Soil Characteristics Power Point Presentation - Agronomy - Kansas

54 Pages·2006·2.91 MB·English

by  Dale Leikam

Soils, Soil Characteristics
and Factors Affecting
Management
What is Soil?
Mineral
- Sand, Silt, Clay
Pore Space Water
25% 25%
Organic Matter
-Decomposed Plants
Organic
Matter - Decomposed Microorganisms
5%
-Decomposed Animal Material
Mineral Matter
45%
Soil Profiles
• Note
difference in
top soil depth,
organic
matter, color
and clay
content
Harney soil
Harney silt
loam
Factors Involved In Soil
Formation
(cid:122) Climate
(cid:122) Parent Material
(cid:122) Ecology (plant and animal life)
(cid:122) Slope
(cid:122) Time
Average Annual Precipitation
Soil Microorganisms
(cid:122) N fixation in legume crops (Rhizobium)
(cid:122) Decompose organic materials
(cid:190) Crop residues
(cid:190) Organic chemicals
(cid:122) Diseases
(cid:122) Mineralize and immobilize nutrients
Soil Microorganisms
Amount of organisms in top foot of soil
Organism Number/gram soil Typical Pounds/acre-foot
soil
Bacteria 1 Billion 750
Actinomycetes 15 Million 1,100
Fungi 1 Million 1,700
Protozoa 1 Million 300
Algae 100,000 250
Yeasts 1,000 ---
Worms and Insects --- 900
T.M. McCalla, Neb. Ag. Exp. Sta. Research Bulletin, 1959
Soil Microbes Mineralize and
Immobilize Plant Nutrients.
Inorganic nutrients
Organic nutrients
Mineralization
Plant Unavailable Plant Available
Form Form
Immobilization