Originally written February 1, 2006 | Last updated February 23, 2014
Of all natural disasters, drought is the most gradual and hard to predict.
Once it has affected crop growth, farmers and producers enter a new territory of
what if's. What if it rains next week? What if it doesn't rain for a month?
Alternative crops may have to be planted or crop loss assistance applied for. If
feed supplies are low, herds may have to be culled and/or feeds purchased. For
farmers who were already facing financial hardship, a drought can force major
decisions about diversification, irrigation, surviving a major loss or even
selling the farm.
The fact that Wisconsin suffered record droughts as recently as 1976-77
and 1988 underscores the fact that droughts are a natural occurrence.
Fortunately, farmers can take some actions to better prepare for and survive
a drought. The key is a combination of sound farmstead planning and sound
decision-making, based on advice and up-to-date information from resources
like your Cooperative Extension Service.p-to-date information from resources
like your Cooperative Extension Service.
Examine your water use efficiency and irrigation needs.
If you already irrigate, contact your agricultural agent about using the
Wisconsin Irrigation Scheduling Program (WISP). This research-based program
assists growers in determining frequency and amounts of irrigation (if any)
throughout the growing season; it can be extremely helpful during a drought.
If you do not currently irrigate, consult with your agricultural agent and
irrigation system dealers now â€” before a drought occurs. Emergency
irrigation systems are difficult to put in place because of the permitting
process (which may take 30 days or more) and possible lack of equipment
mid-season (dealers generally sell equipment during the winter and spring).
Look carefully at irrigation systems as a long-term investment.
Keep up-to-date forage inventories. Accurate forage
inventories in silos, hay mows and other storage areas help you determine
feed supplies during a drought. Note the amount and accessibility of each
lot of uniform quality forage. Your local feed representative or
agricultural agent can assist you with this process.
Consider alternative on-farm related businesses.
Diversification can be a good long-term approach to revenue shortfalls from
drought. Some potential businesses include:
a) Alternative crops such as shiitake
mushrooms, ginseng, specialty vegetables, greenhouse plants, dried and/or
cut flowers, etc.
b) Alternative livestock, such as llamas,
ducks, bees, deer for venison or mink.
c) Forestry, including cord wood, maple syrup,
apple orchards and Christmas trees.
d) Non-production farm-related ventures such as
camping, fee hunting/shooting preserves, trout ponds, farm vacations, bed
and breakfast establishments, summer camps on the farm, herd sitting, boat
and camper storage, and farm markets. Home-based enterprises including
sewing projects, crafts, catering services, upholstery, secretarial
service/word processing, taxidermy, etc.
During a Drought
Discuss financial and feed assistance in the early phase of a
drought. The earlier you enroll in feed assistance or financial
assistance programs, the sooner you will be eligible for help. See your
county agricultural agent about eligibility for grants, loans and other
types of assistance. Likewise, contact your lender about potential problems
before you are in over your head. You may be able to renegotiate current
payment plans and establish an emergency plan if the drought persists and
additional financing is needed.
Look to your county agricultural agent for up-to-date information
on managing during a drought. As part of a network of county, state
and national research and field experts, your agent receives new information
daily on managing during a drought. If your agent doesn't have the answer to
your question, he or she can find the answer or refer you to the person for
Adjust fertilizer rates. If you haven't already applied
fertilizers, adjust your rates based on lower yield expectancy for the
drought year. If little or no production is expected, consider skipping an
Be prepared to use mechanical weed control. Many
herbicides lose effectiveness during dry periods, making mechanical weed
control your second line of defense against weeds.
Protect livestock from heat. Adequate water, shade and
ventilation in buildings are critical during hot, humid weather . Consider
letting livestock out of buildings to cool them at night. Call a
veterinarian if heat stress is a concern.
Consider alternative crops. If your fields have less
than 12 alfalfa plants per square foot or a 75 percent reduction in corn
stand population, consider alternative forages. Some possibilities include
sudangrass, sorghum-sudan hybrids, milage and millet. Corn silage might be
the best forage alternative; even the worst fields have silage potential.
Discuss possible options with your agricultural agent.
Cull unprofitable cattle. If forage is inadequate,
selling unprofitable livestock may be your next best move. Consider culling
the bottom 5 to 15 percent. Review your options and the economics of the
situation with Extension agents.
Recognize the early warning signs of emotional stress.
