Moisture distribution pattern is one of the basic requirements for efficient design and management of an irrigation system. The knowledge of moisture distribution pattern helps in the effectiveness of drip irrigation
Universal soil loss equation, soil loss estimation, factors of USLE, its use and limitation, soil loss measurement by multi slot divisor and coshocton wheel sampler
IN this presentation cover Erosivity and erodibilty
Different methods to calculate soil loss.
Er. Gurpreet Singh
M.tech from PAU, Ludhiana
Assistant Prof.
Khalsa college.
describes the irrigation and irrigation requirements of different crops. this ppt also describes about different methods to measure the soil moisture availability.
Topics:
1, Introduction to Irrigation
2. Methods of Irrigation
3. Indian Agricultural Soils
4. Methods of Improving Soil Fertility & Crop Rotation
5. Soil-Water-Plant Relationship
6. Duty and Delta
7. Depth and Frequency of Irrigation
8. Irrigation Efficiency and Water Logging
Universal soil loss equation, soil loss estimation, factors of USLE, its use and limitation, soil loss measurement by multi slot divisor and coshocton wheel sampler
IN this presentation cover Erosivity and erodibilty
Different methods to calculate soil loss.
Er. Gurpreet Singh
M.tech from PAU, Ludhiana
Assistant Prof.
Khalsa college.
describes the irrigation and irrigation requirements of different crops. this ppt also describes about different methods to measure the soil moisture availability.
Topics:
1, Introduction to Irrigation
2. Methods of Irrigation
3. Indian Agricultural Soils
4. Methods of Improving Soil Fertility & Crop Rotation
5. Soil-Water-Plant Relationship
6. Duty and Delta
7. Depth and Frequency of Irrigation
8. Irrigation Efficiency and Water Logging
This power point presentation will give a complete idea of types of irrigation, water requirement of crops, duty, delta, canal revenue etc. This presentation also contain the numerical for complete understanding the concepts.
Soil moisture characteristic curve is the relationship between the water content and the soil water potential, ψ.
It describes the functional relationship between soil water content and its energy status in terms of its matric potential under equilibrium conditions.
This curve is characteristic for different types of soil.
It is also called the Water retention curve
Soils can process and hold considerable amount of water. They can take in water, and will keep doing so until they are full, or until the rate at which they can transmit water into and through the pores is exceeded. Some of this water will steadily drain through the soil (via gravity) and end up in the waterways and streams, but much of it will be retained, despite the influence of gravity. Much of this retained water can be used by plants and other organisms, thus contributing to land productivity and soil health.
QUALITY OF IRRIGATION WATER AND MANAGEMENT OF SALINE WATER FOR IRRIGATION
GOVARDHAN LODHA
Enroll. No. (160111017)
Department of Agronomy
M.Sc. (Ag) Agronomy 2nd semester
Management Practices for Improving Water Use Efficiency.pptxanju bala
Water use efficiency
Production (of crops) per unit of water applied.
Expressed in kg/ha-mm.
Two distinct terms are used in expressing water use efficiency:
Crop water use efficiency: It is the ratio of crop yield (Y) to the amount of water depleted by the crop in the process of evapotranspiration (ET).
Crop WUE = Y/ET
Field water use efficiency: It is the ratio of crop yield (Y) to the total amount of water used in the field (WR), which include ET, deep percolation and that used in plant metabolic processes.
Field WUE = Y/WR
Classes and availability of soil water | Soil water Relationshipvishal shinde
Classes and Availability of Soil Water (Soil Moisture Relationship)
Gravitational water is that part in excess of hygroscopic and capillary water which will move out of the soil if favourable drainage is provided.
Capillary water is that part in excess of hygroscopic water which exists in the pore space of the soil by molecular attraction.
When an oven-dried sample is kept open in the atmosphere, it absorbs some amount of water from the atmosphere. This is known as hygroscopic water, and is not capable of movement by the gravity or capillary forces.
Soil Moisture tension
The force per unit area that must be exerted in order to extract water from the soil is known as soil moisture tension and is expressed in terms of atmosphere (atm).
also known as Capillary potential, Capillary tension or force of suction.
Soil moisture tension is inversely proportional to moisture content of a soil of given texture and structure.
measured in the laboratory with the Help of various instruments such as centrifuge, tensiometer etc.
Soil moisture stress
Soil moisture stress is defined as the sum of the soil moisture tension and osmotic pressure of soil solution.
Osmotic pressure is the increase in the force (or tension) caused by the salts present in the soil solution.
The growth of plants is a function of both soil moisture tension as well as the osmotic pressure, and hence is a function of soil moisture stress.
Soil moisture constants
Saturation Capacity: amount of water required to fill all the pore spaces between soil particles by replacing all air held in pore spaces
Field capacity: moisture content of the soil after free drainage has removed most of the gravity water
Permeant wilting point: the soil water content at or below which plant roots cannot absorb water any more
Available moisture: difference in water content of the soil between field capacity and permanent wilting point
Readily available moisture: portion of the available moisture that is most easily extracted by plants.
It is approximately 75% of the available moisture.
Moisture equivalent: percentage of moisture retained in a small sample of wet soil 1 cm deep when subjected to centrifugal force 1000 times as greater as gravity, usually for a period of 30 min.
Moisture equivalent = Field capacity
= 1.8 to 2 permanent wilting point = 2.7 Hygroscopic coefficient
Soil-Moisture deficiency (Field moisture deficiency): water required to bring the soil moisture content to its field capacity.
This power point presentation will give a complete idea of types of irrigation, water requirement of crops, duty, delta, canal revenue etc. This presentation also contain the numerical for complete understanding the concepts.
Soil moisture characteristic curve is the relationship between the water content and the soil water potential, ψ.
It describes the functional relationship between soil water content and its energy status in terms of its matric potential under equilibrium conditions.
This curve is characteristic for different types of soil.
It is also called the Water retention curve
Soils can process and hold considerable amount of water. They can take in water, and will keep doing so until they are full, or until the rate at which they can transmit water into and through the pores is exceeded. Some of this water will steadily drain through the soil (via gravity) and end up in the waterways and streams, but much of it will be retained, despite the influence of gravity. Much of this retained water can be used by plants and other organisms, thus contributing to land productivity and soil health.
QUALITY OF IRRIGATION WATER AND MANAGEMENT OF SALINE WATER FOR IRRIGATION
GOVARDHAN LODHA
Enroll. No. (160111017)
Department of Agronomy
M.Sc. (Ag) Agronomy 2nd semester
Management Practices for Improving Water Use Efficiency.pptxanju bala
Water use efficiency
Production (of crops) per unit of water applied.
Expressed in kg/ha-mm.
Two distinct terms are used in expressing water use efficiency:
Crop water use efficiency: It is the ratio of crop yield (Y) to the amount of water depleted by the crop in the process of evapotranspiration (ET).
Crop WUE = Y/ET
Field water use efficiency: It is the ratio of crop yield (Y) to the total amount of water used in the field (WR), which include ET, deep percolation and that used in plant metabolic processes.
Field WUE = Y/WR
Classes and availability of soil water | Soil water Relationshipvishal shinde
Classes and Availability of Soil Water (Soil Moisture Relationship)
Gravitational water is that part in excess of hygroscopic and capillary water which will move out of the soil if favourable drainage is provided.
