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.

Field evaluation of deficit irrigation effects on tomato growth ...

African Journals Online (AJOL)

Two field experiments were conducted using a common tomato cultivar (GS12) to assess the effect of deficit irrigation (DI) regimes on tomato growth performance, and on root-knot nematode Meloidogyne javanica galling and abundance. Irrigation treatments consisted of five irrigation regimes: 20%, 40%, 60%, 80% and ...

Effect of regulated deficit irrigation on growth, flowering and physiological responses of potted Syringa meyeri ‘Palibin’

Directory of Open Access Journals (Sweden)

Michał Koniarski

2014-01-01

Full Text Available The aim of this study was to analyze the physiological and morphological response of Syringa meyeri ‘Palibin’ to different levels of irrigation and to evaluate regulated deficit irrigation (RDI as a possible technique for saving water in nursery production and promoting of flowering. Plants were grown in 3 liter containers in an unheated greenhouse and were subjected to six irrigation treatments for 18 weeks from the be- ginning of June to mid-October 2011. A drip irrigation system was used. Irrigation treatments were established on the basis of evapotranspiration (ETp. Three constant irrigation treatments were used: 1 1 ETp; 2 0.75 ETp; 3 0.5 ETp, while the other three with irrigation varying between phases were as follows: 4 1–0.5–1; 5 1–0.25–1; and 6 0.5–1–0.5 ETp. The 0.75 ETp and 0.5 ETp irrigation regimes adversely affected the growth and visual quality index of plants as well as they resulted in reduced leaf conductance, transpiration, maximum quantum efficiency of photosystem II (Fv/Fm and CCI (chlorophyll content index. Plants grown under the 1–0.5–1 ETp regime had the same morphological parameters as plants grown under the 0.5 ETp treatment. A further reduction of water quantity supplied to plants in the 1–0.25–1 ETp regime resulted in further deterioration of the visual quality index of plants. In this study, the quality index of plants exposed to 0.5–1–0.5 ETp was similar to control plants (1 ETp. These plants were lower, more compact, and had smaller leaves than control plants. The irrigation regimes imposed in this study had no significant effect on the number of floral buds formed in relation to the control regime, except for 1–0.25–1 ETp where this number decreased.

effect of deficit irrigation on growth and yield of okro

African Journals Online (AJOL)

User

reduce the demand for irrigation water (Boland et al., 1993). Deficit irrigation is another way in which water use efficiency can be maximized for higher yields per unit of irrigation water. Stegman (1982) reported that the yield of maize, sprinkler irrigated to induce a 30 - 40 percent depletion of available water between.

Effect of Deficit irrigation on the Productivity of Processing Potato

International Nuclear Information System (INIS)

Darwish, T.M.; Atallah, T.W.

2003-01-01

The area under potatoes in Lebanon has extended to over 15.000 ha to form 17% of irrigated arable land. More farmers rely on processing varieties for prices and marketing reasons. Studies focused so far on irrigation and fertilization of table potatoes. The current recommendations indicate excess N fertilizer input exceeding 600 kg N/ha in the form of compound fertilizers. Potato is irrigated with macro sprinklers with a water input reaching 850 mm/season. Water mismanagement and shortage eventually influence the yield quantity and quality of processing potatoes. Therefore, deficit irrigation is an important water saving tool regarding the increasing pressure on limited water resources in the dry areas. Information on potato response to water stress imposed at different crop stages is available. The aim of this paper is to study the impact of continuous deficit irrigation imposed from the stage of maximum plant development-flowering stage until physiological maturity on the performance of processing potato (Santana) and water and fertilizer use efficiency. Fertilizer placement and irrigation were done through fertigation using drip system. A neutron probe was used to assess water consumption from the soil. The 15 N methodology was used to follow the N recovery as affected by water deficit

Regulated deficit irrigation alters anthocyanins, tannins and sensory properties of cabernet sauvignon grapes and wines.

Science.gov (United States)

Casassa, Luis Federico; Keller, Markus; Harbertson, James F

2015-04-29

Four regulated deficit irrigation (RDI) regimes were applied to Cabernet Sauvignon grapes, which were analyzed for phenolics and also made into wine over three consecutive growing seasons. Relative to an industry standard regime (IS), yield was reduced over the three years by 37% in a full-deficit (FD) regime and by 18% in an early deficit (ED) regime, whereas no yield reduction occurred with a late deficit (LD) regime. Relative to IS, skin anthocyanin concentration (fresh weight basis) was 18% and 24% higher in ED and FD, respectively, whereas no effect was seen in LD. Seed tannin concentration was 3% and 8% higher in ED and FD, respectively, relative to the other two RDI regimes, whereas seed tannin content (amount per berry) was higher in IS than in FD. There were no practically relevant effects on the basic chemistry of the wines. The finished wines showed concentrations of tannins and anthocyanins that generally mirrored observed differences in skin and seed phenolic concentrations, although these were amplified in FD wines. Descriptive sensory analysis of the 2008 wines showed that FD wines were the most saturated in color, with higher purple hue, roughness, dryness and harshness, followed by ED wines, whereas IS and LD wines were less saturated in color and with higher brown and red hues. Overall, FD and ED seemed to yield fruit and wine with greater concentrations of phenolics than IS and LD, with the additional advantage of reducing water usage. However, these apparent benefits need to be balanced out with reductions in crop yields and potential long-term effects associated with pre-véraison water deficits.

Regulated Deficit Irrigation Alters Anthocyanins, Tannins and Sensory Properties of Cabernet Sauvignon Grapes and Wines

Directory of Open Access Journals (Sweden)

Luis Federico Casassa

2015-04-01

Full Text Available Four regulated deficit irrigation (RDI regimes were applied to Cabernet Sauvignon grapes, which were analyzed for phenolics and also made into wine over three consecutive growing seasons. Relative to an industry standard regime (IS, yield was reduced over the three years by 37% in a full-deficit (FD regime and by 18% in an early deficit (ED regime, whereas no yield reduction occurred with a late deficit (LD regime. Relative to IS, skin anthocyanin concentration (fresh weight basis was 18% and 24% higher in ED and FD, respectively, whereas no effect was seen in LD. Seed tannin concentration was 3% and 8% higher in ED and FD, respectively, relative to the other two RDI regimes, whereas seed tannin content (amount per berry was higher in IS than in FD. There were no practically relevant effects on the basic chemistry of the wines. The finished wines showed concentrations of tannins and anthocyanins that generally mirrored observed differences in skin and seed phenolic concentrations, although these were amplified in FD wines. Descriptive sensory analysis of the 2008 wines showed that FD wines were the most saturated in color, with higher purple hue, roughness, dryness and harshness, followed by ED wines, whereas IS and LD wines were less saturated in color and with higher brown and red hues. Overall, FD and ED seemed to yield fruit and wine with greater concentrations of phenolics than IS and LD, with the additional advantage of reducing water usage. However, these apparent benefits need to be balanced out with reductions in crop yields and potential long-term effects associated with pre-véraison water deficits.

Deficit irrigation and sustainable water-resource strategies in agriculture for China’s food security

Science.gov (United States)

Du, Taisheng; Kang, Shaozhong; Zhang, Jianhua; Davies, William J.

2015-01-01

More than 70% of fresh water is used in agriculture in many parts of the world, but competition for domestic and industrial water use is intense. For future global food security, water use in agriculture must become sustainable. Agricultural water-use efficiency and water productivity can be improved at different points from the stomatal to the regional scale. A promising approach is the use of deficit irrigation, which can both save water and induce plant physiological regulations such as stomatal opening and reproductive and vegetative growth. At the scales of the irrigation district, the catchment, and the region, there can be many other components to a sustainable water-resources strategy. There is much interest in whether crop water use can be regulated as a function of understanding of physiological responses. If this is the case, then agricultural water resources can be reallocated to the benefit of the broader community. We summarize the extent of use and impact of deficit irrigation within China. A sustainable strategy for allocation of agricultural water resources for food security is proposed. Our intention is to build an integrative system to control crop water use during different cropping stages and actively regulate the plant’s growth, productivity, and development based on physiological responses. This is done with a view to improving the allocation of limited agricultural water resources. PMID:25873664

Evaluation Yield of Sunflower (Farrokh cultivar under Effects of Conventional Deficit Irrigation and Partial Root Zone Drying

Directory of Open Access Journals (Sweden)

A. Rezaei Estakhroeih

2015-06-01

Full Text Available Water shortage is the most important factors on crop production in the world. Several methods of deficit irrigation are solutions for reduction of irrigation water. To understand the effects of conventional deficit irrigation and partial root zone drying treatments on yield, yield components and water use efficiency of sunflower (Farrokh cultivar, one study was carried out. The research was conducted on Shahid Bahonar University of Kerman in the spring of 2011. A factorial experiment in a randomized complete block design with one control (full irrigation and 18 deficit irrigation treatments in three replications was considered. Deficit irrigation treatments were: conventional deficit irrigation (irrigation with %80, %60 and %40 ETP and partial root zone drying (irrigation with %80, %60 and %40 ETP. Every deficit irrigation treatment was conducted in three growth stage of sunflower (all periods of growth, vegetative growth stage and reproductive growth stage.The results showed that the conventional deficit irrigation treatments (irrigation with 80% ETP in vegetative growth had the highest plant height, leaf area, leaf area index and head diameter. Also, the maximum biological yield equal to49054, maximum grain yield is equal to 9934/3 and maximum oil yield is equal to 2441/2 kg per hectare in the conventional deficit irrigation treatments (irrigation with 80% ETP in vegetative growth occurred.The highest water use efficiency for grain yield is equal to 1/46,forbiological yield equal to7/21 and for dry forage yield is equal 5/7 kilograms per cubic meter of water. According to results,conventional deficit irrigation (irrigation with %80, %60 and %40 ETP is recommended on based.

Investigating deficit irrigation as a climate-smart farming option

Science.gov (United States)

Global water supplies available for irrigation are declining while food demand continues to rise. Deficit irrigation offers a promising strategy to reduce water use with minimal impacts to yields, but is likely to have a range of impacts on soil nutrient cycling processes and climate change mitigati...

Quality attributes of pistachio nuts as affected by rootstock and deficit irrigation.

Science.gov (United States)

Carbonell-Barrachina, Ángel A; Memmi, Houssem; Noguera-Artiaga, Luis; Gijón-López, María del Carmen; Ciapa, Rafał; Pérez-López, David

2015-11-01

In this work, the influence of two regulated deficit irrigation (RDI) treatments and three different rootstocks on the quality of pistachios was evaluated by analyzing different parameters: morphological analysis, physicochemical analysis and sensory analysis. The results obtained in terms of the choice of rootstock revealed that Pistacia atlantica had increased production yields, nut weight, mineral content, higher intensities of characteristic sensory attributes and a higher degree of consumer satisfaction, than the other rootstocks studied. Moreover, the results established that the application of RDI on pistachio cultivation had no significant influence on production yield, weight, size, colour, water activity or mineral composition. Furthermore, T1 treatment (stem water potential < -1.3 MPa) resulted in higher intensities of characteristic sensory attributes and a greater level of satisfaction among international consumers. These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied. © 2014 Society of Chemical Industry.

Thermal infrared sensors for postharvest deficit irrigation of peach

Science.gov (United States)

California has been in a historic drought and the lack of water has been a major problem for agriculture especially for crops that depend on irrigation. A multi-year field study was carried out to demonstrate the feasibility of applying thermal infrared sensors for managing deficit irrigation in an ...

Monthly Optimal Reservoirs Operation for Multicrop Deficit Irrigation under Fuzzy Stochastic Uncertainties

Directory of Open Access Journals (Sweden)

Liudong Zhang

2014-01-01

Full Text Available An uncertain monthly reservoirs operation and multicrop deficit irrigation model was proposed under conjunctive use of underground and surface water for water resources optimization management. The objective is to maximize the total crop yield of the entire irrigation districts. Meanwhile, ecological water remained for the downstream demand. Because of the shortage of water resources, the monthly crop water production function was adopted for multiperiod deficit irrigation management. The model reflects the characteristics of water resources repetitive transformation in typical inland rivers irrigation system. The model was used as an example for water resources optimization management in Shiyang River Basin, China. Uncertainties in reservoir management shown as fuzzy probability were treated through chance-constraint parameter for decision makers. Necessity of dominance (ND was used to analyse the advantages of the method. The optimization results including reservoirs real-time operation policy, deficit irrigation management, and the available water resource allocation could be used to provide decision support for local irrigation management. Besides, the strategies obtained could help with the risk analysis of reservoirs operation stochastically.

Deficit irrigation and sustainable water-resource strategies in agriculture for China's food security.

Science.gov (United States)

Du, Taisheng; Kang, Shaozhong; Zhang, Jianhua; Davies, William J

2015-04-01

More than 70% of fresh water is used in agriculture in many parts of the world, but competition for domestic and industrial water use is intense. For future global food security, water use in agriculture must become sustainable. Agricultural water-use efficiency and water productivity can be improved at different points from the stomatal to the regional scale. A promising approach is the use of deficit irrigation, which can both save water and induce plant physiological regulations such as stomatal opening and reproductive and vegetative growth. At the scales of the irrigation district, the catchment, and the region, there can be many other components to a sustainable water-resources strategy. There is much interest in whether crop water use can be regulated as a function of understanding of physiological responses. If this is the case, then agricultural water resources can be reallocated to the benefit of the broader community. We summarize the extent of use and impact of deficit irrigation within China. A sustainable strategy for allocation of agricultural water resources for food security is proposed. Our intention is to build an integrative system to control crop water use during different cropping stages and actively regulate the plant's growth, productivity, and development based on physiological responses. This is done with a view to improving the allocation of limited agricultural water resources. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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)

Effect of regulated deficit irrigation on the morphology, physiology, carbon allocation and nonstructural carbohydrates of three Kentucky bluegrasses

International Nuclear Information System (INIS)

Liu, J. R.; Ma, L.; Liu, Y. K.; Liu, T. J.; Lu, J. N.; Wang, D. N.

2015-01-01

Regulated deficit irrigation (RDI) has been assessed in a wide number of field and fruit crops. However, few are the studies dealing with turfgrass. This study was conducted to investigate the morphology, physiology and carbon metabolic responses to regulated deficit irrigation for three Kentucky bluegrass (Poa pratensis L.) cultivars. Three Kentucky bluegrass cultivars were grown in PVC (polyvinyl chloride) tubes in a greenhouse and subjected to three soil water treatments in a growth chamber: 1) full irrigation; 2) drought stress, 21 days without water after full irrigation; and 3) drought recovery, stressed plants were re-watered for an additional 21 d. The present study indicated that drought resulted in a decline in turf quality (TQ), leaf relative water content (RWC), and photochemical efficiency (Fv/Fm) and an increase in electrolyte leakage (EL) for the cultivars. The turf quality, RWC, and Fv/Fm of the three Kentucky bluegrass cultivars increased with re-watering. The allocation of /sup 14/ C increased in the roots of these cultivars during the initial phase of drought stress, where a /sup 14/ C distribution shift from the roots to the stem and leaves appeared with further drought stress. Moreover, there was a significant accumulation of total nonstructural carbohydrates (TNC) in the leaves and stem. The TNC content in the leaves, stem, and roots did not completely return to the control levels following 21 d of re-watering, which was consistent with the recovery of TQ, RWC, Fv/Fm, and EL. In addition, during the re-watering treatment, the reduction in the TNC content may be due to increases in the demand or usage as a result of a rapid recovery in the growth and physiological activities as shown by increased TQ, RWC, and Fv/Fm and decreased EL. Our results suggested that the changes in the carbon allocation model and the accumulation and storage of TNC, as well as the changes in TQ, RWC, Fv/Fm, and EL, for the three cultivars are an adaptive reaction to

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...

A comparative study of wireless and wired sensors networks for deficit irrigation management

Science.gov (United States)

Torres Sánchez, Roque; Domingo Miguel, Rafael; Valles, Fulgencio Soto; Perez-Pastor, Alejandro; Lopez Riquelme, Juan Antonio; Blanco Montoya, Victor

2016-04-01

In recent years, the including of sensors in the context of agricultural water management, has received an increasing interest for the establishment of irrigation strategies, such as regulated deficit irrigation (RDI). These strategies allow a significant improvement of crop water productivity (marketable yield / water applied), especially in woody orchards. The application of these deficit irrigation strategies, requires the monitoring of variables related to the orchard, with the purpose of achieving an efficiently irrigation management, since it is necessary to know the soil and plant water status to achieve the level of water deficit desired in each phenological stage. These parameters involve the measurements of soil and plant parameters, by using appropriate instrumentation devices. Traditional centralized instrumentation systems include soil matric potential, water content and LVDT sensors which information is stored by dataloggers with a wired connection to the sensors. Nowadays, these wired systems are being replaced by wireless ones due, mainly, to cost savings in wiring and labor. These technologies (WSNs) allow monitoring a wide variety of parameters in orchards with high density of sensors using discrete and autonomous nodes in the trees or soil places where it is necessary, without using wires. In this paper we present a trial in a cherry crop orchard, with different irrigation strategies where both a wireless and a wired system have been deployed with the aim of obtaining the best criteria on how to select the most suitable technology in future agronomic monitoring systems. The first stage of this study includes the deploying of nodes, wires, dataloggers and the installation of the sensors (same for both, wired and wireless systems). This stage was done during the first 15 weeks of the trial. Specifically, 40 MPS6 soil matric potential, 20 Enviroscan water content and 40 (LVDT and band) dendometers were installed in order to cover the experimental

Resposta das culturas do girassol e do milho a diferentes cenários de rega deficitária Deficit irrigation as a criterion for irrigation water management with sunflower and maize crops

Directory of Open Access Journals (Sweden)

C. M. Toureiro

2007-01-01

the water use optimisation from an environmental point of view. This means that the decision criterion in irrigation management is “deficit irrigation”, rather than maximum ETc as the irrigation water amount. Some experiments with “deficit irrigation” of a sunflower crop (in 2004 irrigation season and maize (in 2005 were carried out in the Irrigation District of Divor (Alentejo, South Portugal. Crop growth and production parameters were evaluated relative to three experimental irrigation regimes: 1 irrigation opportunity and amount with soil available water equalling “optimum yield level”, this corresponding to a non restrictive water use by the crop, according to current procedure, irrigation amount corresponding to maximum ETc; 2 and 3 levels 1 and 2 of deficit irrigation, considering irrigation opportunity with soil available water respectively 10% and 30% under the “optimum yield level” and irrigation amounts 10% and 30% less than ETc between irrigation events. During the flowering periods normal irrigation for full ETc was practiced in all experiment plots. Crop yield data and the economic analysis show that a remarkable potential exists for saving water with “deficit irrigation”.

The effects of bud load and regulated deficit irrigation on sugar, organic acid, phenolic compounds and antioxidant activity of Razakı table grape berries

Directory of Open Access Journals (Sweden)

Tangolar Semih

2015-01-01

Full Text Available This study aims at assessing the effects of increased bud load and irrigation applications on berry quality of the Razakı table grape. Two Regulated Deficit Irrigation (RDI having different irrigation levels (RDI-I and RDI-II based on the growth stages, in addition to a non-irrigated control treatment together with two different bud load practices (K-normal and 2K-two-fold buds of the normal were examined for their effects on quality attributes such as sugar and organic acids contents, phenolic compounds as well as antioxidant capacity of the berries. The non-irrigated vines had highest sugar level (198.86 g/kg in the first year (2013 of the experiment whilst the sugar content of the berries was increased with irrigation (RDI-II in 2014. However the highest organic acid (7.10 g/kg was recorded from the RDI-II treatment in 2013 whereas those of from non-irrigated vines were highest (7.81 g/kg in 2014. Considering the sugar and organic acid content of the berries, bud load effects were not significant. The total phenolic acids were higher under non-irrigated and 2K bud load conditions. Antioxidant activity of berries was increased with RDI-I irrigation and 2K practices in the first year (2013 although no significant effect was recorded in the second year of the experiment. In all applications, glucose among the sugars, tartaric acid among the organic acids, catechin and epicatechin among the phenolic compounds were detected to be higher compared to other components in berries.

Sugar cane yield response to deficit irrigation at two growth stages

International Nuclear Information System (INIS)

Pene, C.B.G.

1995-01-01

A field study on sugar cane (Saccharum officinarum L.) yield response to deficit irrigation during both tillering and stem elongation stages, in order to increase crop water use efficiency, was carried out at Institut des Savanes (IDESSA) experimental station of Ferkessedougou, in Northern Ivory Coast. This cane crop tested was Co 449, an early - maturing genotype of indian origin. This experiment has been conducted for three consecutive years as virgin crop ( from November, 1991 to December 1992 ), first ratoon crop ( from December 1992 to January 1994 ) and as second ratoon crop ( from January 1994 to January 1995 ). The experimental design was a randomized complete block with 10 irrigation treatments in 4 replicates of 54 m sup2 sized plots. Water was applied through an improved furrow irrigation system. Crop water consumption was estimated using the water balance approach based on neutron probe and tensiometer measurements. This field water balance method required the determination of soil hydraulic conductivity as a function of water content and the neutron calibration curve. Data presented are related to the two ratoon crops for which field water balance measurements were investigated. It has been shown in the study that sugar cane growth and yield decline due to water deficit is significantly high during stem elongation as compared to tillering. As a result, the sugar cane tested was much more sensitive to water stress at stem elongation than at tillering. Therefore, deficit irrigation practice as to increase crop water use efficiency might be recommended at tillering rather than stem elongation. The water management strategy to be suggested here may consist of omitting irrigation during tillering ( assuming that the crop is successfully established ), for the benefit of stem elongation. As far as stem elongation is concerned, a moderate water deficit of about 25% with respect to the full irrigation regime appears to increase crop water use efficiency.6 figs

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.

Impacts of deficit irrigation and altered rooting patterns on soil structure and associated soil properties

Science.gov (United States)

A better understanding of belowground systems and overall management impacts on soil health is needed to improve crop production and long-term sustainability under deficit irrigation. This study investigates effects of deficit irrigation on rooting patterns in maize and subsequent impacts on soil pr...

Radiation use efficiency and yield of winter wheat under deficit irrigation in North China

International Nuclear Information System (INIS)

Han, H.; Li, Z.; Ning, T.; Bai, M.; Zhang, X.; Shan, Y.

2008-01-01

An experiment was conducted in North China to investigate the effects of deficit irrigation and winter wheat varieties on the photosynthetic active radiation (PAR) capture ration, PAR utilization and grain yield. Field experiments involved Jimai 20 (J; high yield variety) and Lainong 0153 (L; dryland variety) with non-irrigation and irrigated at the jointing stage. The results showed that whether irrigated at jointing stage or not, there was no significant difference between J and L with respect to the amount of PAR intercepted by the winter wheat canopies. However, significant differences were observed between the varieties with respect to the amount of PAR intercepted by plants that were 60-80 cm above the ground surface. This result was mainly caused by the changes in the vertical distributions of leaf area index. As a result, the effects of the varieties and deficit irrigation on the radiation use efficiency (RUE) and grain yield of winter wheat were due to the vertical distribution of PAR in the winter wheat canopies. During the late growing season of winter wheat, irrespective of the irrigation regime, the RUE and grain yield of J were significantly higher than those of L. These results suggest that a combination of deficit irrigation and a suitable winter wheat variety should be applied in North China

Rainwater deficit and irrigation demand for row crops in Mississippi Blackland Prairie

Science.gov (United States)

Gary Feng; Ying Ouyang; Ardeshir Adeli; John Read; Johnie Jenkins

2018-01-01

Irrigation research in the mid-south United States has not kept pace with a steady increase in irrigated area in recent years. This study used rainfall records from 1895 to 2016 to determine rainwater deficit and irrigation demand for soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and cotton (Gossypium hirsutum L.) in the Blackland Prairie region of Mississippi...

Effect of the season on the free phytoprostane content in Cornicabra extra virgin olive oil from deficit-irrigated olive trees.

Science.gov (United States)

Collado-González, Jacinta; Pérez-López, David; Memmi, Houssem; Gijón, M Carmen; Medina, Sonia; Durand, Thierry; Guy, Alexandre; Galano, Jean-Marie; Fernández, Diego José; Carro, Fernando; Ferreres, Federico; Torrecillas, Arturo; Gil-Izquierdo, Angel

2016-03-30

The effect of regulated deficit irrigation (RDI) on the phytoprostane (PhytoP) content in extra virgin olive (Olea europaea L., cv. Cornicabra) oil (EVOO) was studied. During the 2012 and 2013 seasons, T0 plants were irrigated at 100% ETc, while T1 and T2 plants were irrigated avoiding water deficit during phases I and III of fruit growth and saving water during the non-critical phenological period of pit hardening (phase II), developing a more severe water deficit in T2 plants. In 2013, a fourth treatment (T3) was also performed, which was similar to T2 except that water saving was from the beginning of phase II to 15 days after the end of phase II. 9-F1t -PhytoP, 9-epi-9-F1t -PhytoP, 9-epi-9-D1t -PhytoP, 9-D1t -PhytoP, 16-B1 -PhytoP and 9-L1 -PhytoP were present in Cornicabra EVOO, and their contents increased in the EVOO from RDI plants. Deficit irrigation during pit hardening or for a further period of 2 weeks thereafter to increase irrigation water saving is clearly critical for EVOO composition because of the enhancement of free PhytoPs, which have potential beneficial effects on human health. The response of individual free PhytoPs to changes in plant water status was not as perceptible as expected, preventing their use as biomarkers of water stress. © 2015 Society of Chemical Industry.

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 partial root zone drying and deficit irrigation on nitrogen and phosphorus uptake in potato

DEFF Research Database (Denmark)

Liu, Caixia; Rubæk, Gitte Holton; Liu, Fulai

2015-01-01

Better understanding of the effects of deficit irrigation regimes on phosphorus (P) and nitrogen (N) uptake dynamics is necessary for sustainable water, P and N management. The effects of full (FI), deficit (DI) and partial root-zone drying (PRD) irrigation on potato P and N uptake with P fertili...... was superior to DI in terms of N uptake, but not P uptake. Challenges remain how to maintain crop yield and P uptake under reduced irrigation regimes. Utilization of water and N fertilizer was low when the soil was deficient in P.......Better understanding of the effects of deficit irrigation regimes on phosphorus (P) and nitrogen (N) uptake dynamics is necessary for sustainable water, P and N management. The effects of full (FI), deficit (DI) and partial root-zone drying (PRD) irrigation on potato P and N uptake with P...... fertilization (P1) or without (P0) were investigated in two split-root pot experiments in a soil with low plant available P. Under FI, the plants were irrigated to pot water holding capacity while under DI and PRD, 70% of the water amount of FI was applied on either both or one side of the pots, respectively...

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...

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.

Crop yield response to deficit irrigation imposed at different plant growth stages

International Nuclear Information System (INIS)

Kovaks, T.; Kovaks, G.; Szito, J.

1995-01-01

A series of field experiments were conducted between 1991 - 1994 using 7 irrigation treatments at two fertilizer levels. Nitrogen fertilizers used were labelled with 15 N stable isotope to examine the effect of irrigation on the fertilizer N use efficiency by isotope technique. The irrigation were maintained at four different growth stages of maize, soybean and potato( vegetative, flowering, yield formation and ripening ) in 4 replicates. The aim of study was to compare deficit irrigation( i.e. the water stress imposed, during one growth stage ) with normal irrigation practice included the traditional one. Two watering regimes were established : (1) normal watering when available water was within the range of 60 - 90 %, and (2) deficit irrigation, when the AW was at 30 to 60 %. Neutron probe was used for measuring the soil water status and evaporation data were recorded to determine the amount of irrigation water demand. Reference evapotranspiration ( ETo) was calculated according to Penman - Monteith. Crop water requirement ( ETm) were determined in every year. Actual evapotranspiration ( ETa) was computed using CROPWAT: FAO computer program for irrigation planning and management (1992). Every irrigation treatment was equipped with neutron access tubes in two replicates at a depth from 10 to 130 cm. tensiometers were installed at depths of 30, 50, 60 and 80 cm in one replicate of treatments and were measured on a daily basis while neutron probe measurements were used to monitor the soil water table fluctuations. The irrigation method used was a special type of low pressure drop irrigation. There were measured the amount of rainfall with irrigation water supplied and the moisture distribution profiles were drown for the different treatments. Relationships between relative yield decrease and evapotranspiration and also between the crop yield and water use were determined. 9 tabs, 9 refs, ( Author )

Deficit irrigation of peach trees to reduce water consumption

Science.gov (United States)

Lack of water is a major limiting factor for production tree fruits such as peaches in the San Joaquin Valley of California and many other arid- or semi-arid regions in the world. Deficit irrigation can be used in some cropping systems as a water resource management strategy to reduce non-productiv...

The combined effect of deficit irrigation by treated wastewater and organic amendment on quinoa (Chenopodium quinoa Willd.) productivity

DEFF Research Database (Denmark)

Hirich, Abdelaziz; Choukr-Allah, Redouane; Jacobsen, Sven-Erik

2014-01-01

One of the most important factors that limits crop production is the availability of water. Deficit irrigation is the most important irrigation strategy to increase water use efficiency and crop water productivity. Organic amendment combined with deficit irrigation can be practical solution to co...

Forecasting deficit irrigation adoption using a mixed stakeholder assessment methodology

NARCIS (Netherlands)

Alcón, F.; Tapsuwan, S.; Martínez-Paz, J.M.; Brouwer, R.; de Miguel, M.D.

2014-01-01

Although Deficit Irrigation (DI) can help farmers achieve significant water savings, its adoption is still limited. This study aims to identify the factors that affect DI adoption decisions in a water-scarce area, namely, south-eastern Spain, and to evaluate the importance of these factors. The

Influence of a deficit irrigation regime during ripening on berry composition in grapevines (Vitis vinifera L.) grown in semi-arid areas.

Science.gov (United States)

López, María-Isabel; Sánchez, María-Teresa; Díaz, Antonio; Ramírez, Pilar; Morales, José

2007-11-01

A study was made of the effects of irrigation management strategies during ripening on the quality of Spanish field-grown grapevine (Vitis vinifera L.) cultivars (Baladi, Airén, Montepila, Muscat Blanc à Petits Grains and Pedro Ximénez) grown under the "Montilla-Moriles" Appellation of Origin in Cordoba, Spain. From 1999 to 2002, two water-availability regimes were established: irrigation and non-irrigation. The study aimed to ascertain the effect of irrigation on berry development and ripening, and hence on grape juice quality. Changes in phenological stages, vegetative growth, vineyard yield, berry weight, total soluble solids, titrable acidity, pH, tartaric acid, malic acid, and potassium content were monitored. No significant differences were noted in phenological phases between the non-irrigation and deficit irrigation regimes. The Ravaz index, pruning weight, vineyard yield and berry weight were significantly higher in all varieties and years under deficit irrigation. Deficit irrigation induced higher titrable acidity, higher malic acid and potassium contents and a lower pH, but had no significant effects on berry sugar accumulation or tartaric acid content. Deficit irrigation thus appears to be a promising technique for the production of quality young wines in semi-arid areas.

Water deficit imposed by deficit irrigation at different plant growth stages of maize

International Nuclear Information System (INIS)

Calvache, M.; Reichardt, C.

1995-01-01

The purpose of this study was to identify specific growth stages of maize Crop, at which the plant is less sensitive to water stress so that irrigation can be omitted withhout significant decrease yield. The field experiment was conducted at a University experiment station, Tumbaco, Pichincha, Ecuador, during may - october 1993, on a sandy loam soil ( typic durustoll). Soil moisture was monitored with a neutron probe down to 0.70 m depth, before and 24 h after each irrigation. The actual evapotranspiration of the crop was estimated by the water - balance technique. Field water efficiency and crop water use efficiency were calculated by dividing actual grain yield by irrigation and by ETa, respectively. Nitrogen fertilizer use efficiency was calculated using N - 15 methodology in the 75 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering and yield formation stages were the most sensitive to moisture stress. Nitrogen fertilization significantly increased the grain yield. The crop water use effeciency was the lowest at the flowering and yield formation of the region, the treatments I1 and I7 had the same crop water use efficiency. The results of N - 15 labelled plots ( F1) showed that soil water deficiency significantly affects nitrogen was derived from fertilizer in treatments I3 and I7 and only 11 - 9% in the treatments I2 and I5 respectively. ( Author)

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

Directory of Open Access Journals (Sweden)

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

Yield and water use efficiency of deficit-irrigated maize in a semi ...

African Journals Online (AJOL)

Yield and water use efficiency of deficit-irrigated maize in a semi-arid region of Ethiopia. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE ... African Journal of Food, Agriculture, Nutrition and Development.

Deficit irrigation: is it impacting yield and nutritional quality of fruits?

Science.gov (United States)

Water scarcity, impaired water quality, and decreased soil quality threaten agricultural production in many regions of the world. Farmers’ responses to water shortage and recurrent droughts will ultimately result in the reduced application of water, designated as deficit irrigation (DI). DI may resu...

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

Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

International Nuclear Information System (INIS)

Ebtedaie, M.; Shekafandeh, A.

2016-01-01

The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, ‘Rabbab’ and ‘Shishehgap’. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity) in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC), ‘Rabbab’ showed significantly higher enzyme activity than ‘Shishehgap’. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in ‘Rabbab’ and ‘Shishehgap’, respectively. ‘Rabbab’ showed better growth performance in each level of irrigation than ‘Shishehgap’. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC), a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'.

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.

Nitrogen dynamics in the soil-plant system under deficit and partial root-zone drying irrigation strategies in potatoes

DEFF Research Database (Denmark)

Shahnazari, Ali; Ahmadi, Seyed Hamid; Lærke, Poul Erik

2008-01-01

Experiments were conducted in lysimeters with sandy soil under an automatic rain-out shelter to study the effects of subsurface drip irrigation treatments, full irrigation (FI), deficit irrigation (DI) and partial root-zone drying (PRD), on nitrogen (N) dynamics in the soil-plant system of potatoes...

Soil salinity under deficit drip irrigation of potato and millet in in an arid environment

Directory of Open Access Journals (Sweden)

Kamel Nagaz

2017-06-01

Full Text Available The influence of deficit irrigation (DI with saline water on soil salinity in a drip-irrigated potato and millet fields was investigated. We had compared proportional soil salinity developed under Full and DI under drip irrigation. For both experiments, the treatments were (1 Full, control treatment where rooting zone soil water content was increased to field capacity at each irrigation; (2 DI80; (3 DI60 and DI40; 20, 40 and 60% deficit irrigation compared to Full treatment were applied, respectively. Soil salinity was assessed using the isosalinity maps constructed with grid soil sampling of plant root zone at harvest. Results show that high spatial variability was observed in salinity along soil profiles when applying saline water with drip irrigation for potato. For the DI40 and DI60 treatments, high soil salinity was recorded in the upper soil layer close to the emitter. Increase of soil salinity within soil depths of 30 cm or below was also observed under DI60 and DI40 treatments. The lowest increase was noted under the full treatment. Surface soil salinity was somewhat higher under DI60 and DI40 compared with that of full and DI80 irrigation treatments. The distribution of salts around the dripper changes during the crop season according to applied irrigation treatments, with overall higher concentrations between the drippers and towards the margin of wetted band. Iso-salinity maps at harvest of potato showed that the surface layer of 30 cm depth had the lowest salinity which gradually increased at deeper zones irrespective of the treatment. Salt accumulation essentially occurred at wetting front between the drippers and the plant row. Although salt accumulation was relatively highest along the row under DI treatments, the area of accumulation was relatively shifted toward the center between the rows and the drip line. The results also show the importance of the potato cropping season to benefit from the leaching of soluble salts with the

Integrating Growth Stage Deficit Irrigation into a Process Based Crop Model

Science.gov (United States)

Lopez, Jose R.; Winter, Jonathan M.; Elliott, Joshua; Ruane, Alex C.; Porter, Cheryl; Hoogenboom, Gerrit

2017-01-01

Current rates of agricultural water use are unsustainable in many regions, creating an urgent need to identify improved irrigation strategies for water limited areas. Crop models can be used to quantify plant water requirements, predict the impact of water shortages on yield, and calculate water productivity (WP) to link water availability and crop yields for economic analyses. Many simulations of crop growth and development, especially in regional and global assessments, rely on automatic irrigation algorithms to estimate irrigation dates and amounts. However, these algorithms are not well suited for water limited regions because they have simplistic irrigation rules, such as a single soil-moisture based threshold, and assume unlimited water. To address this constraint, a new modeling framework to simulate agricultural production in water limited areas was developed. The framework consists of a new automatic irrigation algorithm for the simulation of growth stage based deficit irrigation under limited seasonal water availability; and optimization of growth stage specific parameters. The new automatic irrigation algorithm was used to simulate maize and soybean in Gainesville, Florida, and first used to evaluate the sensitivity of maize and soybean simulations to irrigation at different growth stages and then to test the hypothesis that water productivity calculated using simplistic irrigation rules underestimates WP. In the first experiment, the effect of irrigating at specific growth stages on yield and irrigation water use efficiency (IWUE) in maize and soybean was evaluated. In the reproductive stages, IWUE tended to be higher than in the vegetative stages (e.g. IWUE was 18% higher than the well watered treatment when irrigating only during R3 in soybean), and when rainfall events were less frequent. In the second experiment, water productivity (WP) was significantly greater with optimized irrigation schedules compared to non-optimized irrigation schedules in

Effect of Regulated Deficit Irrigation (RDI) and Partial Root zone Drying (PRD) on Quantitative and Qualitative Traits of Strawberry

OpenAIRE

A. Shahnazari; M. Rezaiyan

2016-01-01

Introduction: Deficit irrigation (DI) is a suitable solution to gain acceptable and economic performance by using minimum amount of water. The partial root zone drying (PRD) method introduced in Australia for the first time and its goal was controlling the vine’s excessive growth. This goal gained by alternative drying the rootzone. Basically the theory of PRD method, is expanding the plant’s roots by applying alternative stress on different sides of the roots. So the plants with PRD irrigati...

Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

Directory of Open Access Journals (Sweden)

Morteza Ebtedaie

2016-12-01

Full Text Available The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, ‘Rabbab’ and ‘Shishehgap’. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC, ‘Rabbab’ showed significantly higher enzyme activity than ‘Shishehgap’. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in ‘Rabbab’ and ‘Shishehgap’, respectively. ‘Rabbab’ showed better growth performance in each level of irrigation than ‘Shishehgap’. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC, a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'.

Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

Energy Technology Data Exchange (ETDEWEB)

Ebtedaie, M.; Shekafandeh, A.

2016-07-01

The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, ‘Rabbab’ and ‘Shishehgap’. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity) in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC), ‘Rabbab’ showed significantly higher enzyme activity than ‘Shishehgap’. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in ‘Rabbab’ and ‘Shishehgap’, respectively. ‘Rabbab’ showed better growth performance in each level of irrigation than ‘Shishehgap’. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC), a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'.

Cotton Water Use Efficiency under Two Different Deficit Irrigation Scheduling Methods

Directory of Open Access Journals (Sweden)

Jeffrey T. Baker

2015-08-01

Full Text Available Declines in Ogallala aquifer levels used for irrigation has prompted research to identify methods for optimizing water use efficiency (WUE of cotton (Gossypium hirsutum L. In this experiment, conducted at Lubbock, TX, USA in 2014, our objective was to test two canopy temperature based stress indices, each at two different irrigation trigger set points: the Stress Time (ST method with irrigation triggers set at 5.5 (ST_5.5 and 8.5 h (ST_8.5 and the Crop Water Stress Index (CWSI method with irrigation triggers set at 0.3 (CWSI_0.3 and 0.6 (CWSI_0.6. When these irrigation triggers were exceeded on a given day, the crop was deficit irrigated with 5 mm of water via subsurface drip tape. Also included in the experimental design were a well-watered (WW control irrigated at 110% of potential evapotranspiration and a dry land (DL treatment that relied on rainfall only. Seasonal crop water use ranged from 353 to 625 mm across these six treatments. As expected, cotton lint yield increased with increasing crop water use but lint yield WUE displayed asignificant (p ≤ 0.05 peak near 3.6 to 3.7 kg ha−1 mm−1 for the ST_5.5 and CWSI_0.3 treatments, respectively. Our results suggest that WUE may be optimized in cotton with less water than that needed for maximum lint yield.

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

Interactive effects of deficit irrigation and berry exposure aspect on Merlot and Cabernet Sauvignon in an arid climate.

Science.gov (United States)

Deficit irrigation is used to control vine vigor and enhance water use efficiency yet few studies have compared cultivar response to water deficit in a warm, arid climate with a high amount of solar radiation and measured the interactive effects of water deficit, cultivar and fruit canopy location. ...

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.

A Review of Growth Stage Deficit Irrigation Effecting Sticky Maize Production

Directory of Open Access Journals (Sweden)

Ha Bui Manh

2017-06-01

Full Text Available The shortage of water resources influences the future sustainability of sticky Maize (Zea mays L. production. Deficit irrigation (DI - a water management strategy - has gained much attention from scientists because of enhanced water use efficiency (WUE. Nonetheless, in reality, when applying this technique, its impact on yield and economic returns should be considered. Through an analytical literature review, this study examined the effect of growth stage DI on Maize production factors, i.e. yield, WUE, and economic returns. The results revealed that Maize’s WUE could be improved with the lowest reduction in yield as water stress was imposed during the vegetative or maturation growth stages. Therefore, the profitable returns could be reached even if the yield was reduced; however, the economic return was sensitive to commodity prices. The present review addressed that the Maize flexible capacities under growth stage water stress presented an opportunity for the optimization of irrigated water and profit preservation by accurately judging the managing time of irrigation implementation.

Comparative effects of partial root-zone irrigation and deficit irrigation on phosphorus uptake in tomato plants

DEFF Research Database (Denmark)

Wang, Yaosheng; Liu, Fulai; Jensen, Christian Richardt

2012-01-01

The comparative effects of partial root-zone irrigation (PRI) and deficit irrigation (DI) on phosphorus (P) uptake in tomato (Lycopersicon esculentum Mill.) plants were investigated in a split-root pot experiment. The results showed that PRI treatment improved water-use efficiency (WUE) compared...... to the DI treatment. PRI-treated plants accumulated significantly higher amounts of P in their shoots than DI plants under organic maize straw N fertilisation, whereas similar levels of shoot P accumulation were observed under mineral N fertilisation. Thus, the form of N fertiliser, and thereby...... the different plant N status, affected the accumulation of P in shoots, as reflected by a higher plant N:P ratio following mineral N fertilisation than after organic N fertilisation. Compared to the DI treatment, PRI significantly increased both the physiological and agronomic efficiencies of P-use under...

Impact of regulated deficit irrigation on the physiological ...

African Journals Online (AJOL)

2011

2012-03-22

Mar 22, 2012 ... in plant response to water deficit under field conditions ... firstly related to the reduction in photosynthesis and CO2 ... However, varieties with the highest osmotic ... Indeed, the high potassium consumption in both stressed.

Proanthocyanidin Accumulation and Biosynthesis Are Modulated by the Irrigation Regime in Tempranillo Seeds

Directory of Open Access Journals (Sweden)

Tania Genebra

2014-07-01

Full Text Available The main effects of three different irrigation regimes, i.e., sustained deficit irrigation (SDI, regulated deficit irrigation (RDI and non-irrigated (NI, on seed traits namely proanthocyanidins (PAs were evaluated in the wine grape cultivar Aragonez (syn. Tempranillo grown in Alentejo (Portugal over two growing seasons. Results showed that while the number of seeds per berry was not affected by water availability, seed fresh weight differed among treatments, the NI treatment exhibiting the lowest values. The biosynthetic pathway of flavanols appeared to be modified by the irrigation treatment, and several genes responsible for PA synthesis were up-regulated in the most stressed seeds (RDI and NI. However, this effect had no impact on PA content, suggesting the influence of other factors such as oxidation and/or degradation of PAs at late stages of maturation in grape seeds. The seeds’ non-enzymatic antioxidant capacities (oxygen radical absorbance capacity (ORAC and hydroxyl radical adverting capacity (HORAC were modulated by water deficit and correlated well with PA content. The impact of irrigation strategy on PA biosynthesis, content, and anti-radical activity during seed ripening is discussed in the context of increasing interest in the role of PAs in the color and taste of wine, and the potential health benefits relating to their antioxidant capacity.

Comparative effects of partial root-zone drying and deficit irrigation on nitrogen uptake in potatoes (Solanum tuberosum L.)

DEFF Research Database (Denmark)

Wang, Huiqun; Liu, Fulai; Andersen, Mathias Neumann

2009-01-01

The effects of partial root-zone drying (PRD) as compared with deficit irrigation (DI) and full irrigation (FI) on nitrogen (N) uptake and partitioning in potato (Solanum tuberosum L.) were investigated. Potato plants were grown in split-root pots and were exposed to FI, PRD, and DI treatments...

Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city

Science.gov (United States)

Glenn, E.P.; Mckeon, C.; Gerhart, V.; Nagler, P.L.; Jordan, F.; Artiola, J.

2009-01-01

Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l-1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ETo) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ETo in summer and equal to or slightly greater than ETo in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important. ?? 2008 Elsevier B.V.

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.

Deficit irrigation strategies and their impact on yield and nutritional quality of pomegranate fruit

Science.gov (United States)

In arid regions of the world, farmers use deficit irrigation (DI) strategies to supply water at levels below full crop evapotranspiration throughout the growing season or at specific phenological stages. In water-sensitive regions, growing crops that are water stress-resistant and tolerant of arid e...

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.

REGULATED DEFICIT IRRIGATION AND DIFFERENT MULCH TYPES ON FRUIT QUALITY AND YIELD OF WATERMELON

Directory of Open Access Journals (Sweden)

KLEITON ROCHA SARAIVA

2017-01-01

Full Text Available The objective of this work was to assess the pulp resistance, soluble solids and yield of watermelon fruits grown under different irrigation managements (determined by the ISAREG model and mulches, and their interactions. After a survey carried out on local producers, two experiments were conducted, using a completely randomized block design in split - plot arrangement with four replications, in the Teaching, Research and Extension Unit (UEPE of the Federal Institute of Ceara (IFCE, Jaguaribe - Apodi Irrigation District (DIJA, State of Ceara, Brazil. The treatments consisted of four irrigation managements in the plots, M1 (100% of the available - water capacity (AWC of the soil, M2 (80%, M3 (60% and M4 (average water depth used by local producers and four mulch types in the sub - plots, without mulching (C0 with rice husk (C1, white plastic (C2 and black plastic (C3 as mulches. The results were subjected to analysis of variance, and significant results were subjected to regression (irrigation managements, average test (mulches and trend graphs (interaction between the factors. The irrigation management practiced during the watermelon crop cycle by the local producers of the Irrigation District of Jaguaribe - Apodi (DIJA in the State of Ceara, Brazil, is not appropriated, since they usually apply more water than the highest water depth determined by the ISAREG model (100% of the AWC. The plants grown under irrigation water depth of 365.20 mm (M1 and soils with mulches of rice husk or white plastic had the highest yields and fruits with better quality of soluble solids and pulp resistance.

Comparative effects of partial rootzone drying and deficit irrigation on growth and physiology of tomato plants

Directory of Open Access Journals (Sweden)

Savić Slađana

2009-01-01

Full Text Available The effects of partial rootzone drying (PRD, deficit irrigation (DI, and full irrigation (FI on tomato physiology were investigated. In PRD and DI plants, leaf water potential values and stomatal conductance were significantly lower, while xylem ABA concentration was greater compared to FI plants. Photosynthesis was similar for all treatments. Water use efficiency was improved by PRD and DI, which reduced fruit dry weight, but had no effect on dry weight of leaves and stems.

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

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

S. J. Azimzadeh

2017-03-01

Full Text Available Introduction In agricultural ecosystems, organic fertilizers play an important role in producing sustainable agricultural production. Considering this Sajjadi Nik et al (2011 reported that with increasing of vermicompost inoculation with nitroxin biofertilizer, capsule number per sesame plant increased, so that the most of capsule number per plant (124.7 was observed in 10 t/h vermicompost with nitroxin inoculation. Seyyedi and Rezvani Moghaddam (2011 reported that seed number per plant and the thousand kernel weight in treatment of 80 t/h mushroom compost in comparison with control were increased by 2.98 and 1.56 fold. In another experiment, Kato and Yamagishi (2011 reported that seed yield of wheat in application of manures equal to 80 t/h/ year more than 10 years in comparison with application of nitrogen fertilizer at the rate of 204 kg/h, showed significant increasing from 725 to 885 gr/m2. In another study, Rezvani Moghaddam et al (2010 reported that the most (74.08 and the least (60.94 seed number per capsule in sesame was obtained in the treatments of cow manure and control treatments respectively. The aim of this experiment was evaluation the effects of municipal waste compost, vermicompost and cow manure fertilizers in comparison with chemical fertilizer on yield and yield components of canola under two levels of deficit and full irrigation. Materials and Methods In order to evaluate the replacement probability of organic fertilizer with chemical fertilizers in canola cultivation, an experiment was conducted at research farm of Mashhad Faculty of Agriculture in year of 2013. Treatments were fertilizer and irrigation. Irrigation treatments included full and deficit irrigation. Fertilizer treatments included municipal waste compost, vermicompost, manure and chemical fertilizer. Chemical fertilizer included Nitrogen and Phosphorus. Experiment was conducted as split plot in randomized complete block design with three replications. Organic

Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

Directory of Open Access Journals (Sweden)

Meghan N Pawlowski

Full Text Available Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2, as methane was oxidized and nitrous oxide (N2O emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

Science.gov (United States)

Pawlowski, Meghan N; Crow, Susan E; Meki, Manyowa N; Kiniry, James R; Taylor, Andrew D; Ogoshi, Richard; Youkhana, Adel; Nakahata, Mae

2017-01-01

Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG) footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C) stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2), as methane was oxidized and nitrous oxide (N2O) emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP) compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

[Influence of water deficit and supplemental irrigation on nitrogen uptake by winter wheat and nitrogen residual in soil].

Science.gov (United States)

Wang, Zhaohui; Wang, Bing; Li, Shengxiu

2004-08-01

Pot experiment in greenhouse showed that water deficit at all growth stages and supplemental irrigation at tillering stage significantly decreased the nitrogen uptake by winter wheat and increased the mineral N residual (79.8-113.7 mg x kg(-1)) in soil. Supplemental irrigation at over-wintering, jointing or filling stage significantly increased the nitrogen uptake by plant and decreased the nitrogen residual (47.2-60.3 mg x kg(-1)) in soil. But, the increase of nitrogen uptake caused by supplemental irrigation did not always mean a high magnitude of efficient use of nitrogen by plants. Supplemental irrigation at over-wintering stage didn't induce any significant change in nitrogen content of grain, irrigation at filling stage increased the nitrogen content by 20.9%, and doing this at jointing stage decreased the nitrogen content by 19.6%, as compared to the control.

Can deficit irrigation techniques be used to enhance phosphorus and water use efficiency and benefit crop yields?

Science.gov (United States)

Wright, Hannah R.; Dodd, Ian C.; Blackwell, Martin S. A.; Surridge, Ben W. J.

2015-04-01

Soil drying and rewetting (DRW) affects the forms and availability of phosphorus (P). Water soluble P has been reported to increase 1.8- to 19-fold after air-drying with the majority of the increase (56-100%) attributable to organic P. Similarly, in two contrasting soil types DRW increased concentrations of total P and reactive P in leachate, likely due to enhanced P mineralisation and physiochemical processes causing detachment of soil colloids, with faster rewetting rates related to higher concentrations of P. The intensity of drying as well as the rate of rewetting influences organic and inorganic P cycling. How these dynamics are driven by soil water status, and impact crop P acquisition and growth, remains unclear. Improving P and water use efficiencies and crop yields is globally important as both P and water resources become increasingly scarce, whilst demand for food increases. Irrigation supply below the water requirement for full crop evapotranspiration is employed by agricultural practitioners where water supply is limited. Regulated deficit irrigation describes the scheduling of water supply to correspond to the times of highest crop demand. Alternate wetting and drying (AWD) is applied in lowland irrigated rice production to avoid flooding at certain times of crop development, and has benefited P nutrition and yields. This research aims to optimise the benefits of P availability and uptake achieved by DRW by guiding deficit irrigation management strategies. Further determination of underlying processes driving P cycling at fluctuating soil moisture status is required. Presented here is a summary of the literature on DRW effects on soil P availability and plant P uptake and partitioning, in a range of soil types and cropping systems, with emphasis on alternate wetting and drying irrigation (AWD) compared to continuous flooding in lowland irrigated rice production. Soil water contents and matric potentials, and effects on P dynamics, are highly variable

Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

Directory of Open Access Journals (Sweden)

Y. García-Orellana

2013-01-01

Full Text Available Field-grown lemon trees (Citrus limon (L. Burm. fil. cv. Fino were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS signal intensity (actual MDS/control treatment MDS threshold values of 1.25 (T1 treatment and 1.35 (T2 treatment, which induced two different drought stress levels. Daily variations in leaf (Yleaf and stem (Ystem water potentials, leaf conductance, net photosynthesis, sap flow (SF and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Yleaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Ystem was seen to be a better plant water status indicator than Yleaf. The difference between the two values of Y (Ystem - Yleaf  = DY was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees.

The effects of the regulated deficit irrigation on yield and some yield ...

African Journals Online (AJOL)

user

2011-05-16

May 16, 2011 ... human diet and environment, its production requires a significant amount of water due to its relatively shallow root system. Thus, the amount of ... should be applied. Drip irrigation, reduces deep percolation and evaporation ..... processing tomato yield, water table depth, soil salinity and profitability. Agric.

Peach response to water deficit in a semi-arid region

Science.gov (United States)

Paltineanu, C.; Septar, L.; Moale, C.; Nicolae, S.; Nicola, C.

2013-09-01

During three years a deficit irrigation experiment was performed on peach response under the semi-arid conditions of south-eastern Romania. Three sprinkler-irrigated treatments were investigated: fully irrigated, deficit irrigation treatment, and non-irrigated control treatment. Soil water content ranged between 60 and 76% of the plant available soil water capacity in fully irrigated, between 40 and 62% in deficit irrigation treatment, and between 30 and 45% in control. There were significant differences in fruit yield between the treatments. Irrigation water use efficiency was maximum in deficit irrigation treatment. Fruit yield correlated significantly with irrigation application. Total dry matter content, total solids content and titrable acidity of fruit were significantly different in the irrigated treatments vs. the control. Significant correlation coefficients were found between some fruit chemical components. For the possible future global warming conditions, when water use becomes increasingly restrictive, deficit irrigation will be a reasonable solution for water conservation in regions with similar soil and climate conditions.

Water deficit imposed by partial irrigation at different plant growth stages of common bean

International Nuclear Information System (INIS)

Calvache, M.; Reichardt, K.

1995-01-01

The purpose of this study was to identify specific growth stages of common bean crop, at which the plant is less sensitive to water stress so that irrigation can be omitted without significant decrease in biological nitrogen fixation and yield. Two field experiments were conducted at a University experiments station, Tumbaco, Pichincha, Ecuador, on a sandy loam soil ( Typic durustoll ). The climate is warm and dry ( mean air temperature 16 degree Celcius and mean relative humidity 74% ) during the cropping season and rainfall of 123 mm was recorded during the cropping period. The treatments consisted of combinations of 7 irrigation regimes ( I1 = all normal watering; I2 = all stres; I3 = traditional practice; I4 = single stress at vegetation; I5 flowering; I6 = yield formation and I7 = ripening stages ) and 2 levels of applied N ( 20 and 80 kg/ ha ). Differential irrigation was started after 3 uniform irrigations for germination and crop establishment. Soil moisture was monitored with a neutron probe down to 0.60 m depth, before and 24 h after each irrigation. Biological Nitrogen Fixation was calculated using the N- 15 metodology in the 20 kg N/ ha treatment. From the yield data, it can be concluded that treatments which had irrigation deficit had lower yield than those that had suplementary irrigation. The flowering stage was the most sensitive to number of pods and grain yield. Biological Nitrogen Fixation was significantly affected by water stress at flowering and formation stages. The crop water use efficiency ( kg/ m 3 ) was the lowest at flowering period and the yield response factor ( Ky ) was higher in treatments I2 ( all stress ) and I5 (stress at flowering ). Comparing with traditional practice by farmers of the region, only treatments I1 and I7 had 13 and 10 % higher crop water use effeciency. 15 tabs., 7 refs. ( Author )

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

Directory of Open Access Journals (Sweden)

Maryam Bostani

2017-12-01

Full Text Available Introduction Drought is one of the most important environmental factors that influences yield and quality of tomato (Solanum lycopersicum Peralta & Spoonerin arid and semi-arid regions. Drought stress causes different physiological effects on plant growth. Vegetable crops are more sensitive to water shortage and any deficit in providing water requirement of plant leads to considerable reduction of yield. For future global food security, water use in agriculture must become sustainable. Agricultural water-use efficiency and water productivity can be improved by many approaches and strategies. Super absorbent polymers (SAP as a soil improvement substance, covering soil by different types of mulches and blocking a part of sun light by shading have been used effectively to increase the water use efficiency sustainability of production in agricultural systems. But, still there is a limited knowledge on interactions of SAPs, plastic mulches and shading under deficit irrigation on yield and quality of tomato. Material and Methods In order to evaluate the effects of SAP, black plastic mulches and decreasing light intensity under deficit irrigation on yield and quality of tomato ‘Early Urbana VF 132- 7171’ fruits, the current research carried out in a field experiment at department of Horticulture, Ilam University during 2014 using a 3 × 8 × 3 split plot assay based on a randomized complete block design (RCBD with two factor. The main factor was including three irrigation intervals (once after 3, 6 or 9 days equivalent to soils field capacity and sub-factor was including eight treatments viz., mulch, superabsorbent, shading, mulch + superabsorbent, mulch + shading, superabsorbent¬ + shading, mulch + shading + superabsorbent and control. Light intensity was measured by a digital exposure meter ‘Mastech MS6610’. Data were subjected to ANOVA using SAS software version 9.3. Verification of significant differences was done using Duncan's Test at 5

Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

Energy Technology Data Exchange (ETDEWEB)

Garcia-Orellana, Y.; Ortuno, M. F.; Conejero, W.; Ruiz-Sanchez, M. C.

2013-05-01

Field-grown lemon trees (Citrus limon (L.) Burm. fil. cv. Fino) were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS) signal intensity (actual MDS/control treatment MDS) threshold values of 1.25 (T1 treatment) and 1.35 (T2 treatment), which induced two different drought stress levels. Daily variations in leaf (Y{sub l}eaf) and stem (Y{sub s}tem) water potentials, leaf conductance, net photosynthesis, sap flow (SF) and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Y{sub l}eaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Y{sub s}tem was seen to be a better plant water status indicator than Y{sub l}eaf. The difference between the two values of Y (Y{sub s}tem - Y{sub l}eaf {Delta}{Psi}) was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC) was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees. (Author) 40 refs.

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

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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

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

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

Deficit irrigation and fertilization strategies to improve soil quality and alfalfa yield in arid and semi-arid areas of northern China.

Science.gov (United States)

Jia, Qianmin; Kamran, Muhammad; Ali, Shahzad; Sun, Lefeng; Zhang, Peng; Ren, Xiaolong; Jia, Zhikuan

2018-01-01

In the arid and semi-arid areas of northern China, overexploitation of fertilizers and extensive irrigation with brackish groundwater have led to soil degradation and large areas of farmland have been abandoned. In order to improve the soil quality of abandoned farmland and make reasonable use of brackish groundwater, we conducted field trials in 2013 and 2014. In our study, we used three fertilization modes (CF, chemical fertilizer; OM, organic manure and chemical fertilizer; NF, no fertilizer) and three deficit irrigation levels (I 0 : 0 mm; I 75 : 75 mm; I 150 : 150 mm). The results showed that the activities of soil urease, alkaline phosphatase, invertase, catalase, and dehydrogenase in the OM treatment were significantly improved compared with those in the CF and NF treatments under the three deficit irrigation levels. Compared with NF, the OM treatment significantly increased soil organic carbon (SOC), water-soluble carbon (WSC), total nitrogen, microbial biomass carbon and nitrogen (MBC and MBN), and soil respiration rate, and significantly decreased soil C:N and MBC:MBN ratios and the metabolic quotient, thus improving the soil quality of abandoned farmland. Furthermore, the OM treatment increased alfalfa plant height, leaf area index, leaf chlorophyll content, and biomass yield. Under the CF and OM fertilization modes, the activities of urease and catalase in I 150 were significantly higher than those in I 0 , whereas irrigating without fertilizer did not significantly increase the activity of these two enzymes. Regardless of fertilization, alkaline phosphatase activity increased with an increase in irrigation amount, whereas invertase activity decreased. The results showed that deficit irrigation with brackish groundwater under the OM treatment can improve soil quality. Over the two years of the study, maximum SOC, total nitrogen, WSC, MBC, and MBN were observed under the OM-I 150 treatment, and the alfalfa biomass yield of this treatment was also

Deficit irrigation and fertilization strategies to improve soil quality and alfalfa yield in arid and semi-arid areas of northern China

Directory of Open Access Journals (Sweden)

Qianmin Jia

2018-02-01

Full Text Available Background In the arid and semi-arid areas of northern China, overexploitation of fertilizers and extensive irrigation with brackish groundwater have led to soil degradation and large areas of farmland have been abandoned. In order to improve the soil quality of abandoned farmland and make reasonable use of brackish groundwater, we conducted field trials in 2013 and 2014. Methods In our study, we used three fertilization modes (CF, chemical fertilizer; OM, organic manure and chemical fertilizer; NF, no fertilizer and three deficit irrigation levels (I0: 0 mm; I75: 75 mm; I150: 150 mm. Results The results showed that the activities of soil urease, alkaline phosphatase, invertase, catalase, and dehydrogenase in the OM treatment were significantly improved compared with those in the CF and NF treatments under the three deficit irrigation levels. Compared with NF, the OM treatment significantly increased soil organic carbon (SOC, water-soluble carbon (WSC, total nitrogen, microbial biomass carbon and nitrogen (MBC and MBN, and soil respiration rate, and significantly decreased soil C:N and MBC:MBN ratios and the metabolic quotient, thus improving the soil quality of abandoned farmland. Furthermore, the OM treatment increased alfalfa plant height, leaf area index, leaf chlorophyll content, and biomass yield. Under the CF and OM fertilization modes, the activities of urease and catalase in I150 were significantly higher than those in I0, whereas irrigating without fertilizer did not significantly increase the activity of these two enzymes. Regardless of fertilization, alkaline phosphatase activity increased with an increase in irrigation amount, whereas invertase activity decreased. Discussion The results showed that deficit irrigation with brackish groundwater under the OM treatment can improve soil quality. Over the two years of the study, maximum SOC, total nitrogen, WSC, MBC, and MBN were observed under the OM-I150 treatment, and the alfalfa

Closing the irrigation deficit in Cambodia: Implications for transboundary impacts on groundwater and Mekong River flow

Science.gov (United States)

Erban, Laura E.; Gorelick, Steven M.

2016-04-01

Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and Vietnam, located downstream on the Mekong River. Here we quantify the extent of the dry season ;deficit; area in the Cambodian Mekong River catchment, using a recent agricultural survey and our analysis of MODIS satellite data. Irrigation of this land for rice production would require a volume of water up to 31% of dry season Mekong River flow to Vietnam. However, the two countries share an aquifer system in the Mekong Delta, where irrigation demand is increasingly met by groundwater. We estimate expansion rates of groundwater-irrigated land to be >10% per year in the Cambodian Delta using LANDSAT satellite data and simulate the effects of future expansion on groundwater levels over a 25-year period. If groundwater irrigation continues to expand at current rates, the water table will drop below the lift limit of suction pump wells, used for domestic supply by >1.5 million people, throughout much of the area within 15 years. Extensive groundwater irrigation jeopardizes access for shallow domestic water supply wells, raises the costs of pumping for all groundwater users, and may exacerbate arsenic contamination and land subsidence that are already widespread hazards in the region.

Seasonal population dynamics of Homalodisca vitripennis (Hemiptera: Cicadellidae) in sweet orange trees maintained under continuous deficit irrigation.

Science.gov (United States)

Krugner, Rodrigo; Groves, Russell L; Johnson, Marshall W; Flores, Arnel P; Hagler, James R; Morse, Joseph G

2009-06-01

A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) to determine the influence of plant water stress on the population dynamics of glassy-winged sharpshooter, Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop evapotranspiration rate (ET(c)) and continuous deficit-irrigation regimens at 80 and 60% ET(c). Microclimate and plant conditions monitored included temperature and humidity in the tree canopy, leaf surface temperature, water potential, and fruit quality and yield. Glassy-winged sharpshooter population densities and activity were monitored weekly by a combination of visual inspections, beat net sampling, and trapping. Glassy-winged sharpshooter populations were negatively affected by severe plant water stress; however, population densities were not linearly related to decreasing water availability in plants. Citrus trees irrigated at 60% ET(c) had significantly warmer leaves, lower xylem water potential, and consequently hosted fewer glassy-winged sharpshooter eggs, nymphs, and adults than trees irrigated at 80% ET(c). Citrus trees irrigated at 100% ET(c) hosted similar numbers of glassy-winged sharpshooter stages as trees irrigated at 60% ET(c) and a lower number of glassy-winged sharpshooter nymphs than the 80% ET(c) treatment, specifically during the nymphal density peak in mid-April to early July. Irrigation treatments did not affect populations of monitored natural enemies. Although the adult glassy-winged sharpshooter population was reduced, on average, by 50% in trees under severe water stress, the total number of fruit and number of fruit across several fruit grade categories were significantly lower in the 60% ET(c) than in the 80 and 100% ET(c) irrigation treatments.

Effect of Alternative Irrigation Strategies on Yield and Quality of Fiesta Raisin Grapes Grown in California

Directory of Open Access Journals (Sweden)

Isabel Abrisqueta

2018-04-01

Full Text Available Traditionally, grapes are fully irrigated, but alternative irrigation strategies to reduce applied irrigation water may be necessary in the future as occurrences of drought increase. This study was conducted in the San Joaquin Valley (SJV of California from 2012 to 2014. Three irrigation treatments were used to study the effects on the yield and quality of Fiesta grapes. The treatments included: grower irrigation (GI weekly irrigation lasting for approximately 65 h; sustained deficit (SD equal to 80% of the GI treatment; and regulated deficit (RD equal to 50% of the GI until fruit set when it was increased to 80% of the GI through harvest and reduced to 50% of the GI after harvest. Average water use across treatments was ≈489 mm. Average yield across all treatments was 7.9 t ha−1, 9.1 t ha−1 and 11.8 t ha−1 in 2012, 2013, and 2014, respectively. Yield was sustained in SD and RD, with up to a 20% reduction in applied water use compared to GI. There were no differences in raisin quality and grade among any of the treatments in any year. The percentage of substandard grapes decreased from an average of 12.6% in 2012 to 3.6% in 2013 and 2014. Growers may use a sustained deficit approach during periods of limited water availability to minimize the effect on yield.

Impact of extended maceration and regulated deficit irrigation (RDI) in Cabernet Sauvignon wines: characterization of proanthocyanidin distribution, anthocyanin extraction, and chromatic properties.

Science.gov (United States)

Casassa, L Federico; Larsen, Richard C; Beaver, Christopher W; Mireles, Maria S; Keller, Markus; Riley, William R; Smithyman, Russell; Harbertson, James F

2013-07-03

The impact of extended maceration (EM) was studied in Cabernet Sauvignon grapes sourced from a vineyard subjected to four regulated deficit irrigation (RDI) treatments: (I) 100% replenishment of crop evapotranspiration (100% ETc), (II) 70% ETc, (III) 25% ETc until véraison, followed by 100% ETc until harvest, and IV) 25% ETc. Each vineyard replicate was made into wine with two replicates designated as controls (10-day skin contact) and two as extended maceration (EM, 30-day skin contact). The mean degree of polymerization (mDP), size distribution, concentration, and composition of wine proanthocyanidins (PAs) and monomeric flavan-3-ols of 90 fractions were characterized by preparative and analytical HPLC techniques. The maceration length imparted a larger effect on most chemical parameters. The RDI treatment had no effect on the extraction patterns of anthocyanins, PAs, and/or on the origin of the PAs extracted into the wines. Conversely, EM led to anthocyanin losses and increased PA extraction during maceration, with ~73% of seed-derived PAs. Accordingly, the concentration of monomeric flavan-3-ols, oligomeric (2 ≤ mDP < 5) and polymeric PAs (mDP ≥ 5) was higher in EM wines. The size distribution of the wines' PAs revealed two major peaks as a function of concentration at mDP 2 (22-27% of total PAs mass) and at mDP 6-7 (12-17% of total PAs mass) and was found to follow a non-normal Rayleigh-type distribution.

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

Yield and resource use efficiency of Plukenetia volubilis plants at two distinct growth stages as affected by irrigation and fertilization.

Science.gov (United States)

Gong, He-De; Geng, Yan-Jing; Yang, Chun; Jiao, Dong-Ying; Chen, Liang; Cai, Zhi-Quan

2018-01-08

This study is to test how seedlings (vegetative) and large plants (reproductive) of an oilseed crop (Plukenetia volubilis) responded to regulated deficit irrigation techniques (conventional deficit irrigation, DI; alternative partial root-zone irrigation, APRI) in a tropical humid monsoon area. Seedlings were more sensitive to water deficit than large plants. Although APRI did better than DI in saving water for both seedlings and large plants at the same amount of irrigation, full irrigation (FI) is optimal for faster seedling growth at the expense of water-use efficiency (WUE). The seed number per unit area was responsible for the total seed oil yield, largely depending on the active process of carbon and nitrogen storages at the whole-plant level. The magnitude of the increase in total seed and seed oil yield by fertilization was similar under different irrigation regimes. Compared with FI, DI can save water, but reduced the total seed yield and had lower agronomic nutrient-use efficiency (NUE agr ); whereas APRI had similar total seed yield and NUE agr , but reduced water use greatly. Although the dual goal of increasing the yield and saving water was not compatible, maintaining a high yield and NUEagr at the cost of WUE is recommended for P. volubilis plantation in t he water-rich areas.

Molecular Characterization and Germination Analysis of Cotton (Gossypium hirsutum L. Genotypes under Water Deficit Irrigation

Directory of Open Access Journals (Sweden)

Eminur ELÇİ

2016-09-01

Full Text Available Cotton is an important crop in terms of economic and strategic impacts. Drought stress is one of the most important environmental stress factors which negatively affects growth and yield of plants in Turkey as occurred in many countries in the world. In this study, 11 different cotton cultivars selected based on their agronomical characters were tested under water deficit irrigation strategies. Thus, it was aimed to select and/or determine appropriate new varieties for breeding new national materials resistant to drought stress, and to characterize with the molecular microsatellite markers. According to the different irrigation levels (25%, 50%, 75% and 100% plants were observed under the stressed conditions at the irrigation levels of 50% and 25%. Among the tested varieties, Tamcot Sphinx, Tamcot 94, Tamcot CamdEs and BA525 varieties were found to be more water stress tolerant than others in terms of germination time and germinated plant. The UPGMA (Unweighted Pair-Group Method Using Arithmetic Averages analysis was carried out using 28 markers with average 0.306 polymorphism information content (PIC for molecular characterization studies. Based on the UPGMA results, the varieties were clustered into two groups. It is expected that the results obtained from this study might provide considerable data for improving new drought tolerant varieties.

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 ...

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

Directory of Open Access Journals (Sweden)

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.

Alternate partial root-zone drying irrigation improves fruit quality in tomatoes

DEFF Research Database (Denmark)

Sun, Y.; Holm, Peter Engelund; Liu, Fulai

2014-01-01

Alternate partial root-zone drying (PRD) irrigation and deficit irrigation (DI) are water-saving irrigation strategies. Here, comparative effects of PRD and DI on fruit quality of tomato (Solanum lycopersicum L.) were investigated. The results showed that the irrigation treatments had no effect o...

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 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

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.

Maximizing the value of limited irrigation water: USDA researchers study how producers on limited irrigation can save water and be profitable

Science.gov (United States)

Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

Potentials for Supplemental Irrigation in Some Rainfall Areas of Imo ...

African Journals Online (AJOL)

In addition, there were up to five months of the year during which rainwater was much in deficit of evapotranspiration. All these stress the need for irrigation. Analysis of water quality (surface, groundwater, and rainfall runoff) showed their suitability for irrigation. Quantity assessment of supplemental irrigation during the dry ...

Gain-P: A new strategy to increase furrow irrigation efficiency

International Nuclear Information System (INIS)

Schmitz, G.H.; Wohling, T.; Paly, M. D.; Schutze, N.

