North Dakota State University
NDSU Extension Service
No. 179, October 1999
http://www.ext.nodak.edu/extnews/snouts
This is the final issue of Water Spouts for 1999.
If you have access to the Internet, you can obtain copies out
past issues of Water Spouts at this address:
www.ext.nodak.edu/extnews/snouts/.
The next issue of Water Spouts will be in April of 2000.
Date | Location | |
Dec. 8, 1999 | Bismarck | Radisson Inn |
Dec. 9, 1999 | Bismarck | Radisson Inn |
This workshop is for potential irrigators or those people investigating what is needed to get into irrigation. | ||
Dec. 14, 1999 | Grand Forks | Westward Ho Motel |
The workshops in Bismarck will be held in conjunction with the annual North Dakota Water Users Convention. All workshops will start about 9 a.m. and finish around 4:00 p.m. An application for Certified Crop Advisor (CCA) CEU's will be made for each workshop. The number for CEUs will be announced at the workshops.
A mail announcement with more details will be sent to you in November.
Tom Scherer, (701) 231-7239
Extension Agricultural Engineer
tscherer@ndsuext.nodak.edu
When it comes to wind and sleet, the center pivot is a rather fragile machine. Center pivots that have no nearby protection such as windbreaks should be parked for the winter pointing to the northwest or southeast, not to the northeast or southwest (Figure 1). The ice storm blizzard of April 5-8, 1997 damaged many center pivots that were parked pointing in the wrong direction.
Figure 1. For the winter, point your pivot towards the
northwest or southwest, not the northeast or southwest.
From October to April the worst storms and highest winds come from the northwest. Properly
parking a pivot will present the smallest surface area to the wind. Exceptions to the
parking direction are center pivots that border windbreaks. In this case, the pivot should
be parked next to the windbreak.
While you are parking your pivot for the winter, do the following checks, they could save you some work in the spring.
The well is the heart of any irrigation system when the water source is groundwater. Most groundwater in North Dakota contains small amounts of iron, which provide energy for the growth and development of iron bacteria. These bacteria form a slimy, gelatinous mass on the well screen, casing, pump and in the aquifer surrounding the well screen. If your irrigation equipment has a rust color due to the water or the water has a rotten egg smell, then growth of iron bacteria in the well is a good possibility.
The spread of iron bacteria in the well reduces the amount of open area of the screen and the open area of the spaces in the aquifer formation, thus reducing the well yield. Reduced well yield will affect the operation of the irrigation system and could reduce yields, especially with high value crops like potatoes. The only way to effectively control iron bacteria is by chlorinating the well on an annual basis.
Well chlorination should be performed in the spring and the fall. The object of well chlorination is to raise the chlorine level in the well to 500 parts per million (ppm) and hold it there for a period of time to allow the chlorine to attack and kill the bacteria. It is especially important to also get the chlorine out into the aquifer material surrounding the well screen, Figure 2.
Figure 2. Annual chlorination of a well is needed to control iron bacteria.
The two common sources of chlorine used in well chlorination are household bleach that
contains about 5% chlorine and a dry form of calcium hypochlorite sometimes called HTH.
HTH contains about 70% available chlorine and can be purchased from swimming pool
companies, well drillers and some irrigation dealers. I recommend using common household
bleach for a couple of reasons. Chlorine is a noxious and dangerous gas. Household bleach
is the safest form of chlorine to handle because of its low level of chlorine. Second, it
is easy to obtain as almost all grocery and convenience stores have it in stock.
Irrigators with oil-lubricated, deep well turbine pumps should be especially careful if they use HTH to chlorinate their wells. It is common for these wells to have a layer of oil on top of the water. Mixing chlorine and oil can have explosive repercussions, so if a granulated or pellet form of chlorine is used for chlorination, mix it with a suitable amount of water before pouring into the well.
It is important to chlorinate the well before you pump out your pipelines for the winter. Use the following procedure to chlorinate your well(s):
- Using HTH pellets, drop through the casing access hole to the bottom of the well (with oil lubricated turbines do this very slowly).
- Using HTH granules or powder, dissolve slowly by adding to 10 gallons of water or more. Pour into the well then add at least 100 gallons of water to distribute throughout the well.
- Using liquid bleach, pour into 10 gallons of water and pour into the well. Add at least 100 gallons of water to distribute throughout the well.
Table 1. Quantities of chlorine material to use for each 10 feet of water in the
irrigation well.
Well Diameter |
Gallons of Water in a 10-ft column |
HTH 70% Chlorine |
Bleach 5% Chlorine |
(inches) | Pounds/10 ft | (gallons/10 ft) | |
6 | 15 | 0.1 | 0.1 |
8 | 26 | 0.16 | 0.2 |
10 | 41 | 0.35 | 0.6 |
14 | 80 | 0.5 | 0.8 |
16 | 105 | 0.6 | 1.0 |
18 | 133 | 0.8 | 1.2 |
20 | 164 | 1.0 | 1.5 |
24 | 235 | 1.4 | 2.2 |
Chlorinating your well on a consistent basis should keep the production of the well close to when it was drilled.
Irrigation systems, just like other farm equipment, need regular, routine maintenance especially when most of the equipment stays outdoors all year. Performing the following maintenance items will help ensure your irrigation equipment is in good shape when you start it next spring.
Pipes, valves, tanks, centrifugal pumps, etc. should be drained of water or pumped out to prevent damage from freezing. Underground pipelines are full of water and need to be pumped, drained or blown out before November 15. After the water has been removed from the pipeline, the pipeline should be checked several days later to see that all the water has been removed. Protect pump-out risers and other equipment from livestock. Close or cover any openings that might invite animals or rodents to enter.
