New Tools for Interpreting Foliar Nutrient Status

1. New Tools for Interpreting Foliar Nutrient Status Fertilization Working Group February 8, 2012

2. Operational fertilization decision-making • Forest level considerations • Stand level considerations • operational factors • biological factors • species • stand structure • crown conditions • insect/disease • nutrient status

3. Foliar analysis as a planning tool • Foliar analysis can be used to: • confirm N deficiency

4. Foliar analysis as a planning tool • Foliar analysis can be used to: • confirm N deficiency • identify secondary nutrient deficiencies (e.g., S, B)

5. Foliar analysis as a planning tool • Foliar analysis can be used to: • confirm N deficiency • identify secondary nutrient deficiencies (e.g., S, B) • make appropriate fertilizer prescriptions

6. Foliar analysis as a planning tool • Foliar analysis can be used to: • confirm N deficiency • identify secondary nutrient deficiencies (e.g., S, B) • make appropriate fertilizer prescriptions • assess post-fertilization nutrient uptake and foliar nutrient balance

7. Foliar Sampling Protocol

8. Foliar Sampling Protocol • Sample during the dormant season

9. Seasonal change in foliar %N in Douglas-fir foliage Moderate deficiency May Dec June July Aug Sept Oct Nov Month

10. Seasonal change in foliar %N in Douglas-fir foliage Moderate deficiency May Dec June July Aug Sept Oct Nov Month

11. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage

13. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage • Collect foliage from between top 1/4 and bottom 1/2 of live crown

15. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage • Collect foliage from between top 1/4 and bottom 1/2 of live crown • Collect foliage from healthy, representative trees

17. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage • Collect foliage from between top 1/4 and bottom 1/2 of live crown • Collect foliage from representative trees • Collect foliage from at least 20 trees per stand or stratum

18. Foliar sampling layout Road x x x x x x x x Line 2 x x Line 1 x x x x x x /01 x x x x /02

19. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage • Collect foliage from between top 1/4 and bottom 1/2 of live crown • Collect foliage from representative trees • Collect foliage from at least 20 trees per stand or stratum • For routine diagnoses, combine equal amounts of foliage from individual trees into one composite sample per stratum

20. Foliar Sampling Protocol • Sample during the dormant season • Sample current year’s foliage • Collect foliage from between top 1/4 and bottom 1/2 of live crown • Collect foliage from representative trees • Collect foliage from at least 20 trees per stand or stratum • For routine diagnoses, combine equal amounts of foliage from individual trees into one composite sample per stratum • Keep samples cool until foliage is dried

21. Factors affecting interpretation of foliar nutrient data

22. Factors affecting interpretation of foliar nutrient data • Foliar sampling protocol

23. Factors affecting interpretation of foliar nutrient data • Foliar sampling protocol • Site ecological characteristics

24. from DeLong (2003)

26. from DeLong (2003)

28. Factors affecting interpretation of foliar nutrient data • Foliar sampling protocol • Site ecological characteristics • Laboratory analytical methodology

29. Relationship between foliar N analytical methodologiesdry combustion vs. wet digestion

30. Relationship between foliar S analytical methodologies dry combustion vs. wet digestion

31. Accounting for differences in laboratory analytical methodology • Differences may be large enough to affect interpretation

32. Accounting for differences in laboratory analytical methodology • Differences may be large enough to affect interpretation • Nutrient interpretative criteria do not account for differences in methodology

33. Accounting for differences in laboratory analytical methodology • Differences may be large enough to affect interpretation • Nutrient interpretative criteria do not account for differences in methodology • Known differences in laboratory analytical results can be used to “normalize” foliar data prior to interpretation

34. Accounting for differences in laboratory analytical methodology • Differences may be large enough to affect interpretation • Nutrient interpretative criteria do not account for differences in methodology • Known differences in laboratory analytical results can be used to “normalize” foliar data prior to interpretation • “Normalization” requires inter-laboratory comparisons

35. Accounting for differences in laboratory analytical methodology • Differences may be large enough to affect interpretation • Nutrient interpretative criteria do not account for differences in methodology • Known differences in laboratory analytical results can be used to “normalize” foliar data prior to interpretation • “Normalization” requires inter-laboratory comparisons • The “normalization” process does not make inferences about the quality of foliar nutrient data

36. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment

37. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously collected Pl foliage samples were selected

38. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels

39. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels • Each sample was thoroughly mixed and split into two sub-samples

40. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels • Each sample was thoroughly mixed and split into two sub-samples • One sub-sample was shipped to each lab in December 2011

41. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels • Each sample was thoroughly mixed and split into two sub-samples • One sub-sample was shipped to each lab in December 2011 • For each nutrient, laboratory results were reviewed and subjected to regression analysis

42. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels • Each sample was thoroughly mixed and split into two sub-samples • One sub-sample was shipped to each lab in December 2011 • For each nutrient, laboratory results were reviewed and subjected to regression analysis • Based on previous research, equations were selected to “normalize” foliar nutrient data

43. Inter-laboratory comparisonPacific Soil Analysis vs. Ministry of Environment • 48 previously analyzed Pl foliage samples were used • Samples were selected to cover a broad range of foliar nutrient levels • Each sample was thoroughly mixed and split into two sub-samples • One sub-sample was shipped to each lab in December 2011 • For each nutrient, laboratory results were reviewed and subjected to regression analysis • Based on previous research, equations were selected to “normalize” foliar nutrient data • An Excel spreadsheet was developed to facilitate “normalization” for practitioners

44. Laboratory foliar N comparison PSAI vs. MoE

45. Laboratory foliar S comparison PSAI vs. MoE

46. Laboratory foliar SO4-S comparison PSAI vs. MoE

47. “Normalization” of laboratory foliar nutrient data

48. “Normalization” of laboratory foliar nutrient data

49. “Normalization” of laboratory foliar nutrient data

50. “Normalization” of laboratory foliar nutrient data