North Dakota State University
NDSU Extension Service
No. 171, September 1998
http://www.ext.nodak.edu/extnews/snouts
Aung Hla Accepts Position as Area Extension Irrigation Specialist in Carrington
Temporary Corn Storage
Wind Erosion Under Center Pivots
Field Safety for Anhydrous Ammonia Application
Now is the Time to Start Managing Center Pivot Wheel Tracks
TECH TIPS
Aung Hla (pronounced "Awn La") has joined the NDSU Extension Service as the area irrigation specialist. His office will be located in the Garrison Diversion Conservancy District office in Carrington. This position is a five year, renewable position which is jointly funded by the Garrison Diversion Conservancy District, the U.S. Bureau of Reclamation and the NDSU Extension Service.
Aung received a B.S. in agricultural engineering from Bangladesh Agricultural University in 1973 and an M.S. in agricultural and biosystems engineering from the University of Arizona in 1996. He has also completed the course work and research towards his Ph.D.
Aung has over 18 years of experience working with irrigation development, irrigation management and direct supervision of irrigation operations. Since coming to the U.S. in 1993, he has worked on projects involving crop water use of citrus orchards and water audit surveys of urban drip and sprinkler systems.
We welcome Aung to his new position and to the NDSU Irrigation Task Force. Aung's address is Garrison Diversion Conservancy District, PO Box 140, Carrington, ND, 58421. He can be reached at (701) 652-3194.
Tom Scherer, (701) 231-7239
NDSU Extension Agricultural Engineer
tscherer@ndsuext.nodak.edu
The best option is to store the corn in a building if possible. Pole buildings can make good storage facilities if prepared correctly. Walls may need to be reinforced with cables or braces. Corn exerts a force on a wall of about 23 pounds per foot of grain depth, so with corn 6 feet deep on the wall, the force pushing out at the bottom of the wall is about 138 pounds per square foot. Buildings used for storage should be well drained. Cover floors with plastic to prevent moisture migrating from the soil or through cracks in concrete floors into the grain.
Cooling the corn with aeration is extremely important for storage. Cool temperatures minimize mold growth, limit moisture migration, and control insects. Provide for air to enter and exit the building for aeration.
Corn must be dry when placed into storage. It is nearly impossible to dry corn in temporary storage.
If you must pile the corn outside on the ground, drainage is crucial. The pile should be on high ground and the earth crowned under the pile. Place plastic on the ground to keep ground moisture from wetting the grain. Cover piles with plastic or tarp to reduce wetting by rain and snow and to minimize damage by wind and birds. A smooth surface will aid in drainage. Position and extend the cover so that water is channeled away from the pile. Condensation under the plastic may cause problems unless it is controlled with aeration. Airflow must flow near the plastic to carry the moisture away. Run the pile north and south to allow the sun to dry off the sloping sides. Again cooling the corn with aeration will improve the chances for success.
A newly revised publication AE-84 "Temporary Grain Storage" is available from the NDSU Extension Service. It includes information on placing grain in buildings including wall plans, commercially available storage units, and alternative storage facilities. The publication is available at NDSU Extension Service county offices or can be ordered from the Distribution Center, Box 5655, NDSU, Fargo, ND 58105-5655, phone (701) 231-7882.
Kenneth J. Hellevang, (701) 231-7243
NDSU Extension Agricultural Engineer
kjh-eng@ndsuext.nodak.edu
Center pivots are commonly used to irrigate land with sandy soils and much of this land is prone to wind erosion. In fact, a significant part of irrigated land usually qualifies as highly erodible land.
Wind erosion under center pivots is a problem during two periods of the year, during winters with little snow and immediately following spring seeding. A number of sound management practices and erosion control tools are available to keep wind erosion in check.
