1. Irrigation Modeling for Crops Drip Irrigation & Row Plantings
Mohunnad Massimi
Irrigation Modeling Scholar at Florida (A&M) Univ
Agronomist and Extension Officer at NCARE
Master of Field Crops from JUST

2. Lecture Sep, 9 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. Silage Corn.
Forage Sorghum.
Sudan grass.

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

9. Vegetables Summer Crops: Tomato (2) Eggplant (2) Pepper (2) Squash (2)
Bean (2)
Okra (2)
Melon & Water Melon (2)
Winter Crops:
Cauliflower (1)
Cabbage (2)
Potato (1)
Onion & Garlic (1 or 2)
Faba bean & Peas (2)
Carrot (1)
Lettuce (1)
Radish (1)
Turnip (1)
Spinach (1)

10. Leaf Vegetables & Potato Sensitive (1) = Head Formation or at Enlargement

11. Legumes, Cabbage, Pepper, Tomato, Melons = Flowering, Fruit Filling Sensitive (2)

12. Agronomy Science of Crops Production and Soil Management.
Themes: Seeds, Irrigation, Fertilization, Rotations, Machinery, and Protection.
Olericulture: Growing horticultural vegetable crops.

13. Seeds
Irrigation
Fertilization
Rotation
Machinery
Protection
Agronomy

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

15. 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.

16. 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

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

18. General Modeling 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%.

19. Special Modeling Equation
Case of Drip Irrigation:
[1] Application Rate (mm/hr) =
Emitter Flow Rate / Emitter Spacing * Row Spacing.
[2] Running Time (hr) =
Gross Water Depth / Application Rate

20. Example (1)
Silage Corn hybrid (P1197YHR) 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. drip Irrigation Efficiency is 90 %.

21. Example (2)
Sorghum Sudan grass hybrid (Graze II) grown in Florida. Calculate both application rate (mm/hr) and running time (hr) if you know that emitter flow rate is 17 ml/minute, emitter space is 0.30 m, row spacing is 1.83 m, drip Irrigation Efficiency is 90 %, and Gross water depth is 36.4 mm/m2

22. Amount mm per meter Square is irrigation depth.
In Jordan it measured in m3 / du.
At time of rain, there is another calculations.
Example (3) On May a rain amount of mm dropped. Reschedule your irrigation using inputs of previous examples?

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

24. Timing
Calculate daily irrigation intervals for forage sorghum hybrid (ss2010) if you know that gross irrigation requirement is 36.4 mm/m2 using drip irrigation, and maximum daily requirement is 8 mm.

25. Timing and Amount They are just averages of water irrigation modeling.
Modified according:
Climate.
Growth Stage.