Soils & Growing Media Flashcards
Soil definition
a naturally weathered part of the earth’s surface
fundamentally important port of plant growth
Soil function
source of mineral nutrients
source of water
anchorage
Soil properties
physical -room for air and water -room for root growth -structural base for plant anchorage chemical -plant nutrient source and reservoir
5 components for ideal soil
air (25%) water (25%) inorganic coumpounds (45-47%) organic compounds (3-5%) soil microbes
inorganic mineral component
sand / silt / clay
inorganic mineral component functions
provides some minerals that are plant nutrients
provides a place for other nutrients to attach so they stay in the soil and are held there for plant roots to access
cation exchange capacity
soil particles are negatively charged
nutrient particles are positively electrically charged
this characteristic of soil is called cation exchange capacity
Cation exchange capacity function
mostly on small clay particles
prevents nutrient loss
soils vary in their CEC (cation exchange capacity)
nutrients are ‘exchanged’ by roots (removed from soil particles and moved into xylem of root)
Major nutrients
nitrogen phosphorus potassium calcium sulfur magnesium
nitrogen
proteins/DNA
phosphorus
energy storage/DNA
potassium
metabolism
calcium
cell walls
sulfur
proteins
magnesium
chlorophyll