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Introduction to Soils. What is soil ?. A natural body of broken down and weathered mineral and organic matter capable of growing plants. Five factors of soil formation. Five factors of soil formation. Parent material – source of minerals. Five factors of soil formation.
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What is soil? A natural body of broken down and weathered mineral and organic matter capable of growing plants.
Five factors of soil formation. • Parent material – source of minerals.
Five factors of soil formation. • Parent material – source of minerals. • Topography – landscape position.
Five factors of soil formation. • Parent material – source of minerals. • Topography – landscape position. • Climate – mostly moisture, temperature.
Five factors of soil formation. • Parent material – source of minerals. • Topography – landscape position. • Climate – mostly moisture, temperature. • Organisms – mostly plants, type of plants.
Five factors of soil formation. • Parent material – source of minerals. • Topography – landscape position. • Climate – mostly moisture, temperature. • Organisms – mostly plants, type of plants. • Time!
As soils form over time, distinct layers, or soil horizons form.
Major soil horizons. (Soils may or may not have all of these horizons!) O – organic debris on surface. A – the topsoil. E – ‘eluviated’, leached/bleached. B – weathered, structured subsoil. C – unweathered, unstructured subsoil. R – bedrock.
Effect of natural vegetation on soil development with time and the horizons that develop.
Some examples of soil parent materials.
Alluvium Rich alluvial soil deposits.
Loess Wind-blown, silt-sized deposits.
Residium Weathered bedrock.
The study of soils can be fun and exciting! Can’t you tell by these fine soil scientists in training?
FERTILIZER FACTS AND FIGURES
13 – 13 - 13 % N % P expressed as P2O5 % K expressed as K2O How much is there? Multiply by %/100. How much is needed? Divide by %/100.
Example How much N, P and K are in a 50 lb bag of 10-20-20 fertilizer?
Example How much N, P and K are in a 50 lb bag of 10-20-20 fertilizer? N: 50 lbs X 0.10 = 5 lbs
Example How much N, P and K are in a 50 lb bag of 10-20-20 fertilizer? N: 50 lbs X 0.10 = 5 lbs P: 50 lbs X 0.20 = 10 lbs
Example How much N, P and K are in a 50 lb bag of 10-20-20 fertilizer? N: 50 lbs X 0.10 = 5 lbs P: 50 lbs X 0.20 = 10 lbs K: 50 lbs X 0.20 = 10 lbs
Example 2 How many lbs of 34-0-0, 0-48-0 and 0-0-60 are needed to get 90-45-60 lbs/acre N-P-K?
Example 2 How many lbs of 34-0-0, 0-48-0 and 0-0-60 are needed to get 90-45-60 lbs/acre N-P-K? N: 90 / 0.34 = 265 lbs / acre
Example 2 How many lbs of 34-0-0, 0-48-0 and 0-0-60 are needed to get 90-45-60 lbs/acre N-P-K? N: 90 / 0.34 = 265 lbs / acre P: 45 / 0.48 = 94 lbs / acre
Example 2 How many lbs of 34-0-0, 0-48-0 and 0-0-60 are needed to get 90-45-60 lbs/acre N-P-K? N: 90 / 0.34 = 265 lbs / acre P: 45 / 0.48 = 94 lbs / acre K: 60 / 0.60 = 100 lbs / acre
The difference between fertilizer grade and fertilizer ratio is: EXAMPLE GRADE: 6 – 12 - 24 RATIO: 1 – 2 - 4
soil tilth – relative term describing the workability of the soil for seedbed preparation.
General tillage systems: • Conventional – primary + secondary + seedbed preparation. 2. Conservation tillage – leaves 30% surface residue. 3. No-till – planting into stubble or residue.
CONVENTIONAL TILLAGE PLOW DISK PLANT PREP
Up and Down Hill Planting (Notice the accelerated soil erosion!)
Fallow Farming Used in semi-arid regions with unirrigated crops to conserve moisture. Field is only planted every other year to allow for soil moisture storage.