1. Dona Aña ET Studies By A. Salim Bawazir, Ph.D. and J. Phillip King, Ph.D., P.E Civil and Geological Engineering Department NMSU, Las Cruces, NM This project is funded by the Lower Rio Grande Water Users Organization and administered by the New Mexico Water Resources Research Institute

2. Study Goal and Objective Quantify, using diverse data, the consumptive use of water by crops in the Rincon and Mesilla Valleys Measure Evapotranspiration (ET) of the Pecan Goal

3. Objective Study Goal and Objective Identify major crops in the valleys that have been thoroughly researched such as Cotton and Alfalfa etc. Use historical crop yields and weather data to estimate ET based on Penman method (Jensen et al., 1990)- Penman method Vs. SCS Modified Blaney - Criddle Method Measure actual ET of Pecan

4. Crop Acreage and Yield Data compiled from 1986 to 1995 and summarized by Elephant Butte Irrigation District (EBID) El Paso County Water Improvement District #1 (EPWCID#1) Middle Rio Grande Conservancy District (MRGCD) Other Data Compiled and summarized from 1987 to 1997 Mesilla Valley (New Mexico) Mesilla Valley (Texas) Rincon Valleys

5. Crop Acreage Variability from 1978 through 1999 In the Mesilla and Rincon Valleys

6. 2003 EBID Crop Mix

8. ET Estimates Leyendecker Plant Science Research Center, about 24 km (15 miles) south of Las Cruces (lat 32 o 12'4.44" N, long 106 o 44'32.88" W; elevation 1168 m). Horticulture Weather Station is located about 3.2 km (2 miles) east of Mesilla (lat 32 o 16′43.02′ N, long 106 o 46′15.6″ W; elevation 1183 m).

9. Relative Humidity Ambient Temp

10. Solar Rad.

11. Alfalfa: Kc = 4.05E-01 + 1.11E-03(GDD) - 4.25E-07(GDD) 2 + 3.56E-11(GDD) 3 Pecan: Kc = 2.93E-01 + 1.11E-03(GDD) + 1.85E-07(GDD) 2 -3.23E-10(GDD) 3 Cotton: Kc = 4.24 E-04 +1.20E-03(GDD) - 4.62E-07(GDD) 2 +5.77E-10(GDD) 3 Crop Coefficient Based on Heat Units Example: Penman Equation: Blaney-Criddle Equation: Penman-Sammis:

12. Pecan ET Based on Penman Equation and Cummulative Growing Degree Days In the Mesilla and Rincon Valleys

14. 4.83*4.75*(4.86) Summary of Crop ET in the Mesilla and Rincon Valleys

15. PECAN (ET) ?

16. ALTERNATIVE ET METHODS Eddy covariance methods – 3DECS and OPEC Systems LIght Detection And Ranging - lidar (Raman Water-Vapor Lidar) Heat Pulse Technique (Transpiration) Gas Exchange – Stomata Conductance Others

17. Monitor Groundwater Soil Moisture Meteorological Remote Sensing ALTERNATIVE ET METHODS

18. Eddy Covariance

19. Net Radiation Soil Heat Storage Sensible Heat Latent Heat Land Surface The Energy Budget:

21. Meteorological Penman-Montieth FAO-56 Equation Modified Penman Equation

22. Crop Coefficient

23. NORTH

24. SOUTH

25. WEST

26. EAST

27. PECAN TREE CANOPY APROXIEMETLY 16M (52FT)

28. ONE PROPELLER EDDY COVARIANCE SYSTEM (OPEC)

29. WIND SPEED AND DIRECTION

30. Q.7 NET RADIOMETER

31. CSAT KH20 3D SONIC ANEMOMETER & KRYPTON HYGROMETER A highly sensitive three-dimensional sonic anemometer (3D-CSAT3) and a krypton hygrometer (KH2O) were also installed at a height of 18.44 m (60.5 ft) as check for OPEC system from June 11 DOY 162) through July 31, 2001 (DOY 212).

32. THERMO- COUPLE PROPELLER OPEC SYSTEM

33. GROUNDWATER MONITORING USING WATERLOGGER

34. Sample Results - OPEC System

36. GRAPH 1A

37. GRAPH 1-A

38. PECAN GROUNDWATER DEPTH (June and July) Irrigation

40. Measured ET of Pecan

42. More Work and Future Goals Improvement in weather data collection – Net radiation Continue to collect Pecan ET measurements Young Pecan ? Leaf Area Index for Pecan Measure Soil Moisture Remote Sensing Estimate amount of water applied – for management Real Time Data Collection