Soils and Soil Testing …it’s not just dirt

Soil and Plants Soil supports plant life Plants are producers (autotrophs, which make their own food) Animals get their energy from plants or from animals that eat plant So, food ultimately depends on soil

So, food ultimately depends on the soil Animals get their energy from plants or from animals that eat plants Plants are producers (autotrophs, which make their own food) Soil supports plant life

What is soil? Soil is a mixture of living and nonliving materials Formation of soil depends on the “parent material” – rocks that have broken down, climate, and land topography – the shape of the land Organic matter in soil is living things that have broken down Ex. leaves, microscopic organisms

What is soil? Soil is a mixture of different materials that have different sizes: Sand – large, gritty Silt – small particles with a dry, silky feel Clay – smallest, sticky material that dries into a hardened material

Soil Nutrients and conditions needed for plant growth Nitrogen functions Keeps leaves green Used rapidly by plants Nitrogen fertization is used extensively in agriculture Nitrogen is found in the air and soil Phosphorus functions Storage and production of energy for plant growth Enhanced flower beauty

Soil Nutrients and conditions needed for plant growth Potassium (Potash) Strengthens plant cells, and so makes the plants stronger Aids plant survival Available in only small amounts in soil Acidity – pH Plants “prefer” certain acidic or basic conditions that promote growth pH can be adjusted to improve soil conditions