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From the most recent Corn & Soybean Classic, Dr. Emerson Nafziger presented the following data.

 
      Table 1        Corn Grain Yields in Various Rotations in Northern Illinois____

                                                                  Year___________         Ave        % of      

                                           2008       2009       2010       2011       Yield        SC
Rotation                          —————————–Bu/A———————-

Continuous Corn*           202         184         159          170         180          87

Corn-Soybean                  220         214         197          186         205        100

1^st Yr Corn in C-C-SB      216         211         191          186         202          98
2^nd Yr Corn in C-C-SB     211         196         177          175         191          93______

*4^th Yr Continuous Corn Plus

 

At our Agronology 10 Research Center at Walcott, we are measuring an 11% yield difference on corn following soybeans vs. a long term continuous corn rotation.  Another item to note from the Illinois work is that soybean yields have increased 5% in C-C-SB vs. C-SB rotation.

                                             

The information in Table 1, presented by Dr. Gary Schnitkey at the 2012 Corn and Soybean Classic, demonstrated that our soybean yields are not advancing as strongly as corn.

      Table 1    Corn-to-Soybean Ratios for Price, Yields and Costs, Central Illinois__
    Years__                           Prices                       Yields                       Costs

1976-1988                           0.38                           2.92                           1.51

1989-2000                           0.41                           3.12                           1.47
2001-2010                           0.40                           3.44                           1.56___________

Source:  Illinois Farm Business Farm Management

What are you doing to improve your soybeans?

     

                                                          

With spring not too far off, have you considered the possibility that the seed corn you will be planting in 2012 could be sized as large rounds or large flats?  With these larger seed sizes, what changes/adjustments do you need to make to your planter?                                                

Salt index is the ratio of an increase in osmotic pressure produced by a fertilizer compound compared to a standard sodium nitrate base.  The higher the salt index, the more concern there is that the fertilizer material can affect the germinating seed.  The following table shows salt index for some common starter fertilizers.

                       Table 1                                  Salt Indexes_________________________________

  Product_                           Source of Potassium                             Salt Index

6-24-6                                           K0H                                                      11.5 

9-18-9                                           K0H                                                      16.7

10-34-0                                         —–                                                       20.0

7-21-7                                           KCL                                                      27.8

4-10-10                                         KCL                                                      27.5

7-18-6-2s-.5zn                            KCL                                                      29.0
4-10-10-1s-.25                           KCL                                                      29.0___________________

Sources:  C.A.M Laboski:  2008 Wisconsin Fertilizer, Ag Lime, and Pest Management Conference

                 RH Tinsman Jr.

                                                         

The following, Table 1, illustrates the maximum amounts of salt that can be placed safely close to the germinating seed.

         Table 1                           Maximum Starter Rates________________________

                                                                 Soil Cation Exchange Capacity (CEC)________
Placement of Starter         12 (light texture soils)       >12 (med to heavy texture soils)      

                                                    —————————–lbs. Salt/A*——————————-

In contact with seed                                  5                                              5 to 8

¼ to ½ inch from seed                              8                                              7 to 15

1 to 2 inches from seed                          15                                             20 to 40
Over 2 inches from seed                        20+                                            40+____________

*lbs. nitrogen (N) + lbs. potassium (K)

Table 2 illustrates the pounds of salt found in various fertilizers at 3 different application rates.

           Table 2                      Salt from Starter Applications_____________________
Product                               Rate (Gallons/A)                             Lbs Salt/A

6-24-6-.25s                                       3                                             4.036

                                                            4                                              5.381

                                                            5                                              6.726

9-18-9                                                3                                              6.021

                                                            4                                              8.028

                                                            5                                            10.035______________

                                

Planting depth for corn is extremely critical for proper development of the nodal root system.  If the nodal root system (principal root mass for the corn plant) is located too close to the soil surface, then the nodal root system can be greatly reduced in size.  The impact of a smaller nodal root system can be reduced nutrient uptake.

In recent years past, I have observed with a great frequency that corn planted at 1.5 inches or less is having a problem with nodal root development.  I would recommend that corn be planted at 2 inches of depth and that soybeans be planted at only 1.0 to 1.25 inches of depth.

Dr. Allison Robertson, Associate Professor in the Department of Plant Pathology and Microbiology at Iowa State calls Goss’s wilt the “Disease of the year in 2011.”

