i.

Introduction

this mini project is in a way that late as use the water resource we have to get the
maximum yield of crop production by controlling the water at optimum amount even
considering economical and optimum crop water requirement for individual crops
after precipitation and evaporation for the plant to use for the growth from the first
wetting and cultivation of the land to the last ripe of crops.
We are planning and organizing the plant growth and total irrigation water
requirement considering even soil moisture.

ii. Methodology

The mini irrigation project is done using the data we have and estimating most of the
unknown values in a way that is more convenient and in a way that is to the safe side
of planning and designing a plan for water requirement of the plant. It’s a secondary
source project were the data collected may have a variety of errors so we done
everything calculation saying it’s better to have a little bit more water compared to
having less or no amount of water in a dry soil for the plant .What we use most of the
values are the standards and sometimes a scientific guess or professional rounding’s
of numbers and estimating the monthly data’s from daily basis.

Irrigation engineering Mini Project. Page 1

 Table of Contents
i. Introduction........................................................................................................................................ 1
ii. Methodology...................................................................................................................................... 1
1. Write general background about irrigation, objective of the task and briefly write the result,
discussion and conclusion......................................................................................................................3
The General Background of Irrigation................................................................................................3
MODERNIZATION OF IRRIGATION..................................................................................................... 3
2. Establish Kc curve...............................................................................................................................5
3. Determine monthly crop Evapotranspiration (ETC) and total seasonal crop water requirement......5
i. Coefficient of Crop water requirement per Growth stage throughout the year........................... 5
ii. Daily crop water needed to stratify crop evapotranspiration:...................................................... 6
iii. ETC Monthly crop water requirements from the day...................................................................6
4. Compute monthly Net Irrigation requirement for dry, normal and wet rainfall condition................7
Net Irrigation Requirement NIR= IN.................................................................................................. 7
5. Show the graph of the net irrigation requirement VS months for the three rainfall condition.... 7
6. Determine depth and interval Irrigation.............................................................................................8
Depth of Irrigation............................................................................................................................. 8
Interval of Irrigation........................................................................................................................... 8
7. Compute the gross diversion requirement if the overall Irrigation efficiency is 70%.......................9
Gross diversion requirement:............................................................................................................ 9
Result Discussion and Conclusion.......................................................................................................10
Reference............................................................................................................................................. 11

Irrigation engineering Mini Project. Page 2

 1. Write general background about irrigation, objective of the task and briefly
write the result, discussion and conclusion.

The General Background of Irrigation

Irrigation started on ancient times as a form of preservation of draught effect on crop

production so they divert their nearby rives and flowing water in a way that it will
pass though their farming lands, even though it was a crude way of supplying water
for plants but in its time it was durable and considered an impressive feet for ancient
peoples like that of Egypt whom believed to be the first using irrigation. As time pass
by and technology began to modernize irrigation also modernized with civilization.

“Ancient civilizations in many parts of the world practiced irrigation. In fact,

civilization would probably not be possible without some form of irrigation. The
earliest form of irrigation probably involved people carrying buckets of water from
wells or rivers to pour on their crops.

As better techniques developed, societies in Egypt and China

built irrigation canals, dams, dikes, and water storage facilities. Ancient Rome built
structures called aqueducts to carry water from snow-melt in the Alps to cities and
towns in the valleys below. This water was used for drinking, washing,
and irrigation.” National Geography

As we can see in the statement given on national Geography irrigation was the key to
survival and it is still more so now because human beings need food and to grow more
food and increase crop production irrigation is the best way to do it.

The earliest form of irrigation probably involved people carrying buckets of water
from wells or rivers to pour on their crops. As better techniques developed, societies
in Egypt and China built irrigation canals, dams, dikes, and water storage facilities.

MODERNIZATION OF IRRIGATION

Modern irrigation systems use reservoirs, tanks, and wells to supply water
for crops. Reservoirs include aquifers, basins that collect snowmelt, lakes, and basins
created by dams. Canals or pipelines carry the water from reservoirs to
fields. Canals and pipelines, just like the ancient Roman aqueducts, often rely on the
force of gravity. Pumps may also move water from reservoirs to fields.

Crops are irrigated by several methods: flooding an entire field, channeling water
between rows of plants, spraying water through large sprinklers, or letting water drop
onto plants through holes in pipes.

