182 Chapter 10: Appendix
Conservation Cover (327): Establishing and maintaining perennial vegetative
cover to protect soil and water resources on land retired from agricultural produc-
tion.
Agricultural chemicals are usually not applied to this cover in large quantities
and surface and
water quality may improve where these material are not
used. Ground cover and crop residue will be increased with this practice. Ero-
sion and yields of sediment and sediment related stream pollutants should de-
runoff and receiving water may be
crease. Temperatures of the soil
include increases
reduced. Effects will vary during the establishment period
in
erosion and sediment yield. Due to the reduction of deep
the leaching of soluble material will be reduced, as will be the
for
ing saline seeps.
effects of the practice would reduce agricultural
sources of pollution to all water resources.
Conservation Cropping Sequence (328): An adapted sequence of crops de-
signed to provide adequate organic residue for maintenance or improvement of
soil tilth.
by
matter; resulting in a reduc-
This practice reduces
tion of sediment and associated pollutants to surface waters. Crop rotations that
improve soil tilth may also disrupt disease, insect and weed reproduction cycles,
reducing the need for pesticides. This removes or reduces the availability of some
pollutants in the watershed. Deep percolation may carry soluble nutrients and
pesticides to the ground water. Underlying soil layers, rock and unconsolidated
parent material may block, delay, or enhance the delivery of these pollutants to
The fate of these pollutants will be site specific, depending on the
crop management, the soil and geologic conditions.
Conservation
(329)
Any
and planting system in which
at least 30 percent of the soil surface is covered by plant residue after planting to
reduce soil erosion by water; or, where soil erosion by wind is the primary con-
cern, at least 1,000 pounds per acre of flat small grain residue-equivalent are on
the surface during the critical erosion period.
This practice reduces soil erosion, detachment and sediment transport by provid-
ing soil cover during critical times in the cropping cycle. Surface residues reduce
soil compaction from raindrops, preventing soil sealing and increasing
tion. This action may increase the leaching of agricultural chemicals into the
ground water.
In order to maintain the crop residue on the surface it is difficult to incorporate
fertilizers and pesticides. This may increase the amount of these chemicals in the
runoff and cause more surface water pollution
The additional organic material on the surface may increase the bacterial action
on and near the soil surface. This may tie-up and then breakdown many pesti-
cides which are surface applied, resulting in less pesticide leaving the field. This
practice is more effective in humid regions.
With a no-till operation the only soil disturbance is the planter shoe and the com-
paction from the wheels. The surface applied fertilizers and chemicals are not
incorporated and often are not in direct contact with the soil surface. This
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