Following spring seeding, spots in the field subject to blowing under a pivot can be stopped any time the air temperature is above freezing by moving the pivot around to the blowing area and turning it on. However, enough water has to be applied to prevent it from drying out too fast. Usually a half inch of applied water on sandy soil will provide protection for a few days. Exposed ridges and hill tops are the most susceptible to wind. These spots will be the first to erode every year. When seeding is complete, the pivot can be left parked in these areas.
When the whole field under a pivot begins to blow sand in windy conditions, basic soil management mistakes have been made. Crop residue management is the simplest practical cure.
Minimum cover for wind erosion protection is about 30% of the surface covered with residue. The pounds of residue and percent cover for various crops are shown in Table 1. For example, about 1250 pounds per acre of corn residue will provide about 30% ground coverage. An estimate of the amount of residue left after harvest for selected crops is shown in Table 2.
| Table 1. The percent of ground cover that can be expected from various amounts of small grain, corn, grain sorghum, soybean and sunflower residue. (Reprinted from the NRCS publication: Farming with High Residue for Profit and Erosion Control.) | |||
| Pounds Residue |
Small Grains |
Grain Sorghum, Corn, Soybeans, Sunflowers Before Tillage |
Sunflowers After Tillage |
| - - - - - - - - - percent cover - - - - - - - - - - | |||
| 200 400 600 800 1000 1500 2000 2500 3000 4000 |
10% 20% 30% 40% 50% 65% 75% 80% 90% 85-100% |
— 10% 15% 20% 25% 35% 40% 50% 55% 70% |
— — — — 10% 15% 20% 25% 30% 40% |
| Table 2. Average amount of residue after harvest for common irrigated crops. | |
| Crop | Pounds Residue |
| Wheat Corn, grain Soybean Dry beans |
120 lbs/bu 60-90 lbs/bu 50 lbs/bu 1 lb/lb |
| Example: A 1800 lb/ac yield of dry beans would leave about 1800 lbs of residue per acre. | |
Tillage operations after harvest that leave little or no residue
on the surface invite wind erosion problems to occur. Ideal
protection over winter would leave about 50% of the ground
surface covered with residue. The only sure way to determine how
much residue is on the surface is to measure it. Several
publications on how to do this are available at your local
Extension office or NRCS office.
For low residue crops like potatoes, wind erosion protection can be provided in a number of ways. Rows of tall growing crops such as corn or sunflowers can be planted at some multiple of tillage equipment widths. After harvest, small grain straw can be blown onto the field or in the areas most subject to blowing. If the potatoes are harvested in late August or early September, rye can be planted as a cover crop.
Tree rows and wildlife shrub plantings around the perimeter of center pivots can be seen in some areas because they are a proven wind erosion tool. Maximum protection is needed on the north and west sides. Shrubs that are short enough for the pivot to go over can be planted in the middle of the field to provide protection.
Tom Scherer, (701) 231-7239
NDSU Extension Agricultural Engineer
tscherer@ndsuext.nodak.edu
Every field applicator and nurse tank should be equipped with an emergency breakaway valve. It prevents an uncontrolled release of anhydrous ammonia by separating and stopping the flow of ammonia before excessive tension is placed on the nurse tank hose. Without a breakaway valve, the connecting hose will burst as the nurse tank falls back, allowing anhydrous ammonia to rush out of the broken hose.
When this happens, close the valves on the nurse tank hose and nitrolator, then use the bleeder valves to bleed off anhydrous trapped in the hose and nitrolator. Be sure to close the bleeder valves after bleeding the system. After the nurse tank is re-hitched and the hitch pin is safety-pinned in place, reconnect the nurse tank hose to the nitrolator and open the valves to re-pressurize the system. A properly operating breakaway valve eliminates the dangerous, uncontrolled gush of anhydrous ammonia.