Stress can overwhelm farmers and their families. Some of the warning signs
of severe stress include anxiety, depression, anger, violence and
withdrawal. If you see these signs in yourself, a family member or friend,
get outside assistance. Professional counselors, a clergy member or social
worker can help, as well as the Farmers Assistance Hotline for Wisconsin at
Tillage During a Drought
What to do - and not to do - when soils are dry
The best advice on tillage during a drought may be: avoid it. When soils
are dry, you should do everything you can to conserve remaining moisture.
This may mean holding off on plowing, disking and cultivating so as not to
disturb soils and let moisture escape in the process. Keep in mind that any
operation that brings soil up to the surface may worsen conditions. The
guidelines at right offer some general considerations. For advice specific
to your crops and drought conditions, contact your county Extension agent.
Minimum tillage. Try to use minimum tillage techniques if
possible. These will leave crop residue from the preceding year on the
surface, thereby reducing evaporation of moisture from the soil.
Conservation tillage may be a particularly good method because it leaves
more than 30 percent of the residues, such as old cornstalks, in fields
Weed control. Use chemical weed control, rather than tillage, to
manage weeds. With chemical weed control, you avoid disturbing the soil and
causing moisture loss.
Planting. While it helps to plant in the moist soil below the
dry surface, don't plant beyond the maximum recommended depth for your crop.
Tilling. If you must till, keep it at a shallow level. For
example, when field cultivating, use a depth of 2 to 3 inches, rather than 4
to 5. Do not subsoil.
Chisel plowing. If using a chisel plow, use sweeps instead of
twisted shovels on it. The sweeps bring up less soil, while leaving more
crop residue on the soil surface. As a result, less moisture is lost from
Planting for Conservation Tillage, (A3396)
Row Crop Cultivators, (A3483)
Optimum Corn Planting Practices, (A3264)
Conservation Tillage for Corn,(A3091)
Making Conservation Tillage Work for Corn Production on Your Soil Type, (A3386)
Managing Drought-Stressed Corn and Soybeans, (NCR238)
Irrigation During a Drought
Considerations for non-irrigating farmers
Drought conditions are great anxiety producers, especially if you don't
normally irrigate your crops. As painful as it may be, however, the best
advice for non-irrigators is often to wait things out during a drought.
While some irrigation equipment may be available on an emergency basis from
dealers or area irrigators, the permitting process for surface water or
groundwater sources can take well over a month. Furthermore, the manpower,
training, and financing needed to develop an irrigation system make it
unrealistic as a short-term solution. Running an irrigation system can be a
full-time job in itself, one that can take three years to master, and one
that may take ten years to pay off through increased production.
One thing you can do is realistically evaluate whether an irrigation
system makes sense for you in the the long run. Follow the guidelines at
right to make this determination and to understand the processes involved in
setting up an irrigation system.
Do some research
Consider irrigation in relation to your type of crops, soil, water
availability, time and farm budget. Irrigation systems have become
increasingly sophisticatedâ€”something that makes them more valuable in terms
of productivity, but also more of a commitment in terms of time, management
and financial investment. Discuss the matter with your county Extension
office, other irrigators and equipment dealers.
Collect information on your soils and local climatic conditions.
If you have a sandy soil with lower water-holding capacity, for instance, an
irrigation system can make a significant difference in crop yields. You can
get a county soils report from the local USDA-NRCS office, county Extension
office or Land Conservation department.
Examine the types of crops you currently grow for root depth and
therefore, water needs. You want to be sure that irrigation equipment
costs will be offset by an increase in yields or quality of crop. You should
also consider the possibility of growing higher value crops (using
irrigation) such as potatoes, strawberries, sweet corn, dry beans, snap
beans, cucumbers, potatoes and carrots. Are they realistic for your soil
type and climatic conditions?
Consider water sources. Contact the Wisconsin Geological and
Natural History Survey for information about groundwater sources for your
area. See the section below for guidelines regarding surface water.
Talk to irrigation equipment dealers about irrigation systems and
what might be appropriate for your current or future needs. Topography
and field size are two of many factors affecting system needs.
Consider the economics of irrigation. Discuss potential yields
with other area irrigators as well as your Extension agent. In general,
irrigation may more than double yields in a field, and pay for itself within
10 years. Increases may be 75-80 bushels of corn per acre and four tons more
alfalfa per acre. However, success with irrigation varies depending upon
soils, weather, climate, type of irrigation, etc.
Assess your current economic conditions. Talk to your lenders.
Irrigation may not be a good idea right now because of the financial burden.
