Soils Fertility Final exam

Dordt University soils final study cards

Soil

Weathered upper surface of the Earth's crust that supports plant growth

Soil Forming Factors

Parent Material, Climate, Topography, Organisms, Time, Humans

Aeolian

Wind blown sediment

Soil Forming Processes

Additions, Losses, Translocations (up and down), Transformations (chemical change)

Soil Physical Processes

Color, Texture, Structure, Profile, Density, Pore Space, Aggregation, Water-Holding Capacity

Sand

Gritty

Silt

Smooth

Clay

Sticky

Soil Textural Classes

Sand - 50%, Silt - 15%, Clay - 35%

Soil Structure

Granular < 0.5 cm, Platy, Blocky 1.5-5cm, Columnar, Single-grained

Particle Density

mp/vp

Bulk Density

mp/vb

High Db

Low pore space

Water Potentials

Force that causes water to move or not

Gravitational Water Potential

Acceleration due to gravity x soil height

Matric Water Potential

Adhesion and Capillarity

Osmotic Water Potential

Water movement across a semipermeable membrane to equalize concentration of solutes

Plant Water Use

Evapotranspiration

Types of Water Movement in Soil

Saturated Flow, Unsaturated Flow, Vapor Movement

Types of Irrigation

Surface (Flood), Sprinkler, Drip

What is pH?

Concentration of H+ ions in a solution

5 Sources of H+

Carbonic Acid, SOM, Fertilizers, Cation Uptake, Precipitation

Liming Materials

CaCO3 - Calcium Carbonate (Limestone), CaO - Calcium Oxide (Quick Lime), Ca(OH)2 - Calcium Hydroxide, CaMg(CO3)2 - Dolomite, CaSO4 - Gypsum

Liming Methods

Slow Reaction, Few weeks: Quick Lime and Slaked Lime, Year: Finely ground limestone, LIME 6-12 MONTHS BEFORE SEEDING CROP, REAPPLY EVERY 3-5 YEARS IN FALL

Salinity

Recharge - where H2O comes from, Discharge - where H2O evaporates, Seep - whole network of recharge-discharge