2007-01-01

The new methodology GAIN-P combines Genetic Algorithms, Artificial Intelligence techniques and rigorous Process modeling for substantially improving irrigation efficiency. The new strategy simultaneously identifies optimal values of both scheduling and irrigation parameters for an entire growing season and can be applied to irrigation systems with adequate or deficit water supply. In this contribution, GAIN-P is applied to furrow irrigation tackling the more difficult subject of the more effective deficit irrigation. A physically -based hydrodynamic irrigation model is iteratively coupled with a 2D subsurface flow model for generating a database containing all realistically feasible scenarios of water application in furrow irrigation. It is used for training a problem-adapted artificial neural network based on self-organized maps, which in turn portrays the inverse solution of the hydrodynamic furrow irrigation model and thus enormously speeds up the overall performance of the complete optimization tool. Global optimization with genetic algorithm finds the schedule with maximum crop yield for the given water volume. The impact of different irrigation schedules on crop yield is calculated by the coupled furrow irrigation model which also simulates soil evaporation, precipitation and root water uptake by the plants over the whole growing seasons, as well as crop growth and yield. First results with the new optimization strategy show that GAIN-P has a high potential to increase irrigation efficiency. (author)

Evaluation of superabsorbent efficiency in response to dehydration frequencies, salinity and temperature and its effect on yield and quality of cotton under deficit irrigation

Directory of Open Access Journals (Sweden)

Hamid-Reza Fallahi

2016-03-01

Full Text Available Introduction Reduced availability of water resources in many arid countries including Iran, particularly in response to the indiscriminate harvesting of water reservoirs and climate change, has created concerns. Therefore, the sustainable use of water resources especially in agriculture is a necessity for these countries. Strategies such as deficit irrigation and superabsorbent application are two important ways for improving water use efficiency in agricultural lands. In deficit irrigation the crop must be irrigated less than its required water. Therefore, some reduction may occur in crop yield, but the savings in water will improve the water use efficiency (Akbari Nodehi, 2011. Superabsorbent polymers also increase the nutrients and water holding capacity of soil for a long time and thereby reduce crop water requirement. However, the effectiveness of these materials could be affected by dehydration frequencies, temperature and irrigation water quality (Karimi et al., 2009. Due to the limitation of water resources in many parts of Iran, the aim of this study was to investigate the possibility of cotton production under deficit irrigation along with application of different rates of superabsorbent. In addition, simulation of superabsorbent efficiency at different levels of salinity, temperature and dehydration frequencies (swelling and de-swelling were the other objectives in this study. Materials and methods 1. Laboratory experiments In these experiments the effects of temperature (4, 10, 20, 30 and 40 °C, salinity (0, 0.25, 0.5, 0.75 and 1% NaCl solutions at two temperatures of 10 and 25°C and frequency of partial dehydration (from 1 to 5 stages watering and 70% dewatering were simulated on water absorption capacity of superabsorbent polymer at laboratory of environmental stresses, Sarayan Faculty of Agriculture, Birjand University. 2- Field experiment This experiment was designed at Research Station of Sarayan Faculty of Agriculture

Arbuscular mycorrhizal fungi alleviate abiotic stresses in potato plants caused by low phosphorus and deficit irrigation/partial root-zone drying

DEFF Research Database (Denmark)

Liu, Caixia; Ravnskov, Sabine; Lui, Fulai

2018-01-01

Deficit irrigation (DI) improves water use efficiency (WUE), but the reduced water input often limits plant growth and nutrient uptake. The current study examined whether arbuscular mycorrhizal fungi (AMF) could alleviate abiotic stress caused by low phosphorus (P) fertilization and DI...... or improved plant growth and P/nitrogen (N) uptake when subjected to DI/PRD and P0. However, the positive responses to AMF varied with P level and irrigation regime. Functional differences were found in ability of AMF species alleviating plant stress. The largest positive plant biomass response to M1+ and M2......+ was found under FI, both at P1 and P0 (25% increase), while plant biomass response to M1+ and M2+ under DI/PRD (14% increase) was significantly smaller. The large growth response to AMF inoculation, particularly under FI, may relate to greater photosynthetic capacity and leaf area, probably caused...

Irrigation Water Management in Latin America

Directory of Open Access Journals (Sweden)

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.

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

Directory of Open Access Journals (Sweden)

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.

Improved irrigation scheduling for pear-jujube trees based on trunk ...

African Journals Online (AJOL)

A suitable indicator for scheduling pear-jujube (Ziziphus jujuba Mill.) irrigation in China was developed based on trunk diameter fluctuations (TDF). Parameters derived from TDF responses to variations in soil matrix potential (Ψsoil) were compared under deficit and well irrigation. Maximum daily shrinkage (MDS) increased ...

Assessment of FAO AquaCrop Model for Simulating Maize Growth and Productivity under Deficit Irrigation in a Tropical Environment

Directory of Open Access Journals (Sweden)

Geneille E. Greaves

2016-11-01

Full Text Available Crop simulation models have a pivotal role to play in evaluating irrigation management strategies for improving agricultural water use. The objective of this study was to test and validate the AquaCrop model for maize under deficit irrigation management. Field observations from three experiments consisting of four treatments were used to evaluate model performance in simulating canopy cover (CC, biomass (B, yield (Y, crop evapotranspiration (ETc, and water use efficiency (WUE. Statistics for root mean square error, model efficiency (E, and index of agreement for B and CC suggest that the model prediction is good under non-stressed and moderate stress environments. Prediction of final B and Y under these conditions was acceptable, as indicated by the high coefficient of determination and deviations <10%. In severely stressed conditions, low E and deviations >11% for B and 9% for Y indicate a reduction in the model reliability. Simulated ETc and WUE deviation from observed values were within the range of 9.5% to 22.2% and 6.0% to 32.2%, respectively, suggesting that AquaCrop prediction of these variables is fair, becoming unsatisfactory as plant water stress intensifies. AquaCrop can be reliably used for evaluating the effectiveness of proposed irrigation management strategies for maize; however, the limitations should be kept in mind when interpreting the results in severely stressed conditions.

Specificity of emotion regulation deficits in social anxiety: an internet study.

Science.gov (United States)

Rusch, Silke; Westermann, Stefan; Lincoln, Tania M

2012-09-01

There is evidence for an association between social anxiety and emotion regulation difficulties. This study investigates that emotion regulation difficulties are specific to two domains of social anxiety. An explorative study was conducted to examine the associations between emotion regulation facets and social anxiety in the normal population. N= 149 healthy volunteers participated in an internet-based survey. Emotion regulation deficits were measured by the Difficulties in Emotion Regulation Scale which consists of six subscales. Social anxiety was measured by the Social Phobia Scale and the Social Interaction Anxiety Scale. Hierarchical regression analyses showed that anxiety of interactive social situations is associated with non-acceptance of negative emotions, impulse control difficulties, and lack of functional emotion regulation strategies over and above the impact of age and general psychopathology. In contrast, anxiety of being observed by others was not specifically associated with emotion regulation strategies. The results support the hypothesis that specific emotion regulation deficits are relevant to specific aspects of social anxiety. Implications for further research and therapy are discussed. © 2011 The British Psychological Society.

Effects of irrigation strategies and soils on field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, Seyed Hamid; Andersen, Mathias Neumann; Plauborg, Finn

2010-01-01

Yield and water productivity of potatoes grown in 4.32 m2 lysimeters were measured in coarse sand, loamy sand, and sandy loam and imposed to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after...

Effect of Coated Urea Fertilizer on Yield and Yield Components of Sweet Corn (KSC 403 under Deficit Irrigation

Directory of Open Access Journals (Sweden)

N Farid

2017-11-01

Full Text Available This study was carried out to assess the effect of coated urea fertilizer on yield and yield components of sweet corn (KSC 403 under different irrigation regimes, in Ramin Agriculture and Natural Sciences University, Iran by using strip split plot in a randomized complete block design with four replications. Three levels of deficit irrigation (100%, 80 and 60% of calculated water requirement of sweet corn were assigned as vertical factor and six sources of urea fertilizer (without urea, un-coated urea, sulfur-coated urea fertilizer, starch-coated urea, agar-coated urea and chitin-coated urea were assigned to horizontal factor. Effects of deficit water and source of fertilizer were statistically significant on plant height, 1000 kernel weight, ear diameter, and number of rows per ear, ear yield, biological yield and harvest index. Maximum of plant height (153.23 cm, 1000 kernel weight (104.51 g, grain yield (9853.3 kg/ha and biological yield (12471.6 kg/ha were obtained in chitin coated urea fertilizer. Maximum of ear diameter (4.67 cm and number of row per ear (13.22 were achieved in agar coated urea fertilizer and that of harvest index (45.79% was indicated by starch-coated urea. Maximum of length of ear, number of kernels per row and grain yield were 23.65cm, 25.83 and 7142 kg/ha, respectively, and were obtained with the using of chitin-coated urea fertilizer and 100% water requirement. Minimum values of these traits were 13.54 cm, 5.56 and 871 kg/ha, respectively, and were obtained by using of control (no urea application and 60% water requirement. Results showed that biopolymer coated urea is potent to improve some morphological characteristics and increase grain yield of sweet corn.

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.

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.

Farm level optimal water management : assistant for irrigation under deficit (FLOW-AID)

NARCIS (Netherlands)

Balendonck, J.; Stanghellini, C.; Hemming, J.; Kempkes, F.L.K.; Tuijl, van B.A.J.

2008-01-01

FLOW-AID is an on-going 6th Framework European project (2006-2009) with the objective to contribute to sustainable irrigated agriculture by developing an irrigation management system that can be used for crop production in cases with limited water supply and marginal water quality. The project

Radiation interception and radiation use efficiency of potato affected by different N fertigation and irrigation regimes

DEFF Research Database (Denmark)

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

2016-01-01

Three years of field experiments were carried out to explore the response of potato dry matter production, accumulated intercepted photosynthetic active radiation (Aipar) and radiation use efficiency (RUE) to five N levels providing 0, 60, 100, 140 and 180 kg N ha−1 and three drip irrigation...... strategies, which were full, deficit and none irrigation. Results showed that, irrespective of years, dry matter production and Aipar were increased by prolonged N fertigation, even though N fertigation was carried out from middle to late growing season. The highest total and tuber dry matter and accumulated...... fertilization occurred when most N was applied early in the growing season and the latest N fertilization should be applied no later than 41–50 days after emergence. Deficit irrigation, which received ca.70% of irrigation applied to full irrigation, did not reduce radiation interception and radiation use...

AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

Directory of Open Access Journals (Sweden)

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.

Regulations of irrigation on regional climate in the Heihe watershed, China, and its implications to water budget

Science.gov (United States)

Zhang, X.

2015-12-01

In the arid area, such as the Heihe watershed in Northwest China, agriculture is heavily dependent on the irrigation. Irrigation suggests human-induced hydro process, which modifies the local climate and water budget. In this study, we simulated the irrigation-induced changes in surface energy/moisture budgets and modifications on regional climate, using the WRF-NoahMP modle with an irrigation scheme. The irrigation scheme was implemented following the roles that soil moisture is assigned a saturated value once the mean soil moisture of all root layers is lower than 70% of fileld capacity. Across the growth season refering from May to September, the simulated mean irrigation amount of the 1181 cropland gridcells is ~900 mm, wihch is close to the field measurments of around 1000 mm. Such an irrigation largely modified the surface energy budget. Due to irrigation, the surface net solar radiation increased by ~76.7 MJ (~11 Wm-2) accouting for ~2.3%, surface latent and senbile heat flux increased by 97.7 Wm-2 and decreased by ~79.7 Wm-2 respectively; and local daily mean surface air temperature was thereby cooling by ~1.1°C. Corresponding to the surface energy changes, wind and circulation were also modified and regional water budget is therefore regulated. The total rainfall in the irrigation area increased due to more moisture from surface. However, the increased rainfall is only ~6.5mm (accounting for ~5% of background rainfall) which is much less than the increased evaporation of ~521.5mm from surface. The ~515mm of water accounting for 57% of total irrigation was transported outward by wind. The other ~385 mm accounting for 43% of total irrigation was transformed to be runoff and soil water. These results suggest that in the Heihe watershed irrigation largely modify local energy budget and cooling surface. This study also implicate that the existing irrigation may waste a large number of water. It is thereby valuable to develope effective irrigation scheme to

Comparison of SVAT models for simulating and optimizing deficit irrigation systems in arid and semi-arid countries under climate variability

Science.gov (United States)

Kloss, Sebastian; Schuetze, Niels; Schmitz, Gerd H.

2010-05-01

The strong competition for fresh water in order to fulfill the increased demand for food worldwide has led to a renewed interest in techniques to improve water use efficiency (WUE) such as controlled deficit irrigation. Furthermore, as the implementation of crop models into complex decision support systems becomes more and more common, it is imperative to reliably predict the WUE as ratio of water consumption and yield. The objective of this paper is the assessment of the problems the crop models - such as FAO-33, DAISY, and APSIM in this study - face when maximizing the WUE. We applied these crop models for calculating the risk in yield reduction in view of different sources of uncertainty (e.g. climate) employing a stochastic framework for decision support for the planning of water supply in irrigation. The stochastic framework consists of: (i) a weather generator for simulating regional impacts of climate change; (ii) a new tailor-made evolutionary optimization algorithm for optimal irrigation scheduling with limited water supply; and (iii) the above mentioned models for simulating water transport and crop growth in a sound manner. The results present stochastic crop water production functions (SCWPF) for different crops which can be used as basic tools for assessing the impact of climate variability on the risk for the potential yield. Case studies from India, Oman, Malawi, and France are presented to assess the differences in modeling water stress and yield response for the different crop models.

Effects of irrigation strategies and soils on field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

2011-01-01

Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... density in the furrow. Most roots accumulated in the surface layers of coarse sand as compared to the other soil types. In the deep soil profile (30–70 cm) a higher root density was found in loamy sand compared with the sandy loam and coarse sand. Approximately twice the amounts of roots were found below...

Biochar enhances yield and quality of tomato under reduced irrigation

DEFF Research Database (Denmark)

Saleem Akhtar, Saqib; Li, Guitong; Andersen, Mathias Neumann

2014-01-01

tBiochar is an amendment that can be used for enhancing soil water storage which may increase cropproductivity. The objective of this study was to investigate the effects of biochar on physiology, yield andquality of tomato under different irrigation regimes. From early flowering to fruit maturity...... stages, theplants were subjected to full irrigation (FI), deficit irrigation (DI) and partial root-zone drying irrigation(PRD) and two levels of biochar (0% and 5% by weight). In FI, the plants were irrigated daily to pot waterholding capacity while in DI and PRD, 70% of FI was irrigated on either...... the whole or one side of the pots,respectively. In PRD, irrigation was switched between sides when the soil water content of the dry sidedecreased to 15%. The results showed that addition of biochar increased the soil moisture contents in DIand PRD, which consequently improved physiology, yield, and quality...

The effect of different sowing patterns and deficit irrigation ...

African Journals Online (AJOL)

. The responses of sweet corn (Zea mays) to irrigation frequency and sowing patterns were studied in the field from December 2005 to December 2006. This research was laid out in split plot, with water quantity as main plot and sowing ...

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.

Phenolic compounds and saponins in quinoa samples (Chenopodium quinoa Willd.) grown under different saline and nonsaline irrigation regimens.

Science.gov (United States)

Gómez-Caravaca, Ana María; Iafelice, Giovanna; Lavini, Antonella; Pulvento, Cataldo; Caboni, Maria Fiorenza; Marconi, Emanuele

2012-05-09

Quinoa is a pseudocereal from South America that has received increased interest around the world because it is a good source of different nutrients and rich in antioxidant compounds. Thus, this study has focused on the effects of different agronomic variables, such as irrigation and salinity, on the phenolic and saponin profiles of quinoa. It was observed that irrigation with 25% of full water restitution, with and without the addition of salt, was associated with increases in free phenolic compounds of 23.16 and 26.27%, respectively. In contrast, bound phenolic compounds were not affected by environmental stresses. Saponins decreased if samples were exposed to drought and saline regimens. In situations of severe water deficit, the saponins content decreased 45%, and 50% when a salt stress was added. The results suggest that irrigation and salinity may regulate the production of bioactive compounds in quinoa, influencing its nutritional and industrial values.

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

Effects of Nutrients Foliar Application on Agrophysiological Characteristics of Maize under Water Deficit Stress

Directory of Open Access Journals (Sweden)

Nour Ali SAJEDI

2010-09-01

Full Text Available To investigate effects of nutrients foliar application on agrophysiological characteristics of maize hybrid �KSC 704� water deficit stress conditions, an experiment was arranged in a split plot factorial based on a randomized complete block design with four replications to the Research Station of Islamic Azad University-Arak Branch, Iran in 2007-2008. Main factors studied were four irrigation levels including irrigation equal to crop water requirement, water deficit stress at eight-leaf stage (V8, blister stage (R2 and filling grain stage (R4 in the main plot. Combined levels of selenium treatment (without and with application 20 gha-1 and micronutrients (without and with application 2 lha-1 were situated in sub plots. Results showed that water deficit stress decreased grain yield 19.7% in blister stage as compared with control. Using selenium increased relative content water at R2 and R4 stages significantly. Using selenium in water deficit stress condition increased measured traits except plant height as compared with treatment without selenium. A negative antagonistic interaction was found between selenium and micronutrients on some measured traits. Between treatments of water deficit stress, highest grain yield equal 6799.52 and 6736.97 kgha-1 was obtained from combined treatments of water deficit stress at eight-leaf stage+without selenium+without micronutrients and water deficit stress at eight-leaf stage+selenium+without micronutrients respectively which compared with treatment of irrigation equal to crop water requirement+selenium+microelements did not differ significant. According to the results of experiment, it is concluded that with micronutrients fertilizer spray under optimum irrigation and selenium spray under water deficit obtain optimum yield.

Emotion Regulation and Heterogeneity in Attention-Deficit/Hyperactivity Disorder

Science.gov (United States)

Musser, Erica D.; Galloway-Long, Hilary S.; Frick, Paul J.; Nigg, Joel T.

2013-01-01

Objective: How best to capture heterogeneity in attention-deficit/hyperactivity disorder (ADHD) using biomarkers has been elusive. This study evaluated whether emotion reactivity and regulation provide a means to achieve this. Method: Participants were classified into three groups: children with ADHD plus low prosocial behavior (hypothesized to be…

Automation in irrigation process in family farm with Arduino platform

Directory of Open Access Journals (Sweden)

Kianne Crystie Bezerra da Cunha

2016-03-01

Full Text Available The small farmers tend not to use mechanical inputs in the irrigation process due to the high cost than conventional irrigation systems have and in other cases, the lack of knowledge and technical guidance makes the farmer theme using the system. Thus, all control and monitoring are made by hand without the aid of machines and this practice can lead to numerous problems from poor irrigation, and water waste, energy, and deficits in production. It is difficult to deduce when to irrigate, or how much water applied in cultivation, measure the soil temperature variables, temperature, and humidity, etc. The objective of this work is to implement an automated irrigation system aimed at family farming that is low cost and accessible to the farmer. The system will be able to monitor all parameters from irrigation. For this to occur, the key characteristics of family farming, Arduino platform, and irrigation were analyzed.

Adapting irrigation management to water scarcity: constraints of plant growth, hydraulics and carbon assimilation.

Science.gov (United States)

Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

Optimal simulation based design of deficit irrigation experiments

OpenAIRE

Seidel, Sabine

2012-01-01

There is a growing societal concern about excessive water and fertilizer use in agricultural systems. High water productivity while maintaining high crop yields can be achieved with appropriate irrigation scheduling. Moreover, freshwater pollution through nitrogen (N) leaching due to the widespread use of N fertilizers demands for an efficient N fertilization management. However, sustainable crop management requires good knowledge of soil water and N dynamics as well as of crop water and N de...

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

Directory of Open Access Journals (Sweden)

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.

Evaluation of reservoir operation strategies for irrigation in the Macul Basin, Ecuador

Directory of Open Access Journals (Sweden)

Vicente Tinoco

2016-03-01

Full Text Available Study focus: An irrigation project is planned in the study basin for developing the agriculture as the main income in the region. The proposed water system comprises three large reservoirs damming the rivers Macul and Maculillo. The river basin planning and operation were investigated by modelling alternative reservoir operation strategies aiming at a sustainable balance between irrigation and river ecology by integrated reservoir/river management. New hydrological insights for the region: After simulation of long-term meteorological series in a model of the integrated water system, covering several historical extreme events, results indicate that the planned irrigation volumes are higher than the available water for a sustainable irrigation strategy. Two lines of action are suggested for reaching the target irrigation demands: design of a deficit irrigation system, and modifications to the reservoir's spillway height. Keywords: Reservoir operation, Conceptual model, Irrigation

Effects of citrus and avocado irrigation and nitrogen-form soil amendment on host selection by adult Homalodisca vitripennis (Hemiptera: Cicadellidae).

Science.gov (United States)

Nadel, H; Seligmann, R; Johnson, M W; Hagler, J R; Stenger, D C; Groves, R L

2008-06-01

Host plant water status is thought to influence dispersal of the xylophagous leafhopper Homalodisca vitripennis Germar, especially where plants are grown under high evaporative demand. Preference by adult H. vitripennis for plants grown under different water deficit and nitrogen form fertilization regimens was studied under laboratory conditions. Leafhopper abundance and ovipositional preference were studied on potted 'Washington navel' orange and 'Haas' avocado in cage choice tests, and feeding rate was estimated using excreta produced by insects confined on plants. A similar study compared responses to citrus treated with 1:1 and 26:1 ratios of fertigated nitrate-N to ammonium-N. The insects were more abundant, oviposited, and fed significantly more on surplus-irrigated plants than on plants under moderate continuous deficit irrigation except avocado feeding, which was nearly significant. Plants exposed to drought became less preferred after 3 and 7 d in avocado and citrus, respectively. Citrus xylem fluid tension at this point was estimated at 0.93 MPa. A corresponding pattern of decline in feeding rate was observed on citrus, but on avocado, feeding rate was low overall and not statistically different between treatments. No statistical differences in abundance, oviposition, or feeding were detected on citrus fertigated with 26:1 or 1:1 ratios of nitrate-N to ammonium-N. Feeding occurred diurnally on both plant species. Discussion is provided on the potential deployment of regulated deficit irrigation to manage H. vitripennis movement as part of a multitactic effort to minimize the risk of disease outbreaks from Xylella fastidiosa Wells et al. in southern California agriculture.

Effects of deficit irrigation and partial root-zone drying on soil and plant water status, stomatal conductance, plant growth and water use efficiency in tomato during early fruiting stage

DEFF Research Database (Denmark)

Liu, Fulai; Shahnazari, Ali; Jacobsen, S.-E.

2008-01-01

The effects of 'partial root-zone drying' (PRD), compared with full irrigation (FI) and deficit irrigation (DI), on soil and plant water status, plant growth and water use efficiency (WUE) were investigated in potted tomatoes (Lycopersicon esculentum L., var. Cedrico) at the early fruiting stage...... system, and the irrigated side of the plants was reversed when volumetric soil water content ( ) of the dry side had decreased to 6%. of FI was about 14%. of DI decreased during the first 4-5 days after the onset of treatment (DAT) and was about 7% and 6% thereafter for DI-70 and DI-50, respectively....... of the wet side in PRD-70 declined during 3-6 DAT and was lower than that of FI by 4-6% thereafter. in both wet and dry sides of PRD-50 was slightly lower than that for PRD-70. After 5 DAT, midday leaf water potential was significantly lower in DI and PRD than in FI plants. FI plants had the highest leaf...

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

Science.gov (United States)

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

2015-04-01

In Tunisia, the expansion of irrigated area and the semiarid climate make it compulsory to adopt strategies of water management to increase water use efficiency. Subsurface drip irrigation (SDI), providing the application of high frequency small irrigation volumes below the soil surface have been increasingly used to enhance irrigation efficiency. At the same time, deficit irrigation (DI) has shown successful results with a large number of crop in various countries. However, for some crops like potatoes, DI is difficult to manage due to the rapid effect of water stress on tuber yield. Irrigation frequency is a key factor to schedule subsurface drip irrigation because, even maintaining the total seasonal volume, soil wetting patterns can result different during the growth period, with consequence on crop yield. Despite the need to enhance water use efficiency, only a few studies related to deficit irrigation of horticultural crops have been made in Tunisia. Objective of the paper was to assess the effects of different on-farm irrigation strategies on water use efficiency of potatoes crop irrigated with subsurface drip irrigation in a semiarid area of central Tunisia. After validation, Hydrus-2D model was used to simulate soil water status in the root zone, to evaluate actual crop evapotranspiration and then to estimate indirectly water use efficiency (IWUE), defined as the ratio between crop yield and total amount of water supplied with irrigation. Field experiments, were carried out in Central Tunisia (10° 33' 47.0" E, 35° 58' 8.1° N, 19 m a.s.l) on a potatoes crop planted in a sandy loam soil, during the growing season 2014, from January 15 (plantation of tubers) to May 6 (harvesting). Soil water status was monitored in two plots (T1 and T2) maintained under the same management, but different irrigation volumes, provided by a SDI system. In particular, irrigation was scheduled according to the average water content measured in the root zone, with a total of 8

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.

Effect of Foliar Application of Phosphorus and Water Deficit on Yield and Yield Components of Winter Wheat (Cultivar Alvand

Directory of Open Access Journals (Sweden)

M. Vafapour

2011-04-01

Full Text Available In order to study the effects of foliar application of phosphorus (P and water deficit on yield and yield components of winter wheat (Triticum aestivum L., cv. Alvand, a split-plot experiment, with completely randomized blocks design and three replications, was carried out at the Research Farm of Boyer Ahmad Agricultural and Natural Resources Research Station, 13 km west of Yasouj, in 2008-2009. The main plots were irrigation at three levels (1- full irrigation (control, 2- deficit irrigation from the stem elongation to booting stage, and 3- deficit irrigation from booting stage to the end of growth period and the subplots were five levels of foliar application of P fertilizer (0, 3, 6, 9 and 12 kg/ha KH2PO4. The results showed that the effects of different irrigation regimes and foliar application of P were significant on all traits, and their interaction was significant on plant height, number of grain per spike, grain yield and biological yield. Full irrigation and foliar application of 6 kg/ha P produced the highest grain and biological yield (6000 and 14170 kg/ha, respectively and deficit irrigation from the stem elongation to booting stage without foliar application of P produced the lowest grain and biological yield (2920 and 8219 kg/ha, respectively. Foliar application of P affects significantly the evaluated traits only in drought-stress treatments and its effect was not significant in full irrigation treatment. In general, foliar application of 9 kg/ha P compensated the losses in wheat due to drought stress.

Stomatal closure of Pelargonium × hortorum in response to soil water deficit is associated with decreased leaf water potential only under rapid soil drying.

Science.gov (United States)

Boyle, Richard K A; McAinsh, Martin; Dodd, Ian C

2016-01-01

Soil water deficits applied at different rates and for different durations can decrease both stomatal conductance (gs ) and leaf water potential (Ψleaf ). Understanding the physiological mechanisms regulating these responses is important in sustainable irrigation scheduling. Glasshouse-grown, containerized Pelargonium × hortorum BullsEye plants were irrigated either daily at various fractions of plant evapotranspiration (100, 75 and 50% ET) for 20 days or irrigation was withheld for 4 days. Xylem sap was collected and gs and Ψleaf were measured on days 15 and 20, and on days 16-19 for the respective treatments. Xylem sap pH and NO3 (-) and Ca(2+) concentrations did not differ between irrigation treatments. Xylem abscisic acid (ABA) concentrations ([ABA]xyl ) increased within 24 h of irrigation being withheld whilst gs and Ψleaf decreased. Supplying irrigation at a fraction of daily ET produced a similar relationship between [ABA]xyl and gs , but did not change Ψleaf . Treatment differences occurred independently of whether Ψleaf was measured in whole leaves with a pressure chamber, or in the lamina with a thermocouple psychrometer. Plants that were irrigated daily showed lower [ABA]xyl than plants from which irrigation was withheld, even at comparable soil moisture content. This implies that regular re-watering attenuates ABA signaling due to maintenance of soil moisture in the upper soil levels. Crucially, detached leaves supplied with synthetic ABA showed a similar relationship between [ABA]xyl and gs as intact plants, suggesting that stomatal closure of P. hortorum in response to soil water deficit is primarily an ABA-induced response, independent of changes in Ψleaf . © 2015 Scandinavian Plant Physiology Society.

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

Reducing the water footprint (WF) of growing crops, the largest water user and a significant contributor to the WF of many consumer products, plays a significant role in integrated and sustainable water management. The water footprint for growing crop is accounted by relating the crop yield with the corresponding consumptive water use (CWU), which both can be adjusted by measures that affect the crop growth and root-zone soil water balance. This study explored the scope for reducing the water footprint of irrigated crops by experimenting set of field level technical and managerial measures: (i) irrigation technologies (Furrow, sprinkler, drip and sub-surface drip), (ii) irrigation strategies (full and a range of sustained and controlled deficit) and (iii) field management options (zero, organic and synthetic mulching). Ranges of cases were also considered: (a) Arid and semi-arid environment (b) Loam and Sandy-loam soil types and (c) for Potato, Wheat and Maize crops; under (c) wet, normal and dry years. AquaCrop, the water driven crop growth and soil water balance model, offered the opportunity to systematically experiment these measures on water consumption and yield. Further, the green and blue water footprints of growing crop corresponding to each measure were computed by separating the root zone fluxes of the AquaCrop output into the green and blue soil water stocks and their corresponding fluxes. Results showed that in arid environment reduction in irrigation supply, CWU and WF up to 300 mm, 80 mm and 75 m3/tonne respectively can be achieved for Maize by a combination of organic mulching and drip technology with controlled deficit irrigation strategies (10-20-30-40% deficit with reference to the full irrigation requirement). These reductions come with a yield drop of 0.54 tonne/ha. In the same environment under the absence of mulching practice, the sub-surface drip perform better in reducing CWU and WF of irrigated crops followed by drip and furrow irrigation

Water-Yield Relations of Drip Irrigated Watermelon in Temperate Climatic Conditions

Directory of Open Access Journals (Sweden)

Pejić Borivoj

2016-08-01

Full Text Available The objective of the study, conducted in Vojvodina a northern part of the Serbia Republic, was to analyse the effect of drip irrigation on yield, evapotranspiration and water productivity of watermelon (Cirullus lanatus Thunb. grown with plasticulture. Irrigation was scheduled on the basis of water balance method. Daily evapotranspiration was computed using the reference evapotranspiration and crop coefficient. The yield of watermelon in irrigation conditions (37,28 t/ha was significantly higher compared to non irrigated (9,98 t/ha. Water used on evapotranspiration in irrigation conditions was 398 mm and 117 mm on non irrigated variant. The crop yield response factor of 1,04 for the whole growing season reveals that relative yield decrease was nearly equal to the rate of evapotranspiration deficit. The values of irrigation water use efficiency and evapotranspiration water use efficiency were 9,93 kg/m3 and 10,29 kg/m3 respectively. The determined results could be used as a good platform for watermelon growers in the region, in terms of improvement of the optimum utilization of irrigation water.

Effects of limited irrigation on yield and water use efficiency of two ...

African Journals Online (AJOL)

SERVER

2007-07-04

Jul 4, 2007 ... Although water deficit is unavoidable in the dry environment, studies have shown that judicious irrigation can to some extent counter the adverse effects on the deficit (Musick and. Dusek, 1980; Misra and ... soil organic carbon, 0.8 g•kg-1 total nitrogen, 37 mg•kg-1 alkaline hydrolysis and 4.58 mg•kg-1 ...

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

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.

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 ...

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.

Effect of Different Alternate Irrigation Strategies using Saline and Non-Saline Water on Corn Yield, Salinity and Moisture Distribution in Soil Profile

Directory of Open Access Journals (Sweden)

Ali Reza Kiani

2017-01-01

Full Text Available Introduction: Lack of water and deterioration in the quality of soil and water resources are considered to be the prime cause of reduced crop yield in arid and semi-arid regions ‘More crop per drop’ by trickle irrigation, deficit irrigation, and uncommon water are the best strategies for mitigating water crises. Different irrigation management strategies are needed to increase production in different areas. In areas where sufficient water is available, a full irrigation strategy could be a suitable option, while in areas where water is limited, deficit irrigation would be an appropriate method, and finally in areas where water resources are saline, management strategies for achieving sustainable production as well as economic yields would be suitable. Maize is the third most important grain crop in the world following wheat and rice and it is the main source of nutrition for humans and animals. Because of the importance of maize in the world, increasing maize production under environmental stresses is a big challenge for agricultural scientists. Different methods of irrigation and the use of saline water that had satisfactory results for increasing agricultural production have been studied by several investigators . The main objective of this study was to establish an efficient use of limited water resources as well as to explore the possibility of replacing saline water with fresh water using different management techniques. Materials and Methods: A field experiment was conducted over two maize cropping seasons (2012–2013 in northern Iran (Gorgan Agricultural Research Station to compare different alternate irrigation scenarios using saline water on corn yield, salinity and soil moisture distribution in a randomized complete block design with three replications. Treatments were: T1 and T2 = 100 and 50 % of crop water requirement with non-saline water, respectively; T3 and T4 = variable and fixed full irrigation with saline and non

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 ...

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.

Response of a clingstone peach cultivar to regulated deficit irrigation Resposta de um cultivar de pêssego com caroço aderente à irrigação por défice regulado

Directory of Open Access Journals (Sweden)

Thomas Sotiropoulos

2010-04-01

Full Text Available Regulated deficit irrigation (RDI involves inducing water stress during specific fruit growth phases by irrigating at less than full evapotranspiration. The objectives of this research were to study the effects of RDI perfomed at stage II of fruit growth and postharvest, on productivity of clingstone peaches, fruit quality as well as photosynthetic rate and midday leaf water potential. The research was conducted in a commercial clingstone peach (Prunus persica L. Batch cv. A-37 orchard in Greece. Trees were irrigated by means of microsprinklers and their frequency was determined using local meteorological station data and the FAO 56 Pennman-Monteith method. Photosynthetic rate was measured by a portable infrared gas analyzer. Midday leaf water potential was measured by the pressure chamber technique. During the years 2005 and 2006, the treatment RDII with irrigation applied at growth stage II of the peach tree did not affect productivity, fresh and dry mass of fruits. RDII reduced preharvest fruit drop in comparison to the control. RDII as well as the combined treatment RDII plus RDIP with irrigation applied at postharvest, at both years reduced shoot length of the vigorous shoots inside the canopy. RDII in comparison to the control increased the soluble solids content of the fruits and the ratio soluble solids/acidity. However it did not affect fruit acidity and fruit firmness. RDII as well as RDII plus RDIP in 2006 increased 'double' fruits and fruits with open cavity in comparison to the control and RDIP. Water savings were considerable and associated with the climatic conditions of each year.A irrigação por défice regulado (RDI envolve a indução de défice de água durante fases específicas do crescimento das frutas, irrigando a taxas menores que a evapotranspiração. Os objetivos desse estudo foram verificar os efeitos da RDI no estágio II do crescimento das frutas e no periodo pós-colheita, avaliando a produtividade de p

Comparing Sprinkler and Surface Irrigation for Wheat Using Multi-Criteria Analysis: Water Saving vs. Economic Returns

Directory of Open Access Journals (Sweden)

Hanaa Darouich

2017-01-01

Full Text Available Coping with water scarcity using supplemental irrigation of wheat (Triticum aestivum L. in the semi-arid northeast Syria is a great challenge for sustainable water use in agriculture. Graded borders and set sprinkler systems were compared using multi-criteria analysis. Alternative solutions for surface irrigation and for sprinkler systems were developed with the SADREG and the PROASPER design models, respectively. For each alternative, two deficit irrigation strategies were considered, which were characterized using indicators relative to irrigation water use, yields and water productivity, including farm economic returns. Alternatives were ranked considering two contrasting priorities: economic returns and water saving. A first step in ranking led to a selection of graded borders with and without precise land levelling and of solid set and semi-permanent sprinkler systems. Precise-levelled borders were better for water saving, while non-precise ones ranked higher for economic returns. Semi-permanent set systems have been shown to be better in economic terms and similar to solid set systems when water saving is prioritized. Semi-permanent sprinkler systems rank first when comparing all type of systems together regardless of the considered deficit irrigation strategy. Likely, border irrigation is appropriate when wheat is in rotation with cotton if the latter is surface irrigated. When peace becomes effective, appropriate economic incentives and training for farmers are required to implement innovative approaches.

Emotional Regulation and Executive Function Deficits in Unmedicated Chinese Children with Oppositional Defiant Disorder.

Science.gov (United States)

Jiang, Wenqing; Li, Yan; Du, Yasong; Fan, Juan

2016-05-01

This study aims to explore the feature of emotional regulation and executive functions in oppositional defiant disorder (ODD) children. The emotional regulation and executive functions of adolescents with ODD, as well as the relationship between the two factors were analyzed using tools including Adolescent Daily Emotional Regulation Questionnaire (ADERQ), Wisconsin Card Sorting Test (WCST) and Cambridge Neuropsychological Test Automated Battery (CANTAB), in comparison with attention deficit hyperactivity disorder (ADHD) children without behavioral problem and healthy children; the ADERQ assessed emotional regulation ability and others were used to assess executive function. Compared to normal children, the ODD group displayed significant differences in the scores of cognitive reappraisal, rumination, expressive suppression, and revealing of negative emotions, as well as in the score of cognitive reappraisal of positive emotions. WCST perseverative errors were well correlated with rumination of negative emotions (r=0.47). Logistic regression revealed that the minimum number of moves in the Stocking of Cambridge (SOC) test (one test in CANTAB) and negative emotion revealing, were strongly associated with ODD diagnosis. Children with ODD showed emotion dysregulation, with negative emotion dysregulation as the main feature. Emotion dysregulation and the lack of ability to plan lead to executive function deficits. The executive function deficits may guide us to understand the deep mechanism under ODD.