Capillary water is that part in excess of hygroscopic water which exists in the pore space of the soil by molecular attraction.
When an oven-dried sample is kept open in the atmosphere, it absorbs some amount of water from the atmosphere. This is known as hygroscopic water, and is not capable of movement by the gravity or capillary forces.
Soil Moisture tension
The force per unit area that must be exerted in order to extract water from the soil is known as soil moisture tension and is expressed in terms of atmosphere (atm).
also known as Capillary potential, Capillary tension or force of suction.
Soil moisture tension is inversely proportional to moisture content of a soil of given texture and structure.
measured in the laboratory with the Help of various instruments such as centrifuge, tensiometer etc.
Soil moisture stress
Soil moisture stress is defined as the sum of the soil moisture tension and osmotic pressure of soil solution.
Osmotic pressure is the increase in the force (or tension) caused by the salts present in the soil solution.
The growth of plants is a function of both soil moisture tension as well as the osmotic pressure, and hence is a function of soil moisture stress.
Soil moisture constants
Saturation Capacity: amount of water required to fill all the pore spaces between soil particles by replacing all air held in pore spaces
Field capacity: moisture content of the soil after free drainage has removed most of the gravity water
Permeant wilting point: the soil water content at or below which plant roots cannot absorb water any more
Available moisture: difference in water content of the soil between field capacity and permanent wilting point
Readily available moisture: portion of the available moisture that is most easily extracted by plants.
It is approximately 75% of the available moisture.
Moisture equivalent: percentage of moisture retained in a small sample of wet soil 1 cm deep when subjected to centrifugal force 1000 times as greater as gravity, usually for a period of 30 min.
Moisture equivalent = Field capacity
= 1.8 to 2 permanent wilting point = 2.7 Hygroscopic coefficient
Soil-Moisture deficiency (Field moisture deficiency): water required to bring the soil moisture content to its field capacity.
Evaluation of Irrigation Application Efficiency: Case Study of Chanchaga Irri...AZOJETE UNIMAID
Water is an integral issue needed to attain the desired targets but good quality water for irrigation purpose is gradually become scarce. The seasonal nature of rainfall can give rise to water stress at critical periods of growth. This research attempts to evaluate the irrigation application efficiency of Chanchaga irrigation scheme, Minna, Niger state. A hand auger was used to bore to a desired depth to remove samples of the moist soil. Samples of the moist soil removed was placed in a can, covered and taken to the laboratory. The specific gravity (apparent) of the soil particle and the depth of water applied were determined using volumetric method, water application efficiency is determined using Gravimetric Method of Soil Moisture Content (Pw) Determination. The moisture content of the field after irrigation water is applied falls between the ranges of 51.1% and 51.5%, with an average of 51.28%, in this case the average amount of water applied is about 4.68%, this shows a little increase in the moisture content of the soil in the field. It was concluded that the efficiency of water application obtained is adequate and a good result considering the available management practice in terms of system operation, monitoring and evaluation.
Assessment and Analysis of Maximum Precipitation at Bharkawada Village, Palan...RSIS International
Efficient Storm water network is the main tool to prevent the water gatheration and scattering of a city. Selecting the Bharkawada as study area and its problem was identified to be of very less effective drainage system. In this study methods have been adopted to identify the possibilities of completing the research for designing the storm water drainage design. Our main aim is to design a very efficient and rpid drainage system which should drain the water very fastly with less concentration time and less spreading of water with less provision of slope. The present design is based on rainfall data. Past 30 years rainfall data has been taken for study. The system has been designed considering in total of 65% of the impervious area. Estimated rainfall intensity has been calculated as 33.02527 mm/hour with a recurrence interval of 2 years from the detailed analysis of rainfall data of 34 years. Rainfall Intensity is estimated after frequency analysis of the rainfall data. The calculated runoff is 25.056 m3/s, which can be used as a design discharge for network designing. Different methods can be used for runoff estimation. Here, Rational method seems to be best for use in estimation of storm water runoff. The outfalls of system are directed to proposed lakes. Ere at this stage rainfall calculations have been done and in future work complete rainfall and runoff analysis will be carried out for storm water network.
Effects of different mole spacings on the yield of summer groundnuteSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
"Design of Resilient Agro-Ecosystems" is University of Nebraska research by Trenton Franz. Please attribute accordingly.
The research was presented Sept. 19, 2017 at the Faculty Fellow Dialogue, hosted by the Robert B. Daugherty Water for Food Global Institute at the University of Nebraska.
DEEP PERCOLATION CHARACTERTISTICS VIA SOIL MOISTURE SENSOR APPROACH IN SAIGON...IAEME Publication
As a critical factor of the groundwater balance, the deeper percolation rate plays
an essential role in determining sustainable yields for groundwater resources,
especially in water managements for consecutive drought years. Although, there are
many methods to estimate deeper percolation, investigation of deeper percolation
somehow remains a challenging task. Hence, the paper focused on to explore deep
percolation characteristics of three soil type utilizing Richard’s function (Hydrus 1D)
and observed soil moisture via field moisture sensors. The maximum deep percolation
rate of sand clay loam, sand clay, and clay are estimated to be 4.5 mm/day, 3.5
mm/day, and 2.4 mm/day, respectively. The annual percolation ratios of sand clay
loam, sand clay, and clay are 0.34, 0.27 and 0.04, respectively. The average monthly
percolation rates of sand clay loam, sand clay, and clay vary 2-4.5 mm/day, 1.5-3.5
mm/day, and 0.5-2 mm/day, respectively with the rainfall intensity of 4-14 mm/day.
The experiment gave an insight on deeper percolation characteristics as well as
potential land recharge from rainfall utilizing soil moisture approach for future
groundwater balance evaluation
Influence of Mulch and Ridge-tie on Soil Moisture retention and early growth ...Agriculture Journal IJOEAR
— Water is one of the main requirements for healthy plant growth. Most arid and semi-arid regions, however, suffer from insufficient and unreliable rainfall. The prevailing soils generally cannot absorb the amount of water which rainfalls in such a short time. Based on this and many other factors a study was carried out to determine the influence of mulch and ridge tie on moisture retention and early growth of maize, at the Kebbi State University of Science and Technology Teaching and Research Farm Jega. The results shows that on a short term basis ridge tying had the highest amount of moisture, while on the long terms basis mulch had the highest moisture content and maize plant height is also more observed in the mulched plots as compared to ridge-tie respectively with the value of 45cm-75cm, and 39cm al 54cm at 3 al 5 WAP respectively al dry matter yield also give a similar trend.
Similar to Soil moisture distribution pattern under surface subsurface drip irrigation (20)
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
CW RADAR, FMCW RADAR, FMCW ALTIMETER, AND THEIR PARAMETERSveerababupersonal22
It consists of cw radar and fmcw radar ,range measurement,if amplifier and fmcw altimeterThe CW radar operates using continuous wave transmission, while the FMCW radar employs frequency-modulated continuous wave technology. Range measurement is a crucial aspect of radar systems, providing information about the distance to a target. The IF amplifier plays a key role in signal processing, amplifying intermediate frequency signals for further analysis. The FMCW altimeter utilizes frequency-modulated continuous wave technology to accurately measure altitude above a reference point.