However, it may be something to plan for in the future.
in Wisconsinâ€”the Wisconsin Irrigation Scheduling Program, (WISP), (A3600).
Surface water as an irrigation source
Surface water diversions generally cover rivers, lakes and streams.
Riparian landâ€”land which adjoins these waterwaysâ€”is the first requirement
for irrigators. In order to obtain a surface water diversion permit from the
DNR, you also will need:
- A legal description of the land to be irrigated, such as NE1/4 of
SE1/4 of Sec. 23, T14N, R10E.
- A waiver from downstream irrigators, hydropower dams,
municipal or industrial waste dischargers.
- A â€œchain of titleâ€ test (an abstract examined by an attorney), which
determines the acreage of riparian land.
- The proposed diversion, including the maximum pumping rate of the
diversion, the maximum acreage to be irrigated (tillable acres), the
type of crop, inches of water per irrigation, maximum number of
irrigations anticipated per growing season, start and end dates of
irrigation per growing season.
Groundwater as an irrigation source
Groundwater diversions are covered by DNR high-capacity well permits.
These wells pump 70 gallons per minute (gpm) or more. Contact a local well
driller of the DNR District water manager to initiate the permitting
For a well permit, you will need:
- General information on water needs, property ownerships, location
- Design information, including a well driller's report and pump
- A DNR site inspection for local contamination.
Irrigation equipment dealers can be very helpful in assessing your needs
and potential for irrigation. Equipment ranges from large-volume traveling
sprinklers which can cover 100 acres in a week to center pivots which water
up to 133 acres in two days. The supply of equipment is somewhat limited
during the growing season. Most equipment is sold and delivered during the
winter and early spring. Keep this in mind as you begin irrigation system
Weed Management During a Drought
Herbicide effectiveness and mechanical measures
Dry weather after planting causes many concerns, including the impact of
weeds on annual crops. Many herbicides lose effectiveness during dry
periods; growers who use herbicides on corn and soybean crops are likely to
be affected. Fortunately, an awareness of herbicide effectiveness and the
aggressive use of mechanical weed control measures can make a difference.
Preplant incorporated herbicides. These are applied before planting and
mixed into the soil. They work best when:
a) the product is mixed uniformly with soil to
the depth recommended by the manufacturer;
b) soils have reasonable moisture levels after
incorporation has been completed.
If the soil is only slightly dry, incorporated herbicides generally
perform adequately. Seldom is it so dry early in the season that
incorporated treatments fail. In a true drought, however, they may not give
acceptable weed control. Therefore, be prepared to cultivate if weeds
Pre-emergence herbicides. These depend totally upon
rainfall after applications to â€œactivateâ€ the product. Rainfall positions
the chemical in the upper soil surface where the weed seeds germinate; there
is no chemical change as perhaps the term â€œactivateâ€ suggests. To obtain
adequate herbicide activity, however, rain must fall within 10 to 14 days
after the seedbed was prepared. Without such precipitation, pre-emergence
herbicides generally fail to give acceptable weed control even if a true
drought does not develop. Therefore, mechanical weed control may become
critical within weeks of planting. Two examples:
a) If a field is prepared to plant on April 30,
corn is planted on May 1 and a pre-emergence herbicide is applied on May 2,
rainfall of at least one-quarter to one-half inches is needed within 10 to
14 days to assure adequate performance. If rainfall does not occur by May
12, the grower should begin rotary hoeing.
b) If a field is prepared on April 30 and corn
is planted on May 10, followed by pre-emergence herbicide on May 11, plan to
rotary hoe on May 12 unless rainfall is very likely in the immediate future.
As illustrated above, when planting and spraying are close to the field
preparation time (example a), there is more time to get the needed rainfall
to make a surface-applied herbicide perform adequately. As time between
field preparation and spraying increases (example b), there are fewer days
after an application to get a timely rain. Thus, rotary hoeing becomes
Rotary hoeing kills weeds that have germinated but have not yet
emerged. These weeds are in the â€œwhite rootâ€ stage of development. After
weeds emerge, rotary hoeing is less effective. Rotary hoeing also helps
place the herbicide in the upper soil surface so that when rains do fall,
the herbicide is in a better position to be quickly taken up by weed
seedlings and hopefully kill them. If it has not rained within seven days of
the first rotary hoeing, make a second pass with the rotary hoe to kill the
next generation of weeds.
