1. Irrigation Modeling for Crops Flood Irrigation & Forage Crops
Mohunnad Massimi
Fellow Scholar at Florida A & M University
Agronomist and Extension Officer at NCARE
Master of Field Crop from JUST

2. Lecture Aug, 7 2017 Agricultural Eng Ass Zarqa
Number of Targets: 10 Engineers

3. Irrigation Modeling is a Term

4. Irrigation Modeling Modeling is Scheduling. Scheduling is two terms !!
Irrigation Time.
Irrigation Amount.

5. Irrigation Simply !
Timing
Amount

6. Why Modeling is important ?
Crop Water Requirements.
Drought Sensitive Stages of Crops.
Drought and Salinity.
Treated Waste Water.

7. Sensitive Stages Forage and green plants = after cut. Alfalfa.
Egyptian Clover.
Silage Corn.
Forage Sorghum.
Sudan grass.
Rye grass.

8. Sensitive Stages
Cereal grains and field crops = at time of flowering and tillering.
Barley.
Wheat.
Triticale.
Oat.
Grain Sorghum and Corn.

9. Agronomy Science of Crops Production and Soil Management.
Themes: Seeds, Irrigation, Fertilization, Rotations, Machinery, and Protection.

10. Seeds
Irrigation
Fertilization
Rotation
Machinery
Protection
Agronomy

11. Drought and Salinity = Fx (CC) !!

12. Irrigation Terms Mathematical Modeling. Soil Texture.
Field Capacity %.
Permanent Wilting Point %.
Managed Allowable Depletion.
Root Depth (cm)
Drip Irrigation.
Surface / Flood Irrigation.
Sprinkler Irrigation.
Irrigation Efficiency.

13. Mathematical Modeling
Clay
Silt and Loam
Sand
Texture
Field Capacity (v%)
Permanent Wilting Point (v%)
Sand 10 5
Loamy Sand 12
Sandy Loam 18 8
Sandy Clay Loam 27 17
Loam 28 14
Sandy Clay 36 25
Silt Loam 31 11
Silt 30 6
Clay Loam 22
Silty Clay Loam 38
Silty Clay 41
Clay 42

14. Managed Allowable Depletion % = Percent of water available that taken by the plant.
Usually MAD % around 30 – 50 %.
It is an indicator to irrigate again.

15. Equations
Net Irrigation Requirements = Managed Allowable Depletion % (Field Capacity % - Permanent Wilting Point %) * Root Depth
NIR = MAD % (FC %-PWP%)*D.
Gross Irrigation Requirement = Net Irrigation Requirement / Irrigation Efficiency %
GIR = NIR / E%.

16. Example
Silage Corn hybrid (DK70-01) grown in Florida . Calculate both net and gross irrigation requirements if you know that Managed allowable depletion was 30 %, soil is clay, and root depth is 91 cm. Flood Irrigation Efficiency is 60 %.

17. Amount mm per meter Square is irrigation depth.
In Jordan it measured in m3 / du.
At time of rain, there is another calculations.
On May a rain amount of 2.62 mm dropped. How much your NIR will be now?

18. Timing is Interval Interval is number of days.
Water Depth Stored in Soil = Gross Irrigation Requirement * Irrigation Efficiency %.
WDS = GIR * E %
Interval (days) = Water Depth Stored in Soil / Daily Requirements.
Int = WDS / DR.

19. Timing
Calculate daily irrigation intervals for forage sorghum hybrid (ss2010) if you know that gross irrigation requirement is 7 mm/pot using flood irrigation, and daily requirement is 8 mm.

20. Suggestions ! Lecture on :
Irrigation Modeling Using Drip Irrigation in Vegetables (1 day) ?
Training Course:
Irrigation Modeling for Crops Production (3 days) ?