scholarly journals Effect of Irrigation Pattern and Timing on Root Density of Young Citrus Trees Infected with Huanglongbing Disease

2014 ◽  
Vol 24 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Davie M. Kadyampakeni ◽  
Kelly T. Morgan ◽  
Arnold W. Schumann ◽  
Peter Nkedi-Kizza
Keyword(s):  
Water Distribution ◽  
Root Length Density ◽  
Soil Depth ◽  
Irrigation System ◽  
Field Capacity ◽  
Distribution Patterns ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Fibrous Roots ◽  
Water Contents

Citrus (Citrus sp.) root length density (RLD) can help in understanding and predicting nutrient and water uptake dynamics. A study was conducted at two sites in Florida to investigate root and water distribution patterns among different irrigation and fertigation systems. The results over the 2 years showed that RLD was highest in the 0- to 15-cm soil depth and decreased with depth for all treatments at both sites. About 64% to 82% of the fibrous roots (<1 mm diameter) were concentrated in the irrigated zones of drip- and microsprinkler-irrigated trees and 18% to 36% were found in the nonirrigated zones at the Spodosol site (SS). At the Entisol site (ES), the RLD (<0.5 mm diameter) in the 0- to 15-cm depth soil for intensive microsprinkler or drip irrigation was 3- to 4-fold (nonirrigated zone) and 4- to 7-fold (irrigated zone) greater at the 0- to 15-cm soil depth than that for conventional irrigation system. The trees at SS were symptomatic for Huanglongbing (HLB; Candidatus Liberibacter asiaticus) in the second year, while those at ES were asymptomatic throughout the study. This might have limited the density and extent of root distribution at SS. The water contents remained either close to or slightly above the field capacity. The results showed higher RLD for intensive irrigation and fertigation practices in irrigated zones compared with conventional grower applications suggesting greater water and nutrient uptake potential for the former.

scholarly journals Modeling and Dynamic-Simulating the Water Distribution of a Fixed Spray-Plate Sprinkler on a Lateral-Move Sprinkler Irrigation System

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2296 ◽  
Author(s):  
Yisheng Zhang ◽  
Jinjun Guo ◽  
Bin Sun ◽  
Hongyuan Fang ◽  
Delan Zhu ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Water Distribution ◽  
Irrigation System ◽  
Translational Motion ◽  
Simulated Data ◽  
Sprinkler Irrigation ◽  
Distribution Patterns ◽  
Superposition Method ◽  
Working Pressure ◽  
Uniformity Coefficient

Uniformity of water distribution plays an important role in evaluating irrigation quality. As necessities in calculating irrigation uniformity during designing a lateral-move sprinkler irrigation system (LMSIS), the water distribution patterns of individual sprinkler in motion are crucial. Considering the limitation of the experiment platform, dynamic water distribution of an isolated sprinkler is difficult to measure, especially for a fixed spray plate sprinkler (FSPS) which LMSIS has been widely equipped with in China, therefore developing a model to simulate dynamic water distribution of a moving sprinkler is necessary. The objective of this study was to develop and validate the theoretical basis for calculating water distribution characteristics of a single FSPS in translational motion applying a superposition method, and provide an optimized operation management of LMSIS. The theoretical model’s validity was verified in an indoor experiment using a Nelson D3000 FSPS in motion with 36 grooves and blue-plate spray heads. The software was programmed using the Eclipse Platform and the software was capable of simulating water distribution pattern and Christiansen uniformity coefficient (Cu). The results indicated that the water distribution simulated by the software presents three peaks of maximum application under varying conditions, and the value of water application peaks decreased as working pressure and/or mounting height increased. Conversely, the wetted diameter increased as working pressure and/or mounting height increased. Working pressure, mounting height, and sprinkler spacing each had a significant effect on the Cu. The Cu increased as working pressure and/or mounting height increased but decreased as sprinkler spacing increased. As a consequence, the model can be used to predict the relative water distribution pattern; and the Cu can be calculated with the simulated data, thus providing a tool for designing a new LMSIS.

