FOR 347: Silviculture. Instructor: Dr. Jeremy Stovall Lecture 17: Forest Nutrition 1

Transcription

1 FOR 347: Silviculture Instructor: Dr. Jeremy Stovall Lecture 17: Forest Nutrition 1

2 Context Regeneration Treatments Stand Establishment Intermediate Treatments 2

3 Context 3

4 Group Exercise Describe the perfect soil for growing cherrybark oak. Explain the rationale for each property you identify. How would your answer differ for shortleaf pine? Explain. 4

5 What is the goal of fertilization? Increase growth Crop trees Improves product class Shortens rotation 5

6 What is the goal of fertilization? Fertilizer application is an investment All investments are subject to risk Stand may not respond Stand may not respond enough Stand may respond, but then is subject to disturbance 6

7 Who is applying fertilizer? More than 16 Million acres fertilized in US South by industrial forest landowners 91% of applications were in loblolly pine plantations 80% of applications were on the coastal plain Exceeds all other forest fertilization combined Source: Albaugh, T. J., Allen, H. L., Fox, T. R. (2007). Historical patterns of forest fertilization in the southeastern United States from 1969 to Southern Journal of Applied Forestry, 31(3),

8 Outline A. How do nutrients cycle? B. Is your stand nutrient limited? C. When should you fertilize? D. How much should you fertilize? E. How is fertilizer applied? F. How do stands respond? 8

9 What Limits Growth? SouthEast Tree Research and Education Site Control Plot Fertilizer + Irrigation Plot 9

10 What Limits Growth? Dominant Height (feet) SETRES Results Control Irrigate Only Fertilize Only Fertilize and Irrigate Age (years) Adapted from: Albaugh, T. J., H. L. Allen, P. M. Dougherty, and K. H. Johnsen Long term growth responses of loblolly pine to optimal nutrient and water resource availability. Forest Ecology and Management 192:

11 Is your stand nutrient limited? Stand Potential Demand Nutrient Deficiency Develops Actual Stand Use Remobilized Uptake From Soil Adapted from: Fox, T. R., Allen, H. L., Albaugh, T. J., Rubilar, R., & Carlson, C. A. (2007). Tree nutrition and forest fertilization of pine plantations in the southern United States. Southern Journal of Applied Forestry, 31(1),

12 Nutrient Supply: Liebig s Law of the Minimum concept.nl/eng/pagina/141/prevention through nutrition.html 12

13 What Makes a Tree? Element Symbol % Plant Dry Mass Source Carbon C 45.0 Atmosphere Oxygen O 45.0 Water, Atmosphere Hydrogen H 6.0 Water Nitrogen N 1.5 Soil Potassium K 1.0 Soil Calcium Ca 0.5 Soil Magnesium Mg 0.3 Soil Phosphorus P 0.2 Soil Sulfur S 0.1 Soil 13

14 Where Do Trees Get Nutrients From? Element Source Controlling Process Plant Available Form N Soil OM Biological NH 4+, NO 3 P K Soil OM Ca, Fe, Al Phosphates Primary & Secondary Minerals Biological & Chemical H 2 PO 4 Chemical K + N can be controlled by managing organic matter (leaving tops) and by fertilizer application. N fertilizer responses are short lived (8 years). P can be controlled by managing soil ph (not done in forestry) and by fertilizer application. P fertilizer responses are long lived (2 rotations). K can be controlled through fertilizer application. 14

15 How Do Nutrients Get to the Tree? QUANTITY INTENSITY 15

16 Nutrient Supply: QCI Framework Quantity: Total Amount Present Capacity: Rate of Supply Intensity: Amount Available Even if there is a large quantity of an element present in the soil it does not mean that the plants can get it! 16

17 Nutrient Supply: QCI Framework Example for Nitrogen 2000 kg/ha 6 ppm 17

18 Nitrogen Cycling Figure source: 18

19 Nitrogen Cycling Figure source: 19

20 Nitrogen Cycling Water Movement to Roots Figure source: 20

21 Phosphorus Cycling Reproduced from: Brady, N. C., & Weil, R. R. (2010). Elements of the nature and properties of soils (p. 383). Pearson Prentice Hall. 21

22 Phosphorus Cycling Figure source: Menzies, N., & Lucia, S. (2009). The science of phosphorus nutrition: Forms in the soil, plant uptake, and plant response. Grains Research & Development Corporation Update Papers,

23 Phosphorus Cycling Motavalli, P. P., Kremer, R. J., Fang, M., & Means, N. E. (2004). Impact of genetically modified crops and their management on soil microbially mediated plant nutrient transformations. Journal of environmental quality, 33(3),

24 Phosphorus Cycling Loblolly with abundant ectomycorrhizae Loblolly with normal ectomycorrhizae Photos from: Cordell, C.E.; Anderson, R.L.; Hoffard, W.H.; Landis, T.D.; Smith, R.S. Jr.; Toko, H.V. Forest Nursery Pests. U. S. Department of Agriculture, Forest Service. Agriculture Handbook No December p. 24

25 Objective A Review Nutrient cycling varies among nutrients Nutrient cycling depends on soil texture Most of the nutrients in a soil are not available to trees Assessing nutrient limitations and availability requires an understanding of nutrient cycling 25

26 Outline A. How do nutrients cycle? B. Is your stand nutrient limited? C. When should you fertilize? D. How much should you fertilize? E. How is fertilizer applied? F. How do stands respond? 26

