Pressure-discharge and Hydraulic Gradient along the Lateral of the Drip Irrigation System for Okra

Author(s):  
S. Vanitha ◽  
S. Senthilvel

Micro irrigation system should ensure relatively same amount of water to each plant along the total length of lateral line. In general, the drip irrigation systems are low to medium operating pressure head systems with a pressure requirement in range of 0.5 kg/cm2 to 2.5 kg/cm2 depending on the area irrigated and field layout geometry. However, since these systems are pressure irrigation systems which require appropriate operating pressure heads to deliver the required rates of flow, the inevitable frictional head losses are to be compensated for maintaining uniformity in water application. Hence, the hydraulic gradient compensation needs to be achieved by some viable mechanism so that the inequality in pressure heads and discharges can be eliminated or minimized. The crop production will have its maximum yield and water use efficiency only one the water distribution uniformities at its the highest. Hydraulic gradient compensation assumes a vital role in compensating the operating pressure heads as well as the emitter discharges. The hydraulic gradient compensated drip lateral layout registered high order of water distribution uniformity in the range of 97.8% and irrigation usage efficiency in the range of 17.98 kg/ha/mm to 20.69 kg/ha/mm for 2 lph emitter arrangements.

Irriga ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 86-93
Author(s):  
Verônica Gaspar Martins Leite de Melo ◽  
Leonardo Leite de Melo ◽  
José Antônio Frizzone ◽  
Antônio Pires de Camargo ◽  
Patricia Angélica Alves Marques

PERDA DE CARGA EM FITAS GOTEJADORAS COM EMISSORES MOLDADOS     VERÔNICA GASPAR MARTINS LEITE DE MELO1; LEONARDO LEITE DE MELO2; JOSÉ ANTÔNIO FRIZZONE3; antônio pires de camargo4 E patricia algélica alves marques5   1 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 2 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 3 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected] 4 Faculdade de Engenharia Agrícola – UNICAMP, Av. Cândido Rondon, 501, Cidade Universitária, CEP 13083 - 875, Campinas, SP, e-mail: [email protected] 5 Departamento de Engenharia de Sistemas Agrícola, ESALQ/USP, Av. Pádias, 11, São Dimas, CEP13418-900, Piracicaba, SP, Brasil, e-mail: [email protected]     1 RESUMO   Embora as fitas gotejadoras sejam de baixo custo, é importante que esse material seja avaliado hidraulicamente para prover informações técnicas. O objetivo deste trabalho foi analisar a perda contínua de carga e o fator de atrito em uma fita gotejadora com emissor moldado em seu interior. O experimento foi conduzido no laboratório de irrigação da ESALQ/USP. Utilizou-se a fita gotejadora Rain-Tape® fabricada pela Rain Bird®, espessura de parede de 225 µm e emissores tipo labirinto, espaçados de 0,30 m, vazão nominal de 1 L h-1 e pressão de serviço de 55 kPa. A equação de perda de carga para regime de escoamento turbulento liso em função da vazão e da carga de pressão na entrada da fita apresenta boa habilidade para estimar a perda de carga em fitas gotejadoras com emissores moldados, sendo que 95% das estimativas apresentaram erro relativo de até 6,71%. A equação de Darcy-Weisbach pode ser utilizada para o cálculo da perda de carga desde que o diâmetro seja substituído por uma função da pressão de entrada. Para o cálculo da perda de carga, utilizando a equação de Darcy-Weisbach, o fator de atrito calculado pela equação de Blasius deve considerar um coeficiente a = 0,3408.   Palavras-chave: irrigação por gotejamento, perda de carga por atrito, fator de atrito     MELO, V. G. M. L. de; MELO, L. M. de; FRIZZONE, J. A.; CAMARGO, A. P. de; MARQUES, P. A. A. HEAD LOSS IN DRIP TAPES WITH MOLDED EMITTERS     2 ABSTRACT   Although drip tapes are low-cost equipment, proper hydraulic evaluation is important to provide information required for irrigation system design. The aim of this study was to analyze the friction head loss and the friction factor in drip tapes with molded emitters, that are employed in drip irrigation systems. Experiments evaluated the drip tape model Rain-Tape®, manufactured by Rain Bird, 225-µm wall thickness, labyrinth-type emitters, 0.30-m emitters spacing, 1 L h-1 nominal discharge and operating pressure of 55 kPa. The following conclusions were obtained: (a) the equation of head loss for smooth turbulent flow as a function of flow rate and pressure head at the pipe inlet provided good predictions of head loss in drip tapes with molded emitters, since 95% of predictions presented relative errors less than 6.71%; (b) the Darcy-Weisbach equation may be used for calculating head loss, but the pipe diameter must be replaced by a function considering the lateral inlet pressure; (c) for calculating head loss of the Rain-Tape using the Darcy-Weisbach equation, the friction factor obtained by the Blasius equation should use the coefficient a = 0.3408.   Keywords: drip irrigation, frictional head loss, friction coefficient


2017 ◽  
Vol 9 (4) ◽  
pp. 2261-2263
Author(s):  
Mairaj Hussain ◽  
Sudhiranjan Prasad Gupta

