News -- December 1998 -- Oklahoma Alfalfa

As we approach 1999, it is fitting that we forget about the hot summer of 1998 and the fall floods. We should be thankful for the mild fall temperatures. It is also important that we reflect back on our successes and problems with alfalfa management in 1998. One of the positive things that a number of producers did in the summer was to utilize their alfalfa stands for livestock grazing. In fact many producers continued using alfalfa for grazing throughout the fall. As a result, many of the stands have been over-utilized, and alfalfa root reserves are likely to be low. This will result in reduced alfalfa yields next year. Getting off of these overgrazed fields now would allow stands some much needed rest, and provide better alfalfa production this coming year.

Now is a good time to determine what your alfalfa weed management practices will be for this coming season.

New Fall-Planted Stands: Hopefully most of you controlled the weeds in your alfalfa this fall while they were actively growing and easy to kill. Weed growth has now essentially stopped due to cold weather, so it is too late to spray weeds. Some winter weeds can be controlled again this coming March when they start growing. Examples would be tansy mustard and cutleaf eveningprimrose with BUTYRAC and ryegrass with POAST PLUS. Do not expect to control shepherdspurse and many of the other broadleaf weeds with BUTYRAC or most of the winter grasses with POST PLUS or SELECT applied in March.

If you got your alfalfa in early and did not control the volunteer wheat and cheat this fall, consider flash grazing in early January if the grasses are shading the alfalfa. Flash grazing is also referred to as "mob grazing." Stocking rate should be high enough that the forage is cleaned up in just a few days. When alfalfa plants are shaded, they stop growing and stand loss is possible. You need to flash-graze these areas when the soil is dry or frozen. Weedinfested fields should be harvested early in the spring to minimize the shading damage to the alfalfa. For sure, don't wait until you see blooms.

Established Stands: Good stands of vigorous alfalfa are competitive with weeds, so no herbicide is
needed on these stands.

Keys to maintaining vigorous competitive alfalfa are:
1) maintaining proper soil fertility and
2) scouting and control of insects when they reach economic levels.

Good responses of alfalfa to both surface broadcast phosphorus and injected phosphorus in early
winter have resulted when soil tests indicated phosphorous deficiency. So, you better soil sample and fertilize, if you want your alfalfa to be productive and competitive with the weeds.

Old Stands: Weeds will start showing up in your hay when stands start thinning and do not occupy all of the area. Thinning may just be a sign that phosphorus or potassium is getting low, so soil test and fertilize first.

You can extend the productive life of a thinning stand a couple of ways. You can control the weeds with herbicides and continuing to have weed-free hay, or change focus and utilize the alfalfa and weeds by grazing.

If you want to continue producing weed-free hay, then the most profitable thing to do is control the cool-season weeds in thinning stands by spraying with a herbicide such as SINBAR and VELPAR in January or February. They are effective, dependable and are usually profitable, providing soil fertility is maintained and insects are controlled.

Grazing is an excellent way to utilize the forage from weed-infested thinning stands if you have livestock and can manage the bloat problem. Actually, bloat is not that serious when grazing thinning stands infested with weeds. The quality of the forage in these thinning stands can be improved by drilling in oats this January. Oats will occupy the open areas and compete with weed. These fields can be utilized by "flash" grazing next spring, or by haying. It is probably important to apply at least 100 lb/acre of 18-46-0 down the tube as a starter fertilizer.

--Jim Stritzke
Alfalfa Weed Control Specialist
Plant & Soil Sciences Department

The Board of Directors for the Oklahoma Alfalfa Hay & Seed Association has determined that
$4000 will be available for Research and/or Extension Grant support in 1999. Grant(s) will be awarded to help finance the purchase of equipment, supplies, labor, and travel necessary to conduct applied research and/or extension activities devoted to the improvement of Oklahoma Alfalfa Industry. Preference will be given to active Association members. Proposals should not exceed 2 pages in length and should include the following items:

1. Title
2. Name and Address of Project Leader(s)
3. Introduction to the Problem(s)
4. Objectives
5. Approach and Procedures
6. Budget Summary

Individuals or groups interested in applying should send 10 copies of their proposal to John Caddel, Secretary, by January 11,1999. Proposals will be evaluated by the Board of Directors, and funds will be awarded for selected projects on Feb. 23, 1999 at their Board of Directors Meeting.