HEAP SORT ILLUSTRATED WITH HEAPIFY, BUILD HEAP FOR DYNAMIC ARRAYS.
Heap sort is a comparison-based sorting technique based on Binary Heap data structure. It is similar to the selection sort where we first find the minimum element and place the minimum element at the beginning. Repeat the same process for the remaining elements.
NUMERICAL SIMULATIONS OF HEAT AND MASS TRANSFER IN CONDENSING HEAT EXCHANGERS...ssuser7dcef0
Power plants release a large amount of water vapor into the
atmosphere through the stack. The flue gas can be a potential
source for obtaining much needed cooling water for a power
plant. If a power plant could recover and reuse a portion of this
moisture, it could reduce its total cooling water intake
requirement. One of the most practical way to recover water
from flue gas is to use a condensing heat exchanger. The power
plant could also recover latent heat due to condensation as well
as sensible heat due to lowering the flue gas exit temperature.
Additionally, harmful acids released from the stack can be
reduced in a condensing heat exchanger by acid condensation. reduced in a condensing heat exchanger by acid condensation.
Condensation of vapors in flue gas is a complicated
phenomenon since heat and mass transfer of water vapor and
various acids simultaneously occur in the presence of noncondensable
gases such as nitrogen and oxygen. Design of a
condenser depends on the knowledge and understanding of the
heat and mass transfer processes. A computer program for
numerical simulations of water (H2O) and sulfuric acid (H2SO4)
condensation in a flue gas condensing heat exchanger was
developed using MATLAB. Governing equations based on
mass and energy balances for the system were derived to
predict variables such as flue gas exit temperature, cooling
water outlet temperature, mole fraction and condensation rates
of water and sulfuric acid vapors. The equations were solved
using an iterative solution technique with calculations of heat
and mass transfer coefficients and physical properties.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Soil moisture distribution pattern under surface subsurface drip irrigation
1. Soil moisture distribution patterns under
surface and subsurface drip irrigation
Presented by
ARPNA BAJPAI
L-2016-AE-121-D
Course Instructor
Dr. PPS LUBANA
Professor (Soil and Water Engineering)
Course Name : Credit Seminar
Course Code :- SWE -591
Friday, May 4, 2018 1
2. Micro irrigation system is introduced for increasing the
productivity by economizing the use of water. In this
system, water is applied to plant root zone through
emitters. Water is applied at frequent intervals in
controlled quantities as per the requirements of plant. It
is the most advanced irrigation method with the highest
application efficiency.
Introduction
Friday, May 4, 2018 2
3. Moisture distribution pattern is one of the basic
requirements for efficient design and management of an
irrigation system. The knowledge of moisture
distribution pattern helps in the effectiveness of drip
irrigation (Yaragattikar et al., 2003).
This will ensure precise placement of water
and fertilizer in the active root zone.
Friday, May 4, 2018 3
4. In the design of the trickle system, the volume of soil
wetted by a single emitter is important. This must be
known in order to determine the total number of
emitters required to wet a large volume of soil to ensure
that the plant’s water requirement would be met.
Friday, May 4, 2018 4
5. The volume of soil wetted from a point source is
primarily a function of the soil texture, soil structure,
application rate and the total volume of water applied.
The volume of water applied per irrigation also affects
the width and depth of the wetted soil volume and
therefore influences the optimal emitter spacing
Friday, May 4, 2018 5
6. The extent of soil wetted volume in an irrigation system
determines the sufficient amount of water needed to wet
the root zone. In a study by Goya (2014), soil water stored
in the root zone was determined by the volume of wetted
soil.
The water is delivered
continuously in drops at
the crop root zone and
wets the root zone
vertically by gravity
and laterally by
capillary action.
Friday, May 4, 2018 6
7. The soil moisture distribution and its uniformity
within the soil profile under surface drip were
affected by the distance between drippers rather than
distance between laterals. Lesser the dripper spacing,
more will be the moisture distribution.
Under SDI, the allocation of the irrigation system
plays an important role in soil moisture trend. The
depth of the lateral below soil surface, emitter spacing
and system pressure are important for delivering the
required amount of water to the plant (Badr et al,
2011).
Friday, May 4, 2018 7
8. The total volume of the wetted soil and its shape under a
trickle emitter varies widely with
soil hydraulic characteristics
number of emitters
discharge rate
frequency of water application.
Friday, May 4, 2018 8
9. The wetted-soil volume needs to be determined keeping in
view all the factors that affect its shape and volume, and
thus help ensure that the wetted soil volume matches as
closely as possible with crop rooting pattern.
The volume of soil wetted under point source trickle emitter
is primarily a function of the
soil texture
soil structure
Application rate and
The total volume of water applied
(Lubana et al., 2002; Ekhmaj et al., 2005).
Friday, May 4, 2018 9
10. During infiltration, the soil water content changes both
spatially and temporally and redistribution of water in
the soil is strongly dependent on the
Irrigation method
Soil type
vegetation root distribution and
Rates of water application.
Therefore, for effective design and use of drip systems,
there is a need to predict soil water dynamics taking
into account all these dependencies
(Merill et al., 1978).
Friday, May 4, 2018 10
11. Case Studies 1
Monitoring and modeling the three-dimensional
flow of water under drip irrigation
J. Fernandez-Galvez , L.P. Simmonds
Journal Name :- Agricultural water management
Published year :- 2006
Pages :- 197-208
Volume :- 83Friday, May 4, 2018 11
12. The objectives of the study
(a) To develop and verify a technique for monitoring the
three dimensional spatial and temporal patterns of soil
water content under a drip irrigation system.
b) to produce detailed data-sets of the spatial patterns of
soil moisture immediately before and after a drip
irrigation event, and approximately 24 h after irrigation,
to provide information about the post irrigation
redistribution of water.
Friday, May 4, 2018 12
13. Particle size distribution and bulk density at the experimental site
Vertical profiles of bulk density were made by inserting
steel cores of known volume (196 cm3) into the face of
three soil pits
Friday, May 4, 2018 13
The second horizon shows a remarkable higher bulk density
due to the presence of a ploughed layer developed by intensive
farming. The compact layer just below the depth of cultivation
was also noticed during the installation of the access tubes.
14. Experimental layout.
Access tubes soil moisture determinations
(56 in 1.56m2)
Batavia lettuces
(row spacing
32.5 cm)
Drip line spacing :
65 cm
Dripper spacing :
40 cm
Friday, May 4, 2018 14
15. Capacitance sensors were used for soil water content
determination. The ProfileProbe consists of a sealed composite
rod with six sensors located such that measurements are made at
10, 20, 30, 40, 60 and 100 cm depths in normal operation, with the
probe inserted into the soil via an access tube.
Friday, May 4, 2018 15
(ProfileProbe from Delta-T
Devices Ltd., Cambridge, UK)
Each sensor generates a 100 MHz
electromagnetic field that
penetrates the soil; the dielectric
properties of the soil are
determined from the standing
wave generated.