Nuclear techniques to assess irrigation schedules for field crops. Results of a co-ordinated research programme

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-06-01

This TECDOC summarizes the results of a Co-ordinated Research Programme on The Use of Nuclear and Related Techniques in Assessment of Irrigation Schedules of Field Crops to Increase Effective Use of Water in Irrigation Projects. The programme was carried out between 1990 and 1995 through the technical co-ordination of the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture of the International Atomic Energy Agency. Fourteen Member States of the IAEA and FAO carried out a series of field experiments aimed at improving irrigation water use efficiency through a type of irrigation scheduling known as deficit irrigation. Refs, figs, tabs.

Nuclear techniques to assess irrigation schedules for field crops. Results of a co-ordinated research programme

International Nuclear Information System (INIS)

1996-06-01

This TECDOC summarizes the results of a Co-ordinated Research Programme on The Use of Nuclear and Related Techniques in Assessment of Irrigation Schedules of Field Crops to Increase Effective Use of Water in Irrigation Projects. The programme was carried out between 1990 and 1995 through the technical co-ordination of the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture of the International Atomic Energy Agency. Fourteen Member States of the IAEA and FAO carried out a series of field experiments aimed at improving irrigation water use efficiency through a type of irrigation scheduling known as deficit irrigation. Refs, figs, tabs

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

Local flow regulation and irrigation raise global human water consumption and footprint.

Science.gov (United States)

Jaramillo, Fernando; Destouni, Georgia

2015-12-04

Flow regulation and irrigation alter local freshwater conditions, but their global effects are highly uncertain. We investigated these global effects from 1901 to 2008, using hydroclimatic observations in 100 large hydrological basins. Globally, we find consistent and dominant effects of increasing relative evapotranspiration from both activities, and decreasing temporal runoff variability from flow regulation. The evapotranspiration effect increases the long-term average human consumption of fresh water by 3563 ± 979 km(3)/year from 1901-1954 to 1955-2008. This increase raises a recent estimate of the current global water footprint of humanity by around 18%, to 10,688 ± 979 km(3)/year. The results highlight the global impact of local water-use activities and call for their relevant account in Earth system modeling. Copyright © 2015, American Association for the Advancement of Science.

Adaptive management of irrigation and crops' biodiversity: a case study on tomato

Science.gov (United States)

De Lorenzi, Francesca; Alfieri, Silvia Maria; Basile, Angelo; Bonfante, Antonello; Monaco, Eugenia; Riccardi, Maria; Menenti, Massimo

2013-04-01

We have assessed the impacts of climate change and evaluated options to adapt irrigation management in the face of predicted changes of agricultural water demand. We have evaluated irrigation scheduling and its effectiveness (versus crop transpiration), and cultivars' adaptability. The spatial and temporal variations of effectiveness and adaptability were studied in an irrigated district of Southern Italy. Two climate scenarios were considered: reference (1961-90) and future (2021-2050) climate, the former from climatic statistics, and the latter from statistical downscaling of general circulation models (AOGCM). Climatic data consist of daily time series of maximum and minimum temperature, and daily rainfall on a grid with a spatial resolution of 35 km. The work was carried out in the Destra Sele irrigation scheme (18.000 ha. Twenty-five soil units were identified and their hydrological properties were determined (measured or estimated from texture through pedo-transfer functions). A tomato crop, in a rotation typical of the area, was considered. A mechanistic model of water flow in the soil-plant-atmosphere system (SWAP) was used to study crop water requirements and water consumption. The model was calibrated and validated in the same area for many different crops. Tomato crop input data and model parameters were estimated on the basis of scientific literature and assumed to be generically representative of the species. Simulations were performed for reference and future climate, and for different irrigation scheduling options. In all soil units, six levels of irrigation volumes were applied: full irrigation (100%), deficit irrigation (80%, 60%, 40%, 20%), no irrigation. From simulation runs, indicators of soil water availability were calculated, moreover the marginal increases of transpiration per unit of irrigation volume, i.e. the effectiveness of irrigation (ΔT/I), were computed, in both climate scenarios. Indicators and marginal increases were used to

Effet de l’irrigation déficitaire contrôlée sur la productivité et l’efficience d’utilisation de l’eau du palmier dattier cv Majhoul

Directory of Open Access Journals (Sweden)

A. SABRI

2017-03-01

Full Text Available To test the effect of regulated deficit irrigation on the productivity of date palm cv Majhoul, an experiment was conducted for two consecutive years (March 2012-February 2014. During these times, seven water regimes were applied under drip irrigation: farmer regime (T0, 100% (T1, 80% (T2, 60% (T3, 80-100-60% (T4, 150% (T5 and 60-100-80% (T6 ETM. The measures focused on the monitoring of meteorological parameters, the water irrigation and the evolution of date yields of Majhoul variety. The results obtained show that: i. Water regime has significantly affected the average yields and water use efficiency, ii. Water irrigation needs are, on average, 51 m3/tree/year, and iii. Average date yields and water use efficiencies varied between 31 and 61 kg of dates/tree/year and between 0.44 and 1.36 kg of dates/m3.

Photosynthetic and enzymatic metabolism of Schinus terebinthifolius Raddi seedlings under water deficit

Directory of Open Access Journals (Sweden)

Danieli Pieretti Nunes

Full Text Available ABSTRACT Schinus terebinthifolius Raddi is a tree species that can be used in the recovery of degraded areas, as it exhibits rapid growth and has a very expansive root system, facilitating water uptake from the deeper layers of the soil. The objective of this study was to evaluate photosynthesis and enzymatic activity in S. terebinthifolius seedlings under conditions of water deficit and their potential to recover following re-irrigation. The experiment was conducted in a greenhouse under a plastic covering where plants were distributed into two groups: Group 1 - control plants, where irrigation was maintained at 70% of the water retention capacity, and Group 2 - stressed plants, where irrigation was suspended until the photosynthetic rate neared zero, followed by rehydration for 12 days, then a further suspension of irrigation. At the beginning of the experiment and during the suspension of irrigation and rehydration, plants were evaluated for gas and antioxidant enzyme exchanges. Hydric stress significantly reduced photosynthesis, stomatal transpiration conductance, carboxylation efficiency of Rubisco, and the chlorophyll content of the S. terebinthifolius plants. Following rehydration, plants recovered the carboxylation efficiency of Rubisco, but not the photosynthetic rate. Antioxidant enzyme activity increased in both the aerial part and the root in response to water deficit.

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.

Effects of irrigation strategies and soils on field-grown potatoes

DEFF Research Database (Denmark)

Ahmadi, Seyed Hamid; Andersen, Mathias Neumann; Plauborg, Finn

2010-01-01

Gas exchange was measured in potatoes (cv. Folva) grown in lysimeters (4.32 m2) in 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 received 65% of FI...... measurements showed that An reached peak values during mid-morning and midday, while gs were highest during the morning. Intrinsic water use efficiency (An/gs) correlated linearly well with the leaf to air vapor pressure deficit (VPD) and the slope of the line revealed the rate of An/gs increase per each k......Pa increase in VPD, i.e. approximately 10 μmol mol-1. Transpiration efficiency (An/T) of PRD was higher than DI, which shows slightly better efficient water use than DI. The slope of the linear relationship between transpiration efficiency and VPD decreased from -2.03 to -1.04 during the time course...

Wind Turbine Down-regulation Strategy for Minimum Wake Deficit

DEFF Research Database (Denmark)

Ma, Kuichao; Zhu, Jiangsheng; N. Soltani, Mohsen

2017-01-01

Down-regulation mode of wind turbine is commonly used no matter for the reserve power for supporting ancillary service to the grid, power optimization in wind farm or reducing power loss in the fault condition. It is also a method to protect faulty turbine. A down-regulation strategy based...... on minimum wake deficit is proposed in this paper, for the power improvement of the downwind turbine in low and medium wind speed region. The main idea is to operate turbine work at an appropriate operating point through rotor speed and torque control. The effectiveness of the strategy is verified...... by comparing with maximum rotor speed strategy. The result shows that the proposed strategy can improve the power of downwind turbine effectively....

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

Directory of Open Access Journals (Sweden)

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

Deficits in general emotion regulation skills-Evidence of a transdiagnostic factor.

Science.gov (United States)

Lukas, Christian Aljoscha; Ebert, David Daniel; Fuentes, Hugo Trevisi; Caspar, Franz; Berking, Matthias

2017-12-15

Deficits in emotion regulation (ER) skills are discussed as a transdiagnostic factor contributing to the development and maintenance of various mental disorders. However, systematic comparisons of a broad range of ER skills across diagnostic groups that are based on comparable definitions and measures of ER are still rare. Therefore, we conducted two studies assessing a broad range of ER skills with the Emotion Regulation Skills Questionnaire in individuals meeting criteria for mental disorders (N 1  = 1448; N 2  = 137) and in a general population sample (N = 214). Consistent across the two studies, participants in the clinical samples reported lower general and lower specific ER skills than participants in the general population sample. Also consistent across the two studies, diagnostic subgroups of the clinical samples differed significantly with regard to general and specific ER skills. The studies provide evidence that deficits in ER are associated with various forms of psychopathology. However, mental disorders seem to differ with regard to how strongly they are linked to ER skills. © 2017 Wiley Periodicals, Inc.

Agronomical effects of deficit irrigation in apricot, peach and plum trees

NARCIS (Netherlands)

Torrecillas, Arturo; Corell, M.; Galindo Egea, Alejandro; Pérez-López, David; Memmi, Houssem; Rodriguez, Pedro; Cruz, Zulma N.; Centeno, Ana; Intrigliolo, Diego S.; Moriana, A.; Garcia Tejero, Ivan Francisco; Duran Zuazo, Victor Hugo

2017-01-01

Stone fruits are some of the most important irrigated crops around the world. Their ability to grow in different environments implies great variations in water needs. This chapter discusses the effect of water restriction on yield and quality of the fruits obtained. The information will provide

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

Directory of Open Access Journals (Sweden)

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.

Growth and ionic content of quinoa under saline irrigation

DEFF Research Database (Denmark)

Riccardi, M.; Pulvento, C.; Lavini, A.

2014-01-01

Drought and salinity are the most important abiotic stresses that affect plant's growth and productivity. The aim of the present work was to evaluate the effect of salt and water deficit on water relations, growth parameters and capacity to accumulate inorganic solutes in quinoa plants. An irriga......Drought and salinity are the most important abiotic stresses that affect plant's growth and productivity. The aim of the present work was to evaluate the effect of salt and water deficit on water relations, growth parameters and capacity to accumulate inorganic solutes in quinoa plants...... incorporated salt ions in the tissues (stems, roots, leaves) preserving seed quality. Treatment with a reduction in the irrigation water to 25 % of full irrigated treatment (Q25) caused an increase in WP and a reduced dry matter accumulation in the leaves. Quinoa plants (Q25) were initially negatively affected...... by severe drought with RGR and NAR reduction, and then, they adapted to it. Quinoa could be considered a drought tolerant crop that adapt photosynthetic rate to compensate for a reduced growth....

Context-dependent Dynamic Processes in Attention Deficit/Hyperactivity Disorder : Differentiating Common and Unique Effects of State Regulation Deficits and Delay Aversion

NARCIS (Netherlands)

Sonuga-Barke, Edmund J. S.; Wiersema, Jan R.; van der Meere, Jacob J.; Roeyers, Herbert

The ability to specify differential predictions is a mark of a scientific models' value. State regulation deficits (SRD) and delay aversion (DAv) have both been hypothesized as context-dependent dynamic dysfunctions in ADHD. However, to date there has been no systematic comparison of their common

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 ...

Global sensitivity analysis of a dynamic agroecosystem model under different irrigation treatments

Science.gov (United States)

Savings in consumptive use through limited or deficit irrigation in agriculture has become an increasingly viable source of additional water for places with high population growth such as the Colorado Front Range, USA. Crop models provide a mechanism to evaluate various management methods without pe...

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

Directory of Open Access Journals (Sweden)

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

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

Directory of Open Access Journals (Sweden)

Fathia El Mokh

2014-12-01

Full Text Available Field experiments were conducted on a sandy soil during spring of 2009 and autumn of 2010 in southern Tunisia for evaluating the effects of two drip irrigation methods and three irrigation regimes on soil moisture and salinity, yield and water use efficiency of potato (Solanum tuberosum L.. The surface drip (SDI and subsurface drip (SSDI irrigation methods were used. Irrigation regimes consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI100, 60% (DI60 and 30% (DI30. FI100 was considered as full irrigation while DI60 and DI30 were considered as deficit irrigation regimes. Well water with an ECi of 7.0 dS/m was used for irrigation. Findings are globally consistent between the two experiments. Results show that soil moisture content and salinity were significantly affected by irrigation treatments and methods. Higher soil moisture content and lower soil salinity were maintained with SSDI than SDI for all irrigation treatments. For both irrigation methods, higher salinity and lower moisture content in the root zone are observed under DI60 and DI30 treatments compared to FI100. Potato yields were highest over two cropping periods for the SSDI method although no significant differences were observed with the SDI. Irrigation regimes resulted in significant difference in both irrigation methods on yield and its components. Yields were highest under FI100. Compared to FI100, considerable reductions in potato yields were observed under DI60 and DI30 deficit treatments resulting from a reduction in tubers number/m² and average tuber weight and size. Water use efficiency (WUE was found to vary significantly among irrigation methods and treatments and varied between 5.9 and 20.5 kg/m3. WUE of SSDI method had generally higher values than SDI. The lowest WUE values were observed for the FI100 treatment, while the highest values were obtained under DI30 treatment for both methods. SSDI method provides

The Irrigation Effect: How River Regulation Can Promote Some Riparian Vegetation

Science.gov (United States)

Gill, Karen M.; Goater, Lori A.; Braatne, Jeffrey H.; Rood, Stewart B.

2018-04-01

River regulation impacts riparian ecosystems by altering the hydrogeomorphic conditions that support streamside vegetation. Obligate riparian plants are often negatively impacted since they are ecological specialists with particular instream flow requirements. Conversely, facultative riparian plants are generalists and may be less vulnerable to river regulation, and could benefit from augmented flows that reduce drought stress during hot and dry periods. To consider this `irrigation effect' we studied the facultative shrub, netleaf hackberry ( Celtis reticulata), the predominant riparian plant along the Hells Canyon corridor of the Snake River, Idaho, USA, where dams produce hydropeaking, diurnal flow variation. Inventories of 235 cross-sectional transects revealed that hackberry was uncommon upstream from the reservoirs, sparse along the reservoir with seasonal draw-down and common along two reservoirs with stabilized water levels. Along the Snake River downstream, hackberry occurred in fairly continuous, dense bands along the high water line. In contrast, hackberry was sparsely scattered along the free-flowing Salmon River, where sandbar willow ( Salix exigua), an obligate riparian shrub, was abundant. Below the confluence of the Snake and Salmon rivers, the abundance and distribution of hackberry were intermediate between the two upstream reaches. Thus, river regulation apparently benefited hackberry along the Snake River through Hells Canyon, probably due to diurnal pulsing that wets the riparian margin. We predict similar benefits for some other facultative riparian plants along other regulated rivers with hydropeaking during warm and dry intervals. To analyze the ecological impacts of hydropeaking we recommend assessing daily maxima, as well as daily mean river flows.

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)

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

Directory of Open Access Journals (Sweden)

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.

Grapevine acclimation to water deficit: the adjustment of stomatal and hydraulic conductance differs from petiole embolism vulnerability.

Science.gov (United States)

Hochberg, Uri; Bonel, Andrea Giulia; David-Schwartz, Rakefet; Degu, Asfaw; Fait, Aaron; Cochard, Hervé; Peterlunger, Enrico; Herrera, Jose Carlos

2017-06-01

Drought-acclimated vines maintained higher gas exchange compared to irrigated controls under water deficit; this effect is associated with modified leaf turgor but not with improved petiole vulnerability to cavitation. A key feature for the prosperity of plants under changing environments is the plasticity of their hydraulic system. In the present research we studied the hydraulic regulation in grapevines (Vitis vinifera L.) that were first acclimated for 39 days to well-watered (WW), sustained water deficit (SD), or transient-cycles of dehydration-rehydration-water deficit (TD) conditions, and then subjected to varying degrees of drought. Vine development under SD led to the smallest leaves and petioles, but the TD vines had the smallest mean xylem vessel and calculated specific conductivity (k ts ). Unexpectedly, both the water deficit acclimation treatments resulted in vines more vulnerable to cavitation in comparison to WW, possibly as a result of developmental differences or cavitation fatigue. When exposed to drought, the SD vines maintained the highest stomatal (g s ) and leaf conductance (k leaf ) under low stem water potential (Ψ s ), despite their high xylem vulnerability and in agreement with their lower turgor loss point (Ψ TLP ). These findings suggest that the down-regulation of k leaf and g s is not associated with embolism, and the ability of drought-acclimated vines to maintain hydraulic conductance and gas exchange under stressed conditions is more likely associated with the leaf turgor and membrane permeability.

Irrigation in the Lower Durance: positive impacts of the agriculture

International Nuclear Information System (INIS)

Lacroix, M.; Blavoux, B.

1995-01-01

The water of river Durance is used to produce hydroelectricity and as stretch of water for tourism and since the thirteenth century for irrigation. The inherited situation is a well extended network of gravitation irrigation canals. This system is spendthrift of water, the water supplies are roughly 5 times the farming needs. The impact of this irrigation on the alluvial aquifer of the Lower Durance is the generalisation of the highest level of the water table in summer on the plain though the water budget has an average deficit of 550 mm. In addition, the nitrate concentration is maintained to an average of 17 mg/l in groundwater and 5 mg/l in streams by dilution. In fact, the irrigation dictates an average input of water with 25.4 mg/l of NO 3- . The natural isotopic tracing (oxygen 18) allows to say that 50 to 75% of the water of the alluvial aquifer come from irrigation. To improve the knowledge about the efficiency of irrigation, a mathematical groundwater model has been created. As a result, 53% of the water is lost while reaching the agricultural parcels, 19% is infiltrated during watering at the parcel and only 28% are used to satisfy the needs of plants. The realisation of this model has allowed to simulate the impact on groundwater of changes in irrigation practices which would lead to reduce the consummation of water. In the case of Lower Durance, the reduction of irrigation losses would have a strong impact on the quantity and quality of water in the alluvial aquifer. (J.S.). 10 refs., 9 figs., 2 tabs

Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

NARCIS (Netherlands)

Kadam, N.N.; Yin, X.; Bindraban, P.S.; Struik, P.C.; Jagadish, K.S.V.

2015-01-01

Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other

Severity of the aggression/anxiety-depression/attention child behavior checklist profile discriminates between different levels of deficits in emotional regulation in youth with attention-deficit hyperactivity disorder.

Science.gov (United States)

Biederman, Joseph; Petty, Carter R; Day, Helen; Goldin, Rachel L; Spencer, Thomas; Faraone, Stephen V; Surman, Craig B H; Wozniak, Janet

2012-04-01

We examined whether severity scores (1 SD vs 2 SDs) of a unique profile of the Child Behavior Checklist (CBCL) consisting of the Anxiety/Depression, Aggression, and Attention (AAA) scales would help differentiate levels of deficits in children with attention-deficit hyperactivity disorder (ADHD). Subjects were 197 children with ADHD and 224 without ADHD. We defined deficient emotional self-regulation (DESR) as an aggregate cutoff score of >180 but siblings. In contrast, the CBCL-DESR was associated with higher rates of comorbid disruptive behavior, anxiety disorders, and impaired interpersonal functioning compared with other ADHD children. Severity scores of the AAA CBCL profiles can help distinguish 2 groups of emotional regulation problems in children with ADHD.

Stress Coefficients for Soil Water Balance Combined with Water Stress Indicators for Irrigation Scheduling of Woody Crops

Directory of Open Access Journals (Sweden)

Maria Isabel Ferreira

2017-06-01

Full Text Available There are several causes for the failure of empirical models to estimate soil water depletion and to calculate irrigation depths, and the problem is particularly critical in tall, uneven, deficit irrigated (DI crops in Mediterranean climates. Locally measured indicators that quantify water status are useful for addressing those causes and providing feed-back information for improving the adequacy of simple models. Because of their high aerodynamic resistance, the canopy conductance of woody crops is an important factor in determining evapotranspiration (ET, and accurate stress coefficient (Ks values are needed to quantify the impact of stomatal closure on ET. A brief overview of basic general principles for irrigation scheduling is presented with emphasis on DI applications that require Ks modelling. The limitations of existing technology related to scheduling of woody crops are discussed, including the shortcomings of plant-based approaches. In relation to soil water deficit and/or predawn leaf water potential, several woody crop Ks functions are presented in a secondary analysis. Whenever the total and readily available water data were available, a simple Ks model was tested. The ultimate aim of this discussion is to illustrate the central concept: that a combination of simple ET models and water stress indicators is required for scheduling irrigation of deep-rooted woody crops.

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.

Influence of genotype, cultivation system and irrigation regime on antioxidant capacity and selected phenolics of blueberries (Vaccinium corymbosum L.).

Science.gov (United States)

Cardeñosa, Vanessa; Girones-Vilaplana, Amadeo; Muriel, José Luis; Moreno, Diego A; Moreno-Rojas, José M

2016-07-01

Demand for and availability of blueberries has increased substantially over recent years, driven in part by their health-promoting properties. Three blueberry varieties ('Rocío', V2, and V3) were grown under two cultivation systems (open-field and plastic tunnels) and subjected to two irrigations regimes (100% and 80% of crop evapotranspiration) in two consecutive years (2011-2012). They were evaluated for their phytochemical composition and antioxidant capacity. Genotype influenced the antioxidant capacity and the content of the three groups of phenolics in the blueberries. The antioxidant activity and total flavonols content increased when the blueberries were grown under open-field conditions. Deficit irrigation conditions led to additional positive effects on their phenolics (delphinidn-3-acetilhexoside content was increased under plastic tunnel with deficit irrigation). In conclusion, the amount of phenolic compounds and the antioxidant capacity of blueberries were not negatively affected by water restriction; Moreover, several changes were recorded due to growing system and genotype. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

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

Alternate partial root-zone irrigation improves fertilizer-N use efficiency in tomatoes

DEFF Research Database (Denmark)

Wang, Yaosheng; Liu, Fulai; Jensen, Lars Stoumann

2013-01-01

The objective of this study was to investigate the comparative effects of alternative partial root-zone irrigation (PRI) and deficit irrigation (DI) on fertilizer-N use efficiency in tomato plants under mineral N and organic N fertilizations. The plants were grown in split-root pots in a climate......-controlled glasshouse and were subjected to PRI and DI treatments during early fruiting stage. When analyzed across the N fertilizer treatments, PRI treatment led to significantly higher N yield, agronomic N use efficiency (ANUE), and apparent N recovery efficiency (ANRE) as compared with the DI treatment, indicating...... significantly higher fertilizer-N use efficiency and soil N availability as well as enhanced plant’s N acquisition ability in the PRI treatment. Analysis across the irrigation treatments showed that the mineral N fertilizer treatment (MinN) significantly increased N yield, ANUE and ANRE relative to the organic...

Simulation-Optimization of the Management of Sensor-Based Deficit Irrigation Systems

OpenAIRE

Kloß, Sebastian

2016-01-01

Current research concentrates on ways to investigate and improve water productivity (WP), as agriculture is today’s predominant freshwater consumer, averaging at 70% and reaching up to 93% in some regions. A growing world population will require more food and thus more water for cultivation. Regions that are already affected by physical water scarcity and which depend on irrigation for growing crops will face even greater challenges regarding their water supply. Other problems in such regions...

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

Nitrogen accumulation in lucerne (Medicago sativa L.) under water deficit stress

OpenAIRE

Vasileva Viliana; Vasilev Emil

2013-01-01

In order to study nitrogen accumulation in aboveground and root dry mass in lucerne (Medicago sativa L.) under water deficit stress, a pot experiment was carried out at the Institute of Forage Crops, Pleven, Bulgaria. The plants were grown under optimum water supply (75-80% FC) and 10-days water deficit stress was simulated at the stage of budding by interrupting the irrigation until soil moisture was reduced to 37-40% FC. Mineral nitrogen fertilization (ammonium nitrate) at the doses of 40, ...

Use of small scale electrical resistivity tomography to identify soil-root interactions during deficit irrigation

Science.gov (United States)

Vanella, D.; Cassiani, G.; Busato, L.; Boaga, J.; Barbagallo, S.; Binley, A.; Consoli, S.

2018-01-01

Plant roots activity affect the exchanges of mass and energy between the soil and atmosphere. However, it is challenging to monitor the activity of the root-zone because roots are not visible from the soil surface, and root systems undergo spatial and temporal variations in response to internal and external conditions. Therefore, measurements of the activity of root systems are interesting to ecohydrologists in general, and are especially important for specific applications, such as irrigation water management. This study demonstrates the use of small scale three-dimensional (3-D) electrical resistivity tomography (ERT) to monitor the root-zone of orange trees irrigated by two different regimes: (i) full rate, in which 100% of the crop evapotranspiration (ETc) is provided; and (ii) partial root-zone drying (PRD), in which 50% of ETc is supplied to alternate sides of the tree. We performed time-lapse 3-D ERT measurements on these trees from 5 June to 24 September 2015, and compared the long-term and short-term changes before, during, and after irrigation events. Given the small changes in soil temperature and pore water electrical conductivity, we interpreted changes of soil electrical resistivity from 3-D ERT data as proxies for changes in soil water content. The ERT results are consistent with measurements of transpiration flux and soil temperature. The changes in electrical resistivity obtained from ERT measurements in this case study indicate that root water uptake (RWU) processes occur at the 0.1 m scale, and highlight the impact of different irrigation schemes.

Deficit irrigation based on drought tolerance and root signalling in potatoes and tomatoes

DEFF Research Database (Denmark)

Jensen, Christian Richardt; Battilano, Adriano; Plauborg, Finn

2010-01-01

Agriculture is a big consumer of fresh water in competition with other sectors of the society. Within the EU-project SAFIR new water-saving irrigation strategies were developed based on pot, semi-field and field experiments with potatoes (Solanum tuberosum L.), fresh tomatoes (Lycopersicon escule...

WATER DEFICIT EFFECT ON YIELD AND FORAGE QUALITY OF MEDICAGO SATIVA POPULATIONS UNDER FIELD CONDITIONS IN MARRAKESH AREA (MOROCCO

Directory of Open Access Journals (Sweden)

Mohamed FARISSI

2014-06-01

Full Text Available The present study focused the effect of water deficit on agronomic potential and some traits related to forage quality in plants of Moroccan Alfalfa (Medicago sativa L. populations (Taf 1, Taf 2, Dem and Tata originated from Oasis and High Atlas of Morocco and an introduced variety from Australia (Siriver. The experiment was conducted under field conditions in experimental station of INRA-Marrakech and under two irrigation treatments. The first treatment was normal irrigation, providing an amount of water corresponding to the potential evapo-transpiration of the crop, and the second treatment was water deficit stress (one irrigation per cut. For each treatment, the experiment was conducted as a split plot based on a randomized complete block design with four replications. The plants were measured and analyzed over three cuts. Some agronomic traits as, plant height, fresh and dry forage yields were measured. The forage quality was evaluated by leaf:stem ratio and the contents of plants in proteins and nitrogen. The results indicated that the water deficit has negatively affected the plant height and forage yield. The decrease in leaf:stem ratio was observed under water deficit conditions. However, the proteins and nitrogen contents were unaffected. The behavior of tested alfalfa genotypes was significantly different. The Moroccan alfalfa populations were more adapted to water deficit conditions comparatively to Siriver variety and the Tata population was the most adapted one.

Carbon retention in the soil–plant system under different irrigation regimes

DEFF Research Database (Denmark)

Wang, Yaosheng; Liu, Fulai; Andersen, Mathias Neumann

2010-01-01

their environmental impacts. Tomato plants (Lycopersicon esculentum L., var. Cedrico) were grown in split-root pots in a climate-controlled glasshouse and were subjected to full irrigation (FI), deficit irrigation (DI) and alternate partial root-zone irrigation (PRI) at early fruiting stage. In Exp. I, each plant...... to a greater microbial activity in the two treatments; particularly the PRI induced drying and wetting cycles of the soils may cause an increase of microbial activities and respiration rate, which could lead to more C losses from the soil. However, in both experiments the total C concentration in the PRI...... in the two experiments might have affected the C retention in the soil and in the plant biomass. Nevertheless, with a same degree of water saving, PRI was superior to DI in terms of enhancing C concentration in the plant biomass, which might have contributed to a better fruit quality in tomatoes as reported...

Optimized Subsurface Irrigation System: The Future of Sugarcane Irrigation

Directory of Open Access Journals (Sweden)

M. H. J. P. Gunarathna

2018-03-01

Full Text Available Climate change may harm the growth and yield of sugarcane (Saccharum officinarum L. without the introduction of appropriate irrigation facilities. Therefore, new irrigation methods should be developed to maximize water use efficiency and reduce operational costs. OPSIS (optimized subsurface irrigation system is a new solar-powered automatic subsurface irrigation system that creates a phreatic zone below crop roots and relies on capillarity to supply water to the root zone. It is designed for upland crops such as sugarcane. We investigated the performance of OPSIS for irrigating sugarcane and evaluated its performance against sprinkler irrigation under subtropical conditions. We conducted field experiments in Okinawa, Japan, over the period from 2013 to 2016 and took measurements during spring- and summer-planted main crops and two ratoon crops of the spring-planted crop. Compared with sprinkler irrigation, OPSIS produced a significantly higher fresh cane yield, consumed less irrigation water and provided a higher irrigation water use efficiency. We conclude that OPSIS could be adopted as a sustainable solution to sugarcane irrigation in Okinawa and similar environments.

Stover removal effects on seasonal soil water availability under full and deficit irrigation

Science.gov (United States)

Removing corn (Zea mays L.) stover for livestock feed or bioenergy feedstock may impact water availability in the soil profile to support crop growth. The role of stover in affecting soil profile water availability will depend on annual rainfall inputs as well as irrigation level. To assess how res...

Modified Streamflows 1990 Level of Irrigation : Columbia River and Coastal Basins, 1928-1989.

Energy Technology Data Exchange (ETDEWEB)

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

1993-04-01

The annual operation plans described in the following sections require detailed system regulation computer model studies. These system regulation studies are necessary to evaluate potential new projects and to develop operational rule curves for the existing system of projects. The objective is to provide a basis for evaluating alternative system regulation scenarios. This provides essential input for optimizing the management of existing projects and planning future projects for the most beneficial use of the water supply and resources in the entire region. Historical streamflows per se are inadequate for system regulation studies because the pattern of observed flow has continually changed with each successive stage of irrigation and e development. The problem, therefore, is to adjust for past operation of storage projects and to determine the necessary adjustments that should be made to recorded flows to reflect current stages of irrigation development. Historical flows which have been adjusted to a common level of irrigation development by correcting for the effects of diversion demand, return flow, and change-of-contents and evaporation in upstream reservoirs and lakes are referred to as modified flows. This report describes the development of irrigation depletion adjustments and modified flows for the 1990 level of development for the 61-year period 1928--1989. incremental depletion adjustments were computed in this report for each month of the 61-year period to adjust the effects of actual irrigation in each year up to that which would have been experienced with the irrigation as practiced in 1990.

Design and Application of Drought Indexes in Highly Regulated Mediterranean Water Systems

Science.gov (United States)

Castelletti, A.; Zaniolo, M.; Giuliani, M.

2017-12-01

Costs of drought are progressively increasing due to the undergoing alteration of hydro-meteorological regimes induced by climate change. Although drought management is largely studied in the literature, most of the traditional drought indexes fail in detecting critical events in highly regulated systems, which generally rely on ad-hoc formulations and cannot be generalized to different context. In this study, we contribute a novel framework for the design of a basin-customized drought index. This index represents a surrogate of the state of the basin and is computed by combining the available information about the water available in the system to reproduce a representative target variable for the drought condition of the basin (e.g., water deficit). To select the relevant variables and combinatione thereof, we use an advanced feature extraction algorithm called Wrapper for Quasi Equally Informative Subset Selection (W-QEISS). W-QEISS relies on a multi-objective evolutionary algorithm to find Pareto-efficient subsets of variables by maximizing the wrapper accuracy, minimizing the number of selected variables, and optimizing relevance and redundancy of the subset. The accuracy objective is evaluated trough the calibration of an extreme learning machine of the water deficit for each candidate subset of variables, with the index selected from the resulting solutions identifying a suitable compromise between accuracy, cardinality, relevance, and redundancy. The approach is tested on Lake Como, Italy, a regulated lake mainly operated for irrigation supply. In the absence of an institutional drought monitoring system, we constructed the combined index using all the hydrological variables from the existing monitoring system as well as common drought indicators at multiple time aggregations. The soil moisture deficit in the root zone computed by a distributed-parameter water balance model of the agricultural districts is used as target variable. Numerical results show that

Effect of Irrigation and Preplant Nitrogen Fertilizer Source on Maize in the Southern Great Plains

Directory of Open Access Journals (Sweden)

Jacob T. Bushong

2014-01-01

Full Text Available With the demand for maize increasing, production has spread into more water limited, semiarid regions. Couple this with the increasing nitrogen (N fertilizer costs and environmental concerns and the need for proper management practices has increased. A trial was established to evaluate the effects of different preplant N fertilizer sources on maize cultivated under deficit irrigation or rain-fed conditions on grain yield, N use efficiency (NUE, and water use efficiency (WUE. Two fertilizer sources, ammonium sulfate (AS and urea ammonium nitrate (UAN, applied at two rates, 90 and 180 kg N ha−1, were evaluated across four site-years. Deficit irrigation improved grain yield, WUE, and NUE compared to rain-fed conditions. The preplant application of a pure ammoniacal source of N fertilizer, such as AS, had a tendency to increase grain yields and NUE for rain-fed treatments. Under irrigated conditions, the use of UAN as a preplant N fertilizer source performed just as well or better at improving grain yield compared to AS, as long as the potential N loss mechanisms were minimized. Producers applying N preplant as a single application should adjust rates based on a reasonable yield goal and production practice.

Autism-like Deficits in Shank3-Deficient Mice Are Rescued by Targeting Actin Regulators

Directory of Open Access Journals (Sweden)

Lara J. Duffney

2015-06-01

Full Text Available Haploinsufficiency of the Shank3 gene, which encodes a scaffolding protein at glutamatergic synapses, is a highly prevalent and penetrant risk factor for autism. Using combined behavioral, electrophysiological, biochemical, imaging, and molecular approaches, we find that Shank3-deficient mice exhibit autism-like social deficits and repetitive behaviors, as well as the significantly diminished NMDA receptor (NMDAR synaptic function and synaptic distribution in prefrontal cortex. Concomitantly, Shank3-deficient mice have a marked loss of cortical actin filaments, which is associated with the reduced Rac1/PAK activity and increased activity of cofilin, the major actin depolymerizing factor. The social deficits and NMDAR hypofunction are rescued by inhibiting cofilin or activating Rac1 in Shank3-deficient mice and are induced by inhibiting PAK or Rac1 in wild-type mice. These results indicate that the aberrant regulation of synaptic actin filaments and loss of synaptic NMDARs contribute to the manifestation of autism-like phenotypes. Thus, targeting actin regulators provides a strategy for autism treatment.

Stalk yield of sugarcane cultivars under different water regimes by subsurface drip irrigation

Directory of Open Access Journals (Sweden)

Aderson S. de Andrade Junior

Full Text Available ABSTRACT This study aimed to evaluate the stalk yield of ten sugarcane cultivars (RB962962, RB931011, RB931530, RB98710, RB92579, RB867515, RB863129, SP791011, RB72545 and VAT90212 subjected to water deficit, full irrigation and water surplus by subsurface drip irrigation, during three cropping seasons (2011-2014. The experiment was conducted at the Experimental Field of Embrapa Meio-Norte, Teresina, Piauí State, Brazil, in dystrophic Red Yellow Argisol. The cultivars RB962962 (162.3 Mg ha-1 and RB867515 (158.5 Mg ha-1 have better stalk yield compared with other cultivars in all water regimes and cropping seasons.

Performance analysis of a trickle irrigation subunit installed in an apple orchard

Directory of Open Access Journals (Sweden)

Soccol Olívio José

2002-01-01

Full Text Available Studies were carried out to evaluate the "xique-xique" irrigation system of a trickle irrigated subunit. Initial results showed that the system's performance was average, any Emission Uniformity, Statistical Uniformity and Coefficient of Global Variation were 74.51, 77.69, and 22.31%, respectively. The efficiency parameters were below expectations, and values of Application Efficiency (Ae, Storage Efficiency (Se, Deep Percolation (Dp, Deficit Degree (DD and Adequacy Degree (a were 100, 47.83, 0, 52.17 and 0% respectively. By adopting new management procedures, it was possible to improve the system's efficiency, reaching values of 90.20, 91.68, 9.80, 8.32 and 52.87% for Ae, Se, Dp, DD and "a", respectively.