Post-emergence herbicides also may fail in dry weather. These treatments
work best when weeds are actively growing. When weeds are stressed by lack
of adequate soil moisture, chemical control declines. If you decide to apply
post-emergence herbicides under very dry conditions, be aware that crop
injury may occur and weed control will be poor.
In all situations, be prepared to cultivate once or twice following
rotary hoeing. Some growers mistakenly believe that soil loses more moisture
when cultivated. But remember that weeds transpire water into the atmosphere
every day they are in the field; the longer weeds live, the more soil
moisture is lost and unavailable for the crop, and the harder they are to
eradicate. So it is always a wise decision to cultivate weeds early on.
- Cultivate when the weeds are relatively small and the crop is large
enough (at least 4 inches tall) to allow you to roll some soil into the
row without covering the crop.
- The crop should be at least three times as tall as the weeds when
the first cultivation is done (for example, the crop is 6 inches tall
and the weeds are 2 inches or less tall). This way, the weeds in the row
can be covered with minimal effect on the crop.
- The cultivator need not be set any deeper than a couple of inches to
dislodge the weeds; little if any moist soil will be brought to the
- A second cultivation can be done when the crop is 14 to 18 inches
tall. This requires timely mechanical practices, but keep in mind that
in drought years, a few uncontrolled weeds cost more in reduced yield
than in years with ample moisture.
Reduced Herbicide Rates: Aspects to Consider, (A3563).
Alternative Crops During a Drought
Meeting forage and grain needs in an emergency
Alternative crops can be a major concern during a drought. If planting
was postponed or plants didn't survive because of drought, mid-summer
planting may be necessary for adequate forage or grain. You also may be
concerned about feed supplies for next year and, therefore, wish to plant
additional crops this fall. Unfortunately, no one can predict the longevity
of a drought. But you do have options, and the knowledge that planning ahead
is always a good idea.
Alternative forages for this year
Before giving up on existing crops, examine your current crops for silage
potential. Corn, for example, may be the best forage alternative available.
Also, keep in mind the added labor and cost of establishing alternative
crops. Unfortunately, there is no guarantee regarding yield or quality of
Existing crops as alternative forages. Test these forages and
use the data to obtain efficient use through balanced rations:
a) alfalfa, red clover, trefoil
b) corn and soybeans
c) peas or canning crops
d) small grains
Summer-seeded crops. These generally should be seeded by July 15
and only if moisture is available for germination and emergence. Crops
- sudan, sorghum-sudan and forage sorghum
- hybrid pearl millet
- soybeans (alone or mixed with sorghum-sudan)
- 70-day corn
- brassicas - forage rape, turnips
- millets - common, German, foxtail or Japanese
- winter grain with field peas. These should be planted from mid- to
Alternative cash crops. If you planted cash crops such as wheat
or corn, but drought is causing problems, you may decide to replant. Some
good alternatives are buckwheat and millet, which can be planted in July.
These are very short season crops and both are high in fiber. Consider
whether you have a market to sell these two crops or whether you can feed
them to livestock.
Meeting demands for next year
Spring grains. If moisture is available for germination and
emergence, you can plant spring grains like wheat, oats or barley in August.
These can be harvested until a hard freeze, which usually occurs in late
Winter rye and winter wheat. For the earliest harvest of forage
next spring, plant winter rye in September. It can be harvested mid-May.
Another alternative is winter wheat, which has a higher forage yield but
must be harvested seven to ten days later.
Reducing the risk of drought stress
The only sure method to avoid drought-stressed crops is to use
irrigation. Other management practices, however, can help reduce the risk of
- Early planting. By planting early, you increase the chance
of having pollination completed before the driest part of the season.
- Optimum fertilization. Proper fertilization will
promote healthy plant growth and efficient moisture utilization,
essential for high yields in both normal and dry years.
- Adequate weed control. Weeds compete with crop plants for
water, so controlling weeds will provide more water for the crop.
- Residue management. By maintaining a cover of residue
through conservation tillage or no-till, you can reduce the amount of
evaporation from the soil surface and conserve water for the crop's use.
Salvaging Drought-Stressed Crops
Analyzing nutritional value and safety
Drought-stressed crops may often be salvaged, but testing for nutritional
value and harmful substances is extremely important. Nitrate toxicity and
aflatoxins may be a problem in drought years. Depending on test results,
feed amounts need to be adjusted for animal nutrition and safety.
