WATER QUALITY PRACTICES
Combinations of water quality practices produce risk reduction results that are greater than
the addition of individual practices. As an example, terraces, integrated pest management
(IPM),
no-till, and filter strips all reduce water quality risks. However, using all four together
reduces sediment and pesticide movement into surface water in a wider variety of weather and
pest conditions than any one practice can offer. Terraces can reduce the impacts of heavy
rainfall events, while no-till and filter strips provide major benefits in moderate rainfall
events, and IPM ensures that only economically viable amounts of pesticides and fertilizer are
used.
The following water quality practices can reduce the potential for contaminants to enter
Higginsville City Lake.
Anti-Backsiphoning Devices: Add-on devices, such as check-valves, to prevent pesticides
or other liquid contaminants from entering water supply systems through pipes or hoses used to
fill mixing and spraying tanks. Backsiphoning can occur when the end of the fill hose is left
below the level of the pesticide or fertilizer solution in a spray tank. If the water flow is
shut off, the solution can back up through the fill hose and enter the water supply system.
Anti-backsiphoning equipment is inexpensive and easy to install. Check valves can be installed
on water hydrants and pumping equipment.
Conservation Tillage (and No-Till): Conservation Tillage is any tillage and planting
system in which at least 30 percent of the soil surface is covered by plant residue after
planting. Conservation tillage can reduce soil erosion and associated pesticide runoff.
Conservation tillage includes mulch till, residue management, ridge-till, and no-till. "The
impact of residue management (conservation tillage) on reducing runoff can be significant. By
reducing erosion, residue management reduces runoff of soil-attached atrazine. Surface residue
helps slow water runoff and increases infiltration, reducing total water runoff. This is
especially true for no-till, which leaves maximum crop residue on the soil surface. On
well-drained soils, no-till can reduce total annual atrazine runoff by up to 90 percent
compared to conventional tillage." (Franti, etal, 1996).
"No-till is a planting system where soil is undisturbed except for planting and
fertilizer application. Soil infiltration increases, reducing runoff. However, large runoff
events that occur shortly after atrazine application can result in high atrazine runoff. Total
annual runoff will depend on soil type. Poorly drained clays and silts may not have as great a
runoff reduction with no-till as well-drained soil." (Franti, et al, 1996)
The tillage system to use should be determined by the soil type, soil conditions and producer
goals. No-till studies done on claypan soils did not always show less water and pesticide
runoff when compared to conventional tilled systems. On poorly drained soils, some cases showed
that more water and pesticide runoff occurred under no-till than under conventional tillage. On
soils with poor internal drainage, some type of reduced tillage with incorporation of the
herbicides is recommended (Quarles and Tate, 1995).
Contour Cropping: Contour farming involves preparing land, planting, and cultivating on
the contour, without significant grade in the rows. Depending on soil infiltration rates,
contour rows should not usually exceed 2 percent grade. Grades above 0.4 percent should end in
grassed waterways or other practices to control concentrated flow of runoff. Contour farming
can reduce soil erosion by 40 to 60 percent compared to rows planted up and down the hill.
Because of reductions in water runoff, this technique is also effective in reducing pesticide
runoff.
Contour Grass Strips (and Contour Strip Cropping): Alternating contour row crops with
permanent grass strips on the contour can reduce soil erosion and runoff more than contour
cropping without grass strips. The addifion of permanent grass to a field further reduces the
amount of pesticides used in the field and therefore reduces the potential for pesticides
entering the stream system. Grass strips can also trap some pesticide runoff. Grass strips may
be used for hay or grazed after crop harvest when crop fields are gleaned by livestock.
Cover Crops: Cover crops can be grasses, legumes, or small grain grown primarily to cover
and protect the soil surface during periods when the major crops do not give adequate cover.
They reduce soil erosion and improve soil infiltration, aeration, and tilth.
Cover crops of small grains provide some control of broadleaf weeds. Cover crops of legumes
provide an additional source of nitrogen fertilizer. They may be baled for livestock feed or
grazed before planting spring crops. They may be eliminated using contact herbicides, tillage
or by mowing. Cover crops may be established immediately after row crop harvest or seeded into
standing crops using aerial seeding.
Critical Area Planting: Planting grasses, legumes, trees, or shrubs on high risk areas
can greatly reduce the potential for impaired water quality. Permanent ground cover greatly
reduces soil erosion. Areas that have a high risk for pesticide movement or soil erosion should
be planted to permanent-type vegetation and pesticides should not be used. Critical areas may
be very small portions of fields that are very steep, have high risk soils, or cannot be
protected by other cropping practices. Critical areas may also be larger, such as quarter-mile
buffers surrounding public water supply lakes.
Crop Rotations: Crop rotations can reduce insect and disease problems. Rotations that
include small grains or forage crops can greatly reduce the risk of herbicide runoff. Legumes
such as soybeans, alfalfa, clover, and vetch can provide a cash crop of seed or forage and also
add nitrogen fertilizer for Corn, milo, or small grains. Rotations with forages grown at least
50 percent of the time can improve water quality and diversify farming operations. Marketing and
producing forages requires different equipment and expertise than row crops and should be
undertaken with assistance from University Extension, NRCS, agricultural businesses, and
experienced farmers.
