irrigation water conveyance and requirements. what happens after diversion? ? ? ? ? ? ? ?
TRANSCRIPT
IRRIGATION WATER
CONVEYANCE AND REQUIREMENTS
WHAT HAPPENS AFTER DIVERSION?
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THE REAL WORLD VIEW
DITCH AND CANAL LINERS
PIPE FLOW
OR PUMPS
BY GRAVITY
CROP SEED PRODUCTION
Apply water to meet the crop needs
HAY PRODUCTION
EFFECTIVE ROOT ZONE
ROOT DEVELOPMENT AND SOIL LIMITATIONS
MODIFIED ROOT DEVELOPMENT
50%
33%
17%
0
EFFECTIVE ROOT ZONE
HIGH WATER TABLE
LIMITS ROOT DEVELOPMENT
ONE SIZE DOES NOT FIT ALL!!!
WE OFTEN USE THE METHOD THAT SEEMS MOST FAMILIAR EVEN WHEN THERE ARE BETTER WAYS TO DO IT.
APPLICATION METHODS
MANAGEMENT IS THE
ESSENTIAL REQUIREMENT
WATER MEASUREMENT
TOO MUCH WATER MAY CAUSE
Infiltrating furrow streamTransport
Detachment
Deposition
Source
Inflow
Runoff and sediment loss
Tail Ditch
NWISRLNWISRLKimberly, IDKimberly, ID
Poor Design, Soil & Landscape Variability,Poor Design, Soil & Landscape Variability,Application Rate, etc. Can Create ProblemsApplication Rate, etc. Can Create Problems
NWISRLNWISRLKimberly, IDKimberly, ID
TOO MUCH WATER IN ANY SYSTEM
MAY LEAD TO OTHER PROBLEMS
OVER IRRIGATION AND EROSION
Adequate soil moisture monitoring
SEASONAL USE AT SOIL DEPTHS2003
-100
-80
-60
-40
-20
0
cent
ibar
s
Sensor 1 - 6 inches Sensor 2 - 18 inches
April May
Field Capacity
June July August September OctoberMarch
GRASS HAY - POTOMAC – MISSOULA COUNTY
Sprinkler Efficiency Overview
• NRCS NATIONAL IRRIGATION GUIDE
(Table 6-4)
– Periodic move lateral 60-75%– Traveling sprinkler (big guns) 55-65%– Center pivot - standard 75-85%– Linear (lateral) move 80-87%– LEPA Center pivot or linear 90-95
GROSS Vs NET REQUIREMENTSThe Gross application is that amount applied
over the whole area to get the Net amount in to the soil where it can be used by the plant.
• To obtain a 1inch NET application with a 50% efficient system one must apply 2 inches.
• A 75% efficient system would need to apply a 11/3 inch Gross to get the same 1 inch NET.
EFFECT OF LIGHT APPLICATIONS 2003
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
cent
ibars
Sensor 4 - 6 inches Sensor 5 - 18 inches Sensor 6 - 30 inches
April May June July August September October
Field Capacity
DATA BREAK
SHALLOW APPLICATIONS
LOWER SOILS NOT IRRIGATED
14.8 in.
12.7 in.
SOMETIMES WE MAKE THINGS HARDER THEN NECESSARY
SUMMARY• Conveyance losses (control limits, evaporation,
leakage, etc.) reduce the amount of H2O taken from a source that is available for application to the field.
• Application losses come in many forms: – Weather – Wind, heat, humidity, evaporation, etc.– Soils – Intake limits, water holding capacity effects– System – Uniformity, leaks, maintenance effects– Management – Flow controls, Time limitations, & lack of
Measurements of Flow rate and Soil Moisture
• The remaining water getting to the root zone is what is available to the plant for growth.
QUESTIONS??
