Olive fertilization requirements under intensive cultivation management Arnon Dag, Ran Erel, Alon Ben-Gal and Uri Yermiyahu Gilat Research Center Agricultural Research Organization Ministry of Agriculture, Israel

Outline Transition from rain-fed to irrigated olive cultivation Water quantity and quality effect on olive fertilization requirements Fertilization and olive oil quality Fertilization and olive productivity Bi-annual bearing and nutrients balance in olive Final conclusions

Development in world olive oil production Increased cultivation area Intensification International Olive Council

Modernization in olive cultivation Varieties (fast growing high yielding) Close spaced planting, orchard management Pruning, soil cultivation, plant protection Irrigation - fertigation Water available for irrigating olives לנושא השלישי אפשר להראות צורות עצוב של עץ, tilage non-tilage Scarce optimize irrigation Low quality Recycled wastewater Saline water

Intensive orchards Traditional orchards Limiting factors: water and nutrients Limiting factor: Radiation Close spaced planting Intensive orchards Traditional orchards ca. 10 x 10 m 4 x 7 - 7 x 7 m

Response of leaf mineral concentrations to increasing irrigation levels. Symbols are averages for 4 years of data, n = 4 (Baka) and n = 5 (Revadim). a Nitrogen, b phosphorus, c potassium. Different letters indicate significant (P < 0.01) differences between treatments of the same experiment. Water quantity Zipori, I., Yermiyahu, U., Erel, R., Presnov, E., Faingold, I., Ben-Gal, A. and Dag, A (2015). The influence of irrigation level on olive tree nutritional status Irr. Sci. 33: 277-287.

N, P and K content in recycled and fresh water Water quality

Irrigation of olives using recycled water (total yield 2006-14) b ישום סטנדרטי- 200 ק"ג להקטר של חנקן ו300 של אשלגן ללא זרחן Dag, A., Yermiyahu, U., Ben-Gal, A., Segal, E. and Kerem, Z. (2012). Irrigation of olives with recycled water. In: U.S. EPA Guidelines for Water Reuse, pp. E58-E59.

Nutrient availability Olive irrigation Nutritional demands Nutrient availability

Olive oil quality Dag et al. (2009) J. Sci. Food Agric. 89: 1871-1878. Erel et al (2013) J. Agric. Food Chem. 61: 11261-11272.

Solution treatments גילת 15.6.06 P) ppm( N (ppm ( 0.3 5 K (ppm) 10 0.6 25 48 76 109 152 197 P) ppm( 0.3 0.6 1.2 1.9 4.3 9.3 19.2 K (ppm) 10 19 28 52 80 102 208

3 months 3 years Initiation 6 months 14 months

Oil quality: Acidity N

The effect of N fertilization level on FFA in oil, field trail, 2012-2015 AB B a B a b b 0-45 kg/ha 75 kg/ha 150 kg/ha 300 kg/ha

Oil quality: polyphenol Nitrogen – Polyphenol Polyphenol (mg/kg)

The effect of N fertilization level on polyphenol content in oil, field trial, 2012-2015 ab A ab a A A b ab AB B b B B b B 0-45 kg/ha 75 kg/ha 150 kg/ha 300 kg/ha

The effect of nitrogen availability on oil fatty acids profile Fatty acid composition as a function of N concentration in fruit flesh for the three studied years: 2007 (purple), 2008 (red), and 2009 (blue) and the three manipulated treatments: N (●), P (▲), and K (■). Each point represents an average of six replicates in 2007 and three replicates in 2008 and 2009. The statistical parameters of the model are presented in Table 4. Published in: Ran Erel; Zohar Kerem; Alon Ben-Gal; Arnon Dag; Amnon Schwartz; Isaac Zipori; Loai Basheer; Uri Yermiyahu; J. Agric. Food Chem.  2013, 61, 11261-11272.

Conclusions: ↑ ↓ ↑ N ↑ P ↑ K Excess nitrogen impairs both oil quantity and quality. Phosphorus modifies the oil properties but less than N. Potassium did not affect oil properties. PUFA MUFA P”P FFA C18:3 C18:2 C18:1 ↑ ↓ ↑ N ------ ↑ P -------- ----- ↑ K

Productivity Erel et al. (2008) J. Amer. Soc. Hort. Sci. 133: 639-647. Erel et al. (2013) Scientia Hort. 159: 8-18. Erel et al. (2016) PloS ONE 11(12): e0167591.

