OLIVE PRODUCTIVITY IN RELATION WITH WATER AND CARBON FLUXES

1. OLIVE PRODUCTIVITY IN RELATION WITH WATER AND CARBON FLUXES F. J. Villalobos, F. Orgaz, L. Testi, M.Pastor, E.Fereres UNIV. CORDOBA-IAS/CSIC

2. WHAT IS THE RELATION BETWEEN OIL YIELD AND APPLIED WATER?

3. WHAT SHOULD WE DO WHEN IRRIGATION SUPPLY IS LIMITED ?

4. OLIVE IN EUROPE • > 5 Mha in UE • > 2 Mha in Spain • > 1 MTm oil in Spain • Main crop in many areas around the Mediterranean

5. DENSITY: 100 --> 300-400 ol/ha RAINFED --> DRIP IRRIGATION INTENSIVE TILLAGE --> MIN TILLAGE MANUAL HARVEST --> MACHINES TRENDS IN OLIVE ORCHARDS

6. WATER IN OLIVE ORCHARDS • Main limiting factor • Lack of information on water use and productivity • Use of limited and/or low quality resources • Competence with other areas and crops (200000 ha Jaén)

7. LACK OF INFORMATION • Low investment in research by producing countries • Low efficiency of experimental research (spatial-temporal variability) • Methodological problems • pluri-annual • alternant bearing alternancia

8. OBJECTIVES • RELATE YIELD TO WATER AND CARBON FLUXES AS A FUNCTION OF MANAGEMENT AND ENVIRONMENT • QUANTIFY THE EFFECT OF DEFICIT IRRIGATION ON YIELD

9. METHODS • EXPERIMENTS + MODELS • EXP. 1: FLUXES IN IRRIGATED ORCHARDS • EXP. 2: EFECTS OF WATER DEFICIT/FRUIT LOAD

10. EXPERIMENT 1 OLIVE ORCHARD CV. ARBEQUINO • 4 ha, Córdoba, 38ºN, 110 m altitude • Planted summer 1997 • Spacing 7 x 3.5 m (408 olives/ha) • Drip irrigated (2 drippers/tree) • no tillage

11. MEASUREMENTS • Destructive samples (1-2 per year) • 4 trees/sample • Eddy covariance (CO2, H2O) : 99,01,02 • Growth (LAI, tree size), yield

12. FLUX MEASUREMENTS H2O , CO2 • eddy covariance method • 1-4-week periods • 2-3 periods/season • seasons 1999, 2001, 2002 • CO2 flux from soil surface: chamber + IR analyzer (1999,2001)

13. Velocidad vertical del aire Humedad del aire

14. Velocidad vertical del aire Humedad del aire

15. INSTRUMENTS • 3-d sonic anemometer CSAT3 Campbell Sci. • open-path IR gas analyzer (NOAA-ATDD) • RH&temp. sensor Vaisala • dataloggers CR10X Campbell Sci.

21. GROWTH

22. Potential oil yield • Y = Rsp Qe RUE HI FO • Annual incoming PAR • Fraction intercepted PAR • Radiation-Use Efficiency • Harvest Index • Fraction oil in fruit dry matter

23. Fraction intercepted PAR (summary model) • Tree volume • Planting density • Leaf Area Density

24. Radiation-Use Efficiency

25. RUE in olive • Low photosynthetic capacity • High energy cost of dry matter (oil) • RUE biomass (shoot) • 1.35 g/MJ PAR (Mariscal et al., 2000) • 0.94 g/MJ PAR (this project)

26. RUE OIL • g oil/MJ = • g dm/MJ • g fruit/g dm • g oil/g fruit • RUE HI FO • 1.0 0.5-0.6 0.4 • RUE oil = 1 x IC x 0.4 = 0.20-0.24 g/MJ

27. RUE olive oil

28. WATER LIMITED PRODUCTIVITY Y = Ep WUE HI FO Ep: seasonal transpiration WUE: Water-use Efficiency

29. ET, asimilación

30. Conductancia, asimilación neta

31. A, CONDUCTANCE CHANGE IN PARALEL MAXIMUM 3-4 h AFTER SUNRISE MAXIMUM ET LATER WUE DECREASES DURING THE DAYTIME DIURNAL COURSE

32. CHANGES IN WUE (YEAR)

33. WUE vs VPD

34. Production function • Y = HI • FO •  (WUEi Epi) • WUE = 2.176 (0.52+2.83/D) (g /L) • Ep=f(Intercepted radiation, temperature) • Reduction in Ep: June-September • ORCHARD 400 ol/ha, 50 m3/ol CORDOBA

35. Production function

36. YIELD LOSSES • MODEL 0.23-0.39 kg oil/ m3 • EXPERIMENT with cv. PICUAL (Moriana, Fereres, Orgaz, Pastor) • 0.34 kg oil/ m3 UNIFORM DEFICIT

37. EFFECTS OF DEFICIT IRRIGATION • YIELD 80-90% MAXIMUM • SAVINGS 30% (200 OVER 580 mm) • REDUCED PRUNNING COST • REDUCED RISK DISEASES

38. CURRENT WORK • VALIDATE MODELS WUE • IMPROVED TRANSPIRATION MEASUREMENT • IMPROVED CO2 UPTAKE MEAS. (CHAMBERS, EC)

39. OLIVE 2002 TRANSPIRATION

40. THANKS FOR YOUR ATTENTION