This document outlines Precision Agriculture research and extension programs at the University of Arizona's Maricopa Agricultural Center. It discusses using variable rate technology to map soil electrical conductivity and texture in cotton fields. It also explores using cone index measurements to detect subsoil compaction and instrumenting tractors to study draft and fuel consumption. Canopy multi-spectral reflectance is analyzed to monitor biomass dynamics over time. Auto-guidance systems are evaluated for their ability to improve plant spacing and infrastructure utilization. Yield monitoring techniques are explored for small research plots. Future work proposed includes variable rate irrigation controlled using an information loop system.

1. Precision Agriculture in Arizona : A New Research and Extension Program Pedro Andrade-S á nchez Agricultural and Biosystems Engineering Department Maricopa Agricultural Center, University of Arizona

2. Modern technology for Precision Agriculture

3. Presentation Outline

4. Variable rate technology in Cotton Soil Electrical Survey. 20 ha field in Safford, AZ Veris sensor. Apparent Electrical Conductivity (EC a )

5. VRT in Cotton. Prescription Mapping Soil texture prediction. 20 ha field in Safford, AZ Note: Preliminary tests at MAC show potential for salinity assessment

6. Detection of subsoil compaction

7. CIE i = 0.216 CI i + 2.601 d i - 0.176 CI i d i (R 2 = 0.973) CIE i *= 0.216*(2.0 MPa) + 2.601 d i - 0.176*(2.0 MPa) d i Mapped quantity: CIE i / CIE i * Algorithm for compaction assessment CIE i = Cone Index Equivalent (of the ith layer)

8. Draft and Fuel Consumption Current work: Tractor Instrumentation From N.E. Boon et al., 2005

9. Canopy multi-spectral reflectance

10. Effect of defoliation after 4 hours

11. Date 1 (June 20) Date 2 (July 7) Date 3 (July 21) Biomass dynamics (NIR band – 880 nm)

12. Auto-guidance: Extending infrastructure utilization

13. Auto-guidance: Linear distribution of plants

14. Auto-guidance: Linear distribution of plants Easting Error = E i – E a-b Planting w/ Autoguidance Conventional Planting

15. Yield monitoring

16. Yield monitoring: Small plot research Note: In 2009, yield monitoring using GPS-RTK improved spatial resolution

17. Future Work: Variable Rate Irrigation

18. Information Loop for Variable Rate Irrigation Chavez et al. 2007

19. Control System for Variable Rate Irrigation Chavez et al. 2007