The effect of nitrogen level in irrigation solution on fruit and oil yield Oil yield (Kg/tree) Total harvested fruit (Kg/tree) יבול של שלוש שנים כאשר השנה הראשונה היה יבול נמוך N in irrigation solution (ppm)

The effect of nitrogen level in leaves Total harvested fruit (kg/tree) on fruit and oil yield Total harvested fruit (kg/tree) N in irrigation (ppm) Oil yield (kg/tree) Sufficient level (literature) עד כאן N in leaves (%)

N in fruit flesh as indication for over fertilization N in leaf (%) Fruit yield (kg/tree) לסייג ולומר שהיבולים משפיעים גם הם N in fruit flesh (%)

The correlation between nitrogen level in diagnostic leaves to productivity Fruit set (%) Flowering intensity (%) שנה אחת 2008 איך זה שזה יורד, בפרי, נשירה ! Accumulative # of fruits N in leaf (%)

The correlation between nitrogen level in irrigation solution and fruit drop Fruit drop (%) עד כאן N in irrigation (ppm)

The correlation between phosphorous level in diagnostic leaves and fruit / oil yield Sufficient level (literature)

The correlation between phosphorous level in diagnostic leaves with productivity Fruit set (%) Flowering intensity (%) Accumulative # of fruits P in leaves (%)

Pistil fresh weight as affected by P level. Erel R, Yermiyahu U, Yasuor H, Cohen Chamus D, Schwartz A, et al. (2016) Phosphorous Nutritional Level, Carbohydrate Reserves and Flower Quality in Olives. PLOS ONE 11(12): e0167591. https://doi.org/10.1371/journal.pone.0167591 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0167591

Olive oil production in Israel 1998-2008 K Olive oil production in Israel 1998-2008 אולי להעביר את כל הסיפור של הסרוגיות להמשך.. Source: FAOSTAT

Possible reasons for biennial bearing Heavy yield inhibits concurrent vegetative growth, restricting the platform for flowering sites in the following year. Inhibition of floral bud induction and differentiation by hormones produced by developing seeds. Limited resources (carbohydrates, minerals). Environmental conditions.

% of dry matter Sampling time Changes in the mineral content in leaves and roots of olive trees during biennial yield cycle Fluctuations in the concentrations of potassium in the leaves and the roots of On- and Off-trees (cv. Barnea) during the reproductive cycle of 2006. Values are means of 8 replicates. Bars indicate for ±SE. Bustan et al., Scientia Horticulturae (2013) 152, 44-55.

Leaf potassium level drops down in an ‘On’ year Leaf potassium level drops down in an ‘On’ year. Does this indicate that K is a major element affecting tree productivity ???

The correlation between potassium level in diagnostic leaves and fruit and oil yield Fruit yield (Kg/tree) Oil yield (Kg/tree) Sufficient level (literature) K in leaves (%)

Potassium level is affected by the fruit load, but generally, it does not affect the yield. And nitrogen????

K and Na interaction Can Na replace K in olive? The lack of response to K was very strange… K is generally needed in large quantities, especially under drought When we examine the leaf analysis we can see a major Na accumulation in K1 treatment. Actually, by the end of the experiment Na was almost double the concentration of K in the leaf. CAN Na REPLACE K IN THE OLIVE Can Na replace K in olive? Erel et al., (2014), Tree Physiol. 34: 1102-1117.

CO2 response curve Pn is function of both gs and the photosynthetic apparatus. Therefore, in the present slide, A/Ci response curve is presented rather than direct Pn measurements. A/Ci curve presents the Pn rate versus the internal CO2 concentration and thus avoiding the effect of stomata resistance. The figure speaks for itself: for any given CO2 concentration in the mesophyll the Pn rate was lowest in the 0 K 0 Na treatment, about half of the control, while the addition of Na to K deficient plant recovered most of the Pn rate The difference between the green and the red treatments is only Na. both had no K

Macro-element level in leaves (%) Summary P Yield N K Yield Yield Macro-element level in leaves (%)

Conclusions Irrigation level and water quality affect nutrient availability. Phosphorous availably positively affects olive productivity. Nitrogen availability negatively affects oil quality. Potassium level is affected by the fruit load, but generally, it does not affect the yield.

Thank you !