Root and Shoot Responses to Salt Stress in Jojoba (Simmondsia chinensis)

2020 ◽  
Author(s):  
Jhonathan Ephrath ◽  
Alon Ben-Gal ◽  
Amnon Bustan ◽  
Lina Zhao
Keyword(s):  
Plant Growth ◽  
Root Length ◽  
Root Length Density ◽  
Soil Depth ◽  
Distribution Patterns ◽  
Root Diameter ◽  
Salinity Level ◽  
Simmondsia Chinensis ◽  
Root Number ◽  
Over Time

&lt;p&gt;Salinity affects plant growth due to both osmotic and ionic stress. The root system is essential in defense mechanisms against salinity, particularly involving salt ion avoidance or exclusion. Jojoba (&lt;em&gt;Simmondsia chinensis&lt;/em&gt;) displays significant resistance to salinity. In the present study, Jojoba was planted in 60-L plastic buckets containing perlite growth medium and were provided with eight distinct salinity levels using two operating tanks of final irrigation solutions. Response of Jojoba to salinity was measured in above ground parameters and in roots using minirhizotron access tubes and imaging analysis. Leaf phosphorous and potassium concentrations decreased with increasing salinity level while leaf manganese, calcium, sodium and chloride concentrations increased with irrigation salinity level. Jojoba plants were found to have high level of storage of salt minerals in leaves but without effects on photosynthesis or transpiration. Roots exhibited different distribution patterns under different salinity treatments. Root length density increased with increased salinity at each depth. Root number and root length increased over time. During spring, the plant growth was faster than winter. Root diameter decreased over time due to new root development. Time had a more significant effect on root length density than irrigation water salinity or soil depth. Root number and root length were not significantly affected by the salt treatments.&lt;/p&gt;

scholarly journals INFLUENCE OF THE WATER DISTRIBUTION UNIFORMITY AND IRRIGATION DEPTH ON THE YIELD OF IRRIGATED BEAN CROP

Irriga ◽  
2009 ◽  
Vol 14 (4) ◽  
pp. 458-469 ◽  
Author(s):  
Everardo C. Mantovani ◽  
Gregório G. Faccioli ◽  
Brauliro Gonçalves Leal ◽  
Antonio Alves Soares ◽  
Luis Claudio Costa ◽  
...  
Keyword(s):  
Water Depth ◽  
Water Distribution ◽  
Irrigation System ◽  
Winter Season ◽  
Sprinkler Irrigation ◽  
Field Capacity ◽  
Uniformity Coefficient ◽  
Irrigation Depth ◽  
Distribution Uniformity ◽  
Bean Crop

INFLUENCE OF THE WATER DISTRIBUTION UNIFORMITY AND IRRIGATION DEPTH ON THE YIELD OF IRRIGATED BEAN CROP  Everardo C. Mantovani1; Gregório G. Faccioli2; Brauliro Gonçalves Leal3;Antônio Alves Soares1; Luis Cláudio Costa1; Paulo Sérgio L. Freitas4 1Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, MG [email protected]úcleo de Estudos e Pesquisas do Nordeste, Universidade Federal de Sergipe, São Cristovão, SE3Intec Consultoria e Assessoria Ltda, Viçosa, MG4Departamento de Agronomia, Universidade Estadual de Maringá, Maringá, PR  1 ABSCTRACT This study aimed to evaluate the influence of the water distribution uniformity and three irrigation depths on the production variables for the bean crop, using a conventional sprinkler irrigation system, during the winter season. The treatments consisted of three irrigation depths and two uniformity levels of water distribution represented by the Christiansen uniformity coefficient (CUC). In the treatments L1A and L1B a sufficient water depth was applied to raise the soil water content to field capacity. The distribution uniformities (CUCs) were higher and lower than 80%, respectively. In treatments L2A and L3A, and L2B and L3B, the applied water depths corresponded to 50% and 150% of that applied to the LIA treatment. Because of rainfall events until the sampling date, no significant differences at 5% probability were found among treatments, when the variables were: leaf number, leaf area and dry matter. The F test for the contrast among the treatments with high and low uniformity was significant at 5% probability, when using 50% replacement of the water depth required by the crop. Significant differences were observed at 5% probability for pod number per plant among the treatments, when using 150, 100 and 50% replacement of the water depth required by the crop KEYWORDS: irrigation uniformity, sprinkler irrigation, yield.  MANTOVANI, E. C.; FACCIOLI, G. G.; LEAL, B. G.; SOARES,A. A.; COSTA, L. C.; FREITAS, P. S. L. INFLUÊNCIA DA UNIFORMIDADE DE DISTRIBUIÇÃO DE ÁGUA E LÂMINA DE IRRIGAÇÃO NA PRODUTIVIDADE DO FEIJÃO  2 RESUMO O presente trabalho teve como objetivo avaliar a influência da uniformidade de distribuição de água e de três lâminas de irrigação nas variáveis de produção da cultura do feijão, utilizando um sistema de aspersão convencional, no período de inverno. Os tratamentos constaram de três lâminas de irrigação e dois níveis de uniformidade de distribuição de água, representados pelo coeficiente de uniformidade de Christiansen (CUC). Nos tratamentos L1A e L1B foi aplicada uma lâmina de água suficiente para elevar a umidade do solo à capacidade de campo, com uniformidade de distribuição (CUC) maior e menor que 80%, respectivamente. Nos tratamentos L2A e L3A, e L2B e L3B as lâminas aplicadas foram, respectivamente, 50% e 150% da lâmina aplicada no tratamento L1A. Não existiram diferenças significativas, a 5% de probabilidade, nos tratamentos para seguintes variáveis: número de folhas, área foliar e matéria seca, em razão das chuvas ocorridas até a data da amostragem. O teste F para o contraste entre os tratamentos de alta e baixa uniformidade com 50% de reposição da lâmina requerida pela cultura foi significativo a 5% de probabilidade. Observou-se diferenças significativas, a 5% de probabilidade entre os tratamentos com 150, 100 e 50% de reposição da lâmina requerida pela cultura, para o número de vagens por planta. UNITERMOS: Uniformidade de irrigação, irrigação por aspersão, produtividade.

