1. Drip Irrigation Research in Arkansas Earl Vories University of Arkansas Northeast Research & Extension Center Keiser, Arkansas

2. Center Pivot and Furrow Irrigation Common in the Mid-South

3. Osceola Blytheville Manila Leachville Satellite Image of NE Ark. Aug., 99

4. Drip Irrigation Getting Interest Earlier use in arid areas (AZ, west TX, Israel). Efficient use of limited water. Allows injection of fertilizers/other products in root zone. More recently being investigated in humid areas (southeast, mid-south).

5. Current research efforts in Arkansas using precise water control possible with drip irrigation to investigate irrigation scheduling, rather than investigating the optimal drip irrigated production system.

8. Change in Water Use With Crop Age

9. Computerized Irrigation Scheduler Distributed by University of Arkansas Cooperative Extension Service (www.uaex.edu)

10. Computerized Irrigation Scheduler

12. Reference Evapotranspiration (Etr)

13. Crop Coefficient Function - Cotton

14. Crop Coefficient Function - Corn

15. As you would expect, many differences between the drip irrigation systems on a production-field scale and a small-plot research scale.

16. System Controls Small Plot Field Scale

17. Injector Pumps for Water Conditioners (generally required for groundwater) Fertilizers, Soil Conditioners, etc.

18. Filter Bank for Groundwater Field Scale

19. RPZ Valve and Screen for Municipal Water Small Plot

20. Solenoids for Controlling Water Field Scale Small Plot

21. Lateral Lines Feeding Individual Drip Lines Field Scale Small Plot

22. Much of 2001 growing season spent installing and testing irrigation/control/monitoring systems, probably reducing potential responses.

23. Estimated Soil Water Deficits - Corn No Irr. 75% ET 125% ET Irrigation System Began Operation

24. Corn Yields (bu/acre) Yields not significantly affected by water treatments.

25. Later season allowed more observations in cotton study, more treatment differences observed.

26. Estimated Soil Water Deficits - Cotton Irrigation System Began Operation

27. Watermark sensor

28. Output from Watermark Sensors - Cotton

29. Crop Response to Water 100% ET No Irrigation

30. Physiological Cutout (NAWF=5, DAP)

31. Mean Maturity (DAP)

32. Seedcotton Yields (lb/acre) Yields not significantly affected by water treatments.

33. Conclusions from 2001 System/equipment functioning well. Installation of drip tubing (subsoiling every row) in spring, as well as delays in planting and irrigating due to installation probably affected responses in initial season. Drip irrigation system appears to provide desired water control for studying irrigation scheduling.

34. Acknowledgment Research supported by Arkansas corn and cotton producers through checkoff programs.