Fall 2011 was the first time I had ever seen this disease in the field.

Known facts about Goss’s wilt:

1. 
    The disease is caused by bacterium Clavibacter michiganensis subsp. nebraskaensis.
2. 
   Foliar fungicides and seed treatments are not effective against Goss’s wilt.
3. 
   Disease exists in two phases, the first is leaf blight and second as a wilting stage.
4. 
   Some type of damage by wind, hail, or sand blasting to the plant must occur to allow the bacteria an entry site into the plant.
5. 
   Goss’s wilt overwinters in infected corn residue.
6. 
   Goss’s wilt will be found with a higher risk if weed host such as green foxtail or shattercane are present.

Suggestions for managing Goss’s wilt:

1. 
   Hybrid selection – choose a variety with as high a tolerance to Goss’s wilt as possible.
2. 
   Bury corn residue
3. 
   Plant a nonhost crop like soybeans.    

     Source:  Iowa State Extension                                       Source: Univ. of Nebraska-Lincoln

     

Additives added to your 32% N (UAN) can make a big difference in corn yields.  Many times the same additive can also be added to your hog manures.  The data in Table 1 from the University of Wisconsin demonstrates a 2 year study on the effectiveness of Instinct.^®  When Instinct^® was applied at 35 oz/A, the corn yields at 100 lbs N/A were increased 16 Bu/A, while a spring manure application had an average 21 Bu/A increase.

Table 1

      General Recommendation:  (Total lbs N/A)

               Corn on Corn                          200

               Corn on Soybeans                150

               Corn on Alfalfa                         40

 

Timing for Nitrogen Applications:

                                                                                                      Lbs N/A____________
Operation                             Method                Corn On Soybeans           Corn on Corn

Fall P&K                                Dribble                       24    24    24                  24    24    24

Early Spring                         Dribble                        86    —    50                 136    —    50

Weed & Feed                      Broadcast                   40    40   40                  40     40    40

Sidedress                            Dribble                        —    86    36                  —   136    86

                                                Inject                           —    86    36                  —   136    86

 

Manured fields                   B’cast (W&F)           40

Alfalfa (prev. crop)              B’cast (W&F)           40

 
Additives – should be applied at either early spring dribble or sidedress.
Products                               Rate

Instinct                                  35 oz/A

Nutrisphere                         .0014 gallons · lbs N

N Zone                                   2 qts/ton 32%

The trend to fertilize with hog manure is growing for those farms with the opportunity to do so.  When hog manure is applied according to their manure management plan, generally, most if not all of the phosphorus requirements for crop production are generally met.  However, if phytate feed supplements are utilized in their modern hog rations, then less bypass P is found in the resultant manure.  As increasing amounts of phytate supplements are utilized, the lower the P value for the manure per 1000 gallons.  A check of the manure analysis utilized in determining the application rate is warranted.

A second concern with the current P application rates may be that the P application rate is too low for the higher grain yields being produced.  When this occurs constantly, the soil test P values will decline over time.

How are the application rates of K stacking up to the soil maintenance K value determined by your crop yields?  Frequently, the manure doesn’t have enough K to maintain soil test K values.  To correct this problem, add a liquid application of 1-3-30 (manure special) in a fall dribble band to correct the K deficiency.  This added nitrogen and phosphorus in the 1-3-30 fertilizer will enhance root growth in the zone of application.  This greater root growth, in the application zone, will enhance K uptake in the plant.

In most instances, the hog manure will supply some sulfur, but additional sulfur should be applied to the crop.  However, there exists a need for added zinc and boron for the crop.  The 1 lb. zinc and .2 lb. boron per acre, and whatever level of sulfur required, could be added to the 1-3-30 dribble band application, to a liquid N (32%) solution as a weed & feed application in the spring or the zinc could be added to the starter fertilizer (note:  B should not be applied with the starter fertilizers).

Here are two thoughts dealing with N management and manures.  First, Instinct should be added to all liquid manure at the time of application.  The use rate for Instinct is 35 oz./A.  By adding Instinct to the manure, increased corn yields will be achieved in most instances.  Secondly, a weed & feed broadcast application of 30 to 50 lbs. N per acre in the spring is highly recommended.  This broadcast application will place N in the rooting zone of the newly developing corn plant and give the new plant improved early N status.