Another field hazard is the drooping of hoses between the nitrolator and the injector tip. The hoses should be supported to prevent droops, otherwise liquid ammonia will collect there after the nitrolator has been shut off. Disturbing this sag while unplugging an applicator tip can allow the liquid ammonia to run down the hose to the tip and onto the person working on the applicator. An ammonia burn will result, the seriousness depending on the quantity of liquid left in the hose and the protective equipment worn. All hoses should drain from the nitrolator directly down to the applicator tip.
Always wear the gloves and goggles in the safety kit on the nurse tank when working on the equipment. Not wearing the gloves and goggles is simply asking for an accident; sooner or later it will happen. The kit must contain approved gloves and goggles. Keeping an extra kit on the tractor in the field is an excellent safety practice.
Be sure every nurse tank has the water reservoir filled with 5 gallons of fresh water. The water may need to be changed since it will absorb some ammonia, enough so that it may aggravate the injury when it is used for emergency flushing. A black reservoir may also solar-heat the water to a dangerous temperature.
Everyone who works with anhydrous ammonia should always carry a pocket squirt bottle of first aid flushing water. Change the water every day to prevent it from becoming contaminated with ammonia. The squirt bottle may seem to be a nuisance until it is needed — then the nuisance is instantly seared away by the pain of an ammonia burn.
George Maher, (701) 231-8288
NDSU Extension Agricultural Safety Specialist
gmaher@ndsuext.nodak.edu
Every center pivot irrigator knows that wheel tracks can turn into ruts in some parts of their fields. Deep wheel tracks can cause significant damage to the center pivot as well as tillage and harvesting equipment. The formation of deep wheel tracks is generally caused by saturated conditions which reduce the soil's bearing capacity. Deep wheel tracks will usually be found where water collects in low spots or associated with the first or second tower from the pivot point. After harvest is a good time to consider what causes deep wheel tracks and start making some changes to correct them for the next growing season.
The following are the major factors that affect the depth of pivot wheel tracks:
You can reduce deep wheel track problems using either management or mechanical solutions. Some of the management methods you might use are:
Following are some of the mechanical changes you can do to help your pivot system to reduce deep wheel tracks:
Tom Scherer, (701) 231-7239
Extension Agricultural Engineer
tscherer@ndsuext.nodak.edu
With fall approaching, rodents will be looking for a winter home. Don't let them use your electrical panels or motors. Stuffing steel wool into electrical conduit, holes and other entrances will stop rodents from entering, nesting and feeding on your wires.
BE CAREFUL, disconnect all power, at the meter, before opening any electrical boxes and inspect all wires for damaged insulation.
DON'T DO THIS if you have wires that are exposed. Steel wool will short any exposed wires and you will have fireworks, equipment damage and possible personal injury, the same things we are trying to prevent the rodents from doing.
Dirt and moisture eventually find their way into most electrical panels and control boxes. Using compressed air to blow out all dirt and moisture out of contactors and panels will prevent corrosion and failed contactors. Reseal boxes at the first sign of weather seal damage. Pickup topper seal will work well and has adhesive to make installation a snap.
To prevent misplacing information on your well and pump record it inside the electrical panel or pivot control panel with a permanent marker (ear tag marker works well). BE CAREFUL, disconnect all power, at the meter, before opening any electrical boxes.
Record annual pressure, flow, static and pumping water levels for future comparison and monitoring. Record well depth, depth of pump, screen type, and well capacity. It will make trouble shooting future problems much easier with recorded data.
No. 171, September 1998
NDSU Extension Service, North Dakota State University of
Agriculture and Applied Science, and U.S. Department of
Agriculture cooperating. Sharon D. Anderson, Director, Fargo,
North Dakota. Distributed in furtherance of the Acts of Congress
of May 8 and June 30, 1914. We offer our programs and facilities
to all persons regardless of race, color, national origin,
religion, sex, disability, age, Vietnam era veterans status, or
sexual orientation; and are an equal opportunity employer.
This publication will be made available in alternative formats
for people with disabilities upon request, 701/231-7881.
North Dakota State University
NDSU Extension Service