 What is Depth of Soil?  The thickness of soil layers which have favorable permeability  What is permeability? The downward movement of water in soil.  /meec/module06/Percol ation.html /meec/module06/Percol ation.html

 What to look for to Determine Depth of Soil  What grows in soil?  For agriculture root growth and is important for plant growth.  Why is it important Plant strength, water & nutrient ability

 Root Restrictive Layer A.Rock – layers of jointed or solid rock is unfavorable for root growth. B. Fragipan – compacted, hard & brittle when dry(irregular patterns of yellowish browns) C. Coarse sand or gravel – limits moisture holding ability not enought for roots. D. Dense Glacial Till – tightly bounded & compacted soil – usually massive

 Deep Soils  Roots deeper than 40” is considered deep soils  Anything above 40” is considered to have a root restrictive layer

Plants roots require a favorable balance of air and water for optimal growth. Infiltration – The process of water soaking into the soil (topsoil) Saturation – Is when the pore space in the soil are filled up with water and there is no more to grow What happens to the plants?

Field Capacity Field Capacity When all the pore spaces in the soil capable of hold H20 against the pull of gravity are completely filled. Wilting Point – Only thing is available is hydroscopic H20 & plants begin to wilt (long dry spells)

Found in subsoil Look at subsoil color when moist. Subsoil color Uniform browns or reddish brown to 40” or deeper is good air & H20 movement.

A mixture of light to dark grays or irregular patterns of colors This represents – Drainage problems So how can we improve air and H20 movement in the soil? Install 1. Tile 2. Surface drainage (ditches, grass waterways or diversion channels)

Gravitational Water Is water draining down the soil through the poor space Capillary Water Water held between soil particles against the force of gravity. (dries out travels upward) Hydroscopic Water H20 that forms a thin film around individual soil particles. (even in the driest soils)

WHAT ARE THE 5 FACTORS OF DETERMINING SOIL USAGE?  1. Slope  II. Erosion Depth of Top Soil  III. Soil Texture  IV. Depth of Soil  V. Natural Drainage Class

LAND CAPABILITY CLASSES  This is the overall rating of the soil usage and its difficulty to overcome/  Note:  Always check the most severe

CONSERVATION PRACTICES Used to determine which best conservation practices should be used on this land. It can vary from land to land What is conservation practices? Practices are which help protect, preserve & improve soil.