Funds to support applied alfalfa research and extension activities come from Association members. All contributions are completely voluntary. Money for grants ($4000) this year comes from interest on the Association's Research Fund and extra funds in the general account.

For the last several years, we have talked about an ongoing phosphate fertilization study at the Chickasha Research Station. As we have discussed in many public meetings with producers and the ag industry, alfalfa has a high demand for all nutrients because it is generally high yielding and, since it usually is provided abundant nitrogen through symbiosis with rhizobium, uptake of other nutrients is greater than for most crops. However, our observations around the state, review of soil test information, and visits with other scientists has led us to conclude that the most common yield limiting nutrient is phosphorus. We expect a major reason other nutrients are not as commonly deficient is because the smaller amounts of these nutrients required by alfalfa, and other nutrients are better supplied in the deep soils usually reserved for alfalfa .

The six-year Chickasha study is now complete, and so we can draw conclusions from the results
better now than we have been able to in the past. We hope to do this in a series of articles in the
NEWS. First, let's consider to objectives of the study and how it was designed to answer important questions about phosphate fertilizing.

1. Does it make a difference whether the phosphate is supplied as 18-46-0, 0-46-0, or
10-34-0(liquid, ammonium polyphosphate)? We included all three fertilizers in the study.

* Because large amounts of phosphate are sometimes required and the most common source is
18-46-0, we wondered if the addition of nitrogen would cause the rhizobium to get lazy, or if it would promote weeds in the first year.

2. Should two to three years phosphate needs be applied preplant and incorporated instead of
applying the deficiency indicated by the soil test each year?

* Because surface applied phosphate fertilizer does not easily move down into the soil to feeder roots with water, we recommended that several years requirement be applied preplant when incorporation would position it deeper in the soil where plants would have a better chance for uptake. The soil test called for 80 to 100 lb P₂O₅/acre annually. We used rates of 0, 100 lb P₂O₅/acre annually, 200 lb P₂O₅/acre preplant incorporated followed by 200 lb P₂O₅/acre every other year, and 600 lb P₂O₅/acre preplant incorporated without any follow-up fertilizer. We compared all three fertilizer materials at these rates and methods of application.

3. Would there be any benefit to band applying the phosphate fertilizer?

* Soil fertility researchers have known for a long time that when phosphate fertilizer is placed in a
band, where plant roots can make contact with it, fertilizer contact with soil is minimized and
availability over time is increased. Since the soil is not cultivated once the alfalfa is established, the
band may stay intact for several years. We included a treatments where liquid ammonium
polyphosphate was injected 6" below the surface with knives 20" apart. The rates were 200 lb
P₂O₅/acre preplant followed by 200 lb P₂O₅/acre every other year, and 600 lb P₂O₅/acre preplant without any follow-up fertilizer.

4. Should other nutrients, such as potash and sulfur, be applied to high yielding alfalfa even when the soil test indicates they are adequate?

* Because high yielding alfalfa is very demanding on the soil supply of other essential nutrients, there is often concern for applying them even if the soil test doesn't call for them. We included a treatment of 500 lb K₂O/acre and 50 lb S/acre annually, along with a high rate of phosphate.

--Gordon Johnson
Nutrient Management Specialist
Plant & Soil Sciences Department

Getting alfalfa production information (new and old) to producers is difficult and can be expensive.
A little over a year ago several of the alfalfa research and extension specialists at OSU decided to
undertake a new approach. Put the information on the Internet so it will be more readily available to all who need the information on any day at any time of day or night.

It has been an interesting experience, to say the least. None of us had experience designing a web
page, but we thought we could learn. Several of us have learned a lot, and we have taught several
student about what should be on a web page devoted to providing advice to alfalfa producers.

I believe that everyone who has contributed has found it to be a rewarding experience. The following description should encourage you checked it out. To be sure, it is easy to use and there is a lot of information to be accessed. Let me know of problems you encounter so they can be fixed.

The Oklahoma Alfalfa Production Calendar is designed to supply practical and timely alfalfa
production information. It contains applied information to assist in profitable production of high quality forage desired for marketing and use in Oklahoma and the surrounding area of the Southern Great Plains. Information supplied has long-term applications such as stand longevity and immediate utility such as updates on current insect infestations. Cost-benefit relationships are addressed in most topics.

