Soil Survey of McHenry County, Illinois Part I - Soil Data Mart

176 Soil Survey of
The management concerns affecting the use of the
soils in the survey area for pasture are shown in table
8. The major management concerns affecting pasture
are water erosion, low pH, equipment limitations, low
fertility, a gravelly surface layer, and low available
water capacity.
Pastureland soils that are susceptible to water
erosion meet the following criteria: The value of K
factor multiplied by the slope is greater than 0.8, and
the slope is equal to or greater than 3 percent.
Water erosion reduces the productivity of
pastureland. It also results in onsite and offsite
sedimentation, causes water pollution by
sedimentation, and increases the runoff of livestock
manure and other added nutrients.
Measures that are effective in controlling water
erosion include establishing or renovating stands of
legumes and grasses. Controlling erosion during
seedbed preparation is a major concern. If the soil is
tilled for the reseeding of pasture or hay crops,
planting winter cover crops, establishing grassed
waterways, farming on the contour, and using a
system of conservation tillage that leaves a protective
cover of crop residue on the surface can help to
minimize erosion.
Overgrazing or grazing when the soil is wet
reduces the extent of plant cover and results in
surface compaction and poor tilth, and thus it
increases the susceptibility to erosion. Proper stocking
rates, rotation grazing, and timely deferment of
grazing, especially during wet periods, help to keep
the pasture in good condition. The proper location of
livestock watering facilities helps to prevent surface
compaction or the formation of ruts by making it
unnecessary for cattle to travel long distances up and
down the steep slopes.
Soils that have low pH, or low reaction, have a pH
value equal to or less than 5.5 in the surface layer.
Low soil reaction inhibits the uptake of certain
nutrients by the plants or accelerates the absorption of
certain other elements to the level of toxic
concentrations. Either of these conditions affects the
health and vigor of plants. Applications of lime should
be based on the results of soil tests. The goal is to
achieve the optimum pH level for the uptake of the
major nutrients by the specific grass, legume, or
combination of grasses and legumes.
Soils that have low fertility meet the following
criteria: The average content of organic matter in the
surface layer is less than 1 percent, and the cationexchange
capacity is equal to or less than 7
milliequivalents per 100 grams of soil.
In areas where slopes are 10 percent or more, the
operation of farm equipment may be restricted.
Low fertility levels affect the health and vigor of the
plants and thus have direct impact on the quantity and
quality of livestock produced. Additions of fertilizers
and other organic material should be based on the
results of soil tests, on the needs of specific plant
species, and on the desired level of production.
In areas where the soils have more than 15 percent
gravel in the surface layer, seedbed preparation and
renovation practices may be hindered. The cobbles
and stones can be removed or piled in a corner of the
field.
Available water capacity is low when it is a
weighted average of less than 0.10 inch of water per
inch of soil within a depth of 40 inches or when it is a
weighted average of less than 3 inches in the root
zone if the root zone is less than 40 inches thick.
Available water capacity refers to the capacity of soils
to hold water available for use by most plants. The
quality and quantity of the pasture may be reduced if
the available water is inadequate for the maintenance
of a healthy community of desired pasture species
and, thus, the desired number of livestock. A poor
quality pasture may increase the hazard of erosion
and increase the runoff of pollutants. Planting droughtresistant
species of grasses and legumes helps to
establish a cover of vegetation. Irrigation may be
needed.
Prime Farmland and Other
Important Farmland
Prime farmland is of major importance in meeting
the Nation’s short- and long-range needs for food and
fiber. The acreage of high-quality farmland is limited,
and the U.S. Department of Agriculture recognizes
that government at local, state, and Federal levels, as
well as individuals, must encourage and facilitate the
wise use of our Nation’s prime farmland.
Prime farmland soils, as defined by the U.S.
Department of Agriculture, are soils that are best
suited to food, feed, forage, fiber, and oilseed crops.
Such soils have properties that favor the economic
production of sustained high yields of crops. The soils
need only to be treated and managed by acceptable
farming methods. An adequate moisture supply and a
sufficiently long growing season are required. Prime
farmland soils produce the highest yields with minimal
expenditure of energy and economic resources, and
farming these soils results in the least damage to the
environment.
Prime farmland soils may presently be used as
cropland, pasture, or forestland or for other purposes.
They either are used for food and fiber or are available