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

172 Soil Survey of
Figure 3.—With the population rising in the county, the demand for nursery crops has increased.
breakdown in the soil. Splitting chemical applications,
particularly of nitrogen, is beneficial. This practice
reduces the risk of excessive leaching from a one-time
application. Another measure for preventing groundwater
contamination is planting legumes in a crop
rotation or as a cover crop. This practice adds nitrogen
to the soil, thereby reducing the amount of nitrogen
needed in chemical applications. The practice of crop
rotation is also effective in limiting the buildup of weed
and insect populations and thus reduces the amount
of herbicides and insecticides needed per application.
Finally, planting small grain cover crops after fertilized
corn crops can be effective in taking up some residual
nitrogen from the soil.
Drainage systems have been installed in most
areas of poorly drained and somewhat poorly drained
soils used as cropland in the county. As a result, these
soils are adequately drained for the commonly grown
crops. Measures that maintain the drainage system
are needed. Poorly drained soils, such as Ashkum,
Dunham, Pella, and Selmass soils, have subsurface
drainage. In addition, surface tile inlets or shallow
surface ditches are required in some areas of poorly
drained soils to remove excess water. Some areas of
somewhat poorly drained soils are wet long enough
that in some years productivity is reduced unless they
are artificially drained. Somewhat poorly drained soils,
such as Elburn, Elliott, Grundelein, and Millstream
soils, have subsurface drainage.
Soil tilth is an important factor influencing the
germination of seeds, the amount of runoff, and the
rate of water infiltration. Soils that have good tilth are
granular and porous and have a high content of
organic matter.
Surface crusting can be a problem in areas of
Caprell and Kidami soils, which have a surface layer
of silt loam that is low in organic matter content.
Generally, the structure of these soils is weak, and a
crust forms on the surface during periods of intense
rainfall. This crust is hard when dry. It inhibits seedling
emergence, reduces the infiltration rate, and increases
runoff and erosion. Regular additions of crop residue,