The ultimate audience is alfalfa producers; however, much of the information may reach them through County Extension Educators, Agricultural Consultants, and Crop Scouts. Lending agencies and materials suppliers should also benefit from this web site.

The Oklahoma Alfalfa Production Calendar centers on the month and production categories. Users select the month of interest, then indicate the type of production, storage, or marketing information desired. Most months include the following choices:

Equipment	Marketing
Insect Control	Tools
General Production	Forage Quality
Soil Fertility	Grazing
Variety Choices	Soil Sampling
Water	Liming
Seed Production	Weather Links
Machinery	Storage
Stand Establishment	Weed Control
Harvest Management	Diseases

Following that selection, information is arranged from short statements to more in-depth discussions of topics or to publications with additional information. Included are:

Bullet Statements (1 or 2 sentences) serve as reminders to experienced alfalfa producers.

Production Tips (150 to 500 words) provide new information about products, processes, and
research.

Information Capsules (1 to 10 sentences) have information about a particular alfalfa topic, including trivia.

Short OSU Extension Publications (2 to 8 pages) include fact sheets, current reports, production
technology reports.

OSU Extension Circulars (10 to 30 pages) are normally a single topic such as stand establishment, IPM, harvest management, etc.

Other References

Several hundred photos are provided to help understand problems and opportunities for alfalfa
production, as well as pretty pictures of alfalfa.

We are in the final stages of a major modification of the web page (It should be done before Jan 1.) and would like to get input from users. If you do not have a computer with a modem at your office or home, check your county extension office. They probably have one you could use for a session or so.

--John Caddel
Forage Agronomist
Plant & Soil Sciences Department

Each winter and early spring we have a membership drive to make sure that everyone interested in alfalfa has a chance to become a member of our Association. Every member can help with the drive, and it will not take much time. The following check list should help you remember some of the easy things to do.

Pay your dues early. Dues are for a calendar year. It is the same if you pay in January or May, except the bookkeeping part. I don't want to misplace a member.

Check with your associates and ask if they are members. Ask those who are not if they would like a membership form.

Hand out flyers describing the Association. Let me know if you want a supply 405-744-9643 or check the web page below.

Handout extra copies of the NEWS. Let me know if you want a supply 405-744-9643.

Check out this web page http://ok-alf-assoc.okstate.edu/pur-hist.htm for information about the purpose and history of the Association.

Check out this web page http://ok-alf-assoc.okstate.edu/membrshp.htm for membership forms. It works just like the one on the back page of each newsletter.

Who profits from membership? Many different professions have been members and repeat members, indicating that membership was good for them.. Some examples are below.

Hay Producers	Equipment Dealers	Crop Advisors	Crop Consultants
Seed Producers	Seed Venders	Chemical Dealers/ Representatives, Etc	Researchers
Bankers	Hay Brokers	Financial Advisors	Dairy Hay Feeders
Beef Cattle Feeders	Teachers	Many Others

1. Planting in the spring is risky, at best, here in Oklahoma. This is not a "yes"/ "no" question. It is very risky, but there are several things that you can do to minimize the risks. Each year is very
different.

2. Irrigation may help a spring-sown stand get going if everything else is in good shape.

3. I would certainly recommend against spring replanting if there is any chance the field is even slightly deficient in any plant nutrient. Collect soil samples, have them analyzed, apply what is needed before thinking about thickening the stand.

4. Replanting (thickening up) alfalfa stands is risky. Of all the types of thickening, thickening or replanting a new stand is the least risky. It is most difficult to thicken a stand that has been thick and still has old growing plants throughout (as thin as one plant per square foot).

5. We will be addressing these questions more in the NEWS.

--John Caddel,
Forage Agronomist,
Dept. of Plant & Soil Sciences

Weed Control	Alfalfa Research Fund	Soil Fertility
Annual Meeting	Alfalfa Calendar	Membership Drive
	Replanting Thin Stands
	OTHER LINKS
Oklahoma Alfalfa	Alfalfa Hay & Seed Assoc.	Newsletter
Upcoming Meetings	Current Directors List	Membership Form
	Other Web Pages

368 Ag Hall OSU Plant & Soil Sciences Department Stillwater, OK 74078
December 1998	Volume 22 No. 11