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.

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...

A Critical Review of Self-Regulated Learning Interventions for Children with Attention-Deficit Hyperactivity Disorder

Science.gov (United States)

Reddy, Linda A.; Cleary, Timothy J.; Alperin, Alexander; Verdesco, Arielle

2018-01-01

School practitioners and educators are frequently challenged by the diverse and pervasive academic and behavioral needs of children at risk for and with attention-deficit hyperactivity disorder (ADHD). This paper examines the outcome literature on self-regulated learning (SRL) interventions for youth with ADHD by systematically reviewing the key…

Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

International Nuclear Information System (INIS)

Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

2016-01-01

Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

Energy Technology Data Exchange (ETDEWEB)

Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

2016-07-01

Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

Partial Root-Zone Drying (PRD) Feasibility on Potato in a Sub-Humid Climate

DEFF Research Database (Denmark)

Battilani, A; Jensen, C R; Liu, F

2014-01-01

A field experiment was carried out in Northern Italy, within the frame of the EU project SAFIR, to test the feasibility of partial root-zone drying (PRD) irrigation management in potatoes and to compare the PRD irrigation strategy with regulated deficit irrigation (RDI). PRD increased total...

Using Self-Regulated Strategy Development for Written Expression with Students with Attention Deficit Hyperactivity Disorder

Science.gov (United States)

Reid, Robert; Hagaman, Jessica L.; Graham, Steve

2014-01-01

This review assessed the use of self-regulated strategy development (SRSD) for teaching written composition strategies to students with attention deficit hyperactivity disorders. We examined the participants and the settings in which SRSD has been used, the writing strategies tested, genres addressed, and the effects of SRSD on outcome measures.…

Biological degradation of chernozems under irrigation

Directory of Open Access Journals (Sweden)

Oksana Naydyonova

2014-12-01

reduction the number of microorganisms and the diversity of fungi species, repression of cellulose destroying capacity, decrease invertase activity and the rate of humification, intensifying mineralization processes and soil toxicity increasing. Long-term irrigation of ordinary chernozem (Kharkiv Region with fresh water in moderate regime under 7-field crop rotation including alfalfa caused no disturbances of microbial cenosis. In this case parameters of biological indices did not deviate from the level of its non-irrigated analogue. Irrigation with saline water causes more profound negative changes of microbial cenosis of chernozem, which not always can be corrected using agroameliorative techniques. Intensive irrigation with saline water with total mineralization from 1.2 to 2.2 g/l of ordinary chernozem (Odesa Region for 13 years has led to a significant degradation changes in the structure and functioning of its microbial cenosis, its radical alteration such as oppression of microflora, decrease in the number of its main groups by 30 – 40 %, intensification of its mineralization function. Application of agroameliorative techniques (such as annually use of phosphogypsum 3 t/ha or /and complex measures (phosphogypsum 3 t/ha annually + N150P90K60 + manure 18 t/ha of crop rotation enable to regulate of soil biodynamic processes and partially or completely eliminate the phenomena of biological degradation. It was stated that after the cessation of irrigation the degradation changes of ordinary chernozem’s biological properties caused by irrigation with saline water were gradually restored.

Nitrogen accumulation in lucerne (Medicago sativa L. under water deficit stress

Directory of Open Access Journals (Sweden)

Vasileva Viliana

2013-01-01

Full Text Available In order to study nitrogen accumulation in aboveground and root dry mass in lucerne (Medicago sativa L. under water deficit stress, a pot experiment was carried out at the Institute of Forage Crops, Pleven, Bulgaria. The plants were grown under optimum water supply (75-80% FC and 10-days water deficit stress was simulated at the stage of budding by interrupting the irrigation until soil moisture was reduced to 37-40% FC. Mineral nitrogen fertilization (ammonium nitrate at the doses of 40, 80, 120 and 160 mg N kg-1 soil was applied. It was found that nitrogen accumulation in dry aboveground mass was reduced to 18.0%, and in dry root mass to 26.5% under water deficit stress. Mineral nitrogen fertilization contributed to easily overcome the stress conditions of water deficit stress in lucerne.

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

Directory of Open Access Journals (Sweden)

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

Potential of deficit irrigation, irrigation cut-offs, and crop thinning to maintain yield and fruit quality with less water in northern highbush blueberry

Science.gov (United States)

Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions, including Oregon, Washington, and California. New strategies are needed to maintain yield and fruit quality with less water. Three potential options, including defi...

Phenolic and triterpenoid composition and inhibition of α-amylase of pistachio kernels (Pistacia vera L.) as affected by rootstock and irrigation treatment.

Science.gov (United States)

Noguera-Artiaga, Luis; Pérez-López, David; Burgos-Hernández, Armando; Wojdyło, Aneta; Carbonell-Barrachina, Ángel A

2018-09-30

The current water scarcity forces farmers to adopt new irrigation strategies to save water without jeopardizing the fruit yield and quality. In this study, the influence of 3 regulated deficit irrigation (RDI) treatments and 3 rootstocks on the functional quality of pistachios were studied. The functional parameters studied included, polyphenols, triterpenoids, and inhibition of α-amylase. The results showed that P. terebinthus and P. atlantica rootstocks led to pistachio kernels with higher contents of polyphenols and triterpenoids (mainly betulinic acid with 111 and 102 µg g -1 , respectively) than pistachios obtained using P. integerrima rootstock (81 µg g -1 ). On the other hand, the use of moderate RDI (T1 treatment) increased the total content of polyphenols (∼10%), quercetin-O-galloyl-hexoside (∼15%), keampferol-3-O-glucoside (∼19%), and polymeric procyanidins (∼20%), as compared to the control trees, resulting in pistachios with a better functional profile, lower economic cost and with a lesser environmental impact. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Effect of Different Levels of Irrigation and Nitrogen Fertilizer on Yield and Water Use Efficiency of Potato in Subsurface Drip Irrigation

Directory of Open Access Journals (Sweden)

Mohammad Jolaini

2017-06-01

Full Text Available Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. Several studies showed that drip irrigation is an effective method for enhancing potato yield. Fabeiro et al. (2001 concluded that tuber bulking and ripening stages were found to be the most sensitive stages of water stress with drip irrigation. Water deficit occurring in these two growth stages could result in yield reductions. Wang et al. (2006 investigated the effects of drip irrigation frequency on soil wetting pattern and potato yield. The results indicated that potato roots were not limited in wetted soil volume even when the crop was irrigated at the highest frequency while high frequency irrigation enhanced potato tuber growth and water use efficiency (WUE. Though information about irrigation and N management of this crop is often conflicting in the literature, it is accepted generally that production and quality are highly influenced by both N and irrigation amounts and these requirements are related to the cropping technique. Researches revealed that nitrogen fertilizers play a special role in the growth, production and quality of potatoes. Materials and Methods: A factorial experiment in randomized complete block design with three replications was carried out during two growing seasons. Studied factors were irrigation frequency (I1:2 and I2:4 days interval and nitrogen fertilizer levels (applying 100 (N1, 75 (N2 and 50 (N3 % of the recommended amount. Nitrogen fertilizer was applied through irrigation water. In each plot two rows with within-and between-row spacing of 45 and 105 cm and 20 m length. The amount of nitrogen fertilizer for the control treatment was determined by soil analysis (N1. In all treatments, nitrogen fertilizer

Assessing the adaptive capacity of maize hybrids to climate change in an irrigated district of Southern Italy

Science.gov (United States)

Monaco, Eugenia; Bonfante, Antonello; De Mascellis, Roberto; Alfieri, Silvia Maria; Menenti, Massimo; De Lorenzi, Francesca

2013-04-01

Climate change will cause significant changes in water distribution and availability; as a consequence the water resources in some areas (like Mediterranean regions) will be limiting factors to the cultivation of some species, included cereals. So the perspective of climate change requires an analysis of the adaptation possibilities of food and fiber species currently cultivated. A powerful tool for adaptation is the relevant intra-specific biodiversity of crops. The knowledge, for different crop cultivars, of the responses to different environmental conditions (e.g. yield response functions to water regime) can be a tool to identify adaptation options to future climate. Moreover, simulation models of water flow in the soil-plant-atmosphere system can be coupled with future climate scenarios to predict the soil water regime also accounting for different irrigation scheduling options. In this work the adaptive capacity of maize hybrids (Zea mays L.) was evaluated in an irrigated district of Southern Italy (the "Destra Sele" plain, an area of about 18.000 ha), where maize is extensively grown for water buffalo feeding. Horticultural crops (tomato, fennel, artichoke) are grown, as well. The methodology applied is based on two complementary elements: - a database on climatic requirements of 30 maize hybrids: the yield response functions to water availability were determined from experimental data derived both from scientific literature and from field trials carried out by ISAFOM-CNR. These functions were applied to describe the behaviour of the hybrids with respect to the relative evapotranspiration deficit; - the simulation performed by the agro-hydrological model SWAP (soil-water-plant and atmosphere), to determine the future soil water regime at landscape scale. Two climate scenarios were studied: "past" (1961-1990) and "future" (2021-2050). Future climate scenarios were generated within the Italian National Project AGROSCENARI. Climate scenarios at low spatial

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

Agricultural production capacity contributes to food security in Afghanistan and is largely dependent on irrigated farming, mostly utilizing surface water fed by snowmelt. Because of the high contribution of irrigated crops (> 80%) to total agricultural production, knowing the spatial distribution and year-to-year variability in irrigated areas is imperative to monitoring food security for the country. We used 16-day composites of the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to create 23-point time series for each year from 2000 through 2013. Seasonal peak values and time series were used in a threshold-dependent decision tree algorithm to map irrigated areas in Afghanistan for the last 14 years. In the absence of ground reference irrigated area information, we evaluated these maps with the irrigated areas classified from multiple snapshots of the landscape during the growing season from Landsat 5 optical and thermal sensor images. We were able to identify irrigated areas using Landsat imagery by selecting as irrigated those areas with Landsat-derived NDVI greater than 0.30–0.45, depending on the date of the Landsat image and surface temperature less than or equal to 310 Kelvin (36.9 ° C). Due to the availability of Landsat images, we were able to compare with the MODIS-derived maps for four years: 2000, 2009, 2010, and 2011. The irrigated areas derived from Landsat agreed well r2 = 0.91 with the irrigated areas derived from MODIS, providing confidence in the MODIS NDVI threshold approach. The maps portrayed a highly dynamic irrigated agriculture practice in Afghanistan, where the amount of irrigated area was largely determined by the availability of surface water, especially snowmelt, and varied by as much as 30% between water surplus and water deficit years. During the past 14 years, 2001, 2004, and 2008 showed the lowest levels of irrigated area (~ 1.5 million hectares), attesting to

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

Ecofisiologia de plantas jovens de mogno-africano submetidas a deficit hídrico e reidratação Ecophysiology of young African mahogany plants subjected to water deficit and rewetting

Directory of Open Access Journals (Sweden)

Marcos Paulo Ferreira de Albuquerque

2013-01-01

Full Text Available O objetivo deste trabalho foi avaliar a capacidade de plantas jovens de mogno-africano (Khaya ivorensis em recuperar seu status hídrico e trocas gasosas após período de deficit hídrico. Plantas com aproximadamente 315 dias, irrigadas (controle e não irrigadas, foram avaliadas aos 14 dias da suspensão da irrigação e após um, três e sete dias da retomada da irrigação (reidratação. No dia 14, o potencial hídrico foliar de antemanhã (Ψam das plantas estressadas foi reduzido a -2,66 MPa. Com a restrição hídrica, foram observadas reduções significativas no conteúdo relativo de água na antemanhã (redução de 32%, na taxa de assimilação líquida de CO2 (90%, na condutância estomática (95%, na transpiração (93% e na razão entre concentração intercelular e ambiental de CO2 (37%. Durante a reidratação, o status hídrico das plantas estressadas foi restabelecido após três dias. As trocas gasosas também se restabeleceram, mas de forma mais lenta que o status hídrico. Sob deficit hídrico, a concentração de prolina aumentou e a de carboidratos solúveis totais diminuiu. Plantas jovens de mogno-africano são tolerantes ao deficit hídrico moderado.The objective of this work was to evaluate the capacity of young plants of African mahogany (Khaya ivorensis to recover their water status and gas exchange after water deficit. Plants with approximately 315 days, irrigated (control and non-irrigated, were evaluated after water was withheld for 14 days, and after one, three, and seven days of irrigation resumption (rehydration. On day 14, the predawn leaf water potential (Ψam of stressed plants was reduced to -2.66 MPa. With water deficit, significant decreases were observed in predawn relative water content (32% reduction, in net assimilation rate of CO2 (90%, in stomatal conductance (95%, in transpiration (93%, and in intercellular to ambient ratio of CO2 concentration (37%. During rehydration, the water status of stressed

Chelant-enhanced heavy metals uptake by Eucalyptus trees under controlled deficit irrigation

Science.gov (United States)

Fine, Pinchas; Rathod, Paresh; Beriozkin, Anna; Ein-Gal, Oz; Hass, Amir

2014-05-01

Enhancement of phytoremediation of heavy metal polluted soils employs organic ligands, aimed to solubilize, phytoextract and translocate metals into the canopy. The use of more persistent chelants (e.g. EDTA) is phasing out due to concerns over their role in the environment. We tested the hypothesis that controlled deficit irrigation (CDI) of the fast growing, salinity resistant Eucalyptus camaldulensis coupled with timely EDTA application enhances sediment phytoremediation while minimizing leaching of metal complexes below the root-zone. This was tested in 220-L lysimeters packed with sand mixed with metals polluted biosolids. One year old trees were brought under CDI with tap or RO water for two growing seasons. EDTA, EDDS and citric acid fertigation at 2 mM started in each May for 2.5-3.5 months, and prescribed soil leaching and sampling of tree leaves started thereafter. While all 3 chelants solubilized biosolids metal in batch extraction (EDDS often being the more efficient), EDTA was the only to increased metal concentrations both in the soil solution and in the Eucalyptus leaves. The average concentrations in the soil solution and in the leaves, in the EDTA vs. control (chelant-free) treatments, all respectively, were: Cd - 200 mg L-1 vs. 1.0, and 67 vs. 21 mg kg-1; Cu: 90 vs. 1.5 mg L-1, and 17 vs. 3.0 mg kg-1; Cr: 4.0 vs. 1.4 mg L-1, and 3.0 vs. 1.0 mg kg-1; Ni: 60 mg L-1 vs. 14, and 20 vs. 6.0 mg kg-1; Pb: >44 vs. 0.1 mg L-1, and 9.0 vs. 1.0 mg kg-1; and Zn: 650 vs. 4.0 mg L-1 and 200 vs. 70 mg kg-1. While EDDS was undetectable in all the leachates, EDTA concentrated to up to 100 mM. At 10 mM soil solution concentration, EDDS half-life in acclimated lysimeter media was 5-11 days and that of EDTA was ≥27-d. The study suggests that sustainable phytostabilization and phytoextraction of heavy metals are achievable under CDI with EDTA augmentation at low dose. This was yet futile with the biodegradable EDDS and citric acid. CDI with RO water further widened

Assessment of water use and its productivity in the Spanish irrigation district "Río Adaja"

Science.gov (United States)

Rodriguez-Sinobas, Leonor; Naroua, Iliassou; Sánchez-Calvo, Raúl

2015-04-01

A study of the assessment of the irrigation water use has been carried out in the Spanish irrigation District "Río Adaja" that has analyzed the water use efficiency and the water productivity indicators for the main crops during the first three years of operation (2010/2011, 2011/2012 and 2012/2013). A soil water balance model was applied taking into account climatic data for the nearby weather station and soil properties. Crop water requirements were calculated by the FAO Penman-Monteith with the application of the dual crop coefficient and by considering the readily available soil water content (RAW) concept. Likewise, productivity was measured by the indexes: annual relative irrigation supply (ARIS), annual relative water supply (ARWS), relative rainfall supply (RRS), the water productivity (WP), the evapotranspiration water productivity (ETWP), and the irrigation water productivity (IWP). The results show that the irrigation district applied deficit irrigation in most crops (ARIS<1), and also improved water productivity. This was higher in 2010/2011 which showed the highest effective precipitation Pe. The IWP (€/m3) index varied among crops with the highest values for onion (4.14), potato (2.79), carrot (1.37) and barley (1.21) for the first year and, onion (1.98), potato (1.69), carrot (1.70) and barley (1.16) in the second year. Thus, these crops would be a proper cropping pattern to maximize the gross income in the irrigation district.

Effect of free and symbiotic nitrogen fixing bacterial co-inoculation on seed and seedling of soybean seeds produced under deficit water condition

Directory of Open Access Journals (Sweden)

Hamed Hadi

2016-04-01

Full Text Available Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation, 100 (Middle stress, 150 (Severe stress mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.

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...

Water deficit stress effects on corn (Zea mays, L.) root: shoot ratio

Science.gov (United States)

A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation...

Drip irrigation using a PLC based adaptive irrigation system

OpenAIRE

Shahidian, S.; Serralheiro, R. P.; Teixeira, J. L.; Santos, F. L.; Oliveira, M. R. G.; Costa, J. L.; Toureiro, C.; Haie, Naim; Machado, R. M.

2009-01-01

Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the dail...

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

Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions

Science.gov (United States)

Allende, Ana; Monaghan, James

2015-01-01

There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS) followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves) by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks. PMID:26151764

Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions

Directory of Open Access Journals (Sweden)

Ana Allende

2015-07-01

Full Text Available There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks.

Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions.

Science.gov (United States)

Allende, Ana; Monaghan, James

2015-07-03

There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS) followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves) by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks.

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

Directory of Open Access Journals (Sweden)

ali bafkar

2017-02-01

Full Text Available Introduction: The maximum water efficiency and water productivity of the agricultural sector is one of the most important and effective ways to deal with the water crisis and mitigate the effects of drought. Therefore, scientific and practical agricultural water productivity in terms of planning and development must be followed. Local or drip irrigation systems supply some of the moist around the roots and the plant uses the moisture in the soil. Irrigation systems and irrigation scheduling affect water uptake by plants. Matrials and Methods: In order to evaluate the effect of irrigation on the yield of 4-year-old pomegranate trees with local irrigation system (Bubbler in sandy loam soil with bulk density 1.15 grams per cubic centimeter a research was performed in Agriculture and Natural Resources Research Center of Yazd province with an altitude of 1230 meters . The region has an arid climate with 51 mm average annual rainfall and average annual temperature of 20 ° C, which is located 10 kilometers from the center of the city of Yazd. This project was designed in a factorial experiment with a randomized complete block with three irrigation regimes I1, I2, I3, including irrigation (FC100%, 25% of deficit irrigation (FC75% and 50 percent deficit irrigation (FC50% on two commercial cultivars of pomegranates, which have been growing at 3 × 4 with three replications. To prevent penetration of water per tree, plots adjacent to each block strip (three meters between rows and between plants within one and a half meters without irrigation tape were used as a guard. Trees around the pool shaped a rectangular building with a flow rate of 96 liters per hour for each tree using Bubbler system. The use of such a system with high flow rate, suitability and cost of such a system in orchards and vineyards, water supply reduces energy consumption in a tree in a short time. To prevent clogging of the filter, disc dropper was used at the beginning of the project

Multi-Omics and Integrated Network Analyses Reveal New Insights into the Systems Relationships between Metabolites, Structural Genes, and Transcriptional Regulators in Developing Grape Berries (Vitis vinifera L. Exposed to Water Deficit

Directory of Open Access Journals (Sweden)

Stefania Savoi

2017-07-01

Full Text Available Grapes are one of the major fruit crops and they are cultivated in many dry environments. This study comprehensively characterizes the metabolic response of grape berries exposed to water deficit at different developmental stages. Increases of proline, branched-chain amino acids, phenylpropanoids, anthocyanins, and free volatile organic compounds have been previously observed in grape berries exposed to water deficit. Integrating RNA-sequencing analysis of the transcriptome with large-scale analysis of central and specialized metabolites, we reveal that these increases occur via a coordinated regulation of key structural pathway genes. Water deficit-induced up-regulation of flavonoid genes is also coordinated with the down-regulation of many stilbene synthases and a consistent decrease in stilbenoid concentration. Water deficit activated both ABA-dependent and ABA-independent signal transduction pathways by modulating the expression of several transcription factors. Gene-gene and gene-metabolite network analyses showed that water deficit-responsive transcription factors such as bZIPs, AP2/ERFs, MYBs, and NACs are implicated in the regulation of stress-responsive metabolites. Enrichment of known and novel cis-regulatory elements in the promoters of several ripening-specific/water deficit-induced modules further affirms the involvement of a transcription factor cross-talk in the berry response to water deficit. Together, our integrated approaches show that water deficit-regulated gene modules are strongly linked to key fruit-quality metabolites and multiple signal transduction pathways may be critical to achieve a balance between the regulation of the stress-response and the berry ripening program. This study constitutes an invaluable resource for future discoveries and comparative studies, in grapes and other fruits, centered on reproductive tissue metabolism under abiotic stress.

Multi-Omics and Integrated Network Analyses Reveal New Insights into the Systems Relationships between Metabolites, Structural Genes, and Transcriptional Regulators in Developing Grape Berries (Vitis vinifera L.) Exposed to Water Deficit.

Science.gov (United States)

Savoi, Stefania; Wong, Darren C J; Degu, Asfaw; Herrera, Jose C; Bucchetti, Barbara; Peterlunger, Enrico; Fait, Aaron; Mattivi, Fulvio; Castellarin, Simone D

2017-01-01

Grapes are one of the major fruit crops and they are cultivated in many dry environments. This study comprehensively characterizes the metabolic response of grape berries exposed to water deficit at different developmental stages. Increases of proline, branched-chain amino acids, phenylpropanoids, anthocyanins, and free volatile organic compounds have been previously observed in grape berries exposed to water deficit. Integrating RNA-sequencing analysis of the transcriptome with large-scale analysis of central and specialized metabolites, we reveal that these increases occur via a coordinated regulation of key structural pathway genes. Water deficit-induced up-regulation of flavonoid genes is also coordinated with the down-regulation of many stilbene synthases and a consistent decrease in stilbenoid concentration. Water deficit activated both ABA-dependent and ABA-independent signal transduction pathways by modulating the expression of several transcription factors. Gene-gene and gene-metabolite network analyses showed that water deficit-responsive transcription factors such as bZIPs, AP2/ERFs, MYBs, and NACs are implicated in the regulation of stress-responsive metabolites. Enrichment of known and novel cis -regulatory elements in the promoters of several ripening-specific/water deficit-induced modules further affirms the involvement of a transcription factor cross-talk in the berry response to water deficit. Together, our integrated approaches show that water deficit-regulated gene modules are strongly linked to key fruit-quality metabolites and multiple signal transduction pathways may be critical to achieve a balance between the regulation of the stress-response and the berry ripening program. This study constitutes an invaluable resource for future discoveries and comparative studies, in grapes and other fruits, centered on reproductive tissue metabolism under abiotic stress.

Study of Sesame (Sesame indicum L. Cultivars based on Morphological Characteristics Under Water Deficit Stress Condition Using Factor Analysis

Directory of Open Access Journals (Sweden)

A Asghari

2014-03-01

Full Text Available In order to evaluation sesame cultivars based on morphological characteristics under water deficit stress condition using factor analysis, an experiment was conducted as a split plot based on randomized complete block design with three replications during 2009 in Research Center of Agriculture and Natural Resources in Parsabad. In this experiment, irrigation as the main factor at three levels (50, 75 and 100 percent of crop water requirement and ten sesame cultivars as the sub-factor were studied. The water requirement of sesame was calculated using CROPWAT software (Penman-Monteith method according to FAO-56. Results showed significant differences between the cultivars and the irrigation levels for all studied traits. Interaction between cultivars and irrigation levels was significant for some of traits. Comparisons of means showed that in water deficit condition, yield and all of traits reduced. In all traits the greatest amounts observed in complete irrigation treatment. In 50 percent of water requirement treatment, amount of leaf chlorophyll, root length, root branches and root length/plant height ratio were greater than other treatments. The Karaj1, Ultan, Naze and IS cultivars were better than other cultivars in stress and non stress condition. In factor analysis 5 and 4 first factors in non stress and stress condition explained 91.36 and 89.52 percent of trait variance, respectively. Grouping of sesame cultivars based on first and second factors in non stress conditions showed that Karaj1, Ultan and Naze cultivars were better than other cultivars. Also, in stress conditions Karaj1 and Ultan cultivars grouped as water deficit stress and better cultivars.

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...

Rate and duration of seed filling and yield of soybean affected by water and radiation deficits

Directory of Open Access Journals (Sweden)

Kazem GHASSEMI-GOLEZANI

2015-11-01

Full Text Available Seed filling and yield of soybean under water and radiation deficits were investigated during 2011 and 2012. Treatments were irrigations (I1, I2, I3 and I4 for irrigation after 60, 90, 120 and 150 mm evaporation from class A pan, respectively in main plots and light interceptions (L1: 100 %, L2: 65 % and L3: 25 % sunlight in sub-plots. Seeds per plant under I1 and I2 decreased, but under I3 and I4 increasedas a result of radiation deficit. Maximum seed weight and seed filling duration of plants under 25 % light interception (L3 were higher than those under full sunlight (L1 and 65 % light interception (L2. In contrast, plants under full sunlight had the highest seed filling rate, particularly under water stress. Seed filling duration under severe light deficit (L3 was about 9 days longer than that under full sunlight (L1, leading to 15.8 % enhancement in maximum seed weight. Decreasing seed yield of soybean under well watering and mild water stress and improving it under moderate and severe water deficit due to low solar radiation are directly related with changes in seed filling duration and consequently in seed weight and number of seeds per plant under these conditions.

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

Directory of Open Access Journals (Sweden)

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

Effect of Zinc Sulfate and Ascorbic Acid on some Morpho-Physiological Traits of Echinacea purpurea (Purple coneflower under Water Deficit Conditions

Directory of Open Access Journals (Sweden)

F Farahvash

2015-05-01

Full Text Available To quantify the response of some morpho-physiological traits of Echinacea purpurea to thr application of zinc sulfate and ascorbic acid under water deficit, an experiment was carried out in split plot factorial based on RCBD with three replications at the Agricultural Research Station of Islamic Azad University, Tabriz Branch in 2011-12. Experimental factors consisted of water stress as the main factor with three levels (irrigation after70mm evaporation, irrigation after120mm evaporation and irrigation after 170mm evaporation from class A pan, Secondary factor consisted of: application of microelement with two levels (control and application of zinc sulfate 0.005 concentration and ascorbic acid with four levels (not application, application of 50 mg/l of ascorbic acid, application of 100 mg/l of ascorbic acid and application of 150 mg/l of ascorbic acid. The results showed that the effect of water deficit on purple coneflower caused significant differences in diameter of stem, number of flowering branch, stomata density, zinc concentration of aerial parts plant, fresh weight, relative water content of leaf, LAI, proline concentration, crop growth rate, relative growth rate and net assimilation rate. Comparison of means for water deficits between the different levels of drought stress showed that the maximum LAI, with 2.85, belonged to control. Comparison of means for interaction effects between drought stress and application of zinc sulfate revealed that the maximum proline concentration belonged to spraying plants with zinc sulfate at irrigation after 170mm evaporation from class A pan with 10.16 mg/g.fw. Minimum proline concentration was due to without applying zinc sulfate in complete irrigation (control with 0.08 mg/g.fw. Maximum crop growth rate with 6.77 g/m2.day was was related to control and the minimum, with 4.16 g/m2.day, to irrigation after 170mm. Maximum relative crop growth rate, with 0.19 g/m2.day, belonged to control and the

Irrigation and fruit canopy position modify oil quality of olive trees (cv. Frantoio).

Science.gov (United States)

Caruso, Giovanni; Gucci, Riccardo; Sifola, Maria Isabella; Selvaggini, Roberto; Urbani, Stefania; Esposto, Sonia; Taticchi, Agnese; Servili, Maurizio

2017-08-01

Fruit development and oil quality in Olea europaea L. are strongly influenced by both light and water availability. In the present study, the simultaneous effects of light environment and irrigation on fruit characteristics and oil quality were studied in a high-density orchard over two consecutive years. Olive fruits were harvested from three canopy positions (intercepting approximately 64%, 42% and 30% of above canopy radiation) of fully-productive trees subjected to full, deficit or complementary irrigation. Fruits receiving 61-67% of above canopy radiation showed the highest fruit weight, mesocarp oil content and maturation index, whereas those intercepting only 27-33% showed the lowest values. Palmitoleic and linoleic acids increased in oils obtained from fruits exposed to high light levels, whereas oleic acid and the oleic-linoleic acid ratio decreased. Neither canopy position, nor irrigation affected K 232 , K 270 , ΔK and the concentration of lignan in virgin olive oils (VOOs). Total phenols, 3,4-DHPEA-EDA [2-(3,4-hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate] and p-HPEA-EDA (decarboxymethyl ligstroside-aglycone) increased in VOOs produced from fruits harvested from the top of the canopy, whereas full irrigation decreased total phenols and 3,4-DHPEA-EDA concentrations with respect to the complementary irrigation treatment. Light and water availability are crucial not only for tree productivity, but also they clearly affect olive oil quality. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

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

Directory of Open Access Journals (Sweden)

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

Plasticity in stomatal size and density of potato leaves under different irrigation and phosphorus regimes

DEFF Research Database (Denmark)

Sun, Yanqi; Yan, Fei; Cui, Xiaoyong

2014-01-01

The morphological features of stomata including their size and density could be modulated by environmental cues; however, the underlying mechanisms remain largely elusive. Here, the effect of different irrigation and phosphorus (P) regimes on stomatal size (SS) and stomatal density (SD) of potato...... potentially enhance water-use efficiency as exemplified by the lowered leaf δ13C under fluctuating soil moisture conditions....... leaves was investigated. The plants were grown in split-root pots under two P fertilization rates (viz., 0 and 100mgkg-1 soil, denoted as P0 and P1, respectively) and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation regimes. Results showed that SS and SD were...... unresponsive to P but significantly affected by the irrigation treatment. FI plants had the largest SS, followed by DI, and PRD the smallest; and the reverse was the case for SD. Compared to FI and DI, PRD plants had significantly lower values of specific leaf area (SLA) and leaf carbon isotope discrimination...

WATER DEFICIT EFFECT ON YIELD AND FORAGE QUALITY OF MEDICAGO SATIVA POPULATIONS UNDER FIELD CONDITIONS IN MARRAKESH AREA (MOROCCO)

OpenAIRE

Mohamed FARISSI; Cherki GHOULAM; Abdelaziz BOUIZGAREN

2014-01-01

The present study focused the effect of water deficit on agronomic potential and some traits related to forage quality in plants of Moroccan Alfalfa (Medicago sativa L.) populations (Taf 1, Taf 2, Dem and Tata) originated from Oasis and High Atlas of Morocco and an introduced variety from Australia (Siriver). The experiment was conducted under field conditions in experimental station of INRA-Marrakech and under two irrigation treatments. The first treatment was normal irrigation, providing an...

Fluorescence Indices for the Proximal Sensing of Powdery Mildew, Nitrogen Supply and Water Deficit in Sugar Beet Leaves

OpenAIRE

Leufen, Georg; Noga, Georg; Hunsche, Mauricio

2014-01-01

Using potted sugar beet plants we aimed to investigate the suitability of four fluorescence indices to detect and differentiate the impact of nitrogen supply, water deficit and powdery mildew in two sugar beet cultivars (Beta vulgaris L.). Plants were grown inside a polytunnel under two nitrogen levels combined with water deficit or full irrigation. Changes in plant physiology were recorded at two physiological stages with a multiparametric handheld fluorescence sensor and a fluorescence ima...

Reuse of reclaimed wastewater for golf course irrigation in Tunisia.

Science.gov (United States)

Bahri, A; Basset, C; Oueslati, F; Brissaud, F

2001-01-01

In Tunisia, golf courses are irrigated with secondary treated effluent stored in landscape impoundments. The impact of the conveyance and storage steps on the physical-chemical and biological quality of irrigation water was evaluated on three golf courses over two years. It was found that the water quality varies all along the water route, from the wastewater treatment plant up to the irrigation site: nutrient and bacteria contents decreased along the route in the three cases. This variation depends on the wastewater quality, the length of the pipes conveying water, the number of regulation reservoirs and ponds, the water residence time in pipes, reservoirs and ponds, and the operation of the ponds. The bacteriological quality of irrigation water deteriorates during the irrigation period in the three golf courses as the ponds are operated as continuous flow reactors. The results obtained in this study indicate the inability of golf water supplies, as currently managed, to properly sanitize reclaimed wastewater and meet target quality criteria recommended by WHO (1989) for water intended for recreational use. For a safe reuse of reclaimed wastewater for golf course irrigation, changes in the design and operation of the ponds should be planned or additional treatment steps provided.

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...

Emotion Regulation Difficulties in Boys with Oppositional Defiant Disorder/Conduct Disorder and the Relation with Comorbid Autism Traits and Attention Deficit Traits.

Directory of Open Access Journals (Sweden)

Jantiene Schoorl

Full Text Available Previous research has pointed towards a link between emotion dysregulation and aggressive behavior in children. Emotion regulation difficulties are not specific for children with persistent aggression problems, i.e. oppositional defiant disorder or conduct disorder (ODD/CD, children with other psychiatric conditions, such as autism spectrum disorders or attention-deficit/hyperactivity disorder, have emotion regulation difficulties too. On a behavioral level some overlap exists between these disorders and comorbidity is high. The aim of this study was therefore twofold: 1 to examine emotion regulation difficulties in 65 boys with ODD/CD in comparison to a non-clinical control group (NC of 38 boys (8-12 years using a performance measure (Ultimatum Game, parent report and self-report, and 2 to establish to what extent emotion regulation in the ODD/CD group was correlated with severity of autism and/or attention deficit traits. Results on the Ultimatum Game showed that the ODD/CD group rejected more ambiguous offers than the NC group, which is seen as an indication of poor emotion regulation. Parents also reported that the ODD/CD group experienced more emotion regulation problems in daily life than the NC group. In contrast to these cognitive and behavioral measures, self-reports did not reveal any difference, indicating that boys with ODD/CD do not perceive themselves as having impairments in regulating their emotions. Emotional decision making within the ODD/CD group was not related to variation in autism or attention deficit traits. These results support the idea that emotion dysregulation is an important problem within ODD/CD, yet boys with ODD/CD have reduced awareness of this.

Emotion Regulation Difficulties in Boys with Oppositional Defiant Disorder/Conduct Disorder and the Relation with Comorbid Autism Traits and Attention Deficit Traits.

Science.gov (United States)

Schoorl, Jantiene; van Rijn, Sophie; de Wied, Minet; van Goozen, Stephanie; Swaab, Hanna

2016-01-01

Previous research has pointed towards a link between emotion dysregulation and aggressive behavior in children. Emotion regulation difficulties are not specific for children with persistent aggression problems, i.e. oppositional defiant disorder or conduct disorder (ODD/CD), children with other psychiatric conditions, such as autism spectrum disorders or attention-deficit/hyperactivity disorder, have emotion regulation difficulties too. On a behavioral level some overlap exists between these disorders and comorbidity is high. The aim of this study was therefore twofold: 1) to examine emotion regulation difficulties in 65 boys with ODD/CD in comparison to a non-clinical control group (NC) of 38 boys (8-12 years) using a performance measure (Ultimatum Game), parent report and self-report, and 2) to establish to what extent emotion regulation in the ODD/CD group was correlated with severity of autism and/or attention deficit traits. Results on the Ultimatum Game showed that the ODD/CD group rejected more ambiguous offers than the NC group, which is seen as an indication of poor emotion regulation. Parents also reported that the ODD/CD group experienced more emotion regulation problems in daily life than the NC group. In contrast to these cognitive and behavioral measures, self-reports did not reveal any difference, indicating that boys with ODD/CD do not perceive themselves as having impairments in regulating their emotions. Emotional decision making within the ODD/CD group was not related to variation in autism or attention deficit traits. These results support the idea that emotion dysregulation is an important problem within ODD/CD, yet boys with ODD/CD have reduced awareness of this.