Drip irrigation technology will undoubtedly plays an important role in the future of the agriculture. A field experiment was conducted to evaluate the performance of drip system with five operating pressure viz. I1 (0.4 kg/ cm2), I2 (0.6 kg/cm2), I3 (0.8 kg/cm2), I4 (1.0 kg/cm2), I5 (1.2 kg/cm2). It was observed that the average discharge of drippers was 1.08 lph, 1.24 lph, 1.50 lph, 1.62 lph and 1.74 lph and emission uniformity was 80.55%, 84.89%, 86.30%, 88.88% and 90.80 in each treatment respectively and coefficient of variation was observed 0.12, 0.13, 0.12, 0.11, and 0.09. Flow component was found 0.450 and the value of k was 0.572 while R2 was observed 0.986.Based on the result it can be concluded that the operation of drip irrigation system at 1.2 kg/cm2 pressure head, gives the maximum efficiency in respect of discharge, emission uniformity and coefficient of variation.


2019 ◽  
Vol 1 (3) ◽  
pp. 376-390 ◽  
Author(s):  
Sarker ◽  
Hossain ◽  
Murad ◽  
Biswas ◽  
Akter ◽  
...  

Drip-irrigation can improve uniformity in water distribution, water use efficiency, and crop productivity in the saline and nonsaline regions of South Asia and in Bangladesh where the availability and quality of water resources are scare for sustainable crop production. However, the currently available drip-irrigation systems (DIS) have limitations especially in the design and field performance of emitters. A new type of emitter with low pressure (gravity) was developed, installed and evaluated using the locally produced materials in two locations (nonsaline and saline zones) of Bangladesh. The emitter discharge rate was measured for the variable operating heads of 1.5, 2, and 2.5 meter (m) with 0%, 1%, and 1.5% slopes with eggplant (Solanum melongena L.), a commonly grown vegetable in the region. The tested parameters of the emitter were manufacturer coefficient of variation (CVm), emission uniformity (EU), coefficient of uniformity (CU), and the statistical uniformity (Us) of water application. Our results reveal that the discharge rates of the emitter varied from 3 to 5 L h−1 under the operating head of 1.5 to 2.5 m with the slope of 0–1.5%, with better performance of the DIS at 2 m operating pressure head and for slopes of 0% and 1%. The CU of all the test parameters was more than 80%, implying that the DIS was designed and installed with appropriate dimensions for the efficient application and distribution of water to the individual plants, with the emitter performance classified as fair to excellent considering water application and distribution, as well as crop yield. The new emitter used for DIS in field conditions showed that the eggplant yield, water use, and water productivity were greater by 4.6%, 38%, and 70%, respectively, compared to farmers’ irrigation practice. We conclude that the DIS has a great prospect to save water, and could be a convenient irrigation water application method for sustainable crop production in saline and nonsaline regions of Bangladesh and similar soil and climatic conditions in South Asia.


1986 ◽  
Vol 66 (1) ◽  
pp. 197-200 ◽  
Author(s):  
S. BITTMAN ◽  
E.-Z. JAN ◽  
G. M. SIMPSON

Plot irrigation systems have a number of deficiencies including uneven water distribution and high cost. A system that overcomes many of these problems, using drip irrigation emitters, was designed and tested. It was found to perform well provided that clean water was supplied.Key words: Irrigation system, drip emitters, plots


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1675
Author(s):  
Hussein Al-Ghobari ◽  
Ahmed Z. Dewidar

The center pivot irrigation system is a type of irrigation technology used to apply water effectively and uniformly over a wide variety of areas and topographies. These irrigation systems’ uniformity of water application greatly affects water use, energy consumption, and crop production. Performance tests of the standard lateral galvanized and modified polyethylene plastic pipes in the center pivot irrigation systems were conducted in different regions of Saudi Arabia. Water distribution depths along the laterals, coefficient of uniformity (CU), and distribution uniformity of the low quarter (DU) were determined. The results revealed that profiles of water distribution ranged from 4 to 14 mm for the standard-center pivot irrigation systems, while those for the modified-center pivot irrigation systems ranged from 6.5 to 50 mm. Standard-center pivot irrigation systems’ CU values ranged from 74 to 90%, with an average of 86%. In comparison, the modified-center pivot irrigation systems’ CU values ranged from 62 to 83%, with an average of 78%. The DU values ranged from 60 to 82% for the standard-center pivot irrigation systems, with an overall average of 77%. For the modified-center pivot irrigation systems, the DU values, in contrast, ranged from 31 to 75%, with an average of 65%. Thus, the accuracy and uniformity of the standard-center pivot irrigation systems are superior to those that have been modified. Additionally, a statistical model was developed to investigate the relationship between the water losses and the main climatic factors under field operating conditions. Therefore, the study results are expected to draw attention to standard lateral pipes’ value on the one hand and demonstrate the detrimental consequences of growers’ incorrect practices in pivot irrigation systems, motivating them to take strong action against these activities, on the other hand.


