North Dakota State University
NDSU Extension Service

No. 157, September 1996

Turtle Lake Field Day -- Life After CRP: Farming, Irrigation and Wildlife

Participants at the CRP Field Day set for Sept. 17 at Turtle Lake can learn about options for land coming out of CRP and visit with landowners who are grazing and irrigating former CRP lands.

The Turtle Lake Irrigation Area annual field day will be held Sept. 17 starting at 4 p.m. at the Lake Brekken-Holmes Recreation Area located 1.5 miles north of Turtle Lake on county road 27. A recently completed economic study of the Turtle Lake Area Conceptual Development Plan will be discussed and a short tour of area demonstration projects will be held. The field day is open to the public and lunch will be served.

Turtle Lake Area Irrigation Area Tour and Demonstrations
4 to 6 p.m., September 17, 1996

4 p.m. Meet at Brekken-Holmes recreation area

James Weigel, (701) 652-3194
Extension Area Specialist, Irrigation

Current Statistics for Vegetables

With all of the work in progress in North Dakota on food processing and cooperative development, it might be interesting to take a look at national and state data. We have assembled some bullets and statistics for your information as follows:

Rudy Radke, (701) 845-8528
Area Ag Diversification Specialist
NDSU Extension Service

Maintaining Corn Quality for Wet Milling

Desired corn characteristics for wet milling include uniform kernel size, high kernel integrity (no scratches, holes, cracks or breaks), high test weight, good starch quality, uniform moisture, soft endosperm, and no mold. The milling industry estimates that poor quality corn causes about a 5-10% reduction in milling capacity. Corn producers have some control over corn quality through variety selection, timing and care used in harvesting, selection and operation of dryers and conveyors, and storage management.

Obtaining quality corn for wet milling starts with selecting corn varieties that will reach maturity prior to frost. Frost-damaged corn has small kernels, a low test weight, poor starch quality, and is often susceptible to cracking and breaking.

The optimum moisture content for limiting mechanical damage during harvest is about 22%. Follow the recommendations in the operators manual for combine settings and recommended harvesting procedures.

The kernel temperature should not exceed 140° F during drying to prevent damage to milling quality. At temperatures exceeding about 140° F, milling efficiency is reduced due to starch gelatinization, protein denaturation, proteolytic denaturation, and damage to the germ of the kernel causing a loss of viability. Some wet millers use a germination test to assess corn quality.

In a high temperature cross-flow dryer, even though the average moisture content may be at 14%, the moisture content of grain near the inside of the column may be 6 to 10%, and grain near the outside of the column may be at 16 to 28% moisture content. Also, even though the average temperature may be at 140° F, grain near the inside of the column may be at 200° F, and grain near the outside of the column may be at 80° F. A cross-flow dryer used for drying corn for wet milling should be operated at moderate temperatures or include features to minimize the variations across the column.

The initial moisture content that can be dried by a natural-air or low-temperature system in a full bin is limited to about 21%. An airflow rate of 1.25 cfm/bu will dry 21% moisture content corn to about 15% in about 36 days under average Upper Midwest October conditions. NA/LT drying is not efficient with typical mid to late November weather conditions. Corn can be held over winter then dried in the spring.

For more information on harvesting, drying, and storage of corn for wet milling, a publication will be available from the NDSU Extension Service about mid-September. Obtain the publication from your local extension service office or from the Distribution Center, North Dakota State University.

Dr. Kenneth J. Hellevang, (701) 231-7243
NDSU Extension Agricultural Engineer

CRP Land Conversion to Irrigation

The CRP program was initiated in 1985 and idled approximately 36 million acres of U.S. cropland. CRP acres were predominately planted to perennial grasses or grass/legume stands for 10 years. Future uses of CRP lands is uncertain. The options include: (a) remain in CRP program (if contracts can be renewed or extended), (b) return to annual crop production, and (c) remain in permanent grass for livestock grazing or haying.

CRP expiration in North Dakota is expected as follows:

1996 -- 563,224 acres
1997 -- 963,013 acres
1998 -- 715,573 acres
1999 -- 591,257 acres

It's estimated that approximately two-thirds of these acres will be put back into crop production. Many of the CRP lands are highly erodible lands (HEL) and are comprised of coarse textured soils. These lands could be considered for possible production under irrigation provided certain soil conservation, soil characteristics, and other management practices or guidelines are followed. Now is the time to start planning if certain CRP lands would work successfully under an irrigation management plan. After CRP, soils should be somewhat improved with slightly more organic matter, better soil structure and better water holding capacity. However, experience has shown that within the first two to three years after tilling long-term grasslands, soil tilth will degrade very rapidly. Irrigators should plan to utilize cultural practices and reduced tillage systems that will minimize soil erosion and help preserve or improve soil health which have been gained over the past 10 years.

Some of the problems one will encounter include:

Managing old residues: Plant residues will vary site by site depending on the species planted and stands maintained. The cheapest method to remove residue is burning it off but not the wisest approach. Burn treatments remove most of the surface residue leaving little or no protection against erosion. When tillage is then used for seedbed preparation on burned CRP then the soil is highly exposed to erosion. Also, several plant nutrients can be lost via burning.

