Blueberry Irrigation andSoil Moisture Management
Rong Zhou
President of Mini Rain Company
Deputy Director of China Irrigation Association
Importance of irrigation for blueberry
-Keeping proper soil moisture is very important for blueberry
growth, yields and quality. The soil water is from natural
rain, irrigation and capillary rising from deeper soil.
Irrigation is necessary when the soil water from rain and deeper
soil is not enough .
-The fruits could be smaller ,yield would be reduced and quality
could get lower when the blue berry lacks water frequently.
-Water stressing at critical time of blueberry growth will cause
yield reduction dramatically.
The following factors causes
difficulty for water taking by blueberry
-Root：shallow root system(20-30cm) limits plant to
absorb water from deeper soil.
-Mounding: Growing blueberries on mounds makes
them susceptible to water stress as the mounds are free
draining.
-Poor water penetration: Plastic covered mounds allow
little natural rainfall penetration.
-Use of mulches: woodchip mulches are difficult
to re-wet if allowed to dry out.
-Dripper clogging ：bad filtration makes dripper clogged.
Hazards of over watering
-Over application of water can make mounds
saturated, reduce soil aeration, increase incidence of
root diseases and root death from drowning, and will
also reduce fruit quality. Plant death may also occur.
-Over watering also leaches fertilizer out of the root zone.
This not only wastes fertiliser but also poses a serious
environmental hazard, polluting groundwater with
excessive amounts of nutrients, which contributes to
soil acidification
-Over watering increases cost of water and electricity for
pump operation.
What makes over watering?
-Poor irrigation schedule makes too
much water applied and makes mounds
saturated.
-No soil moisture monitoring or wrong monitoring
makes wrong amount of water application .
-Wrong irrigation system design makes wrong
flow rate from pump and dripper. The operator of
the system losses control of irrigation volume.
Irrigation methods for blueberry
-The traditional surface irrigation should be stopped
since its low efficiency of water and fertilizer application
(lower than 50%)
-Sprinkler irrigation：It is generally not recommended for
blueberry due to the increased humidity created in the
crop resulting in a higher incidence of leaf diseases. The
efficiency
of water and fertilizer application are also lower than drip
method significantly.
-Drip irrigation: It has been worldwide recommended
method for blueberry due to its high water and fertilizer
application efficiency.
Blueberry drip irrigation
Drip line laid
along with
blueberry row
The high
standard and
high quality
Filter and
fertilizer
Injection
system needed
A good drip system means:
-Uniform water application
-Meet demand of blueberry growth and yield
-Flexibility for controlling
-System runs safely
-Advanced features, robust , clogging resistance
-Economic
-Good for fertigation
One drip line or two drip line per row are all
acceptable depending on crop water requirement
and soil.
Single line could be
hanged on the tree
Double lines
laid on the top
Sandy soil needs frequent irrigation
Double lines is good option
Clogging is the weak point of drip irrigation, good
Filtration is always needed. Filtration design:
Surface water: Primary filter +sand media filter+screen filter or disc filter
Under ground water: Hydrocyclone
+screen or disc filter
System automation is good for
Blueberry growth, yield and quality
Since higher efficiency of water
and fertilizer application. Labor
saving is also a good consideration.
Fertilizer should be applied
through drip system
Fertilizer tank and Venturi pipe are
common used, but not the best choice.
The liquid fertilizer for Blueberry
growth should be used for
higher application efficiency.
Venturi pipe
Fertilizer tank
Liquid fertilizer
The dose metering pump should be used for fertilizer
Injection for bigger blueberry farm
Soil moisture monitoring for
Irrigation Schedule making
-Know soil structure and key points of soil water content:
Soil water capacity, wilting point, allowable lowest soil
Water content.
-Monitoring soil moisture continuously along in whole
grow season.
-Making irrigation schedule
according to soil
moisture Variation.
The instruments for
soil moisture monitoring
Tensiometer
Gypsum block meter
TDR meter
Water resource for drip irrigation
Water from reservoir , river, lake ,pond, borehole,
drinking water all can be used for drip irrigation.
But water from yellow river and reservoir far away must
be treated carefully since their rich sand and silt content.
If the water must be from pond, EPDM geomembrane
is recommended since its:
-outstanding resistance to UV exposure
-Easy installation
-10 years Warranty
Thanks！