Dams: Includes grade stabilization dams, water and sediment control basins, and ponds.
Dams can eliminate gully erosion, provide livestock water, trap pesticides and sediment, and
improve wildlife habitat. Livestock should be excluded from the dam and water line. Livestock
watering troughs should be installed below the dam so that livestock will not cause erosion
or disturb aquatic habitat.
Filter Strips (Set-backs, Riparian Corridors, or Buffer Strips): A filter strip is an
area of permanent vegetation (grasses or wooded) between a crop field edge and a surface
waterbody or drainageway. Effective filter strips must distribute surface water runoff over a
large area of the vegetative filter strip. When water flow is concentrated in a narrow area of
the filter strip there is little opportunity for filtering to take place, especially during high
or fast water flow.
Filter strips or riparian zones along streams provide stream bank protection, wildlife habitat,
and some water quality benefits. Eliminating the use of pesticides near water can reduce the
amounts of pesticides being transferred by runoff. Set-backs are required for some pesticides
and can reduce surface water contamination (Franti et al, 1996).
Grassed Field Borders: Field borders and cropland end rows seeded to permanent grasses
can greatly reduce ephemeral gully erosion and trap some sediment from sheet and rill erosion.
Trapped sediment and associated pesticide and fertilizer runoff from sheet flow in low rainfall
events can be significant. Water quality benefits occur through a reduction in potential
contaminant application in this critical area.
Grassed Waterways: Grassed waterways direct concentrated-flow runoff to stable outlets.
They can be used as outlets for terraces, to prevent gullies, or as filter areas for sediment
and pesticides. Some runoff reduction occurs for small rainfall events when water flows slowly
through the waterway, allowing most of the water to infiltrate. Heavy rainfall events may cause
atrazine and other pesticides to stay in suspension or solution and flow into streams.
Integrated Pest Management (IPM): A pest control system (based on field scouting) that
anticipates and prevents pests from reaching economically damaging levels. Pests are controlled
by using all suitable tactics, including natural enemies, pest resistant plants, mechanical
management, and judicious use of pesticides. IPM is a component of Integrated Cropping
Management (ICM). (Refer to ICM and economic threshold in the Glossary.)
Field Scouting: Inspecting fields for pests and pest damages on a regular basis in order
to detect problems and recommend treatment before the problems become too serious to
economically treat. Field scouting is a necessary part of IPM in order to provide prevention
rather than rescue treatment.
Limited Stream and Drainageway Access: Livestock in streams and drainageways can cause
water quality problems. Manure deposited by drinking or loafing livestock in a drainageway adds
nutrients, organic matter, and bacteria to the water. Livestock disturb the channel and
streambanks creating soil erosion that adds sediment to the stream system and water supply
reservoir.
Livestock access to streams and drainageways should be limited by one of the following methods:
1) constructed barriers of woven wire, barbed wire, or electric fencing, 2) living fences of
trees or shrubs, or 3) arrangement of fields accessed by livestock. The type of fence will
depend on the kind of livestock to be excluded and land user objectives. If access is needed
for livestock water or shelter then efforts should be made to reduce impacts by protecting the
soil surface and preventing, manure from entering the stream system.
Manure Applicator Calibration: Land application of livestock wastes can be an
environmentally acceptable means of managing wastes and using the fertilizer value. Due to
environmental concerns, farmers need to closely match manure spreading with crop fertilizer
needs and can no longer afford to just spread manure. The land application operation should be
given the same attention as spreading commercial fertilizer.
Manure applicators (or spreaders) should be calibrated using the weight of manure spread on a
given ground area with a given travel speed, spreader setting, power take-off speed, lane
spacing, and nutrient analysis of the manure. Proper manure applicator calibration will ensure
that manure is managed in an environmentally sound manner with maximum benefit of crop
nutrients. Refer to University of Missouri, Water Quality Guide Sheet WQ-213, "Calibrating
Manure Spreaders."
Pesticide Banding: Total pesticide use can be reduced by applying relatively narrow
bands of chemical, rather than broadcasting over the entire field. Some insects reside primarily
in seed furrows or crop rows. Insecticides to control these particular insects can be applied
either in the furrow or banded directly over the row. Weeds can be controlled between rows by
mechanical cultivation and herbicide use can be reduced to bands directly over the crop row.
Banding pesticides can effectively reduce the amount of pesticides applied. However, caution
should be taken to ensure economic control. Mechanical cultivation is time-consuming and it may
be difficult to cultivate fields before weed pests create an economic problem. Crop scouting and
IPM are strongly recommended complements to pesticide banding in order to improve pest
control.
Pesticide Container Disposal: Empty pesticide containers are not necessarily empty. As
much as 2 to 4 ounces of chemical may remain inside an empty un-rinsed container. An un-rinsed
container cannot legally be disposed of anywhere but in a hazardous waste landfill. Properly
rinsed containers can be disposed of in any landfill. Triple rinsing and jet spray are two
common ways to properly rinse pesticide containers. Recycle containers through a recycling
program whenever possible.
