Texture Soil texture is determined by the size of the weathered rock particles it contains Sand – 0.05 – 2 mm, feels gritty Does not hold water well. Water moves through quickly

Texture Silt – – 0.05mm Need microscope to see Smooth and silky when wet Forms clumps when dry Holds more water than sand

Texture Clay – less than 0.002mm Smallest, need microscope to see Sticky when wet Forms hard clumps when dry Absorbs most water Water moves through slowly

Color Soil may be red, black, brown, yellow, green or even white Red soils contain iron Black or brown soils contain a lot of humus Color can indicate how well water will drain through the soil

Color Geologists have color charts to identify soils Double-click to add graphics

Pore Space Pore space is the spaces between soil particles Water and air move through pore space Soils range between 20 – 60% pore space

Pore Space cat

QUIZ 1)List the four main ingredients of soil 2)What is humus? 3)What helps humus form? 4)Which soil horizon contains the most humus? 5)Horizon A, B and C make up what? 6)How do animals help add air to the soil? 7)Which is the smallest soil particle? 8)Red soil contains what?

Answers 1)Rock particles, humus, water and air 2)Decaying organic matter 3)Bacteria and fungus 4)Horizon A 5)The soil profile 6)By digging in the soil 7)Clay 8)Iron