Fresh forage versus silage
If plants show signs of drought stress, be careful about using them as
fresh forage because nitrate levels may be high. A better option is to use
plants as silage, because the silage fermentation process reduces nitrate
levels. In either case, testing is critical for safe feeding.
Symptoms of nitrate poisoning in livestock include labored breathing,
frothing at the mouth and a brownish color of the nonpigmented skin within a
few hours after feeding. Abortions can occur; death may occur within an hour
in extreme cases.
- Silage should be stored at least three weeks before testing and
feeding take place.
- Testing is available from private companies and state universities.
- Have both a nutritional analysis and nitrate test completed on
crops. Results will take longer for nitrate tests.
- Test results will help you determine safe feeding amounts, as well
as the need for grain and protein supplements.
Oats, Barley and Corn
Test drought-stressed oats and barley for nutritional value.
They often are reduced to empty hulls or a very light grain. The result is
low energy and protein and a limited feeding value for poultry and swine.
Oats and barley may work well in combination with beef and other livestock
Consult with your livestock nutritionist or agricultural agent about
corn use. Corn quality usually is not a concern during drought; corn
kernels may be smaller, but feeding value is not affected to the same degree
as for oats and barley. Ear corn, however, may be lower in nutritional value
due to a higher cob to kernel ratio.
Test for aflatoxins in grain fields. The fungus, Asperilla
flavus, and certain other molds may produce toxic substances in the
field and in storage. They historically have been a problem in southern
states where severe drought and high temperatures more commonly are
experienced. Contact your county agricultural agent for a list of qualified
- Managing Drought-Stressed Corn and Soybeans, (NCR238)
- Protect Livestock From Nitrate Poisoning, (A1889)
- Feeding the Dairy Herd, (NCR346)
After a Drought
Financial issues. Continue to pursue government drought
assistance programs if you have not yet received relief; your county
Extension office can help you through the application process. Also, see
your accountant about tax issues related to the drought. If you received
federal disaster payments, you may be able to postpone reporting them on
your income taxes for a year. Likewise, if you sold livestock because of the
drought, you may be able to postpone reporting gains on the sale for as long
as two years afterward.
Crop testing for feed. Nutritional values of crops are
often affected by drought. Have fresh forage tested for high nitrate levels
and nutritional value. Have oats and barley tested for nutritional value;
nitrates usually are not a problem. Consult with your livestock nutritionist
about corn quality and use. Test for mycotoxins in grain fields.
Soil testing. Because of the potential for herbicide and
fertilizer carryover, soil testing is very important following a drought
year. See the fact sheets â€œFertilizer Application After a Drought,â€ and
â€œHerbicide Concerns After a Drought Year,â€ for test recommendations.
Fertilizer Application After a Drought
Considerations for this year and next
Generally, fertilizer application is not much of an issue during a
drought year. Fertilizers often have been applied before the true extent of
a drought is known. If they haven't already been applied, you need to adjust
rates based on lowered yield expectancy for the drought year. If little or
no production is likely, it may be best to skip an application.
Fertilizer use does become a significant issue the year after a
drought, however. Low crop yields during the drought year mean that
significant amounts of unused nutrients could remain in the soil at the end
of the growing season. Where nutrient carryover is substantial, fertilizer
needs for the following year are likely to be affected. Several methods are
available to help growers determine nitrogen, phosphorous and potassium
carryover and current needs.
Phosphorous and potassium carryover
If phosphorous or potassium was applied but not used because of lower
than expected yields, it usually remains in the top few inches of soil. It
will not be lost over the winter. Therefore, the unused portion can be
credited against nutrient needs for next year's crops.
A formula for determining carryover. One method for estimating unused
phosphorous and potassium is based on the ratio of the actual drought-year
yield and the yield goal used to determine nutrient applications that year.
Drought year application = 75 lb./acre
phosphate and 300 lb./acre potash
Drought year yield goal = 6 tons/acre
(alfalfa). Actual yield = 2 tons/acre. Actual yield/yield goal = 2/6 = 1/3
Therefore, 2/3 of drought-year application is
unused Estimated carryover = 2/3 x 75 lb./acre = 50 lb./acre phosphate = 2/3
x 300 lb./acre = 200 lb./acre potash
Comparison of the actual yield with the expected yield shows that the
drought-year yields were 1/3 of the goal. Under the assumption that nutrient
removal is proportional to yield, approximately 2/3 of the phosphate and
potash applied in the drought year was not used and likely will be available
to the next crop.