The Effect of Water Deficit Imposing Methods on Quantitative and Qualitative Traits of New Potato Cultivar

Directory of Open Access Journals (Sweden)

Kh Parvizi

2016-02-01

Full Text Available Introduction Water deficiency is the main factor that limits crop production in arid and semiarid regions. Due to limitation in water resources, low efficiency of water in surface irrigation method and irregular rainfall application of sprinkle and triple irrigation methods is inevitable in more regions of Iran. In this respect, it is crucial to employ methods that can improve water use efficiency and do not damage the sustainable production of potato in these regions. Introduction of some potato cultivars that have good capability of yield in deficit irrigation is anopportunity in this case. In previous study new released potato cultivar (Savalan and three other promising clones had more yield and growing potential compared with Agriacultivar. Therefore, it was necessary to evaluate new cultivar (Savalan and promising clones in water deficit irrigation. In this respect, as is expected, if cultivars or clones have more tolerance to water deficit they canbe suitable cultivar candidate and germplasms in water critical water conditions in many regions of Iran. Material and Methods This experiment has been conducted in Agricultural and Natural Resources Research Center of Hamedanin split plot design based on Randomized Complete Block in three replications with two factors, including: 1. Water deficit irrigation treatment, 50, 60, 70, 80, 90 and 100% of regular potato irrigation requirement. 2. Three clones accompanied with Savalan and Sante Cultivars. Irrigation system was tape method. Irrigation treatments were established immediately after cultivation of tubers. Water requirement was calculated through corrected vapotranspiration (ETo determined by Penman-Monteith equation considering 90% water use efficiency. During the growing season, fewgrowing indices including, flowering longevity and harvesting time were recorded along with measurement of dry and fresh root weights. Total yield was measured by selecting randomly of 2 m2in every plot

Irrigation practices in long-term survivors of colorectal cancer with colostomies.

Science.gov (United States)

Grant, Marcia; McMullen, Carmit K; Altschuler, Andrea; Hornbrook, Mark C; Herrinton, Lisa J; Wendel, Christopher S; Baldwin, Carol M; Krouse, Robert S

2012-10-01

For some patients diagnosed with rectal cancer, surgery will involve the creation of a temporary or permanent ostomy. When the colostomy is located in the sigmoid or descending colon, regulation of fecal output can occur through irrigation, a procedure that involves instilling fluid into the bowel to flush out gas and fecal material. When successfully used, irrigation can prevent fecal output between irrigations, providing some control over colostomy output. The purpose of this article is to describe participants of a large, multisite, multi-investigator study of health-related quality of life in long-term colorectal cancer survivors who answered questions about colostomy irrigation and reported the potential advantages and disadvantages of the procedure. The article also will explore healthcare professionals' role in ensuring patients and family members are educated and well informed about their options regarding temporary or permanent ostomies.

Characterizing the Effects of Irrigation in the Middle East and North Africa Using Remotely Sensed Vegetation and Water Cycle Observations

Science.gov (United States)

Bolten, John; Ozdogan, Mutlu; Beaudoing, Hiroko; Rodell, Matthew

2012-01-01

A majority of the countries in the Middle East and North Africa (MENA) region suffer from water scarcity due in part to widespread rainfall deficits, unprecedented levels of water demand, and the inefficient use of renewable freshwater resources. Since a majority of the water withdrawal in the MENA is used for irrigation, there is a desperate need for improved understanding of irrigation practices and agricultural water use in the region. Here, satellite-derived irrigation maps and crop-type agricultural data are applied to the Land Data Assimilation System for the MENA region (MENA LDAS), designed to provide regional, gridded fields of hydrological states and fluxes relevant for water resources assessments. Within MENA-LDAS, the Catchment Land Surface Model (CLSM) simulates the location, timing, and amount of water applied through agricultural irrigation practices over the region from 2002-2012. In addition to simulating the irrigation impact on evapotranspiration, soil moisture, and runoff, we also investigate regional changes in terrestrial water storage (TWS) observed from the Gravity Recovery and Climate Experiment (GRACE) and simulated by CLSM.

Evolution of the efficiency and agro-environmental impact of a traditional irrigation land in the middle Ebro Valley (2001-2007)

Energy Technology Data Exchange (ETDEWEB)

Garcia-Garizabal, I.; Causape Valenzuela, J.; Abrahao, R.

2009-07-01

Alternatives in irrigation management can lead to the creation of irrigation lands that are more efficient and more respectful towards the environment. The objective of this work is to analyze the evolution of the agro-environmental impact in a traditional irrigation land of the middle Ebro Valley (Spain) which has experienced changes in its management. For such, water, salt and nitrate balances were accomplished in a hydrological basin (95 ha) in 2001, 2005, 2006 and 2007. The drought of 2005 caused more intensive water use (86%), increasing in 33% the irrigation efficiency when compared to 2001 (53%), even though a high hydric deficit (24%) was caused. Changes in the flood irrigation system management (from rotation to on demand), maximum allocations of irrigation water, billing for the volume of irrigation water consumed and the expansion of crops with lower water and fertilization needs made it possible to achieve irrigation efficiencies of approximately 73% (an increase of 20%) and to halve salt (1.3 Mg ha{sup -}1 year-1) and nitrate (25 kg NO{sub 3} --N ha{sup -}1 year{sup -}1) loads exported in the drainage. The evaluated management changes have been efficient, but nevertheless, crops still suffer certain hydric stress and since 2005 a slight but worrying negative agro-environmental tendency has been observed and should be reversed. (Author)

Effect of Zeolite and Nitrogen Fertilizer Application under Water Deficit Stress Conditions on Agronomical and Physiological Traits of Rapeseed

Directory of Open Access Journals (Sweden)

A. Ghiasvand Ghiasi

2014-08-01

Full Text Available In order to evaluation of zeolite and nitrogen fertilizer application effect on agronomic and physilogical traits of rapeseed (cv RGS003 under water deficit stress conditions, an experiment was conducted in factorial based on randomized complete block design with three replications during 2010 in Qazvin region, Iran. In the where, the two levels of irrigation factor as the normal irrigation (irrigation after 80 mm evaporation from class A pan as control and irrigation cease from stem elongation stage till end of growth, nitrogen factor was at three levels (0, 75 and 150 kg.ha-1 and zeolite factor (0 and 10tons per hectare were studied. Results showed that drought stress decreased evaluated traits such as silique per plant (41%, grain per silique (26%, 1000 seed weight (33%, grain yield (52.5%, oil percent (14%, RWC (31.5% and chlorophyll content (35%. Non-application of nitrogen had adverse effects on total traits and reduced them. However, zeolite application at water deficit stress conditions had positive and significant effect on total traits except of oil percent and chlorophyll content, specially improved grain yield and oil yield. Based on the results of this experiment, application of zeolite (10ton/ha-1 through storage and maintenance of water and nutrients, reduced the intensity and harmful effects of stress in plants and enhances crop yield.

Yield-scaled global warming potential of two irrigation management systems in a highly productive rice system

Directory of Open Access Journals (Sweden)

Silvana Tarlera

2016-02-01

Full Text Available ABSTRACT Water management impacts both methane (CH4 and nitrous oxide (N2O emissions from rice paddy fields. Although controlled irrigation is one of the most important tools for reducing CH4emission in rice production systems it can also increase N2O emissions and reduce crop yields. Over three years, CH4 and N2O emissions were measured in a rice field in Uruguay under two different irrigation management systems, using static closed chambers: conventional water management (continuous flooding after 30 days of emergence, CF30; and an alternative system (controlled deficit irrigation allowing for wetting and drying, AWDI. AWDI showed mean cumulative CH4 emission values of 98.4 kg CH4 ha−1, 55 % lower compared to CF30, while no differences in nitrous oxide emissions were observed between treatments ( p > 0.05. No yield differences between irrigation systems were observed in two of the rice seasons ( p > 0.05 while AWDI promoted yield reduction in one of the seasons ( p< 0.05. When rice yield and greenhouse gases (GHG emissions were considered together, the AWDI irrigation system allowed for lower yield-scaled total global warming potential (GWP. Higher irrigation water productivity was achieved under AWDI in two of the three rice seasons. These findings suggest that AWDI could be an option for reducing GHG emissions and increasing irrigation water productivity. However, AWDI may compromise grain yield in certain years, reflecting the importance of the need for fine tuning of this irrigation strategy and an assessment of the overall tradeoff between relationships in order to promote its adoption by farmers.

Farm-Level Optimal Water Management : assistent for irrigation under deficit, second Executive summery report for FP6-European project nr. 036958

NARCIS (Netherlands)

Balendonck, J.

2008-01-01

FLOW-AID is a 6th Framework European project which started in autumn 2006. Its objective is to contribute to sustainability of irrigated agriculture by developing, testing in relevant conditions, and then optimizing an irrigation management system that can be used at farm level. The system will be

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

Directory of Open Access Journals (Sweden)

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.

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.

The effect of water deficit stress and nitrogen fertilizer levels on morphology traits, yield and leaf area index in maize

International Nuclear Information System (INIS)

Moosavi, S.G.

2012-01-01

In order to study the effect of water deficit stress at different growth stages and N fertilizer levels on morphological traits, yield and yield components of maize cv. Single Cross 704, an experiment was conducted as a split-plot based on a Randomized Complete Block Design with three replications. The main plot included irrigation at four levels (irrigation stop at 10-leaf, tasselling and grain-filling stages and optimum irrigation) and the sub-plot was N fertilizer at three levels (75, 150 and 225 kg N/ha). The results of analysis of variance showed that water-deficit stress and N fertilizer level significantly affected leaf area index at silking stage, ear length, grain number per ear, 1000-grain weight and grain yield. Stem diameter, ear diameter and harvest index were only affected by irrigation treatments and the interaction between irrigation and N level did not significantly affect the studied traits. Means comparison indicated that ear diameter under optimum irrigation was higher than that under the treatments of irrigation stop at 8-leaf, tasselling and grain-filling stages by 29.9, 19.1 and 33.5%, respectively; and ear length was higher than them by 38.1, 28.9 and 25.2%, respectively. Moreover, the highest grain number per ear, 1000-grain weight and grain yield were obtained under optimum irrigation treatment, and irrigation stop at 10-leaf, tasselling and grain-filling stages decreased grain yield by 52.8, 66.4 and 44.9%, respectively; and it decreased grain number/ear by 45.9, 59.3 and 30.1%, respectively. In addition, optimum irrigation treatment with mean 1000-grain weight of 289.2 g was significantly superior over other irrigation stop treatments by 27.6-42.8% and produced the highest leaf area index at silking stage (4.1). Means comparison of traits at different N levels indicated that N level of 225 kg/ha produced the highest ear length (17.82 cm), grain number per ear (401.9), 1000-grain weight (258.8 g), leaf area index at silking stage (4

Analysis of water footprints of rainfed and irrigated crops in Sudan

Directory of Open Access Journals (Sweden)

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.

Factors affecting irrigant extrusion during root canal irrigation: a systematic review

NARCIS (Netherlands)

Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

2013-01-01

The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

Effects of dripper discharge and irrigation frequency on growth and yield of maize in loess plateau of northwest china

International Nuclear Information System (INIS)

Xiukang, W.; Zhanbin, L.; Yingying, X.

2014-01-01

A field experiment was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, in northwestern China from 2010 to 2011 with four treatments and six replicates in a randomized complete block design to determine appropriate dripper discharge and irrigation frequency for maize (Zea mays, L.) irrigated by drip irrigated system. Dripper discharge was applied to maize 1L/h of dripper discharge, 2 days irrigation frequency and 100% of evaporation from a class a pan (T1), 2, 3 and 4 L/h corresponding to 4, 6 and 8 days irrigation frequency, and deficit irrigation water levels was 90%, 80% and 70% of evaporation (T2, T3 and T4), respectively. The results indicated that longest root, root activity, plant height, leaf area, biomass and grain yields values were highest in T1 in both years. The highest grain yield was obtained of 8.78 and 8.84 t ha-1 under T1 in both years, and the minimum yield was obtained with 8.15 and 7.78 t ha-1 under T4 in 2010 and 2011, respectively. The maximum irrigation water use efficiency (IWUE) was 3.247 and 3.283 kg m-3 in both years under T4. Despite the reduction of growth and grain yield in T3, the dripper discharge was 3L/h, 6 days irrigation frequency and 80% of evaporation was still high and acceptable for maize production and irrigation water use efficiency in Loess Plateau of Northwest China. (author)

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

More crop per drop - Increasing input efficiency in sprinkler irrigated potatoes.

Science.gov (United States)

Kostka, Stan; Fang, Lisa; Ren, Haiqin; Glucksman, Robert; Gadd, Nick

2014-05-01

Water scarcity, climate change, and population growth are significant global challenges for producing sufficient food, fiber, and fuel in the 21st century. Feeding an increasingly hungry world necessitates innovative strategies and technologies to maximize crop production outputs while simultaneously increasing crop water productivity. In the 20th century, major advances in precision irrigation enabled producers to increase productivity while more efficiently applying water to crops. While pressurized irrigation systems can deliver water effectively to the soil surface, the efficiency of rootzone delivery may be compromised by intrinsic heterogeneities in soil wetting characteristics related to organic matter, biofilms, and hydrophobic coatings on soil particles and aggregates. Efficiently delivering applied irrigation water throughout the soil matrix is critical to increasing crop productivity. We propose that management of soil water access by surfactants is a viable management option to maintain or increase yields under deficit irrigation. Potato yield and tuber quality under sprinkler irrigation were evaluated under standard production practices or with the inclusion of an aqueous nonionic surfactant formulation (10 wt% alkoxylated polyols and 7% glucoethers) applied at 10L ha-1 between emergence and tuberization. Crop responses from multi-year evaluations conducted on irrigated potatoes in Idaho (USA) were compared to multi-year on farm grower evaluations in Australia and China. Surfactant treatment resulted in statistically significant increases in yield (+5%) and US No. 1 grades (+8%) while reducing culls (-10%) in trials conducted in Idaho, USA. Similar responses were observed in commercial grower evaluations conducted in Australia (+8% total yield, +18% mean tuber weight) and in China in 2011 (+8% total yield and +18% premium, -12% culls). Under diverse production conditions, a single application of the surfactant formulation improved crop water

Regulation of motor proteins, axonal transport deficits and adult-onset neurodegenerative diseases.

Science.gov (United States)

Brady, Scott T; Morfini, Gerardo A

2017-09-01

Neurons affected in a wide variety of unrelated adult-onset neurodegenerative diseases (AONDs) typically exhibit a "dying back" pattern of degeneration, which is characterized by early deficits in synaptic function and neuritic pathology long before neuronal cell death. Consistent with this observation, multiple unrelated AONDs including Alzheimer's disease, Parkinson's disease, Huntington's disease, and several motor neuron diseases feature early alterations in kinase-based signaling pathways associated with deficits in axonal transport (AT), a complex cellular process involving multiple intracellular trafficking events powered by microtubule-based motor proteins. These pathogenic events have important therapeutic implications, suggesting that a focus on preservation of neuronal connections may be more effective to treat AONDs than addressing neuronal cell death. While the molecular mechanisms underlying AT abnormalities in AONDs are still being analyzed, evidence has accumulated linking those to a well-established pathological hallmark of multiple AONDs: altered patterns of neuronal protein phosphorylation. Here, we present a short overview on the biochemical heterogeneity of major motor proteins for AT, their regulation by protein kinases, and evidence revealing cell type-specific AT specializations. When considered together, these findings may help explain how independent pathogenic pathways can affect AT differentially in the context of each AOND. Copyright © 2017 Elsevier Inc. All rights reserved.

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,…

Residue management increases fallow water conservation and yield deficit irrigated crops grown in rotation with wheat

Science.gov (United States)

No-tillage (NT) residue management provides cover to increase precipitation capture compared with disk tillage (DT) or in the absence of a cover crop. Therefore, NT has the potential to reduce irrigation withdrawals from the declining Ogallala Aquifer. In a 4-year study, we quantified DT and NT effe...

Associations Between Childhood Abuse, Posttraumatic Stress Disorder, and Implicit Emotion Regulation Deficits: Evidence From a Low-Income, Inner-City Population.

Science.gov (United States)

Powers, Abigail; Etkin, Amit; Gyurak, Anett; Bradley, Bekh; Jovanovic, Tanja

2015-01-01

Childhood abuse is associated with a wide range of negative outcomes, including increased risk for development of emotion dysregulation and psychopathology, such as posttraumatic stress disorder (PTSD). The goal of the present study was to examine associations between child abuse, PTSD symptoms, and performance on an emotional conflict regulation task that assesses implicit emotion regulation abilities. The sample consisted of 67 (94% African American) females recruited from a public, urban hospital. Childhood abuse was measured using the Childhood Trauma Questionnaire, and PTSD was measured using the modified PTSD Symptom Scale. Task accuracy and implicit emotion regulation were measured through an emotional conflict regulation behavioral task. A multivariate analysis of covariance showed that exposure to moderate to severe childhood abuse was significantly related to worse emotional conflict regulation scores independent of current PTSD symptoms, depressive symptoms, and adult trauma exposure, suggesting a deficit in implicit emotion regulation. We also found an interaction between PTSD symptoms and abuse exposure in predicting accuracy on the behavioral task; high levels of PTSD symptoms were associated with poorer task accuracy among individuals who reported moderate to severe exposure to childhood abuse. However, no relationship between implicit emotion regulation abilities and overall PTSD symptom severity was found. This study provides preliminary evidence of an implicit emotion regulation deficit for individuals exposed to significant childhood abuse and further supports the growing evidence that addressing various aspects of emotion dysregulation, such as awareness of emotions and strategies to manage strong emotions, in the context of treatment would be valuable.

Physiological and gene expression responses of sunflower (Helianthus annuus L.) plants differ according to irrigation placement.

Science.gov (United States)

Aguado, Ana; Capote, Nieves; Romero, Fernando; Dodd, Ian C; Colmenero-Flores, José M

2014-10-01

To investigate effects of soil moisture heterogeneity on plant physiology and gene expression in roots and leaves, three treatments were implemented in sunflower plants growing with roots split between two compartments: a control (C) treatment supplying 100% of plant evapotranspiration, and two treatments receiving 50% of plant evapotranspiration, either evenly distributed to both compartments (deficit irrigation - DI) or unevenly distributed to ensure distinct wet and dry compartments (partial rootzone drying - PRD). Plants receiving the same amount of water responded differently under the two irrigation systems. After 3 days, evapotranspiration was similar in C and DI, but 20% less in PRD, concomitant with decreased leaf water potential (Ψleaf) and increased leaf xylem ABA concentration. Six water-stress responsive genes were highly induced in roots growing in the drying soil compartment of PRD plants, and their expression was best correlated with local soil water content. On the other hand, foliar gene expression differed significantly from that of the root and correlated better with xylem ABA concentration and Ψleaf. While the PRD irrigation strategy triggered stronger physiological and molecular responses, suggesting a more intense and systemic stress reaction due to local dehydration of the dry compartment of PRD plants, the DI strategy resulted in similar water savings without strongly inducing these responses. Correlating physiological and molecular responses in PRD/DI plants may provide insights into the severity and location of water deficits and may enable a better understanding of long-distance signalling mechanisms. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Influence of water deficit on transpiration and radiation use efficiency of chickpea (Cicer arietinum L.)

International Nuclear Information System (INIS)

Singh, P.; Sri Rama, Y.V.

1989-01-01

Information on the relationship between biomass production, radiation use and water use of chickpea (Cicer arietinum L.) is essential to estimate biomass production in different water regimes. Experiments were conducted during three post-rainy seasons on a Vertisol (a typic pallustert) to study the effect of water deficits on radiation use, radiation use efficiency (RUE), transpiration and transpiration efficiency (TE) of chickpea. Different levels of soil water availability were created, either by having irrigated and non-irrigated plots or using a line source. Biomass production was linearly related to both cumulative intercepted solar radiation and transpiration in both well watered and water deficit treatments. Soil water availability did not affect RUE (total dry matter produced per unit of solar radiation interception) when at least 30% of extractable soil water (ESW) was present in the rooting zone, but below 30% ESW, RUE decreased linearly with the decrease in soil water content. RUE was also significantly correlated (R 2 = 0.61, P < 0.01) with the ratio of actual to potential transpiration (T/Tp) and it declined curvilinearly with the decrease in T/Tp. TE decreased with the increase in saturation deficit (SD) of air. Normalization of TE with SD gave a conservative value of 4.8 g kPa kg −1 . To estimate biomass production of chickpea in different environments, we need to account for the effect of plant water deficits on RUE in a radiation-based model and the effect of SD on TE in a transpiration-based model. (author)

Tomato Yield and Water Use Efficiency - Coupling Effects between Growth Stage Specific Soil Water Deficits

DEFF Research Database (Denmark)

Chen, Si; Zhenjiang, Zhou; Andersen, Mathias Neumann

2015-01-01

To investigate the sensitivity of tomato yield and water use efficiency (WUE) to soil water content at different growth stages, the central composite rotatable design (CCRD) was employed in a five-factor-five-level pot experiment under regulated deficit irrigation. Two regression models concerning...... the effects of stage-specific soil water content on tomato yield and WUE were established. The results showed that the lowest available soil water (ASW) content (around 28%) during vegetative growth stage (here denoted θ1) resulted in high yield and WUE. Moderate (around 69% ASW) during blooming and fruit...... effects of ASW in two growth stages were between θ2 and θ5, θ3. In both cases a moderate θ2 was a precondition for maximum yield response to increasing θ5 and θ3. Sensitivity analysis revealed that yield was most sensitive to soil water content at fruit maturity (θ5). Numerical inspection...

The Evolution of Total Phenolic Compounds and Antioxidant Activities during Ripening of Grapes (Vitis vinifera L., cv. Tempranillo Grown in Semiarid Region: Effects of Cluster Thinning and Water Deficit

Directory of Open Access Journals (Sweden)

Inmaculada Garrido

2016-11-01

Full Text Available A study was made of how water status (rainfed vs. irrigated and crop load (no cluster thinning vs. cluster thinning can together affect the grapes of Vitis vinifera cv. Tempranillo vines growing in a semiarid zone of Extremadura (Spain. The grapes were monitored at different stages of ripening, measuring the peroxidase (POX and superoxide dismutase (SOD antioxidant activities and the phenolic content (flavonoids and phenylpropanoids, together with other parameters. The irrigation regime was adjusted to provide 100% of crop evapotranspiration (ETc. The findings confirmed previous results that both thinning and water deficit advance ripening, while irrigation and high crop load (no thinning lengthen the growth cycle. The SOD activity remained practically constant throughout ripening in the thinned treatments and was always lower than in the unthinned treatments, an aspect which could have been the cause of the observed greater level of lipid peroxidation in the water deficit, thinned treatment. The nonspecific peroxidase activity was very low, especially in the thinned treatments. The effect of thinning was enhanced when combined with water deficit, inducing increases in phenylpropanoids and, above all, flavonoids at the harvest stage of ripening, while leaving the polyphenol oxidase activity (PPO unaffected.

Rational Water and Nitrogen Management Improves Root Growth, Increases Yield and Maintains Water Use Efficiency of Cotton under Mulch Drip Irrigation

Directory of Open Access Journals (Sweden)

Hongzhi Zhang

2017-05-01

Full Text Available There is a need to optimize water-nitrogen (N applications to increase seed cotton yield and water use efficiency (WUE under a mulch drip irrigation system. This study evaluated the effects of four water regimes [moderate drip irrigation from the third-leaf to the boll-opening stage (W1, deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W2, pre-sowing and moderate drip irrigation from the third-leaf to the boll-opening stage (W3, pre-sowing and deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W4] and N fertilizer at a rate of 520 kg ha-1 in two dressing ratios [7:3 (N1, 2:8 (N2] on cotton root morpho-physiological attributes, yield, WUE and the relationship between root distribution and dry matter production. Previous investigations have shown a strong correlation between root activity and water consumption in the 40–120 cm soil layer. The W3 and especially W4 treatments significantly increased root length density (RLD, root volume density (RVD, root mass density (RMD, and root activity in the 40–120 cm soil layer. Cotton RLD, RVD, RMD was decreased by 13.1, 13.3, and 20.8%, respectively, in N2 compared with N1 at 70 days after planting (DAP in the 0–40 cm soil layer. However, root activity in the 40–120 cm soil layer at 140 DAP was 31.6% higher in N2 than that in N1. Total RMD, RLD and root activity in the 40–120 cm soil were significantly and positively correlated with shoot dry weight. RLD and root activity in the 40–120 cm soil layer was highest in the W4N2 treatments. Therefore increased water consumption in the deep soil layers resulted in increased shoot dry weight, seed cotton yield and WUE. Our data can be used to develop a water-N management strategy for optimal cotton yield and high WUE.

pH Control of Untreated Water for Irrigation

Science.gov (United States)

Poyen, Faruk Bin; Kundu, Palash K.; Ghosh, Apurba K.

2018-05-01

Irrigation in India still plays a pivotal role in the country's economic and employment structure. But due to unawareness and lack of technological upgradations and ill and careless agricultural practices, the yield from the fields is poor and not to its best capacity. There exists a lot of reasons and factors that brings down the crop productivity. One among them is the quality of irrigation water that is supplied to the fields. It is a common practice in India and other sub-continental countries not to access the water qualitatively before getting fed to the fields. Albeit, it does not have catastrophic effects on the productivity, but it affects the nourishment of the crops to some good extent. Water pH has a strong effect on the soil and crop, when it comes to absorption of nutrients by the plant bodies. With properly regulating the pH level of the irrigation water, it is possible to create an ambiance where the symbiotic effects between the soil and the plant can be optimized. In this paper, it is tried to regulate the pH levels of the water based on the type of soil and the optimal requirement by the crop. The work in this paper involves neutralization of acidic or alkaline water before it is being supplied to the farmlands. The process model is simulation based which gave considerably good and acceptable results.

Sweet corn water productivity under several deficit irrigation regimes applied during vegetative growth stage using treated wastewater as water irrigation source

DEFF Research Database (Denmark)

Hirich, A.; Rami, A.; Laajaj, K.

2012-01-01

Yield and Crop Water Productivity are crucial issues in sustainable agriculture, especially in high-demand resource crops such as sweet corn. This study was conducted to investigate agronomic responses such as plant growth, yield and soil parameters (EC and Nitrate accumulation) to several deficit...

Demand driven decision support for efficient water resources allocation in irrigated agriculture

Science.gov (United States)

Schuetze, Niels; Grießbach, Ulrike Ulrike; Röhm, Patric; Stange, Peter; Wagner, Michael; Seidel, Sabine; Werisch, Stefan; Barfus, Klemens

2014-05-01

Due to climate change, extreme weather conditions, such as longer dry spells in the summer months, may have an increasing impact on the agriculture in Saxony (Eastern Germany). For this reason, and, additionally, declining amounts of rainfall during the growing season the use of irrigation will be more important in future in Eastern Germany. To cope with this higher demand of water, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from the optimized agronomic response at farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF) which provide the estimated yield subject to the minimum amount of irrigation water. These functions take into account the different soil types, crops and stochastically generated climate scenarios. By applying mathematical interpolation and optimization techniques, the SCWPF's are used to compute the water demand considering different constraints, for instance variable and fix costs or the producer price. This generic approach enables the computation for 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 for an effective and efficient utilization of water in order to meet future demands. The prototype is implemented as a web-based decision support system and it is based on a service-oriented geo-database architecture.

Effect of irrigation and nitrogen fertilizer levels on yield and yield components of dill (Anethum graveolens L.

Directory of Open Access Journals (Sweden)

S. Madadi Bonab

2016-05-01

Full Text Available In order to investigate the effect of irrigation and nitrogen fertilizer on yield and yield components of (Anethum graveolens L., a field experiment was performed in Agricultural Research Farm of the University of Tabriz, Iran, during growing season of 2009-2010. The experiment was carried out as split plot based on randomized complete block design with three replications. Irrigation treatments (irrigation after 70, 100, 130 mm evaporation from class A pan and nitrogen levels (0, 40, 80, 120 kg.ha-1 were allocated to main and sub-plots, respectively. The results showed that nitrogen fertilizer had significant (p≤0.05 effect on minor diameter umbrella, 1000-seed weight, seed yield and harvest index. However, irrigation and effect between irrigation and nitrogen were not affected any of the traits. The greatest minor diameter umbrella was obtained with control nitrogen treatment and maximum 1000-seed weight, harvest index and seed yield were obtained from 40 kg.ha-1 nitrogen. There was no any significant difference between 40 and 80 kg.ha-1 nitrogen levels. Therefore, it seems that for producing the highest yield application of 40 kg.ha-1 nitrogen is suitable. As water deficit no significant effects on this traits, of dill, it can be concluded that dill is a tolerant plant to drought stress.

Isohydrodynamic behavior in deficit-irrigated Cabernet Sauvignon and Malbec and its relationship between yield and berry composition

Science.gov (United States)

Cabernet Sauvignon and Malbec grapevines were irrigated at 70 or 23% of estimated crop evapotranspiration (ETc) throughout berry development over four growing seasons. Stomatal behavior was characterized by relating predawn leaf water potential and mid-morning stomatal conductance to mid-morning lea...

The Temporal Variation of Leaf Water Potential in Pistachio under Irrigated and Non-Irrigated Conditions

Directory of Open Access Journals (Sweden)

Yusuf AYDIN

2014-09-01

Full Text Available The present study was carried out in the experimental field of Pistachio Research Institute on pistachio trees which has uzun variety that was 30 years old. The aim of this research was to determine the Leaf Water Potential (LWP of Pistacia vera L. under irrigated and non-irrigated conditions. In the study, the leaf water potential of pistachio was investigated under fully irrigated and non irrigated conditions. The leaf water potential values were measured one day before and after irrigation by using pressure chamber technique at the beginning, mid and end of irrigation season. According to the results obtained from measurements, the LWP value at the beginning of the irrigation season was -3.7 MPa at noon time due to relatively high temperature for both treatments. At the time of pre-dawn and sunset, this value increased and reached to - 1.6 MPa due to relatively low temperature. In general, the LWP values during the mid of irrigation season, in the irrigated treatments, reached to almost -2.5 MPa in the non-irrigated treatment and the value was measured as -3.68 MPa.

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...

Optimal model-based deficit irrigation scheduling using AquaCrop: a simulation study with cotton, potato and tomato

DEFF Research Database (Denmark)

Linker, Raphael; Ioslovich, Ilya; Sylaios, Georgios

2016-01-01

-smooth behavior of the objective function and the fact that it involves multiple integer variables. We developed an optimization scheme for generating sub-optimal irrigation schedules that take implicitly into account the response of the crop to water stress, and used these as initial guesses for a full......Water shortage is the main limiting factor for agricultural productivity in many countries and improving water use efficiency in agriculture has been the focus of numerous studies. The usual approach to limit water consumption in agriculture is to apply water quotas and in such a situation farmers...... variables are the irrigation amounts for each day of the season. The objective function is the expected yield calculated with the use of a model. In the present work we solved this optimization problem for three crops modeled by the model AquaCrop. This optimization problem is non-trivial due to the non...

Effects of foliar application of inactivated yeast on the phenolic composition of Vitis vinifera L. cv. Agiorgitiko grapes under different irrigation levels

Directory of Open Access Journals (Sweden)

Kogkou C

2017-05-01

Full Text Available Charikleia Kogkou,1 Evangelia Chorti,2 Maria Kyraleou,1 Stamatina Kallithraka,1 Stefanos Koundouras,3 Gerard Logan,1 Ioannis Kanakis,4 Yorgos Kotseridis1 1Laboratory of Enology, Department of Food Science and Technology, Agricultural University of Athens, Athens, Greece; 2Cooperative Winery of Nemea, Nemea, Greece; 3Laboratory of Viticulture, School of Agriculture, Aristotle University of Thessaloniki, Thessaloniki, Greece; 4Fassoulis Grapevine Nurseries, Nemea, Greece Abstract: Recent climate changes have caused the rising of average growing season temperatures leading to the advancement of vine phenological stages and to earlier harvests. This could result in the production of grapes with advanced berry sugar accumulation, but incomplete phenolic ripeness, thereby jeopardizing wine quality. This study aims to evaluate the effects of the application of a new product consisting of yeast derivatives on the phenolic maturity and composition of Agiorgitiko grapes and wines, under contrasting water conditions. The experiment was arranged as a 2×2 factorial design in a commercial vineyard situated in southern Greece, combining foliar spraying with LalVigne® Mature (two applications after veraison and an untreated control and water conditions (deficit irrigation and nonirrigated. Irrigation accelerated berry sugar accumulation, increased berry weight and anthocyanin content, and decreased skin tannin concentration. Spraying with yeast derivatives did not affect phenolic content of berry components, and it had no effect on must attributes. Foliar application of yeast derivatives resulted in a higher phenolic potential of the produced wines, only when combined with irrigation. Keywords: foliar spray, deficit irrigation, phenolic maturity, anthocyanins, tannins

The Effect of Chemical, Biological and Organic Nutritional Treatments on Sunflowers Yield and Yield Components under the Influence of Water Deficit Stress

Directory of Open Access Journals (Sweden)

fatemeh soleymani

2016-07-01

Full Text Available Introduction To achieve the higher economic yield of crop plants, supplying enough nutrients to plants is very important. Moreover, nutrient uptakes by plants is influenced by the soil water contents. However, nowadays chemical fertilizer application is important agronomic factor that has significant effects on growth and quantity and quality of final yield, but traditional nutrient management and excessive use of chemical fertilizers may cause the environmental problems such as contamination of soil and water resources, low quality of agricultural products and reduction of soil fertility. These factors have drawn attention to health and ecological sustainable farming systems (Sharma, 2002. In this context, usage of organic and biological products for plant nutrition is considered as one of the solutions to achieve the goals of sustainable agriculture. Materials and methods To evaluate the effect of various feeding systems on yield and yield components of sunflower (Helianthus annuus L. under the influence of water deficit stress, a split-plot experiment based on randomized complete block design with three replications, was carried out in the Agricultural Faculty of Bu-Ali Sina University during the growing season of 2013-2014. Main plots consisted of two irrigation levels: optimum irrigation and deficit irrigation stress (irrigation after 60 and 120 mm evaporation from evaporation pan, class A, respectively and sub-plots included of nine nutrition systems: 1- no bio or chemical fertilizer application, 2- 100% of the recommended chemical fertilizer , 3- vermicompost, 4- phospho nitro kara, 5- vermicompost+ phospho nitro kara, 6- vermicompost+ ½ chemical fertilizer, 7- phospho nitro kara+ ½ chemical fertilizer, 8- vermicompost+ phospho nitro kara+ ½ chemical fertilizer, 9- ½ proposed chemical fertilizer. Phospho-nitro-kara which contains phosphate solubilizing and nitrogen fixing bacteria (Bacillus coagulans, azotobactr chroocuccum and

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...

Inhibition of tomato shoot growth by over-irrigation is linked to nitrogen deficiency and ethylene.

Science.gov (United States)

Fiebig, Antje; Dodd, Ian C

2016-01-01

Although physiological effects of acute flooding have been well studied, chronic effects of suboptimal soil aeration caused by over-irrigation of containerized plants have not, despite its likely commercial significance. By automatically scheduling irrigation according to soil moisture thresholds, effects of over-irrigation on soil properties (oxygen concentration, temperature and moisture), leaf growth, gas exchange, phytohormone [abscisic acid (ABA) and ethylene] relations and nutrient status of tomato (Solanum lycopersicum Mill. cv. Ailsa Craig) were studied. Over-irrigation slowly increased soil moisture and decreased soil oxygen concentration by 4%. Soil temperature was approximately 1°C lower in the over-irrigated substrate. Over-irrigating tomato plants for 2 weeks significantly reduced shoot height (by 25%) and fresh weight and total leaf area (by 60-70%) compared with well-drained plants. Over-irrigation did not alter stomatal conductance, leaf water potential or foliar ABA concentrations, suggesting that growth inhibition was not hydraulically regulated or dependent on stomatal closure or changes in ABA. However, over-irrigation significantly increased foliar ethylene emission. Ethylene seemed to inhibit growth, as the partially ethylene-insensitive genotype Never ripe (Nr) was much less sensitive to over-irrigation than the wild type. Over-irrigation induced significant foliar nitrogen deficiency and daily supplementation of small volumes of 10 mM Ca(NO3 )2 to over-irrigated soil restored foliar nitrogen concentrations, ethylene emission and shoot fresh weight of over-irrigated plants to control levels. Thus reduced nitrogen uptake plays an important role in inhibiting growth of over-irrigated plants, in part by stimulating foliar ethylene emission. © 2015 Scandinavian Plant Physiology Society.

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...

Water and agriculture in arid systems: a dynamic model of irrigation of Mazarron and Aguilas; Agua y agricultural en sistemas aridos: un modelo dinamico del regadio de Mazarron y Aguilas

Energy Technology Data Exchange (ETDEWEB)

Martinez Fernandez, J.; Esteve Selma, M. A.

2009-07-01

The intensive use of groundwater resources in the new irrigated lands of Mazarron-Aguilas has led to the over-exploitation of the local aquifer and thus, to seawater intrusion, water salinization and falling off water tables, all of them key processes of desertification. The simulation results show that the unrealistic perceptions about the relationships between irrigated land and water resources constitutes a key factor to explain the highly unsustainable dynamics of irrigated lands in Mazarron and Aguilas and the whole SE Spain. The increase in water resources does not eliminate the problem because the feedback loops and endogenous factors of the system lead to a further increase in irrigated land and continuation of the water deficit, which shows a highly counter-intuitive behaviour. (Author) 3 refs.

