Soils. Source: Schroeder and Blum, 1992

Transcription

1 Soils Source: Schroeder and Blum, 1992 Literature cited: Schroeder, D. and Blum, W.E.H Bodenkunde in Stichworten. Gebrüder Borntraeger, D-1000 Berlin.

2 Geology and Life

3 Conceptual model Source: Knight, 1994

4 Soil who needs it Video

5 Human-Soil connection Adam = human Adamah = farmland Source:

6 Why is soil important? Source: The University of Vermont

7 What is soil?

8 Minerals

9 Minerals (cont.) mm mm < mm Source:

10 Minerals (cont.) Animation: Weathering of feldspar Exchangeable Ions (x) H 2 0 Source: Schroeder and Blum, 1992

11 Organics

12 Difference Between Organic and Inorganic compounds? Source:

13 Organics Why important? Source: Schroeder and Blum, 1992 Source: Schroeder and Blum,

14 Mineralization Organic Humic Substances (are organic!) Fire Inorganic Source:

15 Decomposition resistance Cellulose Source:

16 Decomposition resistance (cont.) C/N ratio Source:

17 Humic substances Very important for water and nutrient budget of soil! Source: Schroeder and Blum, 1992

18 Soil Water

19 Soil Water (cont.)

20 Soil Water (cont.) Plant available water Field Capacity Sand < Loam < Silt < Clay < Peat Source:

21 Volumetric water content Source:

22 Task (5 minutes/each) Do you think volumetric water content provides some good information of how much water is available for plant growth? Source:

23 Soil Water (Cont.) S Silt C

24 Soil Water (cont.)

25 Gas

26 Soil Air Soil Breathing O 2 CO 2 Diffusion CO 2 O 2 Air pore

27 Bulk density Bulk density = Mass of dry soil/volume of solids and pore space Source: Video

28 Bulk density (cont.) Source: USDA 1999, Soil quality test kit guide

29 Soil chemistry Source: Schroeder and Blum, 1992

30 Reduction-Oxidation Source: Freeman, Biology. Source: Costa Tropical News

31 Soil Color Mn Organic Substances Fe Source: Schroeder and Blum, 1992

32 Crystal lattice minerals are not plant available Exchange reaction in soils Soil Soil solution Plant roots

33 _ Plant-nutrient uptake Soil Soil solution Plant roots

34 Illustration Source:

35 Task - What happened? Deionized water Soil Soil solution

36 Task (everybody) What is more prone to leaching, ammonium fertilizer (NH 4+ ) or nitrate fertilizer (N0 3- ) and why?

37 It s time for some miracle gro

38 ph Activity ph = -log c H + Concentration Selected ecological effects of ph Source: Schroeder and Blum, 1992

39 Ion-exchange capacity ph CEC AEC Al H Ca ++ - Cation Anion PO Soil Particles < mm Clay minerals Humic substances Mg ++ K + Na + NO 3 - Interesting Facts: Humic substances can absorb more cations than clay minerals Soil particles have generally more negatively than positively charged surfaces Ion exchange capacity of clay particle depends on the parent material they were derived from (p.67) Basic acidity of soil depends on parent material: Basalt higher ph than Granit (p.77)

40 Soil texture classification Animation

41 Task (5 minutes/each) Why does soil texture provide some interesting information about soil properties?

42 Soil texture classification Sedimentation method Mechanical Sieving Source:

43 Task (5 minutes/each) Answer the following question: You have a low soil ph (6) should you be concerned about Mg deficiency in your plants?

44 Soil analysis Soil Quality Test Kit Guide

45 You can t judge a soil by looking at its cover Animation

46 Web Soil Survey Coordinates for Osprey Point: ,