Soil tests. Routine soil tests also can be used to determine the
current levels of available phosphate and potash, and to obtain fertilizer
recommendations. They are useful for detecting carryover where relatively
large amounts of nutrients were applied in the drought year, such as in
topdress maintenance fertilizer programs for alfalfa. Relatively small
amounts of carryover, such as those that could occur following application
in a maintenance program for corn, might not be detected. The tests may be
done in spring or fall.
Following a drought year, most nitrogen carryover exists as nitrate in
the plant root zone. However, the possibility of overwinter loss of residual
nitrate makes estimation of carryover more difficult than for phosphorous
and potassium. The amount of residual nitrogen in the soil at the end of the
growing season must be considered, as well as factors affecting overwinter
loss. Specifically, nitrogen carryover is likely where:
- The drought-year crop was corn or a non-legume.
- The crop received moderate to high amounts of nitrogen as fertilizer
or as legume or manure nitrogen credits.
- Yields were below expected levels.
- Soils are silt loam or heavier-textured.
- Overwinter precipitation amounts are normal or below normal.
Testing for nitrogen carryover
A preplant soil nitrate test should be used to determine how much nitrate
has remained in the soil until the next growing season.
Sample in the spring. Soil samples should be collected in the spring
after the frost has left your fields and before preplant applications of
a) Take at least 15 random soil cores from
uniform soil areas no larger than 20 acres.
b) Take separate samples from areas with soil or management practice
c) Sample in 1-foot increments to a depth of 2 feet.
d) Each sample should be placed in a clean container marked for the
e) Thoroughly mix the soil from each depth and collect a 1-cup subsample.
This sample should be sent to a soil testing lab for analysis.
Air dry or freeze samples. Do not store or send composite samples
to the lab in moist condition. If samples can't be taken to the soil testing
lab within one day after collection, they should be air-dried (by spreading
on clean paper for 24 to 48 hours) as soon as possible. Another option is to
freeze your samples immediately after collection and then either transport
them to the testing lab while still frozen or air-dry the samples before
- Provide background information. The soil testing lab needs to know
if you applied manure to your sampled fields or if the previous crop was
- Provide the soil name. The name of the predominant soil and its
organic matter content within the sampled area is needed.
Soil testing labs
Soil testing and analysis are available from the University of Wisconsin
soil testing labs in Madison and Marshfield, and other private soil testing
labs. Your county Extension office can provide names and locations of
commercial labs performing these tests in your area, as well as more
specific sampling instructions and forms. To contact the Madison and
Soil & Plant Analysis Lab
5711 Mineral Point Road
Madison, WI 53705-4453
phone: (608) 262-4364
State Soil & Forage Lab
Marshfield Ag Research Station
8396 Yellowstone Drive
Marshfield, WI 54449
phone: (715) 387-2523
Wisconsin's Preplant Soil Nitrate Test, (A3512)
Sampling Soils for Testing, (A2100)
Step-by-Step Guide to Nutrient Management, (A3568)
Nutrient Management Practices for Wisconsin Corn Production and Water
Quality Protection, (A3557)
Herbicide Concerns After a Drought
Accounting for carryover in next year's crops
When soils are moist during the growing season, herbicides break down
through microbial and chemical processes. These reactions may be slowed
greatly in drought conditions. If herbicide residues are significant, they
may injure rotational crops in the following season. For this reason,
growers need to be aware of herbicide residues and take steps to decrease
risk of injury.
Herbicide carryover levels
Herbicides vary greatly in soil persistence and carryover to next year's
Essentially no risk. Herbicides presenting essentially no risk
of carryover for next year's crops include: 2, 4-D, Roundup, Gramoxone,
Basagran, Poast, Assure, Fusilade, Sutan, Select, Banvel, Clarity, Blazer,
Eptam, Eradicane, Lorox, Buctril, Reflex, Cobra, Butyrac, and MCPA.
Moderate risk. Herbicides presenting a moderate risk of
carryover to next year's crops include: Sencor, Lexone, Bladex, Treflan,
Prowl, Accent, Beacon, Broadstrike, Velpar, Balan, Stinger, Classic,
Pinnacle, Lasso, Dual, Frontier, Surpass and Harness.
High risk. Herbicides presenting a high risk of carryover to
next year's crops include: atrazine, Pursuit, Scepter, Command and Princep.
Avoiding residue problems
Check the label of herbicides used during the drought season. It
will tell you the normal interval between application and planting for a
specific rotational crop. Footnotes frequently show if the risk of carryover
is greater under certain conditions (such as soil pH or dry soils).