Irrigation engineering Mini Project. Page 3

 Objective: To know the amount of land that can be cultivated in each Month
through their respective precipitation and preserver water the is left from the previous
month and how much water can be saved after cultivating the land for preceding
month in the reservoir.

Tables: Given reference Values for monthly transpiration, crop coefficient, and
frequency analysis of rainfall, crop data and command area.

JAN FEB MAR-1-1 MAR APR MAY JUNo15

5 15-31

ETO(mm/day) 4 3.2 4.1 4.4 5.1 4.9 3.8

Crop growth Initial Crop Mid-season Late-season

stage development

Kc(tab) 0.4 0.7 0.4

Kc(corrected 0.5 0.8 0.5

SOWING data JAN 10,2017 HARVESTING DATE JUN 15,

2017

Probability
of JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Exceed

80%(Dry) 42 19 13 0 0 0 0 0 0 0 16 34

50%(Norm 97 59 32 5 0 0 0 0 0 11 46 80
al)

20%(wet) 175 119 60 18 0 0 0 0 0 38 114 145

Irrigation engineering Mini Project. Page 4

 2. Establish Kc curve.

Days 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75

KC 0.5 0.5 0.5 0.5 0.5 0.53 0.57 0.6 0.63 0.67 0.7 0.73 0.77 0.8 0.8 0.8

Days 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155

KC 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.6 0.4 0.2

3. Determine monthly crop Evapotranspiration (ETC) and total seasonal

crop water requirement.

i. Coefficient of Crop water requirement per Growth stage throughout the year

 Initial growth stage Kc= 0.5

 Crop Development stage Kc= 0.6,
 Mid-Season stage Kc=0.8 ,
 Late-Season stage Kc=0.5

Irrigation engineering Mini Project. Page 5

 ii. Daily crop water needed to stratify crop evapotranspiration:

The single crop coefficient approach the crop evapotranspiration, Etc. , is

calculated by multiplying the reference crop evapotranspiration, ETo, by a crop
coefficient,

ETc = Kc * ETo

 Etc for JAN Daily = ETC Jan * ETo Jan = 4 * 0.5 = 2

 Etc for FEB Daily = KC FEB * ETo FEB = 3.2 * 0.6 = 1.92
 Etc for MAR 1 – 15 Daily =KC MAR * ETo MAR 1-15 = 4.1 * 0.6 =2.46
 Etc for MAR 15 – 30 Daily = KC MAR * ETo MAR 15-30 =4.4 * 0.8 =
3.52

=
(1−15 + 15−30) 2.46 + 3.52
2 2
Ava MAR ETC = = 2.99

 Etc for MAR Daily = 2.99

 Etc for APR Daily = KC Apr * ETo Apr = 5.1 * 0.8 = 4.08
 Etc for MAY Daily = Kc May * Eto May = 4.9 * 0.8 = 3.92
 Etc for JUN Daily = Kc Jun * Eto Jun = 3.8 * 0.5 = 1.9

iii. ETC Monthly crop water requirements from the day

Etc month = Daily Etc * Number of days

Etc for JAN = JAN ETC * 20 days =2 * 20 = 40

Etc for FEB = ETC* Number of days = 1.92 * 30 = 57.6

Etc for MAR = ETC * Number of days = 2.99 * 30 =89.7

Etc for APR = ETC* Number of days = 4.08 * 30 = 122.4

Etc for MAY = ETC* Number of days = 3.92 * 30 = 117.6

Etc for JUN = ETC* Number of days = 1.9 * 15 = 28.5

Total Seasonal Crop-water = 40+57.6+89.7+112.4+117.6+28. 5 = 455.8

Total Seasonal Crop-water = 455.8

Irrigation engineering Mini Project. Page 6

 4. Compute monthly Net Irrigation requirement for dry, normal and wet
rainfall condition.

Net Irrigation Requirement NIR= IN

NIR is the amount of irrigation water required in order to meet the

evapo-transpiration need of the crop as well as the other needs and the water lost as
percolation in satisfying other needs such as leaching.

NIR net irrigation water requirement for plants is always positive but if it is negative
that means the plant have more water that needed for its growth at that stage there fore
it is taken as zero (0) because it has the basic water required and we can even must
think of a strategy if it is too excess for the growth of plant but as for our mini project
we simply taken is as zero (0) and any addition of water is not economical there for
for NIR for each month is

Month JAN FEB MAR APR MAY JUN TOTAL

NIR (Dry) 12 38.6 76.7 122.4 117.6 28 395.3

NIR (normal 0 0 57.7 117.4 117.6 28.5 321.2

NIR Wet 0 0 29.7 104.4 117.6 28.5 280.2

Jan and Feb were - NIV meaning there is no need for additional water from irrigation
in those months because there is water content that qualifies the minimum
requirements.

