Soils 205- General Soils

Lecture 1 Handout

Introduction

1.  The subdisciplines of soil science

    -Soil Morphology & Classification

    -Soil Physics   

    -Soil Chemistry

    -Soil Microbiology

    -Soil and Water Management

2.  Why study soils?  The soil plays five main roles, each of which has a significant influence on plant and animal life.

    a.  The functions of soils

        I.

       Essential nutrients

        C,H,O-

        N,P,K,Ca,Mg,S,Fe, Mn,B,Zn,Cu,Cl,Co,Mo,Ni-

C.HOPK_iNS C_aF_e M_anag_ed B_y M_in_e C_ouZ_in MoNi_que Cl_ark

        _II. 

       _III.

        _IV.

        _V.

3.  Composition

    a.  Solid phase

            I.  Solid phase- mineral

            Primary mineral- Mineral that has not been altered since crystallization from molten lava

            examples:

            Quartz-                                                           

            Feldspars-

                    Orthoclase- KALSi₃O₈

                    Anorthite- CaAl₂Si₂O₈

                    Albite-  NaAlSi₃O₈

                                                                             _{Quartz (grey) and feldspar (green) from                                                                                                     Pike's Peek, CO.}

                Micas-

                            - KAl₃Si₃O₁₀(OH)₂

                            -KAl(Fe,Mg)₃Si₃O₁₀(OH)₂

           Secondary minerals-  These minerals are the weathering products of primary minerals

            Hematite- Fe₂O₃

            Clay minerals- Al silicates

            II.  Solid phase- organic

b.  Pore space

Summary- composition of soil