17. 5 cm left 5 cm right
Vertical profiles of volumetric water content (before irrigation,
after irrigation and after redistribution). The four locations
illustrated were all at 5 cm radial distance from dripper 2
Friday, May 4, 2018 17
18. 5 cm down 5 cm up
Friday, May 4, 2018 18
Before irrigation profiles of water contents had similar
shapes in the four locations, with two peaks of soil
water content at around 40–50 cm depth and 80–100
cm depth
and a local
minimum
around 60 cm
depth.
There was no evidence in any of these tubes of a large
short-range fluctuation in water content with depth,
which can be characteristic of problems arising from
artefacts of air-gaps between the access tube and the
surrounding soil.
19. Dripper 2, distance 5 cm Dripper 2, distance 5 cm
After Irrigation After redistribution
Friday, May 4, 2018 19
Vertical profiles of the changes in water content between before
and after irrigation and the changes in water content between
before irrigation and after 24 h of post-irrigation redistribution
The gain in profile water content around dripper 2,
at 5 cm radial distance from the dripper, was
approximately two times larger in two of the
locations
Spatial variation in soil hydraulic properties resulting in the
radial water flow from the dripper being non-uniform.
The apparent gain in water content in the vicinity of an
access tube being dependent on the principal direction of
view of the sensor.
Differences between the tube locations
20. Maps of the gain in profile water content (in mm)
measured at each access tube location.
before and after irrigation
before irrigation and 24 h
after irrigation
For all the access tubes that were measured before and
after the irrigation event, the gain in profile water content
in mm equivalent water depth that was generated by
applying the irrigation of 9.7 mm. There is a clear general
pattern of the largest gains in profile water content being
observed in the access tubes closest to the drip source, and
apparently rather little water appearing to penetrate more
than 25 cm radially from the drip sources.Friday, May 4, 2018 20
21. The effect of distance from the nearest drip source on the measured
gain in profile water content during irrigation. The data points are
from individual access tubes, based on the ‘before’ and ‘after’
irrigation.
Data collected suggest that the radial
penetration of water during the irrigation
was limited to about 20 cm
Friday, May 4, 2018 21
22. Area-weighted average gains in profile water content (in
mm) across the ‘unit cells’, for the irrigation event when
9.7mm of water was applied
The standard deviation of the water balance
estimates for the ‘unit cells’ associated with
individual drippers is around 2mm. It is likely
that the greatest contribution to this error is that
the estimation of the area-average water storage
is based on a small number of samples within a
very heterogeneous environment.
Friday, May 4, 2018 22
23. After wetting Redistribution
Model prediction after irrigation and 24 h
later
During the redistribution period, 24 h after irrigation, there is a
predominant horizontal distribution of water in the top layer
with very little penetration of water below 25 cm.
Friday, May 4, 2018 23
The lack of horizontal spatial heterogeneity produces a
symmetrical irrigation bulb that extends radially up to
25 cm distance after irrigation has ceased.
The model captures extremely well the penetration of the
wetting front, showing how the compacted layer at 25 cm depth
impedes the water to flow through it and, as a result of that, the
water is spread out further in the horizontal direction
24. Dripper 2, After wetting Dripper 2, Redistribution
Friday, May 4, 2018 24
Contour maps of the three-dimensional distribution of
the gain in volumetric soil moisture content during
irrigation. Contour maps are shown for drippers 2, 3, 6
and 7.
27. Dripper 7,
After wetting
Dripper 7,
Redistribution
The radial distance of the irrigation bulb after
irrigation is around 10 cm with the wetting reaching 20
cm depth according to the soil moisture measurements.
Friday, May 4, 2018 27
The spatial pattern in water distribution is quite
different between drippers as would be expected due to
soil heterogeneity, having sites with higher changes in
water content in a smaller volume of soil and sites
where the irrigation bulb is more spread out.
In some cases the irrigation bulb appears off-centre is
due to a displacement of the dripper at the soil surface
with respect to the array.
28. Conclusions
In each case, there is substantial redistribution of water
during the 24 h after irrigation, such that the gain in
water content of the soil just below the dripper
immediately after irrigation ceased (typically 25–30% by
volume) falls to about 12–15% by volume increase in
water content compared with the water content just prior
to irrigation.
Friday, May 4, 2018 28
29. Model predictions capture the impact of the compact
soil layer reducing the penetration of the wetting front
down to 25 cm depth. The simulated irrigation bulb is
symmetric with a homogeneous spread out of the water
supplied showing a larger radial influence extending up
to 25 cm after irrigation and more than 30 cm 24 h
later.
Friday, May 4, 2018 29
30. Modeling for predicting soil wetting radius
under point source surface trickle
irrigation
R. Subbaiah*, H.H. Mashru
Agric Eng Int: CIGR Journal
Vol. 15, No.3 Year 2013
Case Studies 2
Friday, May 4, 2018 30
31. Objective of the study
To develop a simple heuristic model that
can help to determine the wetting radius
from surface point drip irrigation using
infiltration properties of the soil.
Friday, May 4, 2018 31
32. The accuracy of the model is validated by
a) Observing the parameters of the model on
the field and
b) By equating the volume of water supplied
and volume calculated from the geometry of
the bulb defined from above models
Friday, May 4, 2018 32
33. Materials and method
Place of the study College of Agricultural
Engineering and Technology
Gujarat, India
Type of soil Clay loam soil
Emitters discharge
rates
0.002, 0.004 and 0.008 m3 h-1.
The experimental site was slip ploughed to 1.5 m to
thoroughly mix the profile and eliminate any
compacted layers, then chiselled to 0.3 m, disked, and
harrowed.Friday, May 4, 2018 33
34. Radius of wetted bulb (Rw) at depth (d)
The radius of wetted bulb at any depth, d, and time, t,
is expressed heuristically as
where , rw0 is the radius of circular area of entry of water into the
soil (cm) at the surface when time t
The depth of wetting front at any time, ti, is expressed as
Friday, May 4, 2018 34
35. Model validation
Coefficient of determination
Efficiency coefficient
Nash and Sutcliffe, 1970 Liang et al., 1994Friday, May 4, 2018 35
In order to validate the proposed model, the computed
wetted radius at different depths was compared with
the observed radius of spread from the experimental
set up. The relative agreement of each computed wetted
radius with the experimental data was evaluated using
36. Result and discussions
Infiltration characteristics of the soil
d = 0.5t0.45
cumulative depth of infiltration The infiltration rate
I = 0.225t-0.55
Friday, May 4, 2018 36
The depth of infiltration obtained from the double ring
infiltrometer was fitted using Kostiakov equation. The
data obtained were plotted on a double log paper to
obtain the slope and intercept.
38. for 0.002 m3/hr for 0.004 m3/hr
Observed versus calculated radius of water pool on the
ground surface
Wettedradiusrw/cm
Wettedradiusrw/cm
Wettedradiusrw/cm
Friday, May 4, 2018 38
The observed rw as a function of time for three emitter flow rates.
It was observed during experiment, that the radial area of ponded
water develops in the vicinity of the drip emitters. The water
infiltrates from this saturated entry area into the soil.