Simulation of Stomatal Conductance and Water Use Efficiency of Tomato Leaves Exposed to Different Irrigation Regimes and Air CO2 Concentrations by a Modified "Ball-Berry" Model.

Science.gov (United States)

Wei, Zhenhua; Du, Taisheng; Li, Xiangnan; Fang, Liang; Liu, Fulai

2018-01-01

Stomatal conductance ( g s ) and water use efficiency ( WUE ) of tomato leaves exposed to different irrigation regimes and at ambient CO 2 ( a [CO 2 ], 400 ppm) and elevated CO 2 ( e [CO 2 ], 800 ppm) environments were simulated using the "Ball-Berry" model (BB-model). Data obtained from a preliminary experiment (Exp. I) was used for model parameterization, where measurements of leaf gas exchange of potted tomatoes were done during progressive soil drying for 5 days. The measured photosynthetic rate ( P n ) was used as an input for the model. Considering the effect of soil water deficits on g s , an equation modifying the slope ( m ) based on the mean soil water potential (Ψ s ) in the whole root zone was introduced. Compared to the original BB-model, the modified model showed greater predictability for both g s and WUE of tomato leaves at each [CO 2 ] growth environment. The models were further validated with data obtained from an independent experiment (Exp. II) where plants were subjected to three irrigation regimes: full irrigation (FI), deficit irrigation (DI), and alternative partial root-zone irrigation (PRI) for 40 days at both a [CO 2 ] and e [CO 2 ] environment. The simulation results indicated that g s was independently acclimated to e [CO 2 ] from P n . The modified BB-model performed better in estimating g s and WUE , especially for PRI strategy at both [CO 2 ] environments. A greater WUE could be seen in plants grown under e [CO 2 ] associated with PRI regime. Conclusively, the modified BB-model was capable of predicting g s and WUE of tomato leaves in various irrigation regimes at both a [CO 2 ] and e [CO 2 ] environments. This study could provide valuable information for better predicting plant WUE adapted to the future water-limited and CO 2 enriched environment.

Water deficit effects on maize yields modeled under current and greenhouse climates

International Nuclear Information System (INIS)

Muchow, R.C.; Sinclair, T.R.

1991-01-01

The availability of water imposes one of the major limits on rainfed maize (Zea mays L.) productivity. This analysis was undertaken in an attempt to quantify the effects of limited water on maize growth and yield by extending a simple, mechanistic model in which temperature regulates crop development and intercepted solar radiation is used to calculate crop biomass accumulation. A soil water budget was incorporated into the model by accounting for inputs from rainfall and irrigation, and water use by soil evaporation and crop transpiration. The response functions of leaf area development and crop gas exchange to the soil water budget were developed from experimental studies. The model was used to interpret a range of field experiments using observed daily values of temperature, solar radiation, and rainfall or irrigation, where water deficits of varying durations developed at different stages of growth. The relative simplicity of the model and its robustness in simulating maize yields under a range of water-availability conditions allows the model to be readily used for studies of crop performance under alternate conditions. One such study, presented here, was a yield assessment for rainfed maize under possible greenhouse climates where temperature and atmospheric CO 2 concentration were increased. An increase in temperature combined with decreased rainfall lowered grain yield, although the increase in crop water use efficiency associated with elevated CO 2 concentration ameliorated the response to the greenhouse climate. Grain yields for the greenhouse climates as compared to current conditions increased, or decreased only slightly, except when the greenhouse climate was assumed to result in severly decreased rainfall

Using mental-modelling to explore how irrigators in the Murray–Darling Basin make water-use decisions

Directory of Open Access Journals (Sweden)

Ellen M. Douglas

2016-06-01

New hydrological insights for the region: Results suggest support for greater local and irrigator involvement in water management decisions. Many, if not most, of the irrigators understood the need for, or at least the inevitability of, governmental policies and regulations. However, a lack of accountability, predictability, and transparency has added to the uncertainty in farm-based water decision-making. Irrigators supported the concept of environmental sustainability, although they might not always agree with how the concept is implemented. The mental modelling approach facilitated knowledge sharing among stakeholders and can be used to identify common goals. Future research utilizing the mental modelling approach may encourage co-management and knowledge partnerships between irrigators, water managers and government officials.

Effects of water deficit and nitrogen levels on grain yield and oil and protein contents of maize

Directory of Open Access Journals (Sweden)

Kazem Ghassemi-Golezani

2015-02-01

Full Text Available This research was conducted in 2014, to evaluate the effects of water deficit and nitrogen fertilizer on grain yield, oil and protein contents of maize (cv. double Cross 303. The experiment was arranged as split-plot based on Randomized Complete Block design (RCB with three replications. Irrigation treatments (irrigation after 60, 90, 120 and 150 mm evaporation and nitrogen levels (0, 46 and 92 kg N/ha were located in the main and sub plots, respectively. Mean grain yield per unit area decreased with decreasing water availability, but it was improved with increasing nitrogen fertilizer. Grain oil percentage significantly decreased, but protein percentage slightly increased as a result of water deficit. In general, oil and protein yields significantly decreased under moderate and severe water stress, mainly because of decreasing grain yield under these conditions. Nitrogen application decreased oil percentage, but increased protein percentage significantly. Nevertheless, nitrogen fertilizer enhanced oil and protein yields per unit area, with no significant difference between nitrogen rates. These results were positively related with grain yield per unit area in maize.

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.

A short overview of measures for securing water resources for irrigated crop production

DEFF Research Database (Denmark)

Jensen, Christian Richardt; Ørum, Jens Erik; Pedersen, Søren Marcus

2014-01-01

Agriculture is the main user of limited fresh water resources in the world. Optimisation of agricultural water resources and their use can be obtained by both agronomical and political incentives. Important options are: reduction of the loss of irrigation water in conveyance before it reaches...... of the 'virtual water' principles so that water-rich regions secure food supply to dry regions; reduction in waste of food, feed and biofuel from post-harvest to the end consumer; changing of food composition to less water-consuming products; regulating amount of irrigation water by rationing, subsidies or water...... pricing to support water-saving measures such as use of drip, irrigation scheduling and DI. The potential for water saving for different measures is discussed and estimated. Reduction in waste of food and loss of irrigation water from conveyance source to farm both has a great potential for water saving...

Sensory analysis and volatile compounds of olive oil (cv. Cobrancosa) from different irrigation regimes

Energy Technology Data Exchange (ETDEWEB)

Fernandes-Silva, A. A.; Falco, V.; Correia, C. M.; Villalobos, F. J.

2013-05-01

The aim of this study was to assess the effect of different irrigation strategies on the sensory quality of virgin olive oil VOO) from the cv. cobrancosa- integrated into a protected denomination of origin of Azeite de Tras-os-Montes in the Northeast of Portugal. Three irrigation treatments were applied: (T2)-full irrigation, which received a seasonal water equivalent of 100% of the estimated crop evapotranspiration (ET{sub c}), (T1)-continuous deficit irrigation (30% ETc) and (T0)- rainfed treatment. Data were collected from two consecutive crop years (2005-2006). Olive oil samples were analyzed for volatiles by GC-MS and the results compared with sensory evaluation data. Total volatile compounds tended to decrease with the amount of water applied. The characteristics pungent and bitter were more pronounced in olive oils from T0 and T1, which had higher polyphenolic concentrations, with a strong positive relationship with this variable and the bitter attribute. The Principal Components Analysis clearly separates the three olive oils from 2005, the driest year, and aggregates into a single group the three samples from 2006, suggesting no effect of irrigation on volatile compounds in years with a rainy spring and a marked effect in years with severe drought, suggesting that the effect of the trees’ water status on these variables occurs throughout the crop season and not just during the oil accumulation phase. In general, olive oil from the cv. Cobrançosa is more bitter than pungent and has a typical nutty sensory attribute shown by a strong positive relationship between benzaldehyde and the sensory notes of almonds and nuts. (Author) 34 refs.

Modernized Irrigation Technologies in West Africa

Directory of Open Access Journals (Sweden)

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.

Gas exchange in ‘BRS Princesa’ banana (Musa spp. under partial rootzone drying irrigation in the north of Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Marcelo Rocha dos Santos

2017-07-01

Full Text Available This research aimed to evaluate physiological characteristics of 'BRS Princesa' banana under Partial Rootzone Drying irrigation, PRD. The five treatments, 1 - 50% of reduction in water depth (WD with a frequency alternation of irrigation side (FA of seven days during the whole production cycle; 2 - 50% of WD and FA of 14 days in the cycle; 3 - 50% of WD and FA of 21 days; 4 - 50% of WD with a fixed irrigation (only one lateral line on one side of the plant; and 5 - full irrigation (two lateral lines with open shutoff valve throughout the cycle, they were arranged in a randomized block design with five replicates. There is a reduction in photosynthetic rates and water use efficiency as a result of enzymatic impairment or stomatal closure, due to the increased of leaf temperature. The stomatal conductance - gs was lower in plants irrigated with 50% of ETc with fixed irrigation in one side of the plant. Even with water deficit in the soil, using the PRD with 50% of ETc, Photosynthesis - A Transpiration - E; Leaf temperature - Tleaf, internal concentration of CO2 - Ci; stomatal conductance - gs; photosynthetically active radiation - Qleaf; carboxylation efficiency - A/Ci; Quantum efficiency of Photosynthesis - A/Qleaf; and instantaneous water use efficiency - WUE 'BRS Princesa' banana were similar among strategies, highlighting the possibility of use of the irrigation management technique with PRD, saving water, and no physiological changes in the plants.

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

Towards a smart automated surface irrigation management in rice-growing areas in Italy

Directory of Open Access Journals (Sweden)

Daniele Masseroni

2017-02-01

Full Text Available Italy is the leading rice producer in Europe, accounting for more than half of the total high-quality production of this crop. Rice is traditionally grown in fields that remain flooded starting with crop establishment until close to harvest, and this traditional irrigation technique (i.e., continuous submergence is recognised as an important water resource sink (almost 40% of the irrigation water available worldwide is used for paddy areas. Meanwhile, the water management in rice areas requires a high level of labour because it is based on maintaining a predetermined water height in paddy fields and because the regulation of input and output flow is typically operated manually by the farmer. This study reveals the hardware and software characteristics of an automated and remote controlled technology tested for the first time in a rice farm near Pavia (Italy, during the 2016 growing season, aiming at a more efficient and less burdensome irrigation management system for rice fields. A water level sensor in the field provides the data required to govern the inflow regulation gate in real-time, according to the precise time to cut off the flow rate. Using a dedicated web page, the farmer can control flows, volumes and water levels in the fields by operating directly on the gate if necessary or setting the irrigation program according to his agronomic practices.

How Patients Experience Antral Irrigation

Directory of Open Access Journals (Sweden)

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.

Marginal cost curves for water footprint reduction in irrigated agriculture: guiding a cost-effective reduction of crop water consumption to a permit or benchmark level

Directory of Open Access Journals (Sweden)

A. D. Chukalla

2017-07-01

Full Text Available Reducing the water footprint (WF of the process of growing irrigated crops is an indispensable element in water management, particularly in water-scarce areas. To achieve this, information on marginal cost curves (MCCs that rank management packages according to their cost-effectiveness to reduce the WF need to support the decision making. MCCs enable the estimation of the cost associated with a certain WF reduction target, e.g. towards a given WF permit (expressed in m3  ha−1 per season or to a certain WF benchmark (expressed in m3  t−1 of crop. This paper aims to develop MCCs for WF reduction for a range of selected cases. AquaCrop, a soil-water-balance and crop-growth model, is used to estimate the effect of different management packages on evapotranspiration and crop yield and thus the WF of crop production. A management package is defined as a specific combination of management practices: irrigation technique (furrow, sprinkler, drip or subsurface drip; irrigation strategy (full or deficit irrigation; and mulching practice (no, organic or synthetic mulching. The annual average cost for each management package is estimated as the annualized capital cost plus the annual costs of maintenance and operations (i.e. costs of water, energy and labour. Different cases are considered, including three crops (maize, tomato and potato; four types of environment (humid in UK, sub-humid in Italy, semi-arid in Spain and arid in Israel; three hydrologic years (wet, normal and dry years and three soil types (loam, silty clay loam and sandy loam. For each crop, alternative WF reduction pathways were developed, after which the most cost-effective pathway was selected to develop the MCC for WF reduction. When aiming at WF reduction one can best improve the irrigation strategy first, next the mulching practice and finally the irrigation technique. Moving from a full to deficit irrigation strategy is found to be a no-regret measure: it reduces the WF

Marginal cost curves for water footprint reduction in irrigated agriculture: guiding a cost-effective reduction of crop water consumption to a permit or benchmark level

Science.gov (United States)

Chukalla, Abebe D.; Krol, Maarten S.; Hoekstra, Arjen Y.

2017-07-01

Reducing the water footprint (WF) of the process of growing irrigated crops is an indispensable element in water management, particularly in water-scarce areas. To achieve this, information on marginal cost curves (MCCs) that rank management packages according to their cost-effectiveness to reduce the WF need to support the decision making. MCCs enable the estimation of the cost associated with a certain WF reduction target, e.g. towards a given WF permit (expressed in m3  ha-1 per season) or to a certain WF benchmark (expressed in m3  t-1 of crop). This paper aims to develop MCCs for WF reduction for a range of selected cases. AquaCrop, a soil-water-balance and crop-growth model, is used to estimate the effect of different management packages on evapotranspiration and crop yield and thus the WF of crop production. A management package is defined as a specific combination of management practices: irrigation technique (furrow, sprinkler, drip or subsurface drip); irrigation strategy (full or deficit irrigation); and mulching practice (no, organic or synthetic mulching). The annual average cost for each management package is estimated as the annualized capital cost plus the annual costs of maintenance and operations (i.e. costs of water, energy and labour). Different cases are considered, including three crops (maize, tomato and potato); four types of environment (humid in UK, sub-humid in Italy, semi-arid in Spain and arid in Israel); three hydrologic years (wet, normal and dry years) and three soil types (loam, silty clay loam and sandy loam). For each crop, alternative WF reduction pathways were developed, after which the most cost-effective pathway was selected to develop the MCC for WF reduction. When aiming at WF reduction one can best improve the irrigation strategy first, next the mulching practice and finally the irrigation technique. Moving from a full to deficit irrigation strategy is found to be a no-regret measure: it reduces the WF by reducing water

Simulation of Stomatal Conductance and Water Use Efficiency of Tomato Leaves Exposed to Different Irrigation Regimes and Air CO2 Concentrations by a Modified “Ball-Berry” Model

Directory of Open Access Journals (Sweden)

Zhenhua Wei

2018-04-01

Full Text Available Stomatal conductance (gs and water use efficiency (WUE of tomato leaves exposed to different irrigation regimes and at ambient CO2 (a[CO2], 400 ppm and elevated CO2 (e[CO2], 800 ppm environments were simulated using the “Ball-Berry” model (BB-model. Data obtained from a preliminary experiment (Exp. I was used for model parameterization, where measurements of leaf gas exchange of potted tomatoes were done during progressive soil drying for 5 days. The measured photosynthetic rate (Pn was used as an input for the model. Considering the effect of soil water deficits on gs, an equation modifying the slope (m based on the mean soil water potential (Ψs in the whole root zone was introduced. Compared to the original BB-model, the modified model showed greater predictability for both gs and WUE of tomato leaves at each [CO2] growth environment. The models were further validated with data obtained from an independent experiment (Exp. II where plants were subjected to three irrigation regimes: full irrigation (FI, deficit irrigation (DI, and alternative partial root-zone irrigation (PRI for 40 days at both a[CO2] and e[CO2] environment. The simulation results indicated that gs was independently acclimated to e[CO2] from Pn. The modified BB-model performed better in estimating gs and WUE, especially for PRI strategy at both [CO2] environments. A greater WUE could be seen in plants grown under e[CO2] associated with PRI regime. Conclusively, the modified BB-model was capable of predicting gs and WUE of tomato leaves in various irrigation regimes at both a[CO2] and e[CO2] environments. This study could provide valuable information for better predicting plant WUE adapted to the future water-limited and CO2 enriched environment.

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

Nuclear techniques to evaluate the water use of field crops irrigated in different stages of their cycles

International Nuclear Information System (INIS)

Libardi, P.L.; Moraes, S.O.; Saad, M.A.; Jong Van Lier, Q.; Vieira, O.; Luis Tuon, R.

1995-01-01

The search for soil - water management systems that rationalize the water use of field crops should always be emphasized. The present coordinated research programme of the joint division FAO/ AEA has the objective to contribute to a better understanding of this subject by improving the use efficiency of water resources in irrigated agriculture. This project is a contribution to this programme and consisted in the identification of specified development stages of bean ( phaseolus vulgaris, L ) and corn (Zea mays, L ) crops in which plants are less sensitive to water deficit. Experiments were carried out in a tropical soil of agricultural importance in a traditional irrigation field site of the state of Sao Paulo, Brazil. Neutron probe tensiometers were used to determine the soil water balance in different treatments. 3 tabs, 16 refs, (Author)

Controlled water deficit during ripening affects proanthocyanidin synthesis, concentration and composition in Cabernet Sauvignon grape skins.

Science.gov (United States)

Cáceres-Mella, Alejandro; Talaverano, M Inmaculada; Villalobos-González, Luis; Ribalta-Pizarro, Camila; Pastenes, Claudio

2017-08-01

The influence of controlled water deficit on the phenolic composition and gene expression of VvLAR2, VvMYBPA1, VvMYBPA2 and VvMYB4a in Cabernet Sauvignon grape skins throughout ripening was investigated. The assay was carried out on own-rooted Vitis vinifera plants cv. Cabernet Sauvignon in a commercial vineyard from veraison until commercial harvest. Three irrigation regimes were used from veraison until harvest with the following treatments: T1: 3.6 mm day -1 ; T2: 1.8 mm day -1 and T3: 0.3 mm day -1 . The content of total phenols and total anthocyanins in grape skins increased during ripening, but water deficit did not produce differences among treatments in the total anthocyanin concentration. Proanthocyanidins (PAs) decreased throughout ripening, although approximately 25 days after veraison (DAV), their content slightly increased. This effect was more pronounced in the most restrictive treatment (T3). A similar pattern was observed in the transcript abundance of VvLAR2, VvMYBPA1 and VvMYB4a. PAs separation revealed differences in concentration but not in the proportion among fractions among the irrigation treatments. Additionally, controlled water deficit increased the mean degree of polymerization and the flavan-3-ol polymeric concentration in grape skins throughout ripening but with no effects on the extent of PAs galloylation. Our results suggest that the water status of Cabernet Sauvignon grapevines affects the gene expression for proteins involved in the synthesis of PAs, increasing their concentration and also their composition, with further evidence for the efficacy of a convenient, controlled water deficit strategy for grapevine cultivation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Rice agroecosystem of the Muda irrigation scheme, Malaysia

International Nuclear Information System (INIS)

Nashriyah Mat; Ho Nai Kin; Ismail Sahid; Ahyaudin Ali; Lum Keng Yeang

1998-01-01

Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be aware of the potential hazards arising out of improper use of pesticides, to them as well to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical / fertilizer companies as well as those concerned with sustainable farming. The ecologists, chemists, biochemists, entomologists, zoologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts. (Nahrul Khair Alang Md Rashid)

Rice agroecosystem of the Muda irrigation scheme, Malaysia

Energy Technology Data Exchange (ETDEWEB)

Mat, Nashriyah [Malaysian Institute for Nuclear Technology Research MINT, Bangi (Malaysia); Kin, Ho Nai [Muda Agricultural Development Authority MADA, Alor Setar (Malaysia); Sahid, Ismail [Universiti Kebangsaan Malaysia, Bangi (Malaysia); Ali, Ahyaudin [Universiti Sains Malaysia, Penang (Malaysia); Yeang, Lum Keng [Malaysian Agricultural Research and Development Institute, Serdang (Malaysia)

1998-07-01

Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be aware of the potential hazards arising out of improper use of pesticides, to them as well to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical / fertilizer companies as well as those concerned with sustainable farming. The ecologists, chemists, biochemists, entomologists, zoologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts. (Nahrul Khair Alang Md Rashid)

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...

Leaf injury characteristics of grassland species exposed to ozone in relation to soil moisture condition and vapour pressure deficit

International Nuclear Information System (INIS)

Bungener, P.; Balls, G.R.; Nussbaum, S.; Geissmann, M.; Grub, A.; Fuhrer, J.

1999-01-01

A range of plant species typical of semi-natural grasslands were tested for their sensitivity to short-term ozone injury under normal and reduced irrigation, and in relationship to air vapour pressure deficit. Potted specimens of 24 herbs, legumes and grasses were exposed during two seasons to four O 3 treatments in open-top chambers. The ozone treatments were: (a) charcoal-filtered air; (b) charcoal-filtered air plus ozone to match ambient levels; (c) charcoal-filtered air plus O 3 to ambient levels 1.5 and (d) charcoal-filtered air with ozone added to twice ambient levels during selected episodes of 7–13 d. During these ozone episodes, half of the plants in each ozone treatment received reduced irrigation (dry treatment) while the rest was kept under full irrigation (wet treatment). Type and date of first occurrence of leaf injury were noted during individual growth periods. Plants were harvested three times per year, and the percentage of injured leaves was recorded. Depending on species, injury symptoms were expressed as flecking (O 3 -specific injury), leaf yellowing or anthocyanin formation. Carum carvi and most species of the Fabaceae family (Onobrychis sativa, Trifolium repens, Trifolium pratense) were found to be most responsive to O 3 , injury occurring after only a few days of exposure in treatment (b). An episodic reduction in irrigation tended to reduce the expression of O 3 -specific symptoms, but only in species for which a reduction in soil moisture potential and an associated reduction in stomatal conductance during the dry episodes were observed. In other species, the protection from O 3 injury seemed to be of little importance. Using artificial neural networks the injury response of nine species was analysed in relation to Species, stomatal conductance, ozone as AOT40 (accumulated exposure above a threshold of 0.04 ppm for periods with global radiation ≥ 50 W m −2 (Fuhrer et al., 1997)), mean relative growth rate, air vapour pressure

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.

Effect of Different Levels of Irrigation Water on Quantitative and Qualitative Characteristics of Potato and Determination of Its Optimum Consumptive Use of Water in Shahrekord

Directory of Open Access Journals (Sweden)

masoud Naderi

2017-01-01

Full Text Available Introduction: Owing to drought, increasing demand for fresh water resources and low water use efficiency, the optimum use of water is essential in the agricultural sector. Therefore, this study was conducted to investigate the effect of different levels of irrigation water on quantitative and qualitative Characteristics of potato (Burren cultivar and determination of its optimum consumptive use of water under Shahr-e kord environment. Materials and Methods: This study was conducted at the Agricultural Research Center and Natural Resources in Shahr-e kord with longitude and latitude of 32˚18΄ and 50˚51΄ , respectively, in 2013. This experiment was performed in randomized complete block design with 7 treatments consisted of different levels of irrigation water and 3 replications. Different levels of irrigation water were: 40, 55, 70, 85, 100, 115 and 130 % of the soil moisture deficit. Potato seeds (burren cultivar were planted with distance of 20 cm from each other and furrow width of 75 cm. Irrigation program were performed based on the measurement of soil moisture deficit. The irrigation intervals were considered as a fixed 7 day. Irrigation levels were applied to 105 days after planting and the total growth period was 130 days from planting to harvesting. The samples were taken from the two middle furrows. The evaluated parameters were included weight of tubers per plant, tuber diameter, weight of tuber in seed size, weight of tuber production in a plant in marketable size, tuber dry weight, the starch percent, percent of soluble sugars, nitrogen percent. The starch content was determined by Polarimetry method. The soluble sugars content was measured by Colorimetric method, the nitrogen content was measured by wet digestion method and using the Kjeldahl set. Then, the optimal depth of water consumption in conditions of limited water resources were determined by English method Statistical analysis of data and drawing graphs were done with

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 ...

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 ...

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...

Upland cotton growth and yield response to timing the initial postplant irrigation

International Nuclear Information System (INIS)

Steger, A.J.; Silvertooth, J.C.; Brown, P.W.

1998-01-01

Cotton (Gossypium spp.) production in arid and semiarid regions depends on well-managed irrigation systems for optimum yield and production efficiency. Water deficit stress early in the growing season can affect the subsequent growth and development of short-season cotton. A 2-yr field study was conducted in southern Arizona to determine the optimum timing of the initial postplant irrigation for a short-season upland cotton variety based on midday leaf water potential (LWP) measurements, and to evaluate the season-long effects of delayed irrigation on subsequent plant growth patterns. In both years, the short-season upland variety, DPL 20, was planted into a Pima clay loam soil [fine-silty, mixed (calcareous), thermic Typic Torrifluvent] that had received a preplant irrigation of 152 (1993) or 254 mm (1994) approximately 3 wk prior to planting. Treatments, designated T1, T2, and T3, received the initial postplant irrigation when the average midday LWP of the uppermost, fully expanded leaf measured −1.5, −1.9, and −2.3 MPa, respectively. Daily midday LWP measurements were taken using the pressure chamber technique. Soil water was measured at 25-cm depth increments using neutron attenuation. Plant height, number of mainstem nodes, nodes above white flower (NAWF), and canopy closure were measured at weekly intervals. All treatments reached maturity, as measured by NAWF ≤ 5, at approximately the same time during the growing season. Complete canopy closure was delayed in the T3 plots resulting in reduced interception and utilization of available solar radiation early in the growing season. When treatments were initiated, approximately 84% (T1), 62% (T2), and 32% (T3) of the total plant-available water (field capacity less permanent wilting point) was present in the upper 1.5 of the soil profile. Yields were 1263, 1244, and 1110 kg lint ha−1 in 1993 and 1229, 1176, and 1095 kg lint ha −1 in 1994 for T1, T2, and T3, respectively. Lint yields were significantly

Seasonal Population Dynamics of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) in Sweet Orange Trees Maintained under Continuous Deficit Irrigation

Science.gov (United States)

A two-year study was conducted in a citrus orchard [Citrus sinensis (L.) Osbeck cv. ‘Valencia’] to determine influence of plant water stress on population dynamics of glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop...

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.

Growth Of New Alfalfa And Cocksfoot Shoot S During Water-Deficit And Irrigation .2. Modeling

International Nuclear Information System (INIS)

Duru, M.; Langlet, A.

1995-01-01

Eight regrowths of alfalfa and thirteen of cocksfoot were compared with and without irrigation and with two levels of nitrogen supply (cocksfoot). Aerial biomass was modellized according to PARa. Following a water shortage, the efficiency of radiation intercepted decreased more frequently than the efficiency of the conversion of radiation in biomass for cocksfoot, but the contrary was observed for alfalfa. The decrease in PARa resulted from the direct effect of water shortage, but also from indirect (low value of herbage nitrogen level) and deferred (after-effect as residual leaf area index) effects [it

Decision-making in irrigation networks: Selecting appropriate canal structures using multi-attribute decision analysis.

Science.gov (United States)

Hosseinzade, Zeinab; Pagsuyoin, Sheree A; Ponnambalam, Kumaraswamy; Monem, Mohammad J

2017-12-01

The stiff competition for water between agriculture and non-agricultural production sectors makes it necessary to have effective management of irrigation networks in farms. However, the process of selecting flow control structures in irrigation networks is highly complex and involves different levels of decision makers. In this paper, we apply multi-attribute decision making (MADM) methodology to develop a decision analysis (DA) framework for evaluating, ranking and selecting check and intake structures for irrigation canals. The DA framework consists of identifying relevant attributes for canal structures, developing a robust scoring system for alternatives, identifying a procedure for data quality control, and identifying a MADM model for the decision analysis. An application is illustrated through an analysis for automation purposes of the Qazvin irrigation network, one of the oldest and most complex irrigation networks in Iran. A survey questionnaire designed based on the decision framework was distributed to experts, managers, and operators of the Qazvin network and to experts from the Ministry of Power in Iran. Five check structures and four intake structures were evaluated. A decision matrix was generated from the average scores collected from the survey, and was subsequently solved using TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method. To identify the most critical structure attributes for the selection process, optimal attribute weights were calculated using Entropy method. For check structures, results show that the duckbill weir is the preferred structure while the pivot weir is the least preferred. Use of the duckbill weir can potentially address the problem with existing Amil gates where manual intervention is required to regulate water levels during periods of flow extremes. For intake structures, the Neyrpic® gate and constant head orifice are the most and least preferred alternatives, respectively. Some advantages

Drought effect on growth, gas exchange and yield, in two strains of local barley Ardhaoui, under water deficit conditions in southern Tunisia.

Science.gov (United States)

Thameur, Afwa; Lachiheb, Belgacem; Ferchichi, Ali

2012-12-30

Two local barley strains cv. Ardhaoui originated from Tlalit and Switir, sourthern Tunisia were grown in pots in a glasshouse assay, under well-watered conditions for a month. Plants were then either subjected to water deficit (treatment) or continually well-watered (control). Control pots were irrigated several times each week to maintain soil moisture near field capacity (FC), while stress pots experienced soil drying by withholding irrigation until they reached 50% of FC. Variation in relative water content, leaf area, leaf appearance rate and leaf gas exchange (i.e. net CO(2) assimilation rate (A), transpiration (E), and stomatal conductance (gs)) in response to water deficit was investigated. High leaf relative water content (RWC) was maintained in Tlalit by stomatal closure and a reduction of leaf area. Reduction in leaf area was due to decline in leaf gas exchange during water deficit. Tlalit was found to be drought tolerant and able to maintain higher leaf RWC under drought conditions. Water deficit treatment reduced stomatal conductance by 43% at anthesis. High net CO(2) assimilation rate under water deficit was associated with high RWC (r = 0.998; P gas exchange parameters were found, which can give some indications on the degree of drought tolerance. Thus, the ability of the low leaf area plants to maintain higher RWC could explain the differences in drought tolerance in studied barley strains. Results showed that Tlalit showed to be more efficient and more productive than Switir. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Genetic variant for behavioral regulation factor of executive function and its possible brain mechanism in attention deficit hyperactivity disorder.

Science.gov (United States)

Sun, Xiao; Wu, Zhaomin; Cao, Qingjiu; Qian, Ying; Liu, Yong; Yang, Binrang; Chang, Suhua; Yang, Li; Wang, Yufeng

2018-05-16

As a childhood-onset psychiatric disorder, attention deficit hyperactivity disorder (ADHD) is complicated by phenotypic and genetic heterogeneity. Lifelong executive function deficits in ADHD are described in many literatures and have been proposed as endophenotypes of ADHD. However, its genetic basis is still elusive. In this study, we performed a genome-wide association study of executive function, rated with Behavioral Rating Inventory of Executive Function (BRIEF), in ADHD children. We identified one significant variant (rs852004, P = 2.51e-08) for the overall score of BRIEF. The association analyses for each component of executive function found this locus was more associated with inhibit and monitor components. Further principle component analysis and confirmatory factor analysis provided an ADHD-specific executive function pattern including inhibit and monitor factors. SNP rs852004 was mainly associated with the Behavioral Regulation factor. Meanwhile, we found the significant locus was associated with ADHD symptom. The Behavioral Regulation factor mediated its effect on ADHD symptom. Functional magnetic resonance imaging (fMRI) analyses further showed evidence that this variant affected the activity of inhibition control related brain regions. It provided new insights for the genetic basis of executive function in ADHD.

Extensive tissue-specific transcriptomic plasticity in maize primary roots upon water deficit.

Science.gov (United States)

Opitz, Nina; Marcon, Caroline; Paschold, Anja; Malik, Waqas Ahmed; Lithio, Andrew; Brandt, Ronny; Piepho, Hans-Peter; Nettleton, Dan; Hochholdinger, Frank

2016-02-01

Water deficit is the most important environmental constraint severely limiting global crop growth and productivity. This study investigated early transcriptome changes in maize (Zea mays L.) primary root tissues in response to moderate water deficit conditions by RNA-Sequencing. Differential gene expression analyses revealed a high degree of plasticity of the water deficit response. The activity status of genes (active/inactive) was determined by a Bayesian hierarchical model. In total, 70% of expressed genes were constitutively active in all tissues. In contrast, deficit-responsive genes (1915) were consistently regulated in all tissues, while >75% (1501 genes) were specifically regulated in a single root tissue. Water deficit-responsive genes were most numerous in the cortex of the mature root zone and in the elongation zone. The most prominent functional categories among differentially expressed genes in all tissues were 'transcriptional regulation' and 'hormone metabolism', indicating global reprogramming of cellular metabolism as an adaptation to water deficit. Additionally, the most significant transcriptomic changes in the root tip were associated with cell wall reorganization, leading to continued root growth despite water deficit conditions. This study provides insight into tissue-specific water deficit responses and will be a resource for future genetic analyses and breeding strategies to develop more drought-tolerant maize cultivars. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Effects of different irrigation practices using treated wastewater on tomato yields, quality, water productivity, and soil and fruit mineral contents.

Science.gov (United States)

Demir, Azize Dogan; Sahin, Ustun

2017-11-01

Wastewater use in agricultural irrigation is becoming a common practice in order to meet the rising water demands in arid and semi-arid regions. The study was conducted to determine the effects of the full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation practices using treated municipal wastewater (TWW) and freshwater (FW) on tomato yield, water use, fruit quality, and soil and fruit heavy metal concentrations. The TWW significantly increased marketable yield compared to the FW, as well as decreased water consumption. Therefore, water use efficiency (WUE) in the TWW was significantly higher than in the FW. Although the DI and the PRD practices caused less yields, these practices significantly increased WUE values due to less irrigation water applied. The water-yield linear relationships were statistically significant. TWW significantly increased titratable acidity and vitamin C contents. Reduced irrigation provided significantly lower titratable acidity, vitamin C, and lycopene contents. TWW increased the surface soil and fruit mineral contents in response to FW. Greater increases were observed under FI, and mineral contents declined with reduction in irrigation water. Heavy metal accumulation in soils was within safe limits. However, Cd and Pb contents in fruits exceeded standard limits given by FAO/WHO. Higher metal pollution index values determined for fruits also indicated that TWW application, especially under FI, might cause health risks in long term.

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.

Interactive Effects of Elevated CO2 and N Fertilization on Yield and Quality of Tomato Grown Under Reduced Irrigation Regimes

Directory of Open Access Journals (Sweden)

Zhenhua Wei

2018-03-01

Full Text Available The interactive effects of CO2 elevation, N fertilization, and reduced irrigation regimes on fruit yield (FY and quality in tomato (Solanum lycopersicum L. were investigated in a split-root pot experiment. The plants were grown in two separate climate-controlled greenhouse cells at atmospheric [CO2] of 400 and 800 ppm, respectively. In each cell, the plants were fertilized at either 100 or 200 mg N kg-1 soil and were either irrigated to full water holding capacity [i.e., a volumetric soil water content of 18%; full irrigation (FI], or using 70% water of FI to the whole pot [deficit irrigation (DI] or alternately to only half of the pot [partial root-zone irrigation (PRI]. The yield and fruit quality attributes mainly from sugars (sucrose, fructose, and glucose and organic acids (OAs; citric acid and malic acid to various ionic (NH4+, K+, Mg2+, Ca2+, NO3-, SO42-, and PO43- concentrations in fruit juice were determined. The results indicated that lower N supply reduced fruit number and yield, whereas it enhanced some of the quality attributes of fruit as indicated by greater firmness and higher concentrations of sugars and OAs. Elevated [CO2] (e[CO2] attenuated the negative influence of reduced irrigation (DI and PRI on FY. Principal component analysis revealed that the reduced irrigation regimes, especially PRI, in combination with e[CO2] could synergistically improve the comprehensive quality of tomato fruits at high N supply. These findings provide useful knowledge for sustaining tomato FY and quality in a future drier and CO2-enriched environment.

Biogeosystem technique as a base of Sustainable Irrigated Agriculture

Science.gov (United States)

Batukaev, Abdulmalik

2016-04-01

The world water strategy is to be changed because the current imitational gravitational frontal isotropic-continual paradigm of irrigation is not sustainable. This paradigm causes excessive consumption of fresh water - global deficit - up to 4-15 times, adverse effects on soils and landscapes. Current methods of irrigation does not control the water spread throughout the soil continuum. The preferable downward fluxes of irrigation water are forming, up to 70% and more of water supply loses into vadose zone. The moisture of irrigated soil is high, soil loses structure in the process of granulometric fractions flotation decomposition, the stomatal apparatus of plant leaf is fully open, transpiration rate is maximal. We propose the Biogeosystem technique - the transcendental, uncommon and non-imitating methods for Sustainable Natural Resources Management. New paradigm of irrigation is based on the intra-soil pulse discrete method of water supply into the soil continuum by injection in small discrete portions. Individual volume of water is supplied as a vertical cylinder of soil preliminary watering. The cylinder position in soil is at depth form 10 to 30 cm. Diameter of cylinder is 1-2 cm. Within 5-10 min after injection the water spreads from the cylinder of preliminary watering into surrounding soil by capillary, film and vapor transfer. Small amount of water is transferred gravitationally to the depth of 35-40 cm. The soil watering cylinder position in soil profile is at depth of 5-50 cm, diameter of the cylinder is 2-4 cm. Lateral distance between next cylinders along the plant raw is 10-15 cm. The soil carcass which is surrounding the cylinder of non-watered soil remains relatively dry and mechanically stable. After water injection the structure of soil in cylinder restores quickly because of no compression from the stable adjoining volume of soil and soil structure memory. The mean soil thermodynamic water potential of watered zone is -0.2 MPa. At this potential

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.