scholarly journals Cyclic Sprinkler Irrigation of Container Substrate Affects Water Distribution and Marigold Growth

1994 ◽  
Vol 12 (4) ◽  
pp. 208-211
Author(s):  
Nabila S. Karam ◽  
Alexander X. Niemiera ◽  
Carol E. Leda
Keyword(s):  
Water Distribution ◽  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Dry Weight ◽  
Total N ◽  
Continuous Irrigation ◽  
Substrate Solution ◽  
Irrigation Method ◽  
N Concentration ◽  
Water Contents

Abstract Two experiments were conducted to determine how cyclic sprinkler irrigation (daily water allotment applied in more than one application) influenced water distribution and leaching, and marigold growth in a pine bark (PB) or a PB:sand (S) substrate. Marigolds (Tagetes erecta L. ‘Apollo’), were grown in PB-filled 3.8 liter (1 gal) containers. Substrate was allowed to dry via evapotranspiration (ET) to targeted pre-irrigation substrate water contents (PSWC) and respective ET volumes were applied as a single application (continuous) or by multiple applications (cyclic irrigation) via a simulated sprinkler irrigation system; leachates were collected. In the first experiment, the influences of irrigation method, continuous and cyclic irrigation, on water distribution in the top, middle and bottom substrate (9: 1pine bark to sand, by vol) sections were investigated. Two hundred seventy five (275) ml were applied continuously or cyclically (three 92 ml allotments with 1 hr interval between applications) to containers at 84 % of container capacity (CC). In the second experiment, marigolds were grown in a growth chamber for three weeks and received 12 irrigations. In each irrigation, a complete nutrient solution was applied continuously or cyclically (three applications each of one-third of the total volume with 1 hr between applications). Substrate solution N concentration (via pour-through method), leachate N, and plant growth was measured. In the first experiment, gravimetric water contents of top and middle substrate sections were similar, whereas the water content of the bottom section was higher with cyclic than with continuous. In the second experiment, root dry weight was 43% higher, shoot fresh and dry weights were similar, and plant N concentration was 0.7% higher (absolute basis) with cyclic than with continuous irrigation. Irrigation method had no influence on substrate solution and leachate NO3-N and NH4-N concentrations. However, total N leached was 43% higher with continuous than with cyclic irrigation. These results demonstrate that cyclic irrigation increased root N concentration and root growth without a toxic accumulation of N in the substrate solution.

ESTIMATION OF CONSUMPTIVE USE OF POTATO CROP PIANTED UNDER DRIP IRRIGATION SYSTEM BY USING SWRT TECHNOLOGY

2020 ◽  
Vol 10 (1) ◽  
pp. 271-282
Author(s):  
J.N. Abedalrahman ◽  
R.J. Mansor ◽  
D.R. Abass
Keyword(s):  
Water Consumption ◽  
Drip Irrigation ◽  
Soil Depth ◽  
Irrigation System ◽  
Potato Crop ◽  
Block Design ◽  
Organic Fertilizer ◽  
Control Treatment ◽  
Drip Irrigation System ◽  
Spring Season

