soil. soils soil is a dynamic system of living and nonliving components. dirt is soil out of place
Post on 19-Dec-2015
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soil
Soils• SOIL is a dynamic system of living and
nonliving components.
• DIRT is soil out of place
Soil components
• Mineral
• Organic
• Water
• Air
• Living Organisms
Mineral components
• Derived from rock
• The nature of the soil depends on the kind of rock and the degree of weathering
• Mineral soil is quite permanent
Mineral components
• Texture- the name of a soil is based on the mineral components if soil is less than 20% organic , it is called a mineral soil.
• Particle size:– coarse SAND .2 - 2 mm– SAND 20 - 200 um (microns)– SILT 2 - 20 um– CLAY less than 2um
The name of a soil is based on its mineral components.
Water
Soil structure
• How soil clumps or aggregates– Determines pore space– Aggregates are classified by shape
• Flat, prism-shaped, block-like, plate-like, and spheroid
• Spheroid is optimal but the clay in Duluth is plate-like
Physical forces that result in aggregation
• Freezing and thawing
• Wetting and drying
• Action of worms, and other organisms
• Root growth
Organic componentsHumus, litter, duff
• Plant, animal, bacterial, fungal remains
• Always disappearing due to decay
• % of organic matter depends on– Rate of accumulation– Rate of or resistance to decay– Climate
• Cold /dry = minimal decay• Hot/ damp = fast decay
Importance of Organic material
• Holds available minerals and nutrients
• Increases water holding in sandy soil
• Increases drainage by aggregating clay
• Inhibits erosion
Sources of organic material for the garden
• Manure from farm animals ( composted)
• Green manure crops
• Sewage sludge
• compost
Soil Water
Capillary Water = available to plants
• Maximum Cap water = field capacity
• The amount of water available to plants is determined by:– Texture of the mineral component
– % organic material
Water holding capacity = field capacity - wilt
» SANDY SOILSILT/LOAM
• FIELD CAP 7.6 30.4• % WILT 3.7
20.6
• AVAILABLE H2O 3.9 9.8
• Soil texture and % organic mater determines the amount of water available to plants
Soil Atmosphere
• High in CO2, low in O2
• O2 necessary for cellular respiration in roots
• Aquatic plants have special adaptations
Soil Organisms
• Bacteria, Fungi, algae = 75% of the dry weight of organisms
• Worms = 12% dry weight
• Invertebrates = 13%
• A– Leaching
– Most plant growth
– Humification
• B– Deposition
– Less organics
– N+K
C.
Parent material
Horizons
NutrientsMacronutrients
• % dry weight of plant• Ca .5%• Mg .2%• S .1%• O 45%
• H 6%• C 45%• N 1.5%• P .02%• K 1.0%
NutrientsMicronutrients .01% to .00001%
• % dry weight of plant• Mo• B• Fe• Cl
• Cu• Zn• Mn
C HOPKINS CAFÉ MIGHTY GOOD, BUT MANY
MORE PREFER CLARA’S ZANY CUP
Nitrogen Fixation
Oats as a green manure crop
Soil fertilization
• Chemical N:P:K – comes from industry– Very concentrated– Easy to apply
• Organic– Comes from animals plants or rocks– Without a lot of processing– Low nutrient, heavy– Comes with a lot of organic material bulk
Fertilizer analysisis the % by weight of a nutrient
• N in the form of elemental Nitrogen
• P is Phosphorus as P2O5
• K is Potassium as K2O
• All commercial fertilizer must have N:P:K: on the bag.
analysis ratioN P K33 0 0 Ammonium Nitrate 1:0:02 1 2 Sheep Manure 2:1:225 5 10 Lawn Fertilizer 5:1:210 10 10 Vegetable Fertilizer 1:1:1
The ratio is important, grass needs lots of N, veggies will not produce if they get lots of N.
A soil test will tell you what your soil is lacking
• Call or visit the ag extension office and get a soil test kit
• Follow the directions, send it in, and the results take about 2 weeks.
• Add the nutrients as listed on your test report
• Look at table 14-9 pg 437-439