1. Tree Nutrition Arboriculture Spring 2001

2. Eldarica or Virginia? Fertilizer Rules!/ adapted from Vir.Tech DON’T GUESS -- TEST! Virginia pine: maintain soil pH between 5.0 and 6.0 Eldarica pine: maintain soil pH between 6.5 and 7.5 Don’t waste $ on expensive fertilizers unless soil or tissue analysis shows a need. Band fertilize in Years 1 and 2 Broadcast fertilizer beginning Year 3 Apply P in the spring Apply Ca in the fall Maintain soil test calcium at 50-60% saturation and Mg at 10-15% saturation. Use lime or gypsum. If more than 100 lb K/a is needed, apply muriate of potash in two applications or only in fall because of potential fertilizer burn.

3. Eldarica or Virginia? Interpreting Soil Test Results--NM Flynn 2002

4. Complete fertilizer contains N:P:K Incomplete fertilizer is missing one of three Reading a fertilizer bag –10:10:10 contains 10% N, 10% P, & 10% K –46:0:0 contains 45% N alone Mixing 100# 45: 0: 0 + 100# 0:45: 0 + 100# 0: 0:60 = 300# 15:15:20 Eldarica or Virginia? Fertilizer Content

5. Arboriculture Tree Nutrition/ Hartman et al.2000

6. Arboriculture Tree Nutrition RoT –After water, N is the factor that most limits tree growth in the SW. –N ~ 2% of foliage DW –P ~ 10% of N content –Fall fertilization is not bad!

7. Arboriculture Tree Nutrition/ Hartman et al.2000

8. Arboriculture Tree Nutrition Nitrogen –mobile, resulting in general chlorosis, shorter growth –apply 1-2 kg/100 m 2 to soil surface –apply 1 kg/100 L to foliage (wet to runoff) –apply 20-40 g/cm trunk diameter (<15 cm) –apply 40-80 g/cm trunk diameter (> 15 cm)

9. Arboriculture Tree Nutrition/ nutrient stress vs cold-hardiness Winter Injury (%) Pecan Yield (kg/tree) %N /%P

10. Arboriculture Tree Nutrition Nitrogen –Harris et al. Says “one kilogram per 100 m 2 is 1000 kg/ha (2 lb/1000 ft 2 ).”

11. Arboriculture Tree Nutrition Nitrogen –Harris et al. Says “one kilogram per 100 m 2 is 1000 kg/ha (2 lb/1000 ft 2 ).” –What’s wrong with that statement? –Hint: (2 lb/1000 ft 2 )

12. Arboriculture Tree Nutrition Phosphorus –leaves turn purple –incorporate1-4 kg/100 m 2 into soil

13. Arboriculture Tree Nutrition Potassium –interveinal chlorosis and margin scorching –rarely limiting –incorporate 2-15 kg/100 m 2 into soil

14. Arboriculture Tree Nutrition Iron –immobile in plants, new leaves become chlorotic often with green veins –incorporating iron in calcareous soils is ineffective –spray iron citrate or Sequestrene 138 (0.2-0.2 g/100L)

15. Eldarica or Virginia? Fertilizer Content

16. Arboriculture Tree Nutrition How do we know they are telling the truth?

17. Eldarica or Virginia? Put the Fertilizer where the Roots Are! RoT: The radius of root extension ~ height of tree

18. Tree age ApplicationSpringFall (years) Type-------oz/tree------- 1 Band 0.5 - 2 Band 0.5 - 3 Broadcast 0.5 0.5 4 Broadcast 0.5 0.5 http://www.agr.state.nc.us/agronomi/stnote5.htm Eldarica or Virginia? Nitrogen Rates for Virginia pine- NCSU

19. Tree age ApplicationSpringFall (years) Type-------oz/tree------- 1 Band 0.5 - 2 Band 0.5 - 3 Broadcast 0.5 0.5 4 Broadcast 0.5 0.5 http://www.agr.state.nc.us/agronomi/stnote5.htm Eldarica or Virginia? Nitrogen rates for Virginia pine- NCSU

20. http://ohioline.osu.edu/b670/b670_31.html Eldarica or Virginia? Fertilizer Recommendations/ Vir.Tech Preplant or at planting: 1 oz/tree Year 1: 0-46-0 @ 500 lb/ac Year 2: 10-10-10 @ 2-3 oz/tree Year 3: 10-10-10 @ 3-4 oz/tree Year 4: 10-10-10 @ 4-5 oz/tree

21. http://www.agr.state.nc.us/agronomi/stnote5.htm Eldarica or Virginia? Fertilizer Recommendations/ Vir.Tech Preplant or at planting: 1 oz/tree Year 1: 0-46-0 @ 500 lb/ac Year 2: 10-10-10 @ 2-3 oz/tree Year 3: 10-10-10 @ 3-4 oz/tree Year 4: 10-10-10 @ 4-5 oz/tree

22. Eldarica or Virginia? Nitrogen Uptake of Eldarica Pine / Sammis et al. 2002 Above Ground Biomass (kg) 20 g N/tree 90 g N/tree Year-1Year-2Year-3 4 g N/tree

23. Arboriculture Diameter growth of 1” stock after 8 yrs in response to fertilizer (N or N+P) Nitrogen (lb/ac) Diameter Growth (in/yr)

24. Arboriculture Tree Nutrition Soil Incorporation: –“In poorly drained silt and clay-loam soils, Smith and Reisch (1975) found that young crabapple, linden, and maple trees benefited as much when holes were drilled and no fertilizer was added as they did when 3 kg each of N,P,and K was applied in the holes or on the surface.” p. 363

25. Arboriculture Tree Nutrition/ Spikes vs broadcast Tree spike Broadcast granular

26. Arboriculture Tree Nutrition/ Spikes vs broadcast EC (dS/m) TDS (mg/L) mg/L = ppm dS/m = 1 mS/cm 10 meq/L 100 mS/m 1,000  S/m

27. Eldarica or Virginia? Foliar Nutrient Content/ Hartman et al.2000

28. Eldarica or Virginia? Fertilizer Recommendations Bondi, et al. OSU CES 2000

29. Slow Release Fertilizers Compared/ Mickler & Ruter NMPRO 19(3):51:2003 EC (dS/m) Applied 20.4 g/5 gal

30. Nutrient Release of Organic Fertlizers/ Simmons & Maher Acta Hort 644:163:2004 Time (days) N release (% of total)P release (% of total)

31. Arboriculture Tree Nutrition Conclusions: –Fertilize w/ 1-2 kg N /1000 m 2 –Use the cheap stuff –Avoid soil injection –Avoid tree injection –Use foliar feed for tough stuff (Fe, Zn)

32. Arboriculture Tree Nutrition/ how much N?