A field experiment was carried out in the field of the College of Agriculture / University of Wasit, located on longitude  45o   50o   33.5o   East and latitude 32o 29o 49.8o North, in Spring season of the agricultural season 2019, in order to estimate the water consumption of potato crop using SWRT technology and under the drip irrigation system. The experiment was designed according to Randomized Complete Block Design (RCBD) with three replications and four treatments that include of the SWRT treatment (the use of plastic films under the plant root area in an engineering style), and the treatment of vegetal fertilizer (using Petmos), organic fertilizer (sheep manure), and the control treatment . Potato tubers (Solanum tuberosum L.)  var. Burin was planted for spring season on 10/2/2019 at the soil depth of 5-10 cm. The highest reference water consumption for the potato crop during the season was calculated by Najeeb Kharufa, which was 663.03 mm. The highest actual water consumption for the potato crop during the season for the control treatment was 410.1 mm. The results showed increase in the values of the crop coefficient (Kc) in the stages of tubers formation and tubers filling stage as compared to the vegetative and ripening stages, ranged from 1.37-1.92 for the two stages of tubers formation and tubers filling. The SWRT treatment gave the highest water use efficiency during the season, was 3.46 kg m-3 .

Uphoff Norman, Priti Ramamurthy, and Roy Steiner. Managing Irrigation: Analysing and Improving the Performance of Bureaucracies. New Delhi/Newbury Park/London: Sage Publications. 1991. Hardbound. Price not given.

1993 ◽  
Vol 32 (2) ◽  
pp. 226-228
Author(s):  
Zakir Hussain
Keyword(s):  
Water Distribution ◽  
Irrigation System ◽  
Irrigation Management ◽  
Performance Criterion ◽  
New Delhi ◽  
Irrigation Performance ◽  
Factors Affecting ◽  
Wide Range ◽  
Resource Mobilisation ◽  
Management Issues

The book; under review provides a valuable account of the issues and factors in managing the irrigation system, and presents a lucid and thorough discussion on the performance of the irrigation bureaucracies. It comprises two parts: the first outlines the factors affecting irrigation performance under a wide range of topics in the first five chapters. In Chapter One, the authors have attempted to assess the performance of the irrigation bureaucracies, conceptualise irrigation management issues, and build an empirical base for analysis while drawing upon the experience of ten country cases in Asia, Africa, and Latin America. The Second Chapter focuses on the variations in the management structures identified and the types of irrigation systems; and it defines the variables of the management structures. The activities and objectives of irrigation management are discussed in Chapter Three. The objectives include: greater production and productivity of irrigation projects; improved water distribution; reduction in conflicts; greater resource mobilisation and a sustained system performance. The authors also highlight the performance criterion in this chapter. They identify about six contextual factors which affect the objectives and the performance of irrigation, which are discussed in detail in Chapter Four. In Chapter Five, some organisational variables, which would lead to improvements in irrigation, are examined.

Case study: Theoretical calculation model and variable condition analysis research on the water-splashing noise for natural draft wet cooling towers

2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun
Keyword(s):  
Theoretical Model ◽  
Sound Pressure Level ◽  
Water Droplet ◽  
Water Distribution ◽  
Sound Pressure ◽  
Cooling Tower ◽  
Distribution Patterns ◽  
Calculation Model ◽  
Pressure Level ◽  
Cooling Towers

Based on the basic theory of water droplets impact noise, the generation mechanism and calculation model of the water-splashing noise for natural draft wet cooling towers were established in this study, and then by means of the custom software, the water-splashing noise was studied under different water droplet diameters and water-spraying densities as well as partition water distribution patterns conditions. Comparedwith the water-splashing noise of the field test, the average difference of the theoretical and the measured value is 0.82 dB, which validates the accuracy of the established theoretical model. The results based on theoretical model showed that, when the water droplet diameters are smaller in cooling tower, the attenuation of total sound pressure level of the water-splashing noise is greater. From 0 m to 8 m away from the cooling tower, the sound pressure level of the watersplashing noise of 3 mm and 6 mm water droplets decreases by 8.20 dB and 4.36 dB, respectively. Additionally, when the water-spraying density becomes twice of the designed value, the sound pressure level of water-splashing noise all increases by 3.01 dB for the cooling towers of 300 MW, 600 MW and 1000 MW units. Finally, under the partition water distribution patterns, the change of the sound pressure level is small. For the R s/2 and Rs/3 partition radius (Rs is the radius of water-spraying area), when the water-spraying density ratio between the outer and inner zone increases from 1 to 3, the sound pressure level of water-splashing noise increases by 0.7 dB and 0.3 dB, respectively.

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