The wetted width was affected by discharge rate of emitter as well
as duration of water application. This may be due to the
increasing discharge rate, which increased the volume of water
supplied in a given duration that created higher volume of wetted
soil zone. Increased duration of application also increased the
wetted volume.
for 0.008 m3/hr
It is observed that the values of saturated entry radius
increase rapidly with time initially but then increase at
a decreasing rate to limit the radius to a constant value,
15.5
cm 21.82
cm
32.5
cm
39. for 0.002 m3/hr
for 0.008 m3/hr
for 0.004 m3/hr
Observed vs calculated radius of water pool on the ground
surface
Friday, May 4, 2018 39
The rate of trickle discharge and the hydraulic properties of the
soil had a remarkable effect on the shape of wetted soil zone.
Increasing the rate of discharge and decreasing the saturated
conductivity resulted in an increase in the horizontal component
of wetted area.
Condition when emitter flow rate is less than infiltration capacity
of the soil, the depth attained by the wetting front is mainly
controlled by the irrigation time rather than the application rate.
But when the emitter discharge increases beyond the infiltration
capacity of the soil the horizontal component is increased and a
narrower bulb may be seen.
40. Volume of water contained in the bulb
Friday, May 4, 2018 40
The computed cumulative volume with time can also
be approximated well with a polynomial equation of
order four with satisfactory values of goodness of fit
for all emitter discharges
Computed cumulative volume of water stored in the wetted
bulb for different discharges
41. Conclusion
The depth of wetting front was found to be invariant
with emitter flow rate provided the emitter discharge is
less than the infiltration capacity of the soil bounded
with an impervious layer at the bottom
High value of goodness of fit and efficiency
strengthened the confidence in the validity of the model
proposed to predict geometry of wetted soil zone as a
function of emitter discharge.
Friday, May 4, 2018 41
42. The wetted bulb geometry predicted by the equations
above can be considered as satisfactory as the volume of
water contained in the wetted bulb is equal to the volume
of water supplied.
The output of the developed model can be used to
determine the geometry of wetted bulb from surface
point source irrigation for a particular discharge
operating for a specific duration.
Friday, May 4, 2018 42
43. Soil Moisture Profile Analysis Using
Tensiometer under Different Discharge Rates of
Drip Emitter
Int.J.Curr.Microbiol.App.Sci (2017) 6(11): 908-917
Shashi Shekhar, Manish Kumar, Anuradha
Kumari and S.K. Jain
https://doi.org/10.20546/ijcmas.2017.611.106
Case Studies 3
Friday, May 4, 2018 43
44. To evaluate the effects of discharge
rate on moisture profile in the soil
which is measured by the use of
tensiometer.
Objective
Friday, May 4, 2018 44
45. Materials and Methods
Location Experimental farm of Pumps and Wells
laboratory shed of College of
Agricultural Engineering Samastipur
Bihar.
Climate sub- humid- west monsoon
annual rainfall 1270 mm
average minimum and
maximum
temperatures
30– 40˚C and 43 - 44 ˚C
Materials used in the
experiment
Metallic cylindrical tank
Tensiometer
Friday, May 4, 2018 45
46. Methodology adopted for the experiment
Determination of soil texture :- Sandy clay loam soil
Determination of bulk density
Installation of tensiometer
Calibration of tensiometer
sand, silt and clay are
52%, 18% and 30 %
Friday, May 4, 2018 46
47. Installation of set up for the experiment
Cylinder tank :- soil filled Height (90 cm)
Tensiometer were installed at the radial
distances of 15 cm, 30 cm, 45 cm, 60 cm, and
90 cm.
Discharge rates of 2 lph, 4.4 lph and 6 lph
were used for the experiment. Readings were
noted down at regular interval of 15 min for 6
lph discharge rate and 30 min for 4.4 lph and 2
lph discharge rates.
Friday, May 4, 2018 47
48. Plotting of contour maps
Contour maps were plotted from the data
recorded during the experiment for
different discharge rates of 2 lph, 4.4 lph
and 6 lph using the Surfer – 7 software
Friday, May 4, 2018 48
49. Results and Discussion
The bulk density of soil sample taken for discharge 2
lph, 4.4 lph, and 6 lph was obtained 1.46, 1.47 and 1.41
g/cm3 respectively.
Bulk density
Friday, May 4, 2018 49
51. Calibration of the tensiometer
Soil moisture tension (centibar)
Soilmoisturecontent(%)
Friday, May 4, 2018 51
27.4%
23.5%
52. Soil moisture profile at 2 lph emitter discharge
Study of soil moisture profile
Radial distance
Depth
Friday, May 4, 2018 52
In case of iso-moisture lines (contour lines) having moisture
content 17%, the radial distance is 36.5 cm and for iso-moisture
lines having moisture content 18%, the radial distance is 30 cm.
This clearly shows that as the distance from the centre increases
vertically there is a decrease in moisture content i.e. with increase
in distance from the centre there is a decrease in moisture content.
It can be said that changes in moisture content is steeper radially
than vertically. Thus, it is evident that vertical movement of water is
predominant as compared to lateral movement.
53. Soil moisture profile for 4.4 lph discharge rate
Radial distance
Depth
Friday, May 4, 2018 53
54. Radial distance
Depth
Soil moisture profile for 6 lph discharge rate
Friday, May 4, 2018 54
It clearly indicates that greater is the distance
from the centre lesser is the moisture content.
55. Comparison of soil moisture profile at different
discharge rates of emitter
This clearly shows that for the same moisture
content, the radial distance of iso-moisture
lines from the centre is greatest for 6 lph
followed by 4.4 lph and last is 2 lph discharge.
Thus, it can be said that more is the
discharge rate more is the lateral
movement of water.
Friday, May 4, 2018 55
56. This clearly shows that for the same moisture
content, the vertical distance of iso-moisture
lines from the centre is greatest for 2 lph
followed by 4.4 lph and last is 6 lph discharge.
Thus, it can be said that lower is the
discharge rate greater is the vertical
movement of water.
Friday, May 4, 2018 56
57. The vertical spread of water decreases with increase in
emitter discharge rate. The vertical spread was
observed to be about 18.0% and 32.0% less when
discharge was increased from 2 lph to 4.4 lph and 6.0
lph respectively.
Major Conclusions
Horizontal spread of water increases with increase in
discharge of emitter. The horizontal spread was
observed to be about 25.4% and 47.8% more when the
emitter discharge rate increased from 2 lph to 4.4 lph
and 6.0 lph respectively.
Friday, May 4, 2018 57
58. Based on the soil moisture recorded at different
points below the discharging emitter under different
discharge rates it can be concluded that the spread of
water increases in horizontal direction and decreases
in vertical direction when the emitter discharge is
increased.
Hence, the crops which have deeper root
system must be irrigated with smaller
discharge rates compared to crops which have
shallow roots.