Author(s):  
Rajanbir Singh ◽  
Amarinder Singh ◽  
Gurbax Singh ◽  
Amritpal Singh ◽  
Gurloveleen Kaur

Background: Potato (Solanum tuberosum) popularly known as ‘The King of Vegetables’, has emerged as fourth most important food crop in the world after rice, wheat and maize. Indian vegetables basket is incomplete without potato as its, dry matter, edible energy and edible protein makes it nutritionally superior as well as staple food throughout the world. Methods: The experiment during 2016-2018 was laid out in factorial randomized complete block design with three replications to study the effect of bed size on the yield and size of the tuber under different irrigation methods. Results: Maximum yield was obtained in 60cm bed (narrow bed size) whereas in irrigation system drip produced maximum yield. All quality parameters did not influence due to sowing method and irrigation system but chip recovery was more in drip irrigation than furrow system. Maximum yield through interaction was found in drip irrigated 105 cm triple row bed. Around 45-50 per cent water was saved through drip irrigation as compared to furrow irrigation. However, maximum benefit cost ratio was obtained in furrow irrigated 60cm bed size.


1970 ◽  
Vol 1 (2) ◽  
pp. 63-71 ◽  
Author(s):  
Md. Mosiur Rahman ◽  
A.H.M. Kamal ◽  
Abdullah Al Mamun ◽  
Md. Shafi Uddin Miah

Irrigated agriculture has been playing a vital role for the growth in crop production in Bangladesh. Minor irrigation comprising of shallow tubewells (STWs), deep tubewells (DTWs), hand tubewells (HTWs) and low-lift pumps (LLPs) is a major irrigation system in the country. Poor performance of irrigation is an issue for the expansion of irrigated area. The present study was carried out to examine the conveyance efficiency and rate of irrigation water loss in DTW schemes in Bogra, Thakurgaon and Godagari zones of Barind Management Development Authority. There were various types of water distribution identified in these schemes with including Poly Venyl Chloride (PVC) buried pipe, cement concrete (CC) rectangular, Ferro trapezoidal, Ferro semicircular and rectangular earth drain. The average conveyance efficiency of PVC buried pipe for Bogra, Thakurgaon and Godagari zones ranged from 94.46% to 95.37% and rate of water loss ranged from 5.45% to 9.55% in three study zones. Average conveyance efficiency of CC rectangular for Bogra and Godagari zone ranged from 91.20% and rate of water loss from 6.58% to 9.93%. Average conveyance efficiency of Ferro trapezoid for Bogra and Godagari zone ranged from 87.80% to 90.06% and rate of water loss ranged from 9.94% to 12.21%. Average conveyance efficiency of Ferro semicircle for Bogra and Godagari zone ranged between 88.13% and 86.82% and rate of water loss between 11.59% and 11.68%. Average conveyance efficiency and rate of water loss of rectangular earth drain Godagari zone was 58.66% and 42.29% respectively. About 80% farmers recommended buried pipe irrigation system and about 20% semi-circular channel. The study suggests that the improved water distribution system as developed by BMDA is sustainable to increase productivity of irrigation systems in Bangladesh. DOI: http://dx.doi.org/10.3329/jbayr.v1i2.10032


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2276
Author(s):  
David Lozano ◽  
Natividad Ruiz ◽  
Rafael Baeza ◽  
Juana I. Contreras ◽  
Pedro Gavilán

Developing an appropriate irrigation schedule is essential in order to save water while at the same time maintaining high crop yields. The standard procedures of the field evaluation of distribution uniformity do not take into account the effects of the filling and emptying phases of the irrigation system. We hypothesized that, in sloping sandy soils, when short drip irrigation pulses are applied it is important to take into account the total water applied from the beginning of irrigation until the emptying of the irrigation system. To compute distribution uniformity, we sought to characterize the filling, stable pressure, and emptying phases of a standard strawberry irrigation system. We found that the shorter the time of the irrigation pulse, the worse the distribution uniformity and the potential application efficiency or zero deficit are. This effect occurs because as the volume of water applied during filling and emptying phases increases, the values of the irrigation performance indicators decrease. Including filling and emptying phases as causes of non-uniformity has practical implications for the management of drip irrigation systems in sloping sandy soils.


2017 ◽  
Vol 2 (01) ◽  
pp. 72-77
Author(s):  
Ram Kumar ◽  
Joginder Singh

Drip irrigation is basically precise and slow application of water in the form of discrete continuous drops, sprayed through mechanical devices, called emitters into the root zone of the plant. The field experiment on Impact of fertigation and drip system layout were conducted at Research farm at IFTM University Moradabad (UP). The experiment was laid out in factorial randomized block design with treatments. In chilli maximum yield of 812 g/plant which is worked out as 0.006 t/ha was observed for the treatment T2. Even though the yield for the treatment T2 was high and was due to the reduction in the quantity of material for drip irrigation system. At harvesting time, samples of green pepper fruits were randomly harvested from each plot to measure fruit length, fruit diameter. In addition, total weight of fruits in each treatment were recorded by harvesting pepper fruits twice weekly and then the total yield as Kg/fed., was calculated. The maximum yield of crop 900 gm/plant and minimum of yield 600 gm/plant and total yield 52270 gm (52.270 kg).


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