For oil-lubricated deep well turbine pumps, after the pump is cold, open the oiler and let oil drip into the line shaft bearings. Rotate the shaft to distribute the oil over the entire bearing. The cold oil will adhere to the cold bearings and provide good winter protection. Check the packing gland around the shaft on the pump head; if it has worn or missing pieces, replace with new material. On belt driven pumps, remove the belts and store in a dry place. If you can't remove the belts easily, then reduce the tension on the belts. If the belts are worn or frayed, replace with new belts in the spring.
Accurate pressure gages and flow meters are the best way to keep track of the performance of your irrigation pumping system. If possible, remove the flow meter and pressure gages. Cover or plug the holes. If the flow meter does not work, winter is a good time to have it repaired. Note any broken pressure gages and replace with new ones in the spring.
Pipes should be stored on racks so that one end is above the ground to permit drainage and air circulation. Protect them from livestock.
Gaskets are an extremely important part of aboveground pipelines (including gated pipe). Flow testing in Nebraska showed that many aboveground pipelines lost from 10 to 35% of the pumped water between the pump and the irrigation system. Cracks and other leaks in the pipelines accounted for some of the lost water, but most of the water was lost due to old or missing gaskets.
If possible, remove the gaskets when storing pipe for winter. Inspect them and obtain replacements for any that are damaged or leaked during use. Store the gaskets in clean water in a place that will not freeze. This prevents them from cracking and drying out. Do not hang gaskets on a nail or hook. If they cannot be stored in water, place them over a pipe that has a slightly smaller diameter than the gasket and keep out of direct sunlight. Covering the gaskets to restrict air movement will also help to prevent drying out and cracking. If the pipe is to remain in the field, loosen the connectors but don't split all the sections of pipe (some may need to be split to drain water). In the spring, make sure the gaskets are in good condition before inserting in the pipeline.
Chemical injector pumps should be flushed with water, then drained and, if transportable, stored in a clean dry place. If the pump is belt driven, loosen the belt.
Check all electric motor openings to make sure they are properly screened to keep rodents out. Rodents like to chew on motor winding insulation in the winter. Often chewed windings result in shorts and a burned out motor the next year. If a screen is damaged or missing, replace with ΒΌ-inch mesh screen. This screen can then be left in place during operation without plugging with dust and debris. Electric motors are best left open to free air movement to keep moisture condensation in the motor to a minimum. Lubricate all bearings and rotate motor. Change oil in the motor reservoir if discolored.
On electrical control panel doors, replace the seals if hard or broken to keep moisture, dust and rodents out. Seal all openings into the electrical control box to prevent rodents from entering and damaging the wiring. Lock the control box in the "OFF" position. Spraying electrical contacts with contact cleaner will displace dirt and moisture to prevent corrosion.
For internal combustion engines, special attention must be paid to lubrication, the cooling system, ignition, engine openings and the fuel system. Enclosing the engine would be ideal. Where it is impossible to provide housing, proper winterizing is especially important.
Change the oil and filter when the engine is warm, then run the engine briefly to circulate. Clean and replace the air cleaner. Remove and clean the spark plugs, pour 2 ounces of oil into each plug hole and replace plugs. Rotate the crankshaft several turns to allow the oil to thoroughly coat the cylinder walls.
The cooling system should be flushed and refilled with the proper anti-freeze solution. This will prevent rust and scale from forming in the cooling system. For gasoline engines, add fuel stabilizer and run the engine, or drain all fuel from tank, lines, and carburetor. For diesel engines, fill tank, DO NOT drain. Replace the fuel filter and leave all lines and injectors filled with diesel fuel. For LP gas engines, drain the vaporizer-regulator (both fuel and water lines).
Seal all openings, with weatherproof tape (air cleaner inlet, exhaust, distributor cap and crankcase breather tube). Lubricate all accessories. Loosen belts. Remove the battery, charge it and store in a cool, dry place.
A small amount of maintenance and repair will ensure your irrigation system starts and runs properly next growing season.
April 1999 | |
New Center Pivot for Research at Carrington, Dean Steele North Dakota Irrigation Caucus, Tahni Cullen Chemigation: Laws and Equipment, Tom Scherer |
|
May 1999 | |
New Irrigation Publications, Tom Scherer Stubble Height Effects in Alfalfa, Dwain Meyer The US Bureau of Reclamation's Water Conservation Field Services Program, Jim Weigel Tech Tip: Pressure Gages, Tom Scherer |
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June 1999 | |
Make a Calibration Tube for Nitrogen Chemigation, Tom Scherer Calibrating Your Sprayer, Vern Hofman |
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July 1999 | |
Irrigation Scheduling is Important in July and August, Tom Scherer Analyzing Plant Problems, Cheryl Ruby Microirrigation for Row Crops? Aung Hla Disease Control Under Irrigation, Art Lamey |
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August 1999 | |
Irrigation Conference in Alberta, Canada Aerial Photography Using a Radio-Controlled Airplane, Nathan Derby Chemigation Management Tips, Tom Scherer |
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September 1999 | |
New Web Pages to Check Out, Tom Scherer Timing of Last Irrigation, Duane Berglund Stored Grain Management, Ken Hellevang How Long Would You Expect a Center Pivot and its Components to Last? Tom Scherer |
|
October 1999 | |
Park Your Center Pivot in the Right Direction, Tom Scherer Productive Wells Need Fall Chlorination, Tom Scherer Prepare Your Irrigation System for Winter, Tom Scherer |
Water Spouts, No. 179, October 1999
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.