1. IRRIGATE FOR THE FUTURE
Use soil moisture to determine when fields and orchards need
irrigation to avoid overwatering. Different crop types, soil types and
weather conditions all affect the amount and frequency of
irrigation needed for farms and orchards.
OVERWATERING HURTS YOUR PLANTS AND TREES
AND DEPLETES WATER RESERVES!
Why EFFICIENT IRRIGATION BASED ON SOIL
MOISTURE matters:
• Big water savings for everyone—agriculture comprises roughly
70% of total water consumption.
• Irrigation scheduling based on soil moisture can generate
annual water savings of at least 10% or 103 tons per
donum (tons per 1,337.8 m²) based on local studies by SAVE.
1400
• Better water quality with less seawater intrusion. Less pumping
Recommended
protects groundwater reserves.
1200
• Improved crop production, such as sweeter oranges.
Irrigation Requirement
Typical
1000
• Reduced production costs and improved production yields due
800
to less pumping and optimal watering.
(m 3/ha/month)
600
400
VARY IRRIGATION SCHEDULE WITH SEASONS!
200
In certain orchards, the same amount of water is used to irrigate
0
n throughout the year regardless of the actual need of the crops.
Ja Feb ar pr
M A May ne
Ju
ly
Ju Au
g
pt t
This contributes to overwatering in the winter as shown in this
Se Oc Nov
De
c
graph which can harm your crop.
Effects of Overwatering on Crop Production:
• Fruit that is less sweet with less pulp,
• More soil-borne diseases,
• Increased potential for root rot,
• Leaching out of nutrients from the soil,
• Increased costs for pumping and fertilizer use, and
• Ultimately, decreased fruit production.
IRRIGATE BASED ON SOIL MOISTURE,
CROP TYPE & SOIL TYPE!
SOIL TYPES AND WATER-HOLDING CAPACITY
Soil type and texture determine how much water is held in the soil,
how much water is available for plants to use and ultimately how
well they grow. Soil texture indicates the proportions of fine and
coarse material making up the soil. The finer the soil, the higher its
water-holding capacity. Soil types in Cyprus can be divided into three
broad categories with different water-holding capacities:
Light soil: High sand content (coarse material)
Medium soil: High silt content (medium-coarse material)
Heavy soil: High clay content (fine material)
Local Resources
The local agricultural offices, as well as the Turkish Cypriot Chamber
of Agricultural Engineers (TCAE), can be a good source of information
on specific irrigation guidelines for different soil and crop types. Strong
consideration should also be given to growing alternative crops with
Photos from top to bottom: A modern hydroponic irrigation low irrigation requirements, such as pomegranates, capers, and prickly
system; Typical versus recommended irrigation rates; Soil pears. Contact TCAE for more information on alternative crops and
ball method; Soil moisture system with moisture probes and
low-flow irrigation systems.
precipitation gauge.
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2. Key Concepts By adopting irrigation rates based on the specific
When you irrigate your soil, excess water drains away, leaving the water needs of your plants, the soil type they are
soil at its field capacity. Now, the soil has available water that planted in, weather conditions, and by monitoring
can be used by the plants. As the available water is used up by plants soil moisture to fine-tune these irrigation rates, you
and lost to evaporation, the soil moisture reaches a wilting point can irrigate efficiently and help save water.
below which a plant dies.
THE GÜZELYURT/MORPHOU SOIL
MOISTURE PILOT STUDY
Soil is full of water To assess potential water savings through efficient irri-
gation practices, SAVE has been
conducting a pilot soil moisture
WATER DRAINS
FIELD CAPACITY
study in collaboration with local
WATER IS HELD IN SOIL
Water in soil is
available to plants farmer, Mr. Fuat Bağkur, at his
WILTING POINT
citrus and pomegranate orchards
PLANTS DIE
in Bostancı/Zodia.
Soil is almost dry
Mr. Bağkur has his own well and a drip irrigation sys-
tem, giving him full control over the watering schedule
which was already calibrated based on crop type
and soil type, but not checked against actual soil
IMPORTANT! Even though heavy soil has the highest water-
moisture. As part of the pilot study, moisture probes
holding capacity, medium soil has the highest amount of available
were installed next to selected pomegranate and citrus
water for plants. As the soil texture becomes finer as in heavy
trees in three types of soil—light, medium and heavy.
soils, it is harder for plants to suck the water from the soil,
At each location, a combined salinity, temperature, and
hence resulting in less available water.
moisture probe was placed approximately 15cm below
MEASURING SOIL MOISTURE ground surface (bgs), and moisture probes were placed
Knowing the moisture of your soil helps you determine its irriga- at 30 and 50cm bgs. Data were collected from the
tion needs. Soil moisture can be measured using a variety of probes at regular intervals.
methods including soil feel and appearance, soil sampling, ten-
siometers and soil moisture probes. Tensiometers are relatively
inexpensive and available at certain plumbing or hardware stores
in Cyprus. Soil moisture probes, also used in SAVE’s local stud-
ies, provide direct readings which can be saved on a computer.
Such instruments can also measure rainfall and salinity in soil.
SIMPLE SOIL MOISTURE TEST
In most soils, soil moisture can quickly be checked using the “Soil
Ball Method.” To do this, dig a small hole and remove a handful of
soil from 15 to 30 centimeters deep. Using your hand, squeeze the
soil into a ball. Then, open your hand and bounce the ball in the
palm of you hand. If it remains in a ball, the soil has enough moisture
and does not need watering. If it falls apart, the soil needs watering.
It should be noted that this method does not work in light sandy An analysis of the soil moisture data is presented in the
soils.
graph above for the citrus orchard with medium soil.
HOW MUCH TO IRRIGATE SAVE used FAO’s CROPWAT software to estimate
Different crops require different amounts of water. Some of the recommended soil moisture levels, or irrigation re-
water is used for plant growth which is known as transpiration quirements, for this soil and tree type (blue, green,
and some is lost by evaporation from the ground. The two terms yellow and red zones). Each peak on the graph indi-
combined is known as “evapotranspiration,” or the water need cates the increase in soil moisture during an irrigation
of a plant. How much to irrigate then depends on the evapotran- cycle. Relative to the estimated irrigation require-
spiration rate for a Irrigation Rate ments, the data indicated that the trees were being
particular plant AND Texture over-watered at least half the time. Better results were
(cm/hour)
the soil type. The ta- Light (sand) 2.5 – 7.5 seen with the pomegranates. SAVE estimated that 10%
ble shows recom- Medium (loam) or 103 tons of water per donum could be saved
0.75 – 2.0
mended irrigation annually if the citrus was being irrigated more effi-
Heavy (clay) 0.02 – 0.5 ciently. Even greater savings could result on farms and
rates just based on the
three soil types. These irrigation rates further vary by season and orchards not already scheduling irrigation based on soil
by plant type and maturity. For example, orange trees require moisture, crop and soil type.
more water than pomegranate trees. Young trees generally re-
August 2008
quire more water than mature trees.
Source: http://extension.usu.edu
ENVIRONMENT ◊ CULTURAL HERITAGE ◊ GEOGRAPHIC INFORMATION SYSTEMS ◊ SMALL GRANTS
E-MAIL: SAVE-info@irgltd.com www.save-irg.com TEL: (+90) 392 228 1925 / (+357) 22 770 757 FAX: (+90) 392 228 17 56
