Module 3 - Notes 7 - Soil Fertilization
Terms to Know/Definitions:
Topsoil
●The layer of soil that has the highest concentration of organic matter and microorganisms
and is where most of the Earth’s biological activity occurs
●Superficial
●Range from no depth to several feet in depth
Soil texture
●Measurement of the proportion of mineral particles of different sizes that are found in the
same sample of soil (sand, silt, clay, etc.)
●Largest particles include sand
●Medium particles include silt
●Smallest particles include clay
Soil structure
●The way that individual particles - sand, silt, and clay - are arranged into larger distinct
aggregates. It is the major factor determining how fast air and water enter and move
through the soil profile
Soil pores
●Air spaces in between soil particles that allows the passage or absorption of fluids
Soil pH
●A measure of the acidity or alkalinity of soil. It is measured on a negative logarithmic
scale of 1 to 14, with 7 as the middle or neutral value.
Acid and alkaline soil
●Soil pH that are less than 6.5 are acidic.
●Soil pH that are greater than 7.5 are alkaline.
●Soil pH between 6.5 and 7.5 are neutral.
●Soil in Arizona typically range from 7.5 to 8.5 (typically alkaline or basic)
Nutrient deficiency
●16 elements are required for plant growth
●Inadequate supply in soil of 1 or more of the essential elements for plant growth and
development
●Nitrogen, phosphorus, potassium, sulfur, iron, zinc, manganese, magnesium, etc.
Organic matter
●Carbon - based plant or animal remains in the soil that have decayed beyond recognition
Composting
●The aerobic, active, and directed decomposition of organic matter
●Requires oxygen and water
Know the definition of:
peat moss
●Organic soil amendment that can lower the pH of alkaline soil to become more acidic and
raise the nutrient content of zinc, iron, and manganese
perlite – grey-white porous product used in potting mixes made from heating naturally occurring
silica (volcanic) rock mined from lava flows
vermiculite – brown porous product used in potting mixes made from heating micaceous rocks
In closing, I thought you might enjoy the following ancient quote: “To be a successful gardener
one must first know the nature of the soil.” –
Xenophon, 400 B.C.
