Soils Genesis and Characterization Department of Agricultural and Biological Engineering University of Illinois at Urbana-Champaign

95B—Southern Wisconsin and Northern Illinois Drift Plain 98—Southern Michigan and Northern Indiana Drift Plain 105—Northern Mississippi Valley Loess Hills 108A and 108B—Illinois and Iowa Deep Loess and Drift 110—Northern Illinois and Indiana Heavy Till Plain 113—Central Claypan Areas 114B—Southern Illinois and Indiana Thin Loess and Till Plain, Western Part 115A, 115B, and 115C—Central Mississippi Valley Wooded Slopes 120B—Kentucky and Indiana Sandstone and Shale Hills and Valleys, Northwestern Part 131A—Southern Mississippi River Alluvium 134—Southern Mississippi Valley Loess

Typical cross section showing the relationship of parent materials to soils in Cass County.

Soils Occur in Associations

Sable-Ipava Soil Association

This poorly drained "prairie soil" formed in more than 60 inches of loess. There are about 925,000 acres mapped in Illinois. It has a PI of 155. Sable Silty Clay Loam

Typical pattern of soils and parent material in the Drummer-Flanagan association.

This poorly drained "prairie soil" formed in 40 to 60 inches of loess over Wisconsinan drift. It occupies nearly 1.6 million acres. It has a high management level productivity index (PI) of 150. Drummer Silty Clay Loam

Typical pattern of soils and parent material in the Hoyleton-Cisne association.

This poorly drained "gray prairie soil" formed in 30 to 55 inches of loess over Illinoian drift. About 730,000 acres occur in south central Illinois. It has a PI of 115. Cisne Silt Loam

Typical pattern of soils and parent material in the Titus-Beaucoup- Tice association.

Soil Constituents Solid ParticlesSoil SolutionAir

Saturated (all pores filled) ‏ Field Capacity (Some air, some water) ‏ Wilting point (water too tightly held for plant use) ‏

Water held in large pores Available for crop use Capillary Water Gravitational Water Field Capacity Water adheres to soil particles Water drains through soil profile Hydroscopic Water Wilting Point

Flowing Tile Positive Pressure i.e. Saturation must occur above tile drains for water to enter.

Classification of Particles

Simplified Soil Texture Triangle Soils with more than 30% clay are Clays Soils with % clay are Clay Loams Soils with less than 20% clay are Loams unless they have more than 80% sand Soils with more than 80% sand are Sands Soils with more than 50% sand are Sandy Soils with more than 50% silt are Silty Sable

Water States by Soil Texture

Classification by Permeability less than 0.06 inch per hour Very slowly permeable 0.06 to 0.2 inch per hour Slowly permeable to 0.6 inch per hour Moderately slowly permeable to 2 inches per hourModerately permeable 2 2 to 6 inches per hour Moderately rapidly permeable More than 6 inches per hour Rapidly permeable 1

The water table is near the surface only during the very wettest periods Somewhat poorly drained B The water table remains near, at, or above the surface much of the time Very poorly drained The water table is at or near the surface during the wetter seasons of the year Poorly drained A Classification by Natural Drainage

Soil Drainage Groups DRAINAGE GROUP 2A ( moderately permeable, poorly or very poorly drained ) 633 Traer261 Niota136 Brooklyn45 Denny 576 Zwingle218 Newberry120 Huey26 Wagner 474 Piasa208 Sexton112 Cowden16 Rushville 460 Ginat206 Thorp109 Racoon12 Wynoose 287 Chauncey165 Weir84 Okaw 2 Cisne DRAINAGE GROUP 4A ( slowly and very slowly permeable, poorly or very poorly drained ) 316 Romeo329 Will153 Pella125 Selma 648 Clyde252 Harvel 152 Drummer 68 Sable 594 Reddick 244 Hartsburg 142 Patton67 Harpster

A cube of soil measures 10 x 10 x 10 cm and has a total (wet) mass of 1460 g, of which 260 g is water. Determine the volumetric water content, soil porosity, and degree of saturation. Volumetric water content Volume of soil = 10x10x10 = 1000 cm 3 Volume of water = mass of water/density of water = 260 (g) /1 (g/cm 3 ) = 260 cm 3 Volumetric water content = volume of water/volume of soil = 260/1000 = 0.26

A cube of soil measures 10 x 10 x 10 cm and has a total (wet) mass of 1460 g, of which 260 g is water. Determine the volumetric water content, soil porosity, and degree of saturation. Porosity Mass of solids = wet mass of soil – mass of water = 1460 – 260 = 1200 g Volume of solids = mass of solids/density of solids = 1200 (g) / 2.65 (g/cm 3 ) = cm 3 Volume of fluids = total volume – volume of solids = 1000 – = cm 3 Porosity = volume of fluids/volume of soil = 547/1000 = 0.55

A cube of soil measures 10 x 10 x 10 cm and has a total (wet) mass of 1460 g, of which 260 g is water. Determine the volumetric water content, soil porosity, and degree of saturation. Degree of Saturation Degree of saturation = volume of water/volume of fluids = 260/547 = = 47.5%

A bucket contains 22 kg of soil for which the gravimetric water content (mass of water/mass of solids) was found to be Determine the volume of water in the bucket.. Gravimetric water content = mass of water/mass of solids 0.18 = mass of water/(22 – mass of water) mass of water= 22 x 0.18 – 0.18 * mass of water 1.18 * mass of water= 3.96 kg mass of water = 3960 (g) /1.18 = 3356 g Volume of water = mass of water/density of water = 3356 (g) /1 (g/cm 3 ) = 3356 cm 3

A 90 cm soil column has a volumetric water content of Determine the quantity of water that must be added to bring the volumetric water content up to 0.30 Required volume (depth) of water = 90 x 0.3 = 27 cm Current volume (depth) of water = 90 x 0.12 = 10.8 cm Additional volume (depth) of water = 27 – 10.8 = 16.2 cm

Determine the gravity drainable volume (depth) and the plant-available soil water storage capacity in the following soil from Logan County, Illinois. (Porosity = 1 – dry bulk density/2.65) Depth (cm) Dry Bulk Density (g/cm 3 ) Volumetric Water Content 1/3 bar (%) 15 bar (%)

Determine the gravity drainable volume (depth) and the plant-available soil water storage capacity in the following soil from Logan County, Illinois. (Porosity = 1 – dry bulk density/2.65) Sum = Sum = Plant available water (cm) 1/3 bar w.c. – 15 bar water content Gravity drainable volume (cm) Gravity drainable porosity (%) Porosity (%) Depth Increment (cm) Depth (cm)