Select this year's herbicides carefully. Do not choose herbicides or use
rates that have significant injury potential by themselves. Do not use
products that may interact with carryover levels of last year's products.
For example, do not use metribuzin (Sencor, Lexone) in soybeans this year if
atrazine was used in corn planted during the drought year.
Use tillage. Tillage will dilute the herbicide, especially if it
is concentrated near the surface or in bands over the row.
Look for herbicide tolerance. Select crop varieties or hybrids
with greater tolerance to the herbicide used during the drought year. This
information is not available for all varieties. Ask your seed supplier for
Use good management practices. Good seedbeds, proper seeding
depth and rate, adequate soil fertility, and insect and disease protection
will minimize the effect of herbicide carryover. Many crops can tolerate a
single stress relatively well, but two or more stresses can result in
significant loss of crop vigor and yield.
Testing for carryover
If you choose to test for herbicide carryover, the best time to do
between late October and mid-November for most of Wisconsin. By this
time, soil temperatures reach and remain below 50 degrees F., a point at
which herbicide breakdown is minimal. Do not take soil samples for
residues before this time; they may indicate levels greater than actually
present when you plant next year.
A bioassay test may be helpful if doubts remain about planting
because of possible herbicide residues. The test will alert you to
residue problems by comparing the productivity of your intended crop
variety in both affected and unaffected soils. (Follow the guidelines in
the UW-Extension publication â€œA Simple Test for Atrazine
Residues.â€) Begin the test at least three weeks prior to planting so
that sufficient plant growth is available to assess carryover potential. The herbicide label may also contain suggestions on running a
bioassay test, as well as information on crop rotations and carryover
A chemical test for herbicide residues can also be done by private
laboratories. These tests are expensive and the results may not be
easy to interpret. However, they may be appropriate in cases where
bioassays cannot be done or where high value crops are concerned.
A Simple Test for Atrazine Residues, (A2882)
Reduced Herbicide Rates: Aspects to Consider, (A3563)
Row Crop Cultivators, (A3483)
Protecting Livestock From Heat
Strategies for farmers when temperatures climb
When temperatures and humidity begin to rise in Wisconsin, keep a close
eye on livestock. Temperatures in the high 80s and the 90s can cause
problems, as well as a 75 degree F. day coupled with high humidity. Heat
stress can cause general discomfort, decline in animal performance and
Provide shade and night-time cooling
- If animals are kept outside, provide shade during hot weather. Heat
from the sun is a major culprit in overstressed animals.
- Swine may sunburn during hot, sunny weather. Try to keep them out of
the sun. Sun shades can cut the radiant heat load by as much as 40
percent; ask your county Extension agent for information on their
construction. Pasture wallows are also effective for sunburn protection
and wet skin cooling.
- Turn cows outside at night to cool them and cool the barn.
Since animals cool themselves primarily through breathing, barns tend to
get warm and humid quickly.
Provide adequate water
Ample drinking water is vital to animals during hot and humid conditions.
Animals cool themselves by panting (water loss from the lungs) and through
water evaporation from the skin. Increased respiration during hot weather is
especially important for pigs and other animals that do not sweat. Animals
must replace the water loss to cool themselves.
- Maintain access to water. Provide automatic drinking cups
so animals can meet their requirements during hot weather.
- Keep water containers clean.
- Adjust the drinking space for the size and number of
animals in the pen or group. Excessive volumes of water grow warm
and stale throughout the day. (See the fact sheet â€œLivestock Water and
- Check the water delivery systems periodically for plugs or other
- If necessary, spray water on animals to cool them.
Provide good ventilation
Proper ventilation helps maintain livestock health during hot and humid
weather. Without adequate air exchanges and airflow distribution within
livestock buildings, heat and moisture accumulate and animal production is
affected. Contact a ventilation specialist to inspect and update your
system, if necessary.
- When Temperatures Go Up, Does Your Milk Production Go Down? (A2881)
- Cooling Swine, (PIH87).
Midwest Plan Service publications
- Heating, Cooling and Tempering Air for Livestock Housing, (MWPS-34)
- Mechanical Ventilating Systems for Livestock Housing, (MWPS-32)
Use the temperature humidity index as a guide to heat stress. Listen to
local or regional weather reports for the temperature humidity index (THI)
for your area. Some levels of concern include:
- a) Above 75 THI - Heat stress on high-producing cows begins to
decrease feed intake and lower milk production.
