quality of life significantly. The application of colostomy bags has been restricted in 8 (40%) patients. An intraluminal ultrasonographic investigation has been done at 12 (60%) patients at the end of 6 month irrigating period. No changes of the ultrasonographic image of the precolostomic segment of colon has been observed.

Modelling human agency in ancient irrigation

NARCIS (Netherlands)

Ertsen, M.W.

2011-01-01

Human activity is key in understanding ancient irrigation systems. Results of short term actions build up over time, affecting civilizations on larger temporal and spatial scales. Irrigation systems, with their many entities, social and physical, their many interactions within a changing environment

Irrigated agriculture with limited water supply:Tools for understanding and managing irrigation and crop water use efficiencies

Science.gov (United States)

Water availability for irrigated agriculture is declining in both China and the United States due to increased use for power generation, municipalities, industries and environmental protection. Persistent droughts have exacerbated the situation, leading to increases in irrigated area as farmers atte...

Scheduling irrigation for jujube ( Ziziphus jujuba Mill. ) | Zhang ...

African Journals Online (AJOL)

This study was performed to select suitable indicator for scheduling the irrigation of jujube (Ziziphus jujuba Mill.) grown in the Loess Plateau. The relationships between plant-based indicators and soil matrix potential as well as meteorological factors of jujube under deficit irrigation compared with well irrigation were ...

Factors Affecting the Ability of Agriculture to Pay Irrigation-Water Costs

Energy Technology Data Exchange (ETDEWEB)

Hagood, M. A. [Land and Water Development Division, Food and Agriculture Organization of the United Nations, Rome (Italy)

1967-11-15

There are no universally acceptable standard criteria for determining how much agriculture can pay for irrigation water. Justification of cost will depend upon the country's need to develop its soil and water resources for food, for international trade, and for its cumulative effect on other industries in comparison with other possible uses and their over-all contributions to the economy. Social and political conditions often have as much or more influence on development cost decisions than do strictly economic analyses. Many studies indicate that US $0.10/1000 US gal is an upper limit of acceptable costs for developing irrigation water at present economic levels. Under private development and on projects where water users must pay total water costs, methods are available for making feasibility budgets based on present prices. Because of inflation, world food shortage, recessions, future population and other unknown factors, it is hazardous to predict how much farmers or agriculture can pay for irrigation water. Better utilization of water available now offers opportunities for ''developing'' sources at costs much less than those for sources such as sea-water conversion. (author)

Effect of irrigation techniques and strategies on water footprint of growing crops

Science.gov (United States)

Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y. Y.

2014-12-01

technique. This rank though changes in non-moisture limiting condition (wet year) drip performing better in reducing the WF of growing crops than sub-surface drip. It was observed that with all range of irrigation techniques, strategies and field management practices there is more room in reducing the WF of growing crops in loam than sandy-loam soil.

Willingness to Pay Additional Water Rate and Irrigation Knowledge of Farmers in Dinar Karakuyu Irrigation Areas in Turkey

Directory of Open Access Journals (Sweden)

Mevlüt Gül

2017-08-01