A low cost microcontroller-based automated irrigation system for two ...

African Journals Online (AJOL)

Maintaining soil water level is a necessary and pre-requisite for optimum crops production. Water is the essential elements for proper growth of crops in its optimum level; however its excessiveness should be avoided. Since irrigation is a dominant consumer of water, there must be a system which regulates the level of water ...

A comparative study of deficit pattern in theory of mind and emotion regulation methods in evaluating patients with bipolar disorder and normal individuals

OpenAIRE

Ali Fakhari; Khalegh Minashiri; Abolfazl Fallahi; Mohammad Taher Panah

2013-01-01

BACKGROUND: This study compared patterns of deficit in "theory of mind" and "emotion regulation" in patientswith bipolar disorder and normal individuals. METHODS: In this causal-comparative study, subjects were 20 patients with bipolar disorder and 20 normalindividuals. Patients were selected via convenience sampling method among hospitalized patients at Razi hospital ofTabriz, Iran. The data was collected through two scales: Reading the Mind in the Eyes Test and Emotion RegulationQuestionnai...

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.

Seasonal Canopy Temperatures for Normal and Okra Leaf Cotton under Variable Irrigation in the Field

Directory of Open Access Journals (Sweden)

James R. Mahan

2016-11-01

Full Text Available Temperature affects a number of physiological factors in plants and is related to water use, yield and quality in many crop species. Seasonal canopy temperature, measured with infrared thermometers, is often used in conjunction with environmental factors (e.g., air temperature, humidity, solar radiation to assess crop stress and management actions in cotton. Normal and okra leaf shapes in cotton have been associated with differences in water use and canopy temperature. The okra leaf shape in cotton is generally expected to result in lower water use and lower canopy temperatures, relative to normal leaf, under water deficits. In this study canopy temperatures were monitored in okra and normal leaf varieties for a growing season at four irrigation levels. Differences in canopy temperature (<2 °C were measured between the two leaf shapes. As irrigation levels increased, canopy temperature differences between the leaf shapes declined. At the lowest irrigation level, when differences in sensible energy exchanges due to the okra leaf shape would be enhanced, the canopy temperature of the okra leaf was warmer than the normal leaf. This suggests that varietal differences that are not related to leaf shape may have more than compensated for leaf shape differences in the canopy temperature.

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

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

Gender and power contestations over water use in irrigation schemes: Lessons from the lake Chilwa basin

Science.gov (United States)

Nkhoma, Bryson; Kayira, Gift

2016-04-01

Over the past two decades, Malawi has been adversely hit by climatic variability and changes, and irrigation schemes which rely mostly on water from rivers have been negatively affected. In the face of dwindling quantities of water, distribution and sharing of water for irrigation has been a source of contestations and conflicts. Women who constitute a significant section of irrigation farmers in schemes have been major culprits. The study seeks to analyze gender contestations and conflicts over the use of water in the schemes developed in the Lake Chilwa basin, in southern Malawi. Using oral and written sources as well as drawing evidence from participatory and field observations conducted at Likangala and Domasi irrigation schemes, the largest schemes in the basin, the study observes that women are not passive victims of male domination over the use of dwindling waters for irrigation farming. They have often used existing political and traditional structures developed in the management of water in the schemes to competitively gain monopoly over water. They have sometimes expressed their agency by engaging in irrigation activities that fall beyond the control of formal rules and regulations of irrigation agriculture. Other than being losers, women are winning the battle for water and land resources in the basin.

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.

Potato yield and yield structure depending on irrigation

Directory of Open Access Journals (Sweden)

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. .

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

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 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.

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

Evaluating effect of biofertilizer on nodulation and soybean (Glycine max L plants growth characteristics under water deficit stress of seed

Directory of Open Access Journals (Sweden)

M. Tajik Khaveh

2016-05-01

Full Text Available In order to evaluate the effects of biofertilizer on soybean (Glycine max L. seed vigor that produced under water deficit condition and related traits, an experiment was conducted in a factorial layout based of complete randomized block design with four replications at the research greenhouse of Aboureihan campus- Tehran University, Iran. Experimental treatments were include biofertilizer (seed inoculation with Bradyrhizobium japonicum, co-inoculation with Bradyrhizobium japonicum and Pseudomonas fluorescens, co-inoculation with Bradyrhizobium japonicum and Glomus mosseae, Cultivar (Zalta Zalha and Clark×Hobbit line and water deficit stress [irrigation plants after 50 (normal irrigation, 100 (medium stress, 150 (sever stress mm evaporation from pan class A, in parents field]. Results showed that the water deficit stress had negative effects on seed quality and seedling emergence percentage, mean daily seedling emergence, root, leaf and shoot dry weight, number of nodule were decreased. ZaltaZalha cultivar had higher shoot dry weight and number of leaf compared with other cultivars. Applications of biofertilzer was effective on stem diameter, root, leaf and shoot dry weight, number of leaf and nodule and those attributes increased by co-inoculation of Bradyrhizobium japonicum and Glomus mosseae. Also, use of biofertilizer in stress levels was effective on stem dry weight. Stem dry weight was increased by Co-inoculation of cultivar seeds with Bradyrhizobium japonicum and Glomus mosseae.

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.

In-Soil and Down-Hole Soil Water Sensors: Characteristics for Irrigation Management

Science.gov (United States)

The past use of soil water sensors for irrigation management was variously hampered by high cost, onerous regulations in the case of the neutron probe (NP), difficulty of installation or maintenance, and poor accuracy. Although many sensors are now available, questions of their utility still abound....

[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

The comparative study of anatomical structure of stem and ovule development of four cultivars of Glycine max L. merr in water deficit stress

Directory of Open Access Journals (Sweden)

Parissa Jonoubi

2014-08-01

Full Text Available Drought stress is one of the most important limiting factors that affect different aspects of plants vegetative and reproductive growth. It is one of the most important limiting factors of crop productivity. Regarding to the importance of soybean as an oilseed plant, and in order to identify the drought tolerant cultivars as well as evaluating of the effects of drought stress on anatomical structureof four soybean cultivars (Clin, Clark, M9 and L17, two series of experiments were carried out as randomized complete design. In the first experiment, at optimum conditions, plants were irrigated after 50 mm evaporation from germination to the end of growing period, whereas the second experiment was irrigated after 150 mm (sever stress evaporation from evaporation pan. The results showed that the effect of water deficit stress on cortex thickness and number of layers, Phloem and xylem thickness, diameter of vessel elements, number of vessel element rows, number of vessel elements in stem, pith and stele thickness, stem diameter and number of trichomes were significant. Relative acceleration of embryo sac development was observed in all plants under water deficit stress except for Clark cultivar. Evaluation of anatomical factors on these cultivars showed that Clin cultivar was more tolerant to water deficit stress compared to other cultivars.

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.

Calibration and validation of the STICS crop model for managing wheat irrigation in the semi-arid Marrakech/Al-Haouz Plain

International Nuclear Information System (INIS)

Hadria, R.; Khabba, S.; Lahrouni, A.; Duchemin, B.; Chehbouni, A.; Carriou, J.; Ouzine, L.

2007-01-01

In the first part of this work, we shoot growth module and grain yield of the STICS crop model were calibrated and validated by using field data which was collected from irrigated winter wheat fields in the Haouz plain near Marrakech. The calibration was performed on the thermal units between the four phonological stages that control the dynamics of leaf area index and thermal unit between emergence and beginning of grain filling. The plant phenology was calibrated for three fields monitored during the 2002/03 season. Evaluation of the green yields and the temporal evolution of leaf area index were done for six validation fields during 2003/04. The results showed the significant accuracy of the model in simulating these variables and also indicated that the plants mainly suffered from lack of nitrogen. The results in the second part show the potential of crop modeling to schedule irrigation water, on the assumption that the plants were growing under optimal conditions of fertilization. In this case, the model was used to manage the time of irrigation according to a threshold for water deficit. Various simulations displayed logical trends in the relationship between the grain yield and both the amount and timing of irrigation water. These results were finally compared with those obtained from real irrigation practices. For the particular climate pf 2003/04, the comparison showed that 70mm 40 mm of water could be saved in case of early and late showing, respectively. (author)

Maternal emotion regulation mediates the association between adult attention-deficit/hyperactivity disorder symptoms and parenting.

Science.gov (United States)

Mazursky-Horowitz, Heather; Felton, Julia W; MacPherson, Laura; Ehrlich, Katherine B; Cassidy, Jude; Lejuez, C W; Chronis-Tuscano, Andrea

2015-01-01

Mothers with elevated Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms demonstrate parenting deficits, as well as difficulties in emotion regulation (ER), which may further impact their ability to effectively parent. However, no empirical research has examined potential mediators that explain the relations between maternal ADHD symptoms and parenting. This prospective longitudinal study examined difficulties with ER as a mediator of the relation between adult ADHD symptoms and parenting among 234 mothers of adolescents recruited from the community when they were between the ages of nine to twelve. Maternal ratings of adult ADHD symptoms, difficulties with ER, and parenting responses to their adolescents' expressions of negative emotions were collected over the course of three years. We found that maternal ADHD symptoms were negatively associated with positive parenting responses to adolescents' negative emotions, and positively associated with harsh parenting and maternal distress reactions. Moreover, maternal ER mediated the relation between adult ADHD symptoms and harsh parenting responses, while controlling for adolescent ADHD and disruptive behavior symptoms. However, maternal ER did not mediate the relation between ADHD symptoms and positive or distressed parental responses. Thus, it appears that ER is one mechanism by which maternal ADHD symptoms are associated with harsh responses to their adolescents' expressions of negative emotion. These findings may have downstream implications for adolescent adjustment.

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

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.

Daytime soybean transcriptome fluctuations during water deficit stress.

Science.gov (United States)

Rodrigues, Fabiana Aparecida; Fuganti-Pagliarini, Renata; Marcolino-Gomes, Juliana; Nakayama, Thiago Jonas; Molinari, Hugo Bruno Correa; Lobo, Francisco Pereira; Harmon, Frank G; Nepomuceno, Alexandre Lima

2015-07-07

Since drought can seriously affect plant growth and development and little is known about how the oscillations of gene expression during the drought stress-acclimation response in soybean is affected, we applied Illumina technology to sequence 36 cDNA libraries synthesized from control and drought-stressed soybean plants to verify the dynamic changes in gene expression during a 24-h time course. Cycling variables were measured from the expression data to determine the putative circadian rhythm regulation of gene expression. We identified 4866 genes differentially expressed in soybean plants in response to water deficit. Of these genes, 3715 were differentially expressed during the light period, from which approximately 9.55% were observed in both light and darkness. We found 887 genes that were either up- or down-regulated in different periods of the day. Of 54,175 predicted soybean genes, 35.52% exhibited expression oscillations in a 24 h period. This number increased to 39.23% when plants were submitted to water deficit. Major differences in gene expression were observed in the control plants from late day (ZT16) until predawn (ZT20) periods, indicating that gene expression oscillates during the course of 24 h in normal development. Under water deficit, dissimilarity increased in all time-periods, indicating that the applied stress influenced gene expression. Such differences in plants under stress were primarily observed in ZT0 (early morning) to ZT8 (late day) and also from ZT4 to ZT12. Stress-related pathways were triggered in response to water deficit primarily during midday, when more genes were up-regulated compared to early morning. Additionally, genes known to be involved in secondary metabolism and hormone signaling were also expressed in the dark period. Gene expression networks can be dynamically shaped to acclimate plant metabolism under environmental stressful conditions. We have identified putative cycling genes that are expressed in soybean leaves

Extending extant models of the pathogenesis of borderline personality disorder to childhood borderline personality symptoms: the roles of affective dysfunction, disinhibition, and self- and emotion-regulation deficits.

Science.gov (United States)

Gratz, Kim L; Tull, Matthew T; Reynolds, Elizabeth K; Bagge, Courtney L; Latzman, Robert D; Daughters, Stacey B; Lejuez, C W

2009-01-01

Although research has been conducted on the course, consequences, and correlates of borderline personality disorder (BPD), little is known about its emergence in childhood, and no studies have examined the extent to which theoretical models of the pathogenesis of BPD in adults are applicable to the correlates of borderline personality symptoms in children. The goal of this study was to examine the interrelationships between two BPD-relevant personality traits (affective dysfunction and disinhibition), self- and emotion-regulation deficits, and childhood borderline personality symptoms among 263 children aged 9 to 13. We predicted that affective dysfunction, disinhibition, and their interaction would be associated with childhood borderline personality symptoms, and that self- and emotion-regulation deficits would mediate these relationships. Results provided support for the roles of both affective dysfunction and disinhibition (in the form of sensation seeking) in childhood borderline personality symptoms, as well as their hypothesized interaction. Further, both self- and emotion-regulation deficits partially mediated the relationship between affective dysfunction and childhood borderline personality symptoms. Finally, results provided evidence of different gender-based pathways to childhood borderline personality symptoms, suggesting that models of BPD among adults are more relevant to understanding the factors associated with borderline personality symptoms among girls than boys.

Effect of Zeolite Rates and Irrigation Management on Some Properties of Saffron Corms

Directory of Open Access Journals (Sweden)

Abbas Khashei Siuki

2016-11-01

Full Text Available Saffron (Crocus sativus L. is a subtropical and valuable crop which is reproduced by corms. Due to the importance of corm weight in saffron yield, it is important to study the different factors that affect yield such as drought stress. For this purpose, this research was conducted as a factorial design based on completely randomized design (CRD in the Agricultural Research Station of the University of Birjand during the period 2013-2015. The treatments consisted of Zeolite at four rates (0: Z0, 0.5: Z1, 1: Z2 and 2: Z3 as weight percentage and irrigation management at three levels (traditional: I1, deficit irrigation as 70% moisture depletion: I2 and full irrigation: I3 with three replications. The results showed that zeolite rates has a significant effect on corm weight, number of corms less than 2gr, number of 6-8gr corms and number of replacement corms (P≤0.01. Irrigation management also has a significant effect on corm weight (P≤0.01, number of corms 6-8gr and number of replacement corms (P≤0.05. The treatments with no zeolite amended (Z0I1, Z0I2 and Z0I3 showed a reduction in corm weight compared to Z3I3 (P≤0.05. Z3I3, Z3I2 and Z3I3 showed an increase in the number of replacement corms while Z0I1 and Z0I2 had the least number of replacement corms. In conclusion, Z2I1 is recommended as the best treatment by considering the reduction in zeolite and water used, which increased corm weight by 26.64%, 23.88% and 17.81% compared to Z0I1, Z0I2 and Z0I3, respectively.

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

Temporal dynamics of stomatal conductance of plants under water deficit: can homeostasis be improved by more complex dynamics?

Directory of Open Access Journals (Sweden)

Gustavo Maia Souza

2004-07-01

Full Text Available In this study we hypothesized that chaotic or complex behavior of stomatal conductance could improve plant homeostasis after water deficit. Stomatal conductance of sunflower and sugar beet leaves was measured in plants grown either daily irrigation or under water deficit using an infrared gas analyzer. All measurements were performed under controlled environmental conditions. In order to measure a consistent time series, data were scored with time intervals of 20s during 6h. Lyapunov exponents, fractal dimensions, KS entropy and relative LZ complexity were calculated. Stomatal conductance in both irrigated and non-irrigated plants was chaotic-like. Plants under water deficit showed a trend to a more complex behaviour, mainly in sunflower that showed better homeostasis than in sugar beet. Some biological implications are discussed.Este estudo testou a hipótese de que a condutância estomática de uma população de estômatos em uma folha poderia apresentar um comportamento caótico ou complexo sob diferentes condições hídricas, o que poderia favorecer a capacidade homeostática das plantas. A condutância estomática em folhas de girassol e de beterraba cultivadas com irrigação diária e sob deficiência hídrica foi medida com um analisador de gás por infra-vermelho em condições controladas. Os dados foram registrados a cada 20s durante 6h. As séries temporais obtidas foram analisadas por meio dos coeficientes de Lyapunov, dimensão fractal, entropia KS e complexidade LZ relativa. A condutância estomática nas plantas cultivadas com e sem deficiência hídrica exibiu um comportamento provavelmente caótico. As plantas sob estresse hídrico mostraram uma tendência para um comportamento mais complexo, principalmente as plantas de girassol cuja capacidade homeostática foi superior. Algumas implicações biológicas destes comportamentos são discutidas no texto.

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)

Biomass Accumulation, Photosynthetic Traits and Root Development of Cotton as Affected by Irrigation and Nitrogen-Fertilization

Directory of Open Access Journals (Sweden)

Zongkui Chen

2018-02-01

Full Text Available Limitations of soil water and nitrogen (N are factors which cause a substantial reduction in cotton (Gossypium hirsutum L. yield, especially in an arid environment. Suitable management decisions like irrigation method and nitrogen fertilization are the key yield improvement technologies in cotton production systems. Therefore, we hypothesized that optimal water-N supply can increase cotton plant biomass accumulation by maintaining leaf photosynthetic capacity and improving root growth. An outdoor polyvinyl chloride (PVC tube study was conducted to investigate the effects of two water-N application depths, i.e., 20 cm (H20 or 40 cm (H40 from soil surface and four water-N combinations [deficit irrigation (W55 and no N (N0 (W55N0, W55 and moderate N (N1 (W55N1, moderate irrigation (W75 and N0 (W75N0, W75N1] on the roots growth, leaf photosynthetic traits and dry mass accumulation of cotton crops. H20W55N1 combination increased total dry mass production by 29–82% and reproductive organs biomass by 47–101% compared with other counterparts. Root protective enzyme and nitrate reductase (NR activity, potential quantum yield of photosystem (PS II (Fv/Fm, PSII quantum yield in the light [Y(II] and electron transport rate of PSII were significantly higher in H20W55N1 prior to 82 days after emergence. Root NR activity and protective enzyme were significantly correlated with chlorophyll, Fv/Fm, Y(II and stomatal conductance. Hence, shallow irrigation (20 cm with moderate irrigation and N-fertilization application could increase cotton root NR activity and protective enzyme leading to enhance light capture and photochemical energy conversion of PSII before the full flowering stage. This enhanced photoassimilate to reproductive organs.

A new approach for assessing the future of aquifers supporting irrigated agriculture

Science.gov (United States)

Butler, James J.; Whittemore, Donald O.; Wilson, Blake B.; Bohling, Geoffrey C.

2016-03-01

Aquifers supporting irrigated agriculture are under stress worldwide as a result of large pumping-induced water deficits. To aid in the formulation of more sustainable management plans for such systems, we have developed a water balance approach for assessing the impact of proposed management actions and the prospects for aquifer sustainability. Application to the High Plains aquifer (HPA) in the state of Kansas in the United States reveals that practically achievable reductions in annual pumping (determining the net inflow (capture) component of the water balance. The HPA is similar to many aquifers supporting critically needed agricultural production, so the presented approach should prove of value far beyond the area of this initial application.

Effects of progressive soil water deficit on growth, and physiological and biochemical responses of populus euphratica in arid area: a case study in China

International Nuclear Information System (INIS)

Yang, Y.; Chen, Y.; Li, W.; Zhu, C.

2015-01-01

The aim of this study was to investigate the responses of Populus euphratica seedlings under a short-term soil water deficit. To mimic natural conditions in which drought stress develops gradually, stress was imposed by subjecting plants to a gradual decrease of soil water content for a period of 21 d. We studied growth, physiological and biochemical responses to progressive soil water deficit of potted Populus euphratica seedlings at outdoors. Results showed that, in 6 d of water withholding, the soil moisture content decreased to a slight drought stress level, and it reached a severe drought stress level after 15 d of water withholding in July. In the process of soil water declining from saturated to severe drought levels, the increasing soil water deficit resulted in decreases in the height, stem base diameter, number of lateral branches. Leaf predawn water potential decreased after 15 d of withholding irrigation. After 21 d of withholding irrigation, actual photochemical efficiency of photosystem II (PSII) in light-adapted leaves and photochemical quenching coefficient decreased, respectively; the peroxidase activity, the content of chlorophyll a and chlorophyll b decreased. There were no significant changes in proline, malondialdehyde content, chlorophyll a/b value and superoxide dismutase activity. (author)

Influence of time scale wind speed data on sustainability analysis for irrigating greenhouse crops

Science.gov (United States)

Díaz Méndez, Rodrigo; García Llaneza, Joaquín; Peillón, Manuel; Perdigones, Alicia; Sanchez, Raul; Tarquis, Ana M.; Garcia, Jose Luis

2014-05-01

Appropriate water supply at crop/farm level, with suitable costs, is becoming more and more important. Energy management is closely related to water supply in this context, being wind energy one of the options to be considered, using wind pumps for irrigation water supply. Therefore, it is important to characterize the wind speed frequency distribution to study the technical feasibility to use its energy for irrigation management purpose. The general objective of this present research is to analyze the impact of time scale recorded wind speed data in the sustainability for tomato (Solanum lycopersicum L.) grown under greenhouse at Cuban conditions using drip irrigation system. For this porpoise, a daily estimation balance between water needs and water availability was used to evaluate the feasibility of the most economic windmill irrigation system. Several factors were included: wind velocity (W, m/s) in function of the time scale averaged, flow supplied by the wind pump as a function of the elevation height (H, m) and daily greenhouse evapotranspiration. Monthly volumes of water required for irrigation (Dr, m3/ha) and in the water tank (Vd, m3), as well as the monthly irrigable area (Ar, ha), were estimated by cumulative deficit water budgeting taking in account these factors. Three-hourly wind velocity (W3h, m/s) data from 1992 till 2008 was available for this study. The original data was grouped in six and twelve hourly data (W6h and W12h respectively) as well as daily data (W24h). For each time scale the daily estimation balance was applied. A comparison of the results points out a need for at least three-hourly data to be used mainly in the months in which mean wind speed are close or below the pumps threshold speed to start-up functioning. References Manuel Esteban Peillon Mesa, Ana Maria Tarquis Alfonso, José Luis García Fernández, and Raúl Sánchez Calvo. The use of wind pumps for irrigating greenhouse tomato crops: a case study in Cuba. Geophysical

Supplemental irrigation to improve wheat production and water use efficiency under rainfed farming conditions

International Nuclear Information System (INIS)

Hussain, Q.; Bhatti, A.A.; Ahmad, M.M.

2007-01-01

The stochastic behaviors of rainfall pose serious limitations for sustained and profitable crop production in rainfed areas; farmers hesitate to apply fertilizers when they are not sure about rainfall. In view of these limitations a research study was conducted for three years (2003-2006) at field station of Water Resources Research Institute (WRRI), National Agricultural Research Centre(NARC), Islamabad to examine the effects of supplemental irrigation (SI) on wheat production and water use efficiency (WUE). Irrigation treatments employed under the experiment were: i) Rainfed without irrigation and fertilizer application (I/sub 0/); ii) SI of 25 mm was applied to non-fertilizer field at 75% management allowed deficit (MAD)(I/sub 1/); iii) Rainfed with fertilizer application at sowing time (I/sub 2/); and iv) SI of 25 mm was applied at 75% MAD and at the time of fertilizer application as top dressing (I/sub 3/). Supplemental irrigation increased the crop yield during the years 2003-2006 under both fertilizer and non-fertilizer conditions. Increased in grain yield under non-fertilizer conditions (I/sub 1/) ranges between 770-980 kg/ha, which is 27 to 48% higher than the rainfed yield (I/sub 0/). Supplemental irrigation and split application of fertilizer (treatment I/sub 3/) increased in grain yield within the range of 1000-1350 kg/ha, which is 27-49% higher than yield under treatment I/sub 2/. Whereas, due to synergetic effect of supplemental irrigation and fertilizer application, increased in grain yield ranges between 1550-2030 kg/ha, which is 49% to 100% higher than the rainfed and non-fertilizer field. WUE was calculated for rain (WUE/sub r/) for total water (grass: previous soil water storage + rain + irrigation) (WUE/sub g/), for SI water only (WUE/sub si/) and for synergetic effect (SI water + fertilizer application) (WUE/sub sis/) Water use efficiencies namely the WUE/sub r/, WUE/sub g/ and WUE/sub si/ during the period of three years under non fertilizer

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

Directory of Open Access Journals (Sweden)

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

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.

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...

Does colostomy irrigation affect functional outcomes and quality of life in persons with a colostomy?

Science.gov (United States)

Kent, Dea J; Long, Mary Arnold; Bauer, Carole

2015-01-01

Colostomy irrigation may be used by patients with colostomies to regulate bowel evacuations by stimulating emptying of the colon at regularly scheduled times. This Evidence-Based Report Card reviews the effect of colostomy irrigation on frequency of bowel evacuation, flatus production, odor, and health-related quality of life. We systematically reviewed the literature for studies that evaluated health-related quality of life in persons aged 18 years or older with colostomies of the sigmoid or descending left colon. A professional librarian performed the literature search, which yielded 499 articles using the search terms "colostomy," "colostomies," "therapeutic irrigation," "irrigation," and "irrigator." Following title and abstract reviews, we identified and retrieved 4 studies that met inclusion criteria. Colostomy irrigation reduces the frequency of bowel evacuations when compared to spontaneous evacuation and containment using a pouching system. Regular irrigation is associated with reductions in pouch usage. This change in bowel evacuation function frequently results in absence of bowel evacuations for 24 hours or longer, enabling some to discontinue ongoing use of a pouching system. Subjects using CI report reductions in flatus and odors associated with presence of a colostomy. One study was identified that found persons using CI reported higher health-related quality of life than did those who managed their colostomies with spontaneous evacuation using the Digestive Disease Quality of Life-15, but no differences were found when health-related quality of life was measured using the more generic instrument, the Medical Outcomes Study: Short Form-36. Instruction on principles and techniques of colostomy irrigation should be considered when managing patients with a permanent, left-sided colostomy.

Deficit irrigation strategies

DEFF Research Database (Denmark)

Stikic, Radmilla; Savíc, Sladjana; Jovanovic, Zorica

2010-01-01

Book Description: Horticulture is the industry and science of plant cultivation, including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding...... grafting techniques at the seedling stage to overcome soil-borne diseases, the application of biotechnology tools in the conservation of critically endangered plant species, salinity tolerance of ornamental horticultural species, and others....

A model exploring whether the coupled effects of plant water supply and demand affect the interpretation of water potentials and irrigation management

OpenAIRE

Spinelli, GM; Shackel, KA; Gilbert, ME

2017-01-01

© 2017 Elsevier B.V. Water potential is a useful predictive tool in irrigation scheduling as it, or a component, is associated with physiological responses to water deficit. Increasing atmospheric demand for water increases transpiration and decreases water potential for the same stomatal conductance. However, based on supply by the soil-plant-atmosphere-continuum, decreasing soil water potential should decrease stomatal conductance and thus transpiration but also decrease water potential. Su...

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 ...

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...

Influence of deficit irrigation and crop load on the yield and fruit quality in Wonderful and Mollar de Elche pomegranates

NARCIS (Netherlands)

Cano-Lamadrid, Marina; Galindo Egea, Alejandro; Collado-González, Jacinta; Rodríguez, Pedro; Cruz, Zulma N; Legua, Pilar; Burló, Francisco; Morales, Donaldo; Carbonell-barrachina, Ángel A; Hernández, Francisca

2017-01-01

BACKGROUND The working hypothesis of the present study was that, by proper simultaneous control of irrigation (hydroSOStainable products) and crop load (thinning), it is possible to promote the accumulation of bioactive compounds and improve fruit appearance (size and weight). The effects of (i)

Health and taste related compounds in strawberries under various irrigation regimes and bio-stimulant application.

Science.gov (United States)

Kapur, Burcak; Sarıdaş, Mehmet Ali; Çeliktopuz, Eser; Kafkas, Ebru; Paydaş Kargı, Sevgi

2018-10-15

Strawberry has a unique status within the fruit species in terms of health and taste related compounds. This experimental study concerned the application of a bio-stimulant at various drip irrigation levels (IR125, IR100, IR75 and IR50). The effects of the bio-stimulant (seaweed extract) on the eating quality, i.e., the taste-related (TSS, fructose, glucose, sucrose and citric, malic, l-ascorbic acid), and health-related (antioxidant activity, total phenol, myricetin and quercetin) compounds were studied in two strawberry cultivars. The 'Rubygem' with its higher sugar and lower acid content has been more preferable than the 'Kabarla' cultivar. The bio-stimulant contributes to taste by improving the TSS, fructose, sucrose and also to health by increasing the quercetin content of the fruit which is associated to the cardiovascular properties and cancer reducing agents. The experiment conducted revealed significant increases only in the TSS contents and antioxidant activity under the IR50 and IR75 deficit irrigation treatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

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)

Evaluation of Yield and Yield Components of Some Pinto bean (Phaseolus vulgaris L. Genotypes under Late Season Water Deficit Conditions

Directory of Open Access Journals (Sweden)

somayyeh soheili movahhed

2017-10-01

Full Text Available Introduction Drought or water deficit stress is the most important environmental factor which has severe negative impacts on crop yields, especially when the water stress occurs in the flowering stage. Iran is located in arid and semi-arid areas, therefore, attention to the effects of water deficit stress in different stages of plants growth seems necessary. Bean (Phaseolus vulgaris L. is one of the most important legumes that has a major contribution to human diet and provides an important part of the human protein. According to studies, cultivation areas of legumes in Iran are about 97300 hectares and its total production is about 208350 tons of grain. Bean is a fast-growing plant (Tran and Singh, 2002, thus soil water must be sufficiently available to ensure its desirable growth and yield. The aim of this study was to investigate the effect of drought stress on yield and yield components of some pinto bean (Phaseolus vulgaris L. cultivated in Zanjan province. Materials and methods An experiment was conducted as spilt plot based on randomized complete block design with four replications in Zanjan university research farm. Irrigation levels (control and drought stress and genotypes (Local khomein, Sadri, Ks21193 and Ks21189 were set in the main and subplot, respectively. Water deficit stress was applied during flowering stage (50% of the plants were at anthesis. Sampling was performed to measure yield and yield components at the end of the growth period and final maturity. In this experiment number of pod per Plant, numberof grain per pod, 100 grain weight, grain yield, biological yield and harvest index were measured. Results and Discussion In this experiment it was observed that drought stress, genotype and interact irrigation×genotyps were significantly for all traits except biological yield. Drought stress reduced number of pod perplant, number of grain per pod, 100 grain weight, grain yield, biological yield and Harvest Index. Results

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

Quantification of the impacts of coalmine water irrigation on the underlying aquifers

Energy Technology Data Exchange (ETDEWEB)

Vermeulen, D.; Usher, B.; van Tonder, G. [University of Free State, Bloemfontein (South Africa). Institute of Groundwater Studies

2009-07-15

It is predicted that vast volumes of affected mine water will be produced by mining activities in the Mpumalanga coalfields of South Africa, The potential environmental impact of this excess water is of great concern in a water-scarce country like South Africa. Research over a period of more than 10 years has shown that this water can be used successfully for the irrigation of a range of crops. There is, however, continuing concern from the local regulators regarding the long-term impact that large-scale mine water irrigation may have on groundwater quality and quantity. Detailed research has been undertaken over the last three years to supplement the groundwater monitoring programme at five different pilot sites, on both virgin soils (greenfields) and in coalmining spoils. These sites range from sandy soils to very clayey soils. The research has included soil moisture measurements, collection of in situ soil moisture over time, long-term laboratory studies of the leaching and attenuation properties of different soils and the impact of irrigation on acid rock drainage processes, and in depth determination of the hydraulic properties of the subsurface at each of these sites, including falling head tests, pumping tests and point dilution tests. This has been supported by geochemical modelling of these processes to quantify the impacts. The results indicate that many of the soils have considerable attenuation capacities and that in the period of irrigation, a large proportion of the salts have been contained in the upper portions of the unsaturated zones below each irrigation pivot. The volumes and quality of water leaching through to the aquifers have been quantified at each site. From this mixing ratios have been calculated in order to determine the effect of the irrigation water on the underlying aquifers.

Deficit Irrigation Effects on Yield, Yield Components and Seed Production of Three Cultivas of Watermelon (Citrullus lanatus (Thunb Matsum and Nakai

Directory of Open Access Journals (Sweden)

P. Jafari

2015-09-01

Full Text Available A two-year study (2005 - 2006 was carried out to explore the effect of deficit irrigation treatments according to evaporation from a class A basin, including ET= 1 (T1, ET = 0.75 (T2, and ET = 0.5 (T3, on yield, yield components and seed yield of three varieties of watermelon (Charleston Gray, Sugar Baby and Crimson Suite in the Varamin Agricultural Research Center of Iran. A randomized complete block design with a split plot arrangement with four replications was used. The results showed that fruit yield, yield components and seed yield were not significantly different in T1 and T2 treatments in contrary to T3 treatment. Among the yield components, number of fruits per plant most suffered from the negative impact of severe water stress (T3 (1.20 fruit per plant. Rind thickness, percent soluble solids in fruit and seed yield were not affected by water stress. According to phenotypic traits, and correlation coefficients, a significant positive correlation (1% probability level was observed between the weighted average, and the number of fruit with the fruit yield. Crimson Suite cultivar produced the highest yield (2533 kg ha-1 compared to the cultivars Charleston Gray and Sugar Baby. Sugar Baby and Crimson Suite cultivars, with 311.7 and 298.2 kg ha-1, respectively, produced the highest amount of seed. Crimson Suite cultiavr had the highest percentage of soluble solids in fruit (1.35. Rind thickness in Crimson Suites, Charleston Gray and Sugar Baby cultivars were 1.35, 1.13 and 1.10 cm, respectively. The results of this study showed that under a moderate moisture stress condition (ET = 0.75, fruit and seed yield could be similar to the no-water stress conditions.

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...

Evaluation of the Increased Rates of Water Super Absorbent and Humic Acid Application under Deficit Irrigation Condition on Some Agroecological Characteristics of Zea Mays Using Response Surface Methodology

Directory of Open Access Journals (Sweden)

M Jahan

2017-03-01

Full Text Available Introduction Water super absorbents are water absorbing natural or synthetic polymers (they may contain over 99% water. They have been defined as polymeric materials which exhibit the ability of swelling in water and retaining a significant fraction (> 20% of water within their structure, without dissolving in water content. The applications of hydrogels are grown extensively. These materials do not have any harm to the environment. Development of using super absorbent hydrogels to reduce crises such as soil erosion, frequent droughts or providing food security requires knowledge of their behaviors and performances in the soil. Humic substances are a mixture of different organic compounds that extract from various sources such as soil, humus, peat, oxidized lignite and coal. They are different in molecular size and chemical structure. A little amount of humic acid increase soil fertility by improving the physical, chemical and biological characteristics of soil. Increase in agricultural production and productivity depends, to a large extent, on the availability of water. Hence, the importance of irrigation is however, the availability of irrigation facilities which is highly inadequate in Iran. Determining the optimal amount of irrigation water has always been a main goal of researchers. Among the problems of excessive irrigation can be pointed to leach the nutrients especially nitrogen from the soil, the pollution of groundwater and environment and reduce fertilizer use efficiency, especially water-soluble fertilizers. To determine the optimal irrigation water and fertilizer, the use of mathematical models is inevitable. One of the most common methods used to optimize these factors is the central composite design. A central composite design is an experimental design, useful in response surface methodology, for building a second order (quadratic model for the response variable without needing to use a complete three-level factorial experiment

Evaluation some Forage Legumes in Limited Irrigation Condition

Directory of Open Access Journals (Sweden)

Hassan Moniri Far

2015-11-01

Full Text Available Forage legumes respond differently to limited irrigation regimes. Their evaluation may, thus, help to select drought tolerant types for limited irrigation conditions. In this study four type of forage legume were studied for two years in Tikma-Dash Research Station of East Azarbaijan Agricultural and Natural Research Center, Tabriz, Iran, in a randomized complete block design using split-plot experiment in 2011-2013 years. Irrigation regimes (without irrigation, one irrigation and two irrigations were assigned to main plots and four forage types (hairy vetch, grass pea, Pannonica sativa and lathyrus were assigned to subplots. The results of analysis of variance showed that the effect of irrigation on plant height, number of shoots, leaf area and plant fresh and dry weights were not significant. Howere, legume types affected these traits significantly (P≤0.01. The effect of irrigation levels and legume types on protein content of hay were significant (P

Craving Facebook? Behavioral addiction to online social networking and its association with emotion regulation deficits.