CORN
Crop Observation and Recommendation Network

For March 15-31, 1999
C.O.R.N. 99-3

In This Issue:

A) Rhizobium Inoculation of Soybean
B) Tips on Handling Rhizobium Inoculate
C) Starter Fertilizers for Corn

A) Rhizobium Inoculation of Soybean - Jim Beuerlein CORN Questions

During 1995 through 1998 we have conducted 22 field trials which included several inoculation materials. How do the new inoculates differ from past products?  First, the new inoculates are produced on sterile media which means the desirable bacteria do not compete with other bacteria on the media mix which results in a purer product.  Second, the bacteria used in the newer Asterile@ inoculates tend to infect the root system more extensively, fix more nitrogen, and may survive longer in the soil than older strains.  More productive strains are being developed using gene transfer technology and will enter the market in a few years.  Also listed below is research on Initiate. Initiate is a signal compound that expedites nodule formation early in the
season when soils are cold, and it has increased yield during very limited testing

The average yield increase has been 3.0 bu/ac and the cost of inoculation is normally $1.00 to $2.00 per acre leaving a profit of about $13.00 per acre.  The test fields were typically in a soybean-corn rotation, had good fertility, appropriate pH values and were very productive.  We have had good results in both tilled and no-till fields.  Many producers can expect this level of
profitability from inoculating their soybean seed.   The following table show the results from 22 field trials.
 

Soybean Yield Increases due to Various Inoculation Materials by Year.

B) Tips on Handlinng Rhizobium Inoculate - Jim Beuerlein CORN Questions

Rhizobium bacterial inoculate are living biological organism. Due to this characteristic they require some care in handling to maintain their effectiveness.  Without following handling suggestions, the user will not reap the potential benefits of these products. Below are some tips for handling and use of bacterial inoculates.
 

1. Inoculates should be stored in a cool place and not exposed to the sun prior to use. When exposed to heating bacteria do die.  Prior to use both liquids and peat based inoculates should be stored at room temperature of 65-70 degrees. If frozen liquid product is purchased, keep frozen prior to use.  Refer to product labels for specific handling recommendations.
2. Product labels will have stamped on them an expiration date.  It is recommended to buy just enough inoculate for a single season.  The safest approach is to buy fresh inoculate each year.
3. Once the carrier of the inoculate dries on the seed, the bacterial cell starts dying.  Seed should be planted within four hours of inoculation.  Bacteria cells do not remain alive on the seed longer than 12 to 24 hours.
4. When applying a fungicide or using fungicide treated seed, be sure the fungicide has dried before applying inoculate to the seed.  Inoculate should NOT be mixed with fungicides and applied together.
5. When loading a drill or planter using an auger, inoculation materials (liquid or dry) should be added to the seed as it enters the auger for thorough application.  When loading a drill or planter from bags, fill the seed box to a depth of three inches and scatter the appropriate amount of inoculate over the seed and mix it in thoroughly.  Continue to add seed in six-inch deep layers, treating each until the seed box is filled.  With some dry materials it may be desirable to slightly moisten seed to increase the adherence of inoculate. Individual seeds need no more than a three to five percent coating of dry material.  Liquid materials will usually cover most of the seed.
6. What effects do inoculates have on seed metering?  Once dry, liquids have little or no effect on the seed metering rates.  Dry materials usually reduce the flow rate of seed through fluted seed metering devices (most grain drills) and may also have undesirable effects on vacuum and air metering systems. Seeding equipment should be calibrated using treated seed.  Some seeding rate monitors allow a continuous check of seeding rates so adjustments can be made to the seeding rate if and when necessary.

Both fungicide seed treatments and inoculation can produce large returns relative to their cost and in most cases both should be used.  Inoculates must be handled and applied properly to maintain their effectiveness. When only one can be used, the fungicide will likely be the more profitable.

C)  Starter Fertilizers for Corn - Ed Lentz  CORN Questions

Starter fertilizer is another area that we can examine for cost savings in a year with low commodity prices.   This cost saving may come from not using starters or only using the nutrients that we expect to get a yield response.  Generally, we do not see a yield benefit from starter fertilizer in a plowed or reduced-tillage system, unless soil phosphorus and/or potash are low.  No-till systems have the greatest chance for a yield response from starter fertilizer.

Since soils tend to be cold and wet in a no-till system, it was thought that phosphorus provided the most benefit to slow developing root systems.  Research has shown that nitrogen (rather than phosphorus) in a starter fertilizer is the nutrient that most consistently causes a yield response.  The addition of phosphorus to a starter for no-till would be recommended in cases where soil phosphorus levels are low to medium.  However, phosphorus may be left out in soils testing high.   Further costs may be eliminated by not adding micronutrients (zinc, manganese, boron, etc.) or sulfur to starters where there is no field history of a deficiency in these nutrients.

Placement of fertilizer in 2 X 2 band (2” below and 2” to the side of the seed) has been one of the more common methods of applying starters.   The common rate for this method is 20-40 pounds of nitrogen, phosphorus, and/or potash per acre.  If applications are applied in-furrow (pop-up) be careful not to apply too much nitrogen or potash.  Pop-up applications should be less than 10 pounds of nitrogen and/or potash to avoid potential salt injury.  Sandy soil should use even less.   In general, it does not matter whether liquid or dry formulations of fertilizer are used in 2 X 2 or pop-up programs.

Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.

Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/

C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.

Contributors to C.O.R.N. this week include: STATE SPECIALISTS: Pat Lipps (Extension Specialist, Plant Pathology), Jeff Stachler (Extension Associate, Weed Science), Ed Lentz (Northwest District Agronomy Specialist), Jim Beuerlein (Extension Specialist, Soybean and Small Grains), Peter Thomison (Extension Specialist, Corn Production); EXTENSION AGENTS: Larry Lotz (Fayette), Bruce Clevenger (Defiance), Greg LaBarge (Fulton), Dennis Baker (Darke), Ray Wells (Ross) and Barry Ward (Marion).

Editor: Greg LaBarge        Web Editor: Steve Lichtensteiger

Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.

TDD # 1 (800) 589-8292 (Ohio only) or (614) 292-1868

  | C.O.R.N. | Newsletter | Archive | Search | Questions? | Ohioline | Publications |