Horticulture - Soil Pt. 2

Synthetic

fertilizers are chemically manufactured nutrients added to soil to enhance plant growth, often containing macronutrients like nitrogen, phosphorus, and potassium.

• Imitates a “natural product”

There is no difference between the organic and synthetic source of

Nitrate and Ammonium

Plants absorb nitrogen in 2 forms

as nitrate and ammonium from the soil.

• Nitrate to ammonium 2:1

Nitrification

is the biological process by which ammonia is converted into nitrate through the action of bacteria, making nitrogen available for plant absorption.

• Organic compounds from OM are are broken down leaving NH4+ (Ammonium)

• Ammonia and/or ammonium is converted to nitrite (NO2-) then nitrate (NO3-)

Mineralization

is the process by which organic matter is decomposed, releasing nutrients like nitrogen in forms that plants can absorb, chiefly ammonium and nitrate.

• Occurs naturally in the environment

• Various bacteria are responsible

• Ammonia and/or ammonium is produced by the breakdown of organic matter - proteins -

Soil Biology

is the study of the organisms in the soil ecosystem, including bacteria, fungi, and invertebrates, and their roles in nutrient cycling, soil formation, and overall soil health.

• Bacteria, Fungi, Soil Algae, Nematodes, Worms, and Soil Insects are key components

Mycorrhizae

symbiotic associations between fungi and plant roots that enhance nutrient and water uptake for plants.

• Fungi assist absorption of water and nutrition, fights infection

• Increases the root system several hundred to several thousand times

• Roots provide sugar (glucose) to the fungus

pH

Soil Acidity or Alkalinity, measured on a scale from 0 to 14. It affects nutrient availability, microbial activity, and overall soil health.

pH

Negative logarithm of the hydrogen ion concentration in the soil solution

• <7 = Acidic

• 7 = Neutral, H+ = OH-

• >7 = Basic

pH of 5 is __ more acidic than a pH of 6

10x

pH of 5 is __ more acidic than a pH of 7

100x

pH influences a soil’s ability to be

fertile

Most plants have a pH balance of

6/6.5-7 for optimal growth

How to raise soil pH

Adding limestone or other amendments

• Reacts with soil colloid, displaces H+

• Creating H2o, raise pH

• Because of “buffer capacity” (reserve acidity)

Turf grass uses __ more water than any other soil

3-6x

Turf grass is not

a natural ecosystem and requires regular maintenance and watering compared to native plants.

• Biodiverse