Friday, May 4, 2018 58
59. ASSESSMENT OF WETTING PATTERN AND
MOISTURE DISTRIBUTION UNDER POINT
SOURCE DRIP IRRIGATION
Binyebebe Maurice, Nsengumuremyi Emile,
and Uwimpuhwe Charlotte
International Journal of Innovation and Scientific Research
ISSN 2351-8014 Vol. 26 No. 2 Sep. 2016, pp. 484-493
Case Studies 4
Friday, May 4, 2018 59
61. Material and methods
STUDY AREA Farm of University
of Rwanda- Nyagatare Campus
Mean annual rainfall 850 mm
Annual mean maximum
and minimum
temperatures
32˚C and 15˚C
Average maximum and
minimum relative
humidity
92 % (8:22 hrs) and 39 % (14:22
hrs)
mean daily
evaporation
3.5 to 7.6 mm
Friday, May 4, 2018 61
62. SOIL PROPERTIES OF EXPERIMENTAL
SITE
Texture
Sandy
Loam
Friday, May 4, 2018 62
63. T1S1 - Drip lateral at surface with irrigation water at 1.0
IW / CPE ratio
T2S1 - Drip lateral at 10 cm depth from surface with
irrigation water at 1.0 IW / CPE ratio
T3S1 - Drip lateral at 20 cm depth from surface with
irrigation water at 1.0 IW / CPE ratio
EXPERIMENTAL DESIGN
Friday, May 4, 2018 63
64. WETTING PATTERN MEASUREMENT
HORIZONTAL WETTED ZONE
VERTICAL WETTED DEPTH
The average radius of the
wetted zone was estimated
over time during emission
by measuring the actual
distance in four directions
as the wetting pattern has
almost a circular shape
using the measuring scale.
Immediately after measuring
the horizontal wetting front,
the discharge was stopped.
Then, the soil was cut
vertically along downward to
record the vertical movement
of wetting front after the
specified time
Friday, May 4, 2018 64
65. Result
MOISTURE DISTRIBUTION IN SOIL DURING
DIFFERENT PERIOD
Distance from emitters, cm
Depth,cm
30DAS60DAS
Friday, May 4, 2018 65
66. Distance from emitters, cm
Depth,cm
90DAS120DAS
Moisture distribution before irrigation at surface, 10
cm and 20 cm depths
While analysing the horizontal behaviour of soil
moisture, the general trend showed that the
moisture decreased with increase in distance
from the emitting point for all the treatments
Philip (1984) and Muthuchamy (1998) that the
moisture content was decreased while the distance
from the emitter point increased.
Friday, May 4, 2018 66
67. Moisture content (%) 24 hours after irrigation at 30, 60, 90
and 120 DAS
Friday, May 4, 2018 67
68. Horizontal wetting front advancement and
vertical wetted zone depth
Friday, May 4, 2018 68
the horizontal wetted zone
radius increased linearly
with increase in elapsed
time. It was observed the
faster movement of wetting
front in horizontal
direction for surface drip
treatments than the
treatments of subsurface
lateral installations at 10
cm and 20 cm depth.
Vertical wetting front
advance increased
with increase in
elapsed time. Inversely
to horizontal wetted
zone radius, the
wetting front advance
in vertical direction
was faster in the
subsurface treatments.
70. HORIZONTAL WETTED RADIUS
The following equations representing predicted values
were obtained:
(i) Y (0 cm) = 0.1026X + 10.437 (surface drip)
R2 = 0.8062
(ii) Y (10 cm) = 0.1059X + 6.4858 (sub surface drip, 10 cm depth)
R2 = 0.8621
(iii) Y (20 cm) = 0.1035X + 5.543 (sub surface drip, 20 cm depth)
R2 = 0.891
Where,
Y = horizontal wetted radius, cm
X = elapsed time and
A, C = constants
Horizontalwetted
zoneradius,cm
Time, minFriday, May 4, 2018 70
The range of variation of obtained regression coefficients varied
between 0.8 and 0.9 .This states that the obtained regression line
perfectly fits the data.
indicated that the
variation of
horizontal wetted
radius was highly
correlated to time
increase
71. VERTICAL WETTED RADIUS
(i) Y (0 cm) = 0.217X + 5.2203 (surface drip)
R2 = 0.9532
(ii) Y (10 cm) = 0.2996X + 5.8946 (subsurface drip, 10 cm depth)
R2 = 0.9647
(iii) Y (20 cm) = 0.2927X + 6.7402 (subsurface drip, 20 cm depth)
R2 = 0.957
Where,
Y = horizontal wetted radius, cm
X = elapsed time and A, C = constants.
Verticalwetted
zoneradius,cm
Time, minFriday, May 4, 2018 71
indicated that the
variation of Vertical
wetted radius was
highly correlated to
time increase
72. Conclusion
The percentage of moisture was decreasing with increase in
distance from the emitting point in both cases investigated i.e.
before and 24 hours after irrigation.
The surface soil appeared to be almost dry before irrigation in
upper depth of soil say from surface to 15 cm depth. However 24
hours after irrigation is supplied, the moisture content for the
treatments of surface laterals became higher from surface to 15 cm
deep and lesser in the depth of 15 – 30 cm. In case of subsurface
drip treatments, the moisture content observed 24 hours after
irrigation was found to be higher in deeper installation.
Analyzing the contours of 10 cm and 20 cm depths of lateral
placement at different irrigation levels, the moisture content was
evenly distributed 24 hrs after irrigation.Friday, May 4, 2018 72
73. EFFECT OF SUBSURFACE DRIP IRRIGATION
SYSTEM DEPTH ON SOIL WATER CONTENT
DISTRIBUTION AT DIFFERENT DEPTHS AND
DIFFERENT TIMES AFTER IRRIGATION
DOUH B.*, BOUJELBEN A., KHILA S., BEL HAJ
MGUIDICHE A.
Larhyss Journal
March 2013, pp.7-16
Case Studies 5
Friday, May 4, 2018 73
75. MATERIALS AND METHODS
Place Higher Institute of Agronomy of
Chott Mariem, Tunisia
Duration May to July 2010
climate Mediterranean
Annual rainfall 230 mm
evaporation 6 mm/day
Avg minimum and maximum
temperature in winter
6 and 18 ℃
Avg minimum and maximum
temperature in summer
23 and 38℃
Soil type sandy loam with average basic
infiltration rate
of 14 mm h-1.
Bulk density 1.40 g cm-3Friday, May 4, 2018 75
76. Crop Maize
Sowing date 1st May
Crop spacing 80 cm
Irrigation Type Drip irrigation (subsurface)
Emitter depth 5, 20 and 35cm
Location of the dripper respectively at 5, 20 and 35 cm depth
Friday, May 4, 2018 76
77. Equipment's used
Soil moisture sensors (Time domain reflectometry tubes)
Emitter discharge :- 4 L.h-1.
Soil moisture was recorded 2 hours before the irrigation, 2, 4,
and 6 h after the irrigation experiment started.
Soil sampling :- 0, 20, and 40 cm away from the emitter and at 10,
20, 30, 40, 50 and 60 cm depths
Trime FM
Friday, May 4, 2018 77
78. Moisture distribution patterns
Water distribution in soil profile was presented by
contour maps.
For each treatment, six locations around the drippers
were selected.
The total number of moisture data points was 24
points by depth. These 24 point were arranged in a
matrix of 3 columns and 6 rows and the program
(SURFER 8) was used for developing moisture
content lines.
Friday, May 4, 2018 78
79. RESULTS AND DISCUSSION
Soil moisture distribution before and after the irrigation
T1 T2 T3
Before Irrigation
2 h after
Irrigation
4 h after
Irrigation
6 h after
Irrigation
For (T1), and before irrigation,
the water content under the
emitter is at the order of 13%
and then increases from the
emitter to reach high values of
20 to 25%.
2 hours after irrigation, water
content increases to 23% but
remains low at the emitter.
