1. RISER
Row-crop Irrigation Science Extension and Research
Agronomic Practices And Irrigation Management Strategies That Optimize Soybean Water Use Efficiency Wilks Wood

2. Delta Issues Aquifer decline Permitted values Metering program
Increased regulation

3. Prior Research

4. Yield by Planting Date and Maturity Group
Early Planting Date
Mid Planting Date
Late Planting Date

5. Early Planting Date
Mid Planting Date
Late Planting Date

6. Early Planting Date
Mid Planting Date
Late Planting Date

7. Early Planting Date
Mid Planting Date
Late Planting Date

8. Irrigation Water Use Efficiency
P<.01
Early Planting Date
Mid Planting Date
Late Planting Date

9. Early Planting Date
Mid Planting Date
Late Planting Date

10. Early Planting Date
Mid Planting Date
Late Planting Date

11. Early Planting Date
Mid Planting Date
Late Planting Date

12. Row Spacing by Plant Population

13. 1. Computerized hole selection
RISER Cost Per Year
3. Soil sensors
2. Surge irrigation
1. Computerized hole selection

14. Irrigation Application Efficiency
Pipe Planner
Type/Size of Polytubing
Size/Quantity of holes
Application efficiency
$10/Acre savings

15. Irrigation Application Efficiency
Surge Results
Reduces surface runoff losses
Decreases deep percolation losses
Improves infiltration sealing soils
Application efficiency 25% higher than conventional

16. Irrigation Application Efficiency
Cracking Clays
Anecdotal evidence indicates efficiency approaches 30%
Efficiency is a function of furrow length in cracking clays
Preliminary data indicated up to 35% reduction in water use

17. Plant Available Water
50% MAD
-1500 cbar
-33 cbar
0 cbar

18. Soil Moisture Sensor Reading

19. Moisture Sensors Yield

20. Moisture Sensors Yield (IWUE)

21. On-Farm Evaluations Producer Riser P-value 69.3 11.5 7.2 543 68.6 9.1
Yield
Water Use
WUI
Return
---Bu/acre---
---Acre-in---
--Bu/acre-in--
-----$-----
Producer
69.3
11.5
7.2
543
Riser
68.6
9.1
9.8
556
P-value
0.6703
0.0198
0.0194
0.5376
N = 20 farms Mississippi and Arkansas
7% of the population exceeded permitted value, 18 acre-in/yr
79% population applied more irrigation water than RISER
21% population applied less water than RISER

22. Conclusion
Plant Early.

23. Conclusion Plant Early.
Highest yield potential and irrigation water use efficiency.

24. Conclusion Plant Early.
Highest yield potential and irrigation water use efficiency.
Maturity Group IV great choice.

25. Conclusion Plant Early. Yield increase with < 30” rows.
Highest yield potential and irrigation water use efficiency.
Maturity Group IV great choice.
Yield increase with < 30” rows.

26. Conclusion Plant Early. Yield increase with < 30” rows.
Highest yield potential and irrigation water use efficiency.
Maturity Group IV great choice.
Yield increase with < 30” rows.
Utilize tools available.

27. Conclusion Plant Early. Yield increase with < 30” rows.
Highest yield potential and irrigation water use efficiency.
Maturity Group IV great choice.
Yield increase with < 30” rows.
Utilize tools available.
Computerized hole selection, SURGE valve and moisture sensors.

28. Acknowledgements
Mississippi Soybean Promotion Board Summer Workers Fellow Graduate Students Committee Members

29. Questions
Wilks Wood