1. How Can I Improve My Soils? Nutrient Deficiencies and Fertilization Rob Harrison, PNW Stand Management Cooperative http://www.forestsoils.org/

2. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

3. Table 1 US Timber trends. Data from: Howard, James L. 2003. U.S. timber production, trade, consumption, and price statistics 1965 to 2002. Res. Pap. FPL-RP-615. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 90 p.

4. outli ne Tree Nutrition Nutrition of DF forests as compared to annual plants Diagnoses of nutritional needs of DF trees Sources of nutrients in DF forest ecosystems Mechanisms by which the nutritional needs of DF trees are met Nutrient conservation retention processes by forest ecosystems

5. Advantages of Forests as a Perennial Plant System Uptake can take place year around Internal translocation of nutrients takes place Growth of a tree builds on an existing structure Nutrient loss from harvesting is significantly less

6. nutrients in D-fir Nutrient Content of DF tissue Tree component Nutrient content (%) N P K Ca Mg Foliage 1.40 0.21 0.85 0.45 0.11 Bark 0.29 0.07 0.31 0.42 0.13 Cones 0.65 0.13 1.26 0.06 0.10 Branches 0.36 0.07 0.21 0.51 0.05 Bole 0.08 0.01 0.05 0.10 0.05

7. Sources of Nutrients Weathering Nitrogen fixation Atmospheric additions Mineralization Fertilization

8. SOIL SUPPLY POTENTIAL USE ACTUAL USE REMOBILIZED UPTAKE FROM SOIL NUTSUPDM Nutrient Supply and Use Source: Forest Nutrition Cooperatie

10. Essential Elements

11. Slide Relative growth

12. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

13. Regional Long-term Site Productivity Studies Mineral Soil Carbon and Nitrogen to 0.6 m depth: 13 BoistfortGrove

14. Sustainable Soil Productivity Removals effects on Nitrogen status Potential Growth Reduction Bole-only harvesting removes ~ 5% of N pool Total-tree harvesting removes ~ 10% of N pool (after Johnson et al. 1982) 14

15. Nitrogen Risk Ratings - Generalized Concept 15 Increasing risk of nitrogen (N) limitations as A / T proportion increases… A = Aboveground Total N Pool (kg/ha): forest floor + understory vegetation + standing crop S = Soil Total N pool (kg/ha) - rooting depth T = A + S = T A = S = Evans, J.1999. Sustainability of forest plantations—the evidence. A review of evidence concerning the narrow-sense sustainability of planted forests. Report for the Department for International Development, London, UK. 64 p.

16. Nitrogen Risk Ratings - Generalized Concept 16 Proportion of site N pool removed: Increasing risk (after Evans, 1999) Low Serious Imminent decline 0.1 0.3 0.5 Example 1: Fall River LTSP, Boistfort soil A / T = 1300 kg N /ha / 14500 kg N/ha = 0.09 = T A = S =

17. Nitrogen Risk Ratings - Generalized Concept 17 Proportion of site N pool removed: Increasing risk (after Evans, 1999) Low Serious Imminent decline 0.1 0.3 0.5 Example 1: Fall River LTSP, Boistfort soil A / T = 1300 kg N /ha / 14500 kg N/ha = 0.09 = T A = S =

18. Nitrogen Risk Ratings - Generalized Concept 18 Proportion of N pool removed: Increasing risk (after Evans, 1999) Low Serious Imminent decline 0.1 0.3 0.5 Example 2: Matlock LTSP, Grove series A / T = 605 kg N /ha / 3705 kg N /ha = 0.16 = T A = S =

19. Nitrogen Risk Ratings - Generalized Concept 19 Proportion of N pool removed: Increasing risk (after Evans, 1999) Low Serious Imminent decline 0.1 0.3 0.5 Example 2: Matlock LTSP, Grove series A / T = 605 kg N /ha / 3705 kg N /ha = 0.16 = T A = S =

20. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

21. Diagnoses of Nutritional Requirements Daignostic indicators of deficency symptoms Foliage deficiency symptoms Foliage and soil analysis Nutrient uptake rates

22. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

23. Percent volume response N rate (lb N/acre) N200 N300 N200-P88-S154 N200-P88-S168+ N100 N52-P12-K220

24. Percent volume response N rate (lb N/acre) N100 N52-P12-K220 N300 N100 N200-P88-S154 N200-P88-S168+ N200 N52-P12-K220 N+P

26. Installations of the PNW Stand Management Cooperative

27. RFNRP Installations

31. Forest floor C/N ratio

32. Overall results of SMC studies Response vs. N rate. Sidell thesis. (1)

38. Results of RFNRP studies 1)N response averaging 20% (unthinned) - 30% (thinned) with 400 kg N, highly site dependent. 2)Clearly, both response to N and other nutrients is site controlled. Indicates need for larger scale studies on a wide variety of sites to pin response to site variables. 3)Effects of N fertilization appear to be very long-lived.

42. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

44. Nutrient Deficiency Levels solution cultures (Walker and Gessel 1991) Element Douglas-fir Hemlock WR Cedar Sitka Spruce Abies 1.8 0.25 1.1 0.18 Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur 1.25 0.16 0.6 0.25 0.17 0.35 1.5 0.13 0.6 0.20 0.12 0.4 1.8 0.09 0.4 0.06 0.15 1.15 0.15 0.50 0.12 0.07

45. Estimating forest productivity and potential for response to fertilization: SMC/CIPS paired- tree fertilization project

46. Hypotheses Soil and other will predict Douglas-fir response to N fertilization -Soil bulk density, porosity and texture -Soil organic matter and nutrient pools -Climate and soil temperature -Precipitation and soil moisture -Site index -LAI -Elevation, slope and slope position -Aspect -Stand stocking, type and development

47. Current Paired Tree Trials 6 sites installed winter 2007 28 sites installed summer 2008 2 sites ready spring 2009 Scouting more to fit into matrix sedimentary glacial igneous

48. Soil Nitrogen

49. Covered today 1) Tree nutrition 2) Nutrient limitiations 3) Risk-rating soils for biomass/nutrient removal 4) Fertilization to maintain/enhance fertility 5) Identifying nutrient deficiency 6) BMP for maintaining or enhancing soil fertility

50. Nitrogen Risk Ratings - Generalized Concept 50 Proportion of site N pool removed: Increasing risk (after Evans, 1999) Low Serious Imminent decline 0.1 0.3 0.5 Example 1: Fall River LTSP, Boistfort soil A / T = 1300 kg N /ha / 14500 kg N/ha = 0.09 = T A = S =

51. Conclusions -Nitrogen commonly limits forest productivity in PNW - N-fertilization of forestlands of the Pacific Northwest is an important treatment resulting in higher productivity -Low sites show the highest % response, high sites the lowest. Higher rates result in higher response. -Interestingly, N fertilization seems to have long- term effects on new stands, but we have limited data on this. -Our ability to predict response stand-by-stand is quite limited.