- b) Above 80 THI - Severe heat stress may occur for cows on pasture.
Shade and adequate ventilation are essential to minimize milk loss.
- c) Above 83-85 THI - Danger of fatal heat stress occurs.
Keep an eye on animals. If heat stress is a concern, check animal
temperature. Dairy cow temperatures approaching 104 to 106 degrees F. are
dangerous. At 107 degrees F., spontaneous heart failure is possible. Call a
veterinarian and use methods listed above to keep animals cool.
Managing Livestock During a Drought
When water and feed supplies become a concern
Drought usually gets its reputation from its impact on crops. But its
impact on livestock can be equally dramatic. Hot, dry weather increases the
water needs of livestock but often decreases water supplies. Crops may not
yield as planned, causing a feed shortage. Consequently, farmers may face
special challenges, including decisions about whether to buy feed or sell
Water requirements may increase to double the normal intake for animals
during hot weather. Clean, fresh water is important. If animals do not meet
their water needs, they may refuse to eat, experience lowered production,
become sick or die.
Water supplies also may become a problem as the drought wears on. Wells
and piping may be inadequate if water demand increases dramatically; shallow
wells and streams may dry up. You may need to transport water. Contact your
local emergency government office or your county Extension office for
information on water supply assistance.
Some general water estimates for various conditions and animals:
Daily water intake for beef cattle at 88 degrees F.:
a) Cows -16.5 gallons for nursing calves; 14
gallons for bred dry cows and heifers.
b) Bulls - 18 gallons.
c) Growing cattle - 9 gallons for 400 lb. animal; 12 for 600 lb.; 14 for 800
d) Finishing cattle - 14 for 600 lb. animal; 17 for 800 lb.; 20 for 1,000
lb.; 22.5 for 1,200 lb.
Daily water intake for dairy cattle at 80 degrees F.:
a) Dry cows (for maintenance and pregnancy) -
16.2 gallons for 1,400 lb. animal; 17.3 for 1,700 lb.
b) Lactating, 1,400-lb. cows (for maintenance and milk production) - 17.9
gallons for 20 lb. milk production; 24.7 for 60 lb. milk production; 38.7
for 80 lb. milk production; 45.7 for 100 lb. milk production.
c) Heifers - 3.3 gallons for 200 lb. animal; 6.1 for 400 lb.; 10.6 for 800
lb.; 14.5 for 1,200 lb. (for maintenance and pregnancy).
Average daily water intake for swine:
a) Breeding herd - 2 to 3 gallons for gestating
sows and boars; 4 to 5 gallons for lactating sows.
b) Young pigs - One-half to 1 gallon for weaned pigs (15-50 lb.); 1 gallon
for growing pigs (50-120 lb.); 1.5-2 gallons for finishing pigs (120 lb. to
Increase amounts for hot, dry conditions.
When feed becomes an emergency
Feed supplies may run low if crops are compromised or lost because of dry
weather. Farmers unable to afford additional feed may face an emergency
situation. Some considerations include:
Develop an inventory of livestock numbers and feed supplies. An
inventory will help you plan for current and long-term feed needs.
Get advice and assistance. When a feed shortage is imminent,
contact a nutritionist or your county Extension office for guidance, your
lender for early discussion of potential problems or needs and the NRCS for feed
assistance program information.
Two major options when facing a feed shortage are to:
- Buy or obtain additional feed. Feed
assistance may be available from relief groups, the ASCS or through loans.
Volunteer organizations typically offer hay lifts during drought years. Contact your county Extension office for more information.
- Sell non-essential animals. The money received can help buy additional
feed for remaining animals.
Plant alternative crops for forage. A number of crops, including 70-day
corn, buckwheat and millet, may be planted mid-summer to offset early
losses. (See the fact sheet â€œAlternative Crops During a Drought.â€)
Talk about it. Drought can bring feelings of great anger,
frustration and hopelessness to farmers, especially for those already
experiencing tough financial times. It's critical that producers talk about
the stress they are feeling, rather than isolating themselves from family or
neighbors. In some cases, intervention may be needed to connect farmers with
counselors, clergy members or other professionals.
1988 North American Drought. Wikipedia. http://en.wikipedia.org/wiki/1988_North_American_drought
North American Drought: A Paleo Perspective. NOAA. http://www.ncdc.noaa.gov/paleo/drought/drght_history.html
Examples of Historical Heat Waves and Droughts. The Weather Channel.