27 Is your stand nutrient limited? What tools does industry use? LAI Soil data models What tools can consultants or non industrial private landowners use? Foliar nutrient tests Soil tests Simplified soil models 27

28 Nutrients Grow Leaves Leaves Grow Trees Leaf Area Index (LAI) unit area leaf / unit area ground LAI = 3 LAI = 1 28

29 Why is LAI Important? 600 VOLUME GROWTH (ft 3 /acre/yr) Light Interception LEAF AREA INDEX Growth Efficiency Adapted from: Fox, T. R., H. L. Allen, T. J. Albaugh, R. Rubilar, and C. A. Carlson Tree nutrition and forest fertilization of pine plantations in the southern United States. Southern Journal of Applied Forestry 31:

30 LandSat Image of East Texas Flores, F. J., Allen, H. L., Cheshire, H. M., Davis, J. M., Fuentes, M., & Kelting, D. (2006). Using multispectral satellite imagery to estimate leaf area and response to silvicultural treatments in loblolly pine stands. Canadian Journal of Forest Research, 36(6),

31 LAI Remote Sensing Estimation of LAI Using Landsat Imagery Flores, F. J., Allen, H. L., Cheshire, H. M., Davis, J. M., Fuentes, M., & Kelting, D. (2006). Using multispectral satellite imagery to estimate leaf area and response to silvicultural treatments in loblolly pine stands. Canadian Journal of Forest Research, 36(6), y = 0.59x - 1 R 2 = Simple Ratio 0 (SR=NIR/R) 31

32 Estimated Stand Peak LAI Flores, F. J., Allen, H. L., Cheshire, H. M., Davis, J. M., Fuentes, M., & Kelting, D. (2006). Using multispectral satellite imagery to estimate leaf area and response to silvicultural treatments in loblolly pine stands. Canadian Journal of Forest Research, 36(6),

33 Soil Data Models Soil Recommendation Acres Establishment & Juvenile Fertilization B13cf5CUx 125#/Ac DAP w/ veg control 12.1 C25cf6CYx 250#/Ac DAP w/ veg control 24.8 Mid Rotation Fertilization Response B13cf5CUx High 12.1 C25cf6CYx Medium 24.8 Courtesy of Campbell Timberland Management, LLC. 33

34 Critical Levels of Foliar Nutrients Source: Jokela, E. J. (2004). Nutrient management of southern pines. Slash pine: still growing and growing,

35 Soil Tests Mehlich 3 results indicating stand may respond: P < 6 ppm K < 12 ppm Ca < 40 ppm Mg < 10 ppm Nitrogen much more difficult to predict from soil testing This is a MAJOR barrier to NIPF landowners fertilizing 35

36 Simplified Soil Models Jokela, E. J., & Long, A. J. (2010). Using soils to guide fertilizer recommendations for southern pines. Circular 1230, University of Florida: IFAS Extension. 36

37 A B C E F G CRIFF Soil Groups D Slide provided by Tom Fox 37

38 CRIFF A: Severely P deficient soils tend to occur in a band near the coast 38

39 Objective B Review Most forests in the US South are nutrient limited, primarily by N and P, but also by K, B, or other micronutrients. It is important to determine what nutrients are limiting on your stand as a first step in prescribing fertilizer application. There are a variety of imperfect tools to help assess nutrient limitations. 39

40 Outline A. How do nutrients cycle? B. Is your stand nutrient limited? C. When should you fertilize? D. How much should you fertilize? E. How is fertilizer applied? F. How do stands respond? 40

41 When should you apply fertilizer? When are nutrients limiting? How long does a stand take to respond? How long is the duration of the response? 41

42 When are nutrients limiting? P, K, or micronutrients may be limiting at establishment. If such a deficiency exists, a site prep or establishment application may be recommended. N is usually not limiting until a stand approaches canopy closure. Industry has moved away from establishment applications of N, and more towards midrotation treatments. 42

43 When are nutrients limiting? Source: Albaugh, T. J., Allen, H. L., Fox, T. R. (2007). Historical patterns of forest fertilization in the southeastern United States from 1969 to Southern Journal of Applied Forestry, 31(3),

44 How long does a stand take to respond to a fertilizer application? Gent, J. A., Allen, H. L., Campbell, R. G., & Wells, C. G. (1986). Magnitude, duration, and economic analysis of loblolly pine growth response following bedding and phosphorus fertilization. Southern Journal of Applied Forestry, 10(3),

45 How long is the duration of the growth response? Total Height (feet) Control N100 N200 N300 Basal Area (sq ft per acre) Control N100 N200 N Growing Seasons After Fertilization (years) Growing Seasons After Fertilization (years) Data from: Amateis, R. L., Liu, J., Ducey, M. J., & Allen, H. L. (2000). Modeling response to midrotation nitrogen and phosphorus fertilization in loblolly pine plantations. Southern Journal of Applied Forestry, 24(4),

46 When do you apply each year? Avoid hot weather N volatilization of urea Can be reduced by combining with boron Various products Efficacy TBD Apply during growing season March May ideal 46

47 Objective C Review Fertilize with P at establishment on poorly drained clayey soils in the lower coastal plain Fertilize with N and P at midrotation Midrotation applications should be at least 5 years before a harvest (thin or clearcut) Midrotation treatments can be spaced at ~5 8 year intervals The goal of midrotation treatments should be to increase diameter of the final crop trees 47