Triple Rinsing: 1) Empty the container into the spray tank and let it drain for 30
seconds. 2) Fill containers designed to hold less than 5 gallons about one-fourth full with
clean water. Fill containers designed to hold 5 gallons or more about one-fifth full with clean
water. 3) Shake or swirl the container vigorously to time all inside surfaces. 4) Empty the
rinsate into the spray tank and let it drain for 30 seconds. 5) Repeat the procedure two more
times. 6) Puncture the bottom so the container cannot be reused.
Jet Spray: 1) Drain the container into the spray tank. 2) While the container is still
on the tank, thrust the pressure rinse nozzle through the bottom of the container and rinse for
sixty seconds. Rinsate must drain directly into the spray tank. 3) Allow time to drain, then
remove the clean container. * Rinse containers immediately after emptying to prevent the
chemical from drying. Dry, caked chemicals make the containers harder to rinse. * Do not dump
pesticide rinse water on the ground. * Always wear protective clothing.
Pesticide Selection: Pesticide selection should be based on costs, economic thresholds,
soil characteristics (such as organic matter and potential for runoff and leaching), pest
pressure, and watershed sensitivity. University Extension agronomists, ICM specialists, crop
scouts, and pesticide sales representatives can provide advice. Pesticide labels, soil tests,
and the county soil survey are effective selection tools. Pesticides should be selected by
considering environmental and economic impacts and goals. The cheapest or most expensive
pesticide may not necessarily be the best economic or environmental choice.
Pesticide Timing: The timing of pesticide application should be based on soil moisture,
anticipated weather conditions, and realistically anticipated pest pressures. Using IPM (crop
scouting and economic thresholds) can be the most cost-effective and environmentally safe way
to use pesticides.
Soil Tests for Plant Nutrient and Fertilizer Application: High yields of top quality
crops require an abundant supply of nutrients. Soil testing and recommendations for optimum
yields offer the most economic and environmental approach to crop fertility. Optimum yields are
more desirable than maximum yields. A field may produce 250 bushels of corn using a large
amount of fertilizer, but maximum net return may be the result of a 150 bushel yield where less
fertilizer is required. Refer to University of Missouri, Agricultural Guides 9075 "How to
Take a Good Soil Sample," 9076 "Soil Treatments Based on Soil Tests," and 9100 "Soil Test
Interpretations for Fertilizing and Liming Missouri Soils."
Split Herbicide Application: Split application of some herbicides using early pre-plant
and later pre-emerge or post-emerge applications can increase the effectiveness of weed control
and reduce environmental risks. Split application costs more since it involves an additional
pass over the field and increases the risk that weather will prevent timely weed control. The
benefits of additional weed control on yield may offset the additional application cost.
Farmers and water-users benefit from the environmental advantages of split application.
Sprayer Calibration: Accurate applicator calibration can avoid uneven application of
pesticides. As a minimum, each spray nozzle should be checked (calibrated) to determine if all
nozzles are applying equal streams of pesticide and fertilizer solution. This should be done at
the beginning of each planting or spraying season and every time that nozzles are changed. If
application is not even then nozzles, hoses, and injection manifolds should be cleaned or
replaced as needed. Refer to University of Missouri, Agricultural Guide 1270, "Sprayer
Calibration - Broadcast Sprayers."
Terraces: Terraces reduce soil erosion and sediment content in runoff, improve water
quality, intercept and conduct surface runoff at a non-erosive velocity to a stable outlet,
retain runoff for moisture conservation, prevent gullies, and reduce flooding. Terraces should
be constructed as close to the contour as possible. Contour farming combined with terraces can
reduce soil erosion by 50 to 70 percent.
Grassed backslope and narrowbase terraces improve wildlife habitat by providing grassed areas
in row-crop fields. Grasses are a source of food, cover, and nesting habitat.
Wetland Development: Creation of wetlands can provide water quality benefits, improve
and increase fish and wildlife habitat, reduce flooding, and provide educational and aesthetic
benefits. Wetlands provide water quality benefits by filtering sediment and attached nutrients
and pesticides. They slow the flow of water to allow nutrients to be taken up by the plants and
micro-organisms. Leaching of nutrients and pesticides into groundwater is usually reduced
because wetlands are often situated on slowly permeable soils. Wetlands created along and in
drainageways to Higginsville City Lake can provide water quality benefits to the public water
supply reservoir.
Development consists of excavating the area or constructing dikes to contain the wetlands.
Suitable sites have soils that will retain water without excessive seepage, are suitable for
construction of embankments, and have an adequate surface or subsurface water supply. Water
level control structures can also be used for wetland development purposes. These structures
control water levels with gates or stop logs.
Wetlands should be constructed with an irregular shoreline to create more edge habitat. At least
50 percent of the planned water area should be 18 inches deep or less. All earth spillways
should be established in permanent-type vegetation. Side slopes along the shoreline should be
relatively flat (8:1 or flatter) to encourage natural revegetation and prevent muskrat damage.
Livestock should be excluded from all wetland areas to maintain wetland wildlife habitat and
water quality benefits.
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