5. Show the graph of the net irrigation requirement VS months for the three
rainfall condition.

Column1 NIR (DRY) NIR(NORMAL) NIR(WET)

JANUARY 12 0 0
FEBRUARY 38.6 0 0
MARch 76.7 57.7 29.7
APRIL 122.4 117.4 104.4
MAY 117.6 117.6 117.6
JUNE 28 28.5 28.5
SUM 395.3 321.2 280.2
Irrigation engineering Mini Project. Page 7
 6. Determine depth and interval Irrigation.

Irrigation takes place when the permissible percentage (p) of available water (Sa) is
depleted from the root depth, i.e. to replenish the depleted water. Therefore:

Net depth of irrigation dose (d) (mm) = (Sa × p) D

Depth of Irrigation => for maize the effective root zone is 5ft to 6ft (reference from...)

We have taken 5.85ft and it is 178.31Cm.

 Dnet = s * d *(FC – PWP)*P

We have taken from internet depletion factor to be 0.55

 Dnet = 1.2*178.31cm*(0.27-0.13)*0.55 = 14.209cm

Depth of Irrigation Dnet = 16.476cm

Interval of Irrigation = the time gap, usually expressed in days, between two
subsequent irrigations. The total amount of water required by a crop for producing an

Irrigation engineering Mini Project. Page 8

 optimum yield is termed as delta of water and it is synonymous with water
requirement of crop.

This is the number of days between two consecutive irrigations, i = d ÷ ETc, where d
is the net depth of irrigation application (dose) in millimeters and ETc is the daily
crop evapotranspiration in millimeters per day.

 I (days) = Dnet / Etcpeak

I = 16.476 cm/ Etc peak ---- Etc peak from Excel = 4.08cm/day

I = 16.476cm/0.408cm = 40.38 Days

The next irrigation should be held after 41 days.

7. Compute the gross diversion requirement if the overall Irrigation efficiency is

70%.
Gross diversion requirement: The total amount of water inclusive of water in the
field applied through irrigation is termed as gross irrigation requirement, which in
other words is net irrigation requirement plus application and other losses.
Consumptive use of water:

To calculate Gross Irrigation Requirement we divide the net irrigation requirement by

the overall irrigation efficiency.
NIR
Ea
GIR =

For Dry condition, NIR = = 395.3mm

395.3
0.7
GIR = = 564.7143 mm

For normal condition, NIR = 321.2mm

321.2
0.7
GIR = = 458.857 mm

For wet condition, NIR = 280.2mm

280.2
0.7
GIR = = 400.286 mm

Irrigation engineering Mini Project. Page 9

 Result Discussion and Conclusion

It’s a secondary source project were the data collected may have a variety of errors
and our accurate data is still not known for sure but by estimation we concluded that
the plant high suitable soil for irrigation and have an optimum soil moisture content
but as a side effect there is a highly variation in precipitation from seasons to seasons
and there is almost a 42 days gap between two irrigation planting periods there for it
is advisable to use a temperature change variation resistance type crops and crops that
can store a high amount of water and a root with a medium range root size, from 10 +
15 maximum root length to use the soil moisture efficiently and survive from season
to next season relatively easily.

we done everything calculation saying it’s better to have a little bit more water
compared to having less or no amount of water in a dry soil for the plant .What we
use most of the values are the standards and sometimes a scientific guess or
professional rounding’s of numbers and estimating the monthly data’s from daily
basis. So there is a high chance there going to occur excessive amount of water
therefore a good drainage line must be made.

Irrigation engineering Mini Project. Page 10

 Reference

http://ecoursesonline.iasri.res.in/mod/page/view.php?id=8933#:~:text=The%20term%
2C%20interval%20of%20irrigation,with%20water%20requirement%20of%20crop.

http://uap-bd.edu/ce/Handouts/CE-461/PP/Chap03.pdf

http://www.fao.org/3/a1336e/a1336e06.pdf

https://www.researchgate.net/

Handout and Lecture Power point

Irrigation Engineering, And Hydraulic Structures By Santosh Kumar Garg

Irrigation engineering Mini Project. Page 11