Healthy Soil? The Nature of Soil Soil- a mixture of weathered rock, decayed organic matter, mineral fragments, water and air Healthy Soil?

Factors that Affect Soil Formation Climate Slope of the land Types of rock Types of vegetation Amount of time the rock has been weathered

Soil has small sediments Clay Silt sand

Humus Decayed plants Decayed animals Dark color Good soil has equal amount of humus & weathered rock

Soil Profile Different layers of soil Usually distinguishable by the color difference Most soils have three main horizons that we label Horizon A, Horizon B, & Horizon C

A Horizon Top layer of soil Could contain litter We call it the topsoil Usually dark in color- know why?

B Horizon Less organic matter Lighter in color than A Less fertile Contains material from leaching

C Horizon Consists mostly of weathered rock At the bottom of a soil profile It is often the thickest layer Not much organic matter at all Parent rock is found here

Soil Profiling Watch here to see a real life profile Do a soil test

Charlotte Trotter Vian Middle School