Haying or grazing existing vegetation to remove it, chopping it and then treating with Roundup to kill existing vegetation is perhaps the best alternative. The management of old grass residue should start in the late summer and fall prior to the planned next year's cropping season. Also, certain perennial weeds are best controlled and killed by herbicide treatments in late summer and fall. Spring is a difficult time to get satisfactory control of most perennial weeds. Alfalfa in the CRP stands are best controlled in the fall compared to spring application. In summer, management of existing vegetation is best completed in late summer and early fall prior to contract expiration. If growers plan to use tillage alone, problems with existing vegetation can and will be a problem the first cropping season.

Soil fertility needs: CRP lands will be somewhat low in fertility. Both nitrogen and phosphorous will be low or limited for maximum irrigated crop yield potential. Total N in the 0-4 feet range have been as low as 4 to 15 lbs/A in soil tests. It is critical to take soil samples and have then tested to ensure that adequate levels of nutrients are available for an irrigated crop. Use of certain legume crops that fix N on their own should work well the first year out of CRP. With other crops such as corn, potatoes, small grains and sunflower, adequate supplemental N would be required via split applications. Too much N applied at one time on coarse-textured soils may leach and be lost from the crop rooting zone.

Tillage: Some limited tillage maybe required to prepare a seedbed and to place needed amounts of phosphorus. Also some tillage will be needed if the CRP lands are excessively rough and uneven.

Rodents, other animals and ant-hills can be problems for cropping. Tillage operations such as discing, chisel plowing or using an undercutter can help level the ground. In Oklahoma, a large V-blade undercutter was very effective in controlling grasses and certain weeds. The V-blade could be used in the fall after chemical burn-down or in the spring prior to planting.

Pest problems: Problems which may follow CRP conversion include certain soil insects which survive well in sod. These include wireworms, certain cutworms, white grubs and perhaps grasshoppers. Producers must be aware of the potential pest and treat accordingly. For plant diseases, certain root rots may be a problem in small grains or corn. Be sure to kill the existing vegetation well before planting the irrigated crop. Ergot could be a potential problem in certain small grains following CRP grasslands.

In Summary

Remember much of the CRP land is highly erodible. Farming methods to bring these acres back into crop production should be aimed at minimizing the potential for soil erosion while maintaining or improveing organic matter. Don't farm the steep-sloped CRP lands, utilize or leave any grassed waterway areas already in place, and do not burning CRP lands is not advised. Production inputs the first year coming out of CRP may cost considerably more than in later years.

Duane R. Berglund, (701) 231-8135
NDSU Extension Agronomist

Fall is a Good Time to Start Managing Center Pivot Wheel Tracks

Center pivot irrigators know 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 soils 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:

  1. The soil type; usually the heavier soils (clay, clay loams) have deeper tracks because they remain wet due to higher water holding capacity and slower drainage. They also usually occur in the low spots where water collects naturally.
  2. The number of revolutions the pivot makes in the tracks before tillage levels them.
  3. The weight supported by each tower.
  4. The amount of wheel contact area with the soil surface.

You can reduce deep wheel track problems using either management or mechanical solutions. Some of the management methods you might use are:

  1. Schedule irrigation water applications to avoid unnecessary pivot revolutions.
  2. Allow the soil surface to dry between irrigations, especially the soil in the wheel tracks. Sometimes this option is not feasible after a full crop canopy develops and shades the wheel tracks.
  3. Keep tire inflation pressure at the manufacturer's recommended level. This will maintain the proper amount of tire contact area.
  4. If you have deep wheel tracks in a perennial crop such as alfalfa, consider cutting and harvesting within the circles.
  5. During the season you have observed the pivot while it operates. If excessive ponding was occurring due to the applied irrigation water, you have to reduce the amount of applied water during each rotation of the pivot. This might require increasing the speed of the pivot, but this will require you to watch your plant water requirements more closely.

Following are some of the mechanical changes you can do to help your pivot system to reduce deep wheel tracks:

  1. You can build a road for the tower wheels. This can be done by running the system to mark the wheel track location, then using a plow, disc plow, or blade to build a ridge where the track is located. Be sure to pull soil from both sides of the track.
  2. Manufacturers of pivot systems offer a wide range of tire sizes that are designed to minimize deep wheel tracks. However, if you go to larger tires, you may have to increase the size and strength of the drive mechanism.
  3. You can put directional sprinklers on either side of a tower. This directs water away from the wheel track.
  4. You can attach track closing disks to each tower. A disk located on each side of the track pushes soil into the track as the tower moves through the field. A problem with using this option is that the pivot can only be moved in one direction.
  5. The sprinklers near the tower can be located on "boom-backs." The boomback allows the sprinkler to apply water to the soil behind the wheel so that the track is dry when the tower passes. As in the previous suggestion, the pivot can only be moved in one direction.

Tom Scherer, (701) 231-7239
Extension Agricultural Engineer

Tech Tip: Steel wool and fabric softener hinders rodents

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.

Fabric softener strips are reported to prevent rodents from entering enclosed areas. I read about it in a sportsman magazine and I have been putting them under my boat cover for years. I haven't had any damage, but I didn't have any before using them either. It is worth a try.

Tech Tip: Seal control panels and boxes.

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 contractors and panels will prevent corrosion and failed contractors. Reseal boxes at the first sign of weather seal damage. Pickup topper seal will work well and has adhesive to make installation a snap.

Tech Tip: Record critical water data on site.

To prevent misplacing information on your well and pump, record it on the inside of the electrical 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

Jim Weigel, (701) 652-3194
Area Irrigation Specialist, Carrington

No. 157, September 1996

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