Soils & Growing Media

Question 1

Soil definition

Answer 1

a naturally weathered part of the earth’s surface

fundamentally important port of plant growth

Question 2

Soil function

Answer 2

source of mineral nutrients
source of water
anchorage

Question 3

Soil properties

Answer 3

physical 
-room for air and water
-room for root growth
-structural base for plant anchorage
chemical 
-plant nutrient source and reservoir

Question 4

5 components for ideal soil

Answer 4

air (25%)
water (25%)
inorganic coumpounds (45-47%)
organic compounds (3-5%)
soil microbes

Question 5

inorganic mineral component

Answer 5

sand / silt / clay

Question 6

inorganic mineral component functions

Answer 6

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

Question 7

cation exchange capacity

Answer 7

soil particles are negatively charged
nutrient particles are positively electrically charged

this characteristic of soil is called cation exchange capacity

Question 8

Cation exchange capacity function

Answer 8

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)

Question 9

Major nutrients

Answer 9

nitrogen
phosphorus 
potassium
calcium
sulfur
magnesium

Question 10

nitrogen

Answer 10

proteins/DNA

Question 11

phosphorus

Answer 11

energy storage/DNA

Question 12

potassium

Answer 12

metabolism

Question 13

calcium

Answer 13

cell walls

Question 14

sulfur

Answer 14

proteins

Question 15

magnesium

Answer 15

chlorophyll

Question 16

minor minerals

Answer 16

iron
zinc
manganese
copper
boron
molybdenum 
chlorine 
cobalt+nickel

Question 17

what influences nutrient uptake by a plant from soil

Answer 17

how much nutrients is in the soil
solubility of the nutrient ion 
CEC of the soil 
soil pH
how much organic matter is in the soil

Question 18

Horticulturally we can influence

Answer 18

how much nutrients is in the soil 
- add fertilizer
soil pH
- add sulfur or lime
how much organic matter is in the soil
- add organic matter

Question 19

air and water components

Answer 19

are/need to be balanced

Question 20

functions of OM

Answer 20

water holding
nutrient holding
nutrient source
soil structure

Question 21

Soil organisms component

Answer 21

micro and macro organism
algae, bacteria, fungi, nematodes, earthworms, insects, moles, etc.
beneficial/harmful

Question 22

functions of organisms

Answer 22

decompose organic matter
open space in soil
fix nitrogen from air to soil
form mutualistic relationships