4 hours after irrigation,
moisture increases with
distance from the emitter
After 6 hours of irrigation, the
water content under the
emitter reaches 23% and form
circular curves.
For T2, before irrigation, the
water content varies between 15
and 22%. After irrigation, the
curves of equal water contents of
circular shape around the
dripper have the higher values of
(29%). After four hours of
irrigation, water content
recorded at the emitter is
approximately 24.5% and
decreases away to the sides to
reach values of 18%. After 6
hours and at 30 cm on either side
of the dripper, the water content
is around 13% where it has a
maximum root density.
For T3, before and just after
irrigation, at 20 cm on either
side of the emitter, low water
content of about 17% due to root
uptake has been registered.
After 4 hours of irrigation, there
is a high water content of about
21.5% due to the water source
located at (0,0) and a low water
content at 20 cm on both the
other of the dripper.
After 6 h of irrigation, the water
content is low at the emitter of
about 15% moisture and spreads
to the ends up to 21% at 40 cm
on either side of the dripper.Friday, May 4, 2018 79
80. Soil moisture distribution in different depths
Vertical Soil moisture distribution respectively under
subsurface drip irrigation (T1), (T2) and (T3) 24 hours
after an irrigation of one hour with 4lh-1 flow
The results show that soil moisture is relatively more
stable for T3 than T1 and T2 with slight difference
except of water’s contributions. The study indicated that
soil moisture content under subsurface drip irrigation at
35 cm depth was more uniform as compared to that at 5
and 20 cm.
The results provide evidence that 35 cm below the soil
surface was so dry as it was hypothesized that SDI
method would improve the water use efficiency of maize
crop by minimizing the evaporative loss and delivering
water directly to the root zone
Soil water content for the depth of 20 to 35 cm was
higher in T3. These results are confirmed by
Bajracharya and Sharma (2005) who put the same
hypothesis to explain the amplification of water use
efficiency of cucumber and tomato crops relatively to
SDI.
Friday, May 4, 2018 80
81. Conclusions
This study indicated that soil moisture content
under subsurface drip irrigation at 0.35 m depth was more
uniform in comparison to that at 0.05 m and 0.20 m.
Subsurface drip irrigation allows uniform soil moisture,
minimize the evaporative loss and delivery water directly
to the plant root zone which increases use efficiency and
yield
Friday, May 4, 2018 81
82. Hussein Mohammed Al-Ghobari and
Mohamed Said Abdalla El Marazky
Surface and subsurface irrigation systems wetting
patterns as affected by irrigation scheduling
techniques in an arid region
African Journal of Agricultural Research Vol. 7(44), pp. 5962-
5976, 20 November, 2012
DOI: 10.5897/AJAR11.2194
Case Studies 6
Friday, May 4, 2018 82
83. MATERIALS AND METHODS
Place Experimental Farm of the College of
Food and Agriculture Sciences of King
Saud University, Riyadh.
Crop Tomato
Irrigation Method Drip Irrigation (Surface and
subsurface)
Friday, May 4, 2018 83
84. Layout of experimental field
The study site was divided into two main fields, each
divided into three plots as shown in Figure. One field had a
DI system, while the other had an SI system. The DI and SI
systems consisted of 16 mm inside diameter thin-wall drip
lines with emitter spacing of 50 cm and emitter discharge
of 4 lphFriday, May 4, 2018 84
85. Physical properties of different soil layers in the
experimental field.
Friday, May 4, 2018 85
86. Diagram showing soil sampling locations in lateral
and perpendicular directionsFriday, May 4, 2018 86
87. Scheduling techniques
ET-System :- uses weather sensors and automatically
determines the crop ET (ETc).
automatic (Watermark 200SS-V) sensor
Control system which was based on automatic
weather station (Davis Cabled – vantage pro2)
Watermark 200SS-V
Davis Cabled –
vantage pro2
Friday, May 4, 2018 87
88. Uniformity parameter calculations
where; Cus = Christiansen’s coefficient of uniformity of soil water
content below soil surface,
θi = the measured gravimetric soil water
content at depth i,
θ = the mean gravimetric soil water content, and
N = number of measured points.
Friday, May 4, 2018 88
89. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h after
Wetting patterns in lateral and perpendicular directions
in root zone area under drip irrigation system with smart
irrigation scheduling 24 and 48 h after irrigation.
Friday, May 4, 2018 89
90. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
The distribution of soil moisture with soil
depth was more even with 48 h after
irrigation than 24 h after irrigation in both
lateral and perpendicular directions.The shape and volume of moisture distribution was
homogeneous for 48 hour after irrigation in both parallel
and perpendicular directions, but was non-homogeneous,
with a conical shape with 24 h after irrigation.
Friday, May 4, 2018 90
91. Wetting patterns in lateral and perpendicular directions in root
zone area under drip irrigation system with sensor based irrigation
scheduling 24 and 48 h after irrigation.
Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h after
In the parallel direction, the soil moisture
distribution in the top 20 cm of the soil profile
was better with 48 than 24 h.
Friday, May 4, 2018 91
92. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
The soil moisture distribution throughout the soil
profile was more homogeneous in both parallel and
perpendicular directions with 48 h after irrigation, but
was less homogenous in both parallel and
perpendicular directions for 24 h after irrigation
Friday, May 4, 2018 92
93. Wetting patterns in lateral and perpendicular directions in root
zone area under drip irrigation system with manually controlled
irrigation 24 and 48 hours after irrigation.
Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h after
The soil moisture content was higher horizontally
than vertically in both parallel and perpendicular
directions for 48 h after irrigation, but was higher
vertically in both lateral and perpendicular
directions 24 h after irrigation.
Friday, May 4, 2018 93
94. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
It can also be seen that the increase in soil moisture
content from 48 to 24 h after irrigation was higher
parallel to the drip line than perpendicular to the
line.
This trend did not occur for the other treatments.
The best wetting patterns were observed in the
parallel direction, especially under the emitter
compared with the perpendicular direction.
Friday, May 4, 2018 94
95. Wetting patterns in lateral and perpendicular directions
in root zone area under sub drip irrigation system with
smart irrigation scheduling 24 and 48 h after irrigation.
Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h afterFriday, May 4, 2018 95
The distribution of soil moisture with depth was
greater with 48 h after irrigation than 24 h after
irrigation in both lateral and perpendicular
directions.
96. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
It was clear that the soil moisture was distributed
deeper for 48 h irrigation. The data show that after
irrigation the soil moisture content increased in
both horizontal and vertical directions to be near
field capacity throughout the soil profile.
Friday, May 4, 2018 96
97. Wetting patterns in lateral and perpendicular directions in root
zone area under subsurface irrigation system with sensor based
irrigation scheduling 24 and 48 h after irrigation.
Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h after
The distribution of soil moisture against
soil depth in the parallel direction, both 24
and 48 h after irrigation was greater than
in the perpendicular direction.
Friday, May 4, 2018 97
98. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
The contour lines in the perpendicular direction
were very large under the dripper line compared
with the contour lines in the parallel direction
which were apart from each other
Friday, May 4, 2018 98
99. Wetting patterns in lateral and perpendicular directions in root
zone area under a subsurface irrigation system with manually
controlled irrigation 24 and 48 h after irrigation.
Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Parallel- 24 h after Parallel- 48 h after
The increase in the soil moisture content under different
irrigation scheduling techniques was greater vertically
than horizontally, in both lateral and perpendicular
directions 24 h after irrigation
Friday, May 4, 2018 99
100. Distance from emitter (cm) Distance from emitter (cm)
Soilprofiledepth(cm)
Perpendicular- 24 h after Perpendicular- 48 h after
The overall wetted area, delimited by the wetting front was
largest for the manually scheduled DI and SI systems, and
smallest for the smart controller scheduled DI and SI systems,
which was consistent with the results reported by Lubana and
Narda (2001).
Friday, May 4, 2018 100
101. Coefficients of average uniformity of applied water
(Cus) as a function of soil depth, for drip (DI) and
subsurface (SI) irrigation system using three irrigation
scheduling methods.
The higher value for the SI system can be explained by the
hydraulic gradients existing within the unevenly wetted soil which
cause water movement within the soil profile parallel and
perpendicular to the irrigation lines, resulting in the water
movement within the soil to be more uniformly distributed.
Friday, May 4, 2018 101
102. Conclusions
1. Using all three irrigation scheduling techniques, smart
controllers; moisture sensors; and manual control; the soil
moisture content under the SI system increased more
vertically than horizontally for 24 h after irrigation in
both parallel and perpendicular directions. The soil
moisture content under SI was also higher horizontally than
vertically for 48 h after irrigation in both parallel and
perpendicular directions.
Friday, May 4, 2018 102
103. 2. The shape of the soil moisture distribution was close
to conical for all the irrigation scheduling techniques
studied. The soil water distribution pattern showed the
highest water content near the drip line under the SI
system for all scheduling techniques, with the water
content increasing with distance and depth in both
lateral and perpendicular directions 24 h after
irrigation.
Friday, May 4, 2018 103
104. 3. The soil moisture contour lines were denser for
the SI system than the DI system with all
irrigation scheduling techniques, for 24 and 48 h
after irrigation in both lateral and perpendicular
directions. This difference may be attributed to the
improved water distribution with SI systems compared with
DI systems.
Friday, May 4, 2018 104
105. 4. The moisture distribution in the soil indicated
the wetting pattern in lateral directions in
both surface and subsurface plots
produced wider soil wetting patterns
especially near the soil surface compared to
the perpendicular direction.
Friday, May 4, 2018 105
106. Soil moisture distribution under different lateral and
dripper spacing of surface drip irrigation system in
clay loam soil
Sanjay Singh chouhan. K. A asthi, R. K. Nema and L.D.
Koshta
International Journal of Agriculture, Environment and
Biotechnology
DOI Number: 10.5958/2230-732X.2015.00082.0
IJAEB: 8(3): 743-751 September 2015
Case Studies 7
Friday, May 4, 2018 106
107. Material and Methods
Place Jawaharlal nehru krishi vishwa
vidyalaya Jabalpur Madhya Pradesh
Duration 2012-13 and 2013-14
Climate semi tropical
Annual temperature 25.7°C
average
annual rainfall
1350 mm
Average bulk density 2.65 g/cm3
Field capacity 27%
permanent wilting point 15%.
The soil of the study area was clay loam soil in texture contain clay
28.7%, silt 23.7% and sand 47.6%.Friday, May 4, 2018 107
108. Experimental Details
Surface drip irrigation system was installed with three
lateral spacing
i.e. T1 – 60 cm,
T2 –80 cm and
T3 – 100 cm
with three dripper spacing S1 – 30 cm, S2 – 40 cm and
S3 – 50 cm in three replication under a split plot design
on the same site.
Friday, May 4, 2018 108
109. Statistical parameters of soil moisture content
soil moisture distribution pattern varied with the different lateral
and dripper spacing, although the same amount of irrigation was
applied in each plot. The mean and median of soil moisture content
in 0-60 cm depth of soil gradually decreases with increase of both
lateral spacing and dripper spacing.
Friday, May 4, 2018 109
119. Water storage efficiency
Effect of different lateral and dripper spacing on
water storage efficiency
Friday, May 4, 2018 119
This may be due to uniform coverage of
moisture in whole cropped area under
closer lateral spacing as compare to
wider lateral spacing
120. Conclusion
The soil moisture uniformity under dense dripper
geometry is better rather than wider. Installing the
system at 60 cm lateral with 30 cm dripper spacing
is the one to be recommended as it provide a uniform
moisture distribution with high water storage efficiency
of 85.73 % in the active root zone for most vegetable
and cereals crops and leads to better water saving in
clay loam soils.
Friday, May 4, 2018 120
121. Department Studies
Soil water dynamics model for trickle irrigated tomatoes
Prit Pal Singh Lubana*, N.K. Narda
Agricultural Water Management 37 (1998) 145±161
Results
1) The daily volumetric moisture content in several different soil
layers was monitored for a number of irrigation cycles. The predicted
values are compared with the field observed values in the different
soil layers at the end of each drying cycle. Predicted volumetric
moisture content values are found within 2 to 17% of measured
values.
Friday, May 4, 2018 121
122. It is also found that as the evapotranspirational demand
increases, the wetted soil volume decreases.
Considerable amount of water can be lost due to dispersion
from the root zone into the surrounding soil. It has been noted
that dispersion losses have a profound effect on the soil water
regime and water balance in the root zone.
To prevent increasing the radius of the wetting front, R(t)
down to the root zone depth, the best time to irrigate is when
water uptake by the roots is at its peak. At this time, the
evapotranspiration rate can best compete with the downward
movement of the wetting front.
Friday, May 4, 2018 122
123. 2 Department study
Simulation of soil moisture profiles for scheduling of irrigations
Anchal K. Jain, V.V.N. Murty
Agricultural Water Management
Volume 10, Issue 2, September 1985, Pages 175-181
A mathematical model for simulating soil water content in the
root zone was developed by taking into consideration soil
physical properties, crop and climatic parameters. The governing
differential equation for unsaturated flow of water in the soil was
solved numerically using the Crank-Nicholson finite difference
technique. The water uptake by plants was simulated by using
two different sink functions. The model predictions were in good
agreement with field data and thus it is possible to schedule
irrigations.
Friday, May 4, 2018 123
124. Simulation of soil moisture movement under rice field using
Hydrus-2D
MAHESH CHAND SINGH*, ANCHAL KUMAR JAIN AND
SUNIL GARG
Crop Res. 45 (1, 2 & 3) : 45-53 (2013)
Department study 3
Conclusions
The results from the experiment revealed that the soil
moisture content was more in upper layer of the soil profile as
compared to the lower layers due to effect of puddling.
The application of Hydrus-2D confirmed that the simulated
depth wise soil moisture content values were in good
agreement with observed data.
Friday, May 4, 2018 124
125. The model performance was evaluated by using parameters,
namely, root mean square error, absolute percentage error,
correlation coefficient and model efficiency.
During validation, the average absolute error varied from 2.19 to
13.21%, root mean square error varied from 0.006 to 0.032 cm,
correlation coefficient varied from 0.773 to 0.996 and the average
model efficiency was 98.6%. The use of Hydrus-2D model can be
successfully adopted for simulating soil moisture profiles under
rice crop.
Friday, May 4, 2018 125