Glen Sampson
Components of soil
 Soil is a complex
mixture of organic and
inorganic components
and living organisms.
Soil profile
 Consists of layers
called horizons.
 Simplest:
 A = topsoil
 B = subsoil
 C = parent material
 But most have O, A, E,
B, C, and R
Humus
 Dark, crumbly mass of undifferentiated material made up
of complex organic compounds
 Soils with high humus content
 hold moisture better
 are more productive for plant life.
Soil profile
 O Horizon: Organic or litter layer
 A Horizon: Topsoil. Mostly inorganic minerals with some
organic material and humus mixed in. Crucial for plant growth
 E Horizon: Eluviation horizon; loss of minerals by leaching, a
process whereby solid materials are dissolved and transported
away
 B Horizon: Subsoil. Zone of accumulation or deposition of
leached minerals and organic acids from above
 C Horizon: Slightly altered parent material
 R Horizon: Bedrock
Soil characterization
 Soil can be characterized by color and several other traits:
 texture
 Structure
 pH
 Best for plant growth is loam, an even mix of these three
types.
Classifications of soil
 Sandy
 Nutrient-poor soil
 Dries out quickly
 Little binding capacity
 Loamy
 Best soil for growing turf
 Drains well
 Able to retain
important nutrients
 Clay
 Tightly compacted soil
 Does not drain well
Soil amendments
 Organic (material) amendments
 Organic material improves soil structure.
 Organic material can be added to sandy soils to increase
nutrient and moisture retention.
 Clay soils can also be amended with organic material to help
loosen the soil and provide better aeration and drainage.
 Compost is the easiest organic material to use.
 A rotary tiller works best to incorporate the organic material
to your soil.
 A layer of 1 - 2 inches spread over your site should be tilled to
a depth of 3 - 6 inches.
 Agronomically, "excessive" use of these products is the problem.
 Insufficient aeration to incorporate the newly applied material
into the growing media will result in a "layering" effect. The
additional problems are with odour, residents not wanting this
material in the immediate area etc.
 Uless there is a deep layer of organics, the plant roots have a
difficult time penetrating the organic layer and rooting in the
mineral layer beneath. The result is shallow rooting.
 The organic media can easily dry out resulting in turf stress and
an enhanced growth of weeds and insect infestations. Where
applicable, diseases appear more quickly than in mineral soils.
 In brief organic media is more difficult to grow turf in, requires
more intense management.
Benefits and disadvantages of
organic-based sod
 Lighter, easier to install
 Promotes more surface growth with longer deeper
roots which improves survival
 Holds more moisture and nutrients which helps
survival rate when harvested and transplanted
 Retain moisture which helps conserving water
 Holds fertilizer close to root system
 Soil conditioning and improvement abilities
 Peat based sod is suited for residential applications.
 Organic soils, by the nature of their formation, are
poorly drained and require artificial drainage to
prevent injury to turf and to allow maintenance and
harvesting operations to proceed smoothly.
 Maintaining a high water table will reduce soil
subsidence and increase water use efficiency. Lowering
the water table is essential for harvesting and
establishment operations.
Mineral soils
 Consideration should be given to depth of soil, presence of
hardpan layers, stones and drainage.
 Sod grown on mineral soils is preferred for heavy traffic
areas such as athletic fields, tees and playgrounds.
 Sod produced on mineral soil weighs more than sod from
organic soil. The lighter weight of the organic soil allows
cheaper transportation costs and greater ease in harvesting
and handling.
 The time required to produce a harvestable crop is 12 to 18
months on organic soil while the production period on
mineral soil is often 3 to 6 months longer. However, the
cultural practices affect the production time considerably.
 When considering soil type:
 look at the depth of the soil and the uniformity of both the
soil depth and the depth within a field.
 Consider the need for tile drainage and drainage ditches as
well as the feasibility of lowering the entire drainage system.
 Sandy loam is the best soil for sod production.
 Although sod will grow on muck or organic soils, the yield
is much lower.
 Harvesting is very difficult on sod that is grown on heavy
ground or clay because it gets too heavy when it is wet and
too hard when it is dry.
 Lime can be applied to the soil to increase the pH to
5.5-6.0 on organic soils and 6.0-6.5 on mineral soils.
 Nitrogen use should be based on
 soil texture
 rate of nitrogen release from the soil, especially on
organic soils
 requirements for the turfgrass species or cultivars
 moisture conditions
 growth rate of the grass, giving particular attention to
the effect of temperature.
 The release of nitrogen from the organic soil is an
important variable which must be considered.
 Increasing the rate of nitrogen application can result
in decreased root and rhizome weights in September
 The higher nitrogen treatment can increase shoot
growth, causing a decrease in the soluble carbohydrate
levels found in the rhizomes in September. There can
be a corresponding decrease in sod strength
measurements in October.
 The nitrogen response of turfgrass grown for sod on
mineral soils is more consistent than that of turfgrass
on organic soils.
 Timing of nitrogen applications is also an important
factor in sod production.
 By doubling the rate of nitrogen application in
September, Kurtz (2) found a significant increase in
the rhizome length compared to uniform monthly
applications.
 Sod strength was also increased by the higher nitrogen
application in September.
Sod on Organic soils
 Organic soils, by the nature of their formation, are poorly
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drained and require artificial drainage to prevent injury to turf
and to allow maintenance and harvesting operations to proceed
smoothly.
In many cases the drainage water must be lifted by pumping into
an outlet. A drainage reservoir will allow control of the water
table in the soil, if adequate tiling exists.
Maximum flexibility is obtained if the water table can be varied
field by field and according to the season of the year.
Maintaining a high water table will reduce soil subsidence and
increase water use efficiency.
Lowering the water table is essential for harvesting and
establishment operations.
 Rolling is generally more effective on organic soils
because of their more elastic nature.