AMENDMENT NO. 1 TO
                   AMENDED AND RESTATED VOTING TRUST AGREEMENT


         This  AMENDMENT  NO. 1 TO AMENDED AND RESTATED  VOTING TRUST  AGREEMENT
(the "Amendment") made as of the 29th day of October,  1999, by and among S. LEE
KLING,  FRANKLIN A. JACOBS,  ROBERT J. FREEMAN,  SANFORD WEISS, WAYNE C. DUDLEY,
DENNIS DUDLEY, VICKI JO HARKEN,  JACKIE WILDEBOER,  STEPHEN L. KLING, JR., FRANK
FREDERICK KLING, LEE C. KLING, and ALLAN B. KLING (the "Shareholders"),  who are
the  beneficial  owners of certain  of the shares of the issued and  outstanding
common  stock  of  TOP  AIR  MANUFACTURING,   INC.,  an  Iowa  corporation  (the
"Corporation"), and ROBERT J. FREEMAN AND DENNIS DUDLEY (the "Voting Trustees").

                                  WITNESSETH:

         WHEREAS,  the Shareholders and the Trustees are parties to that certain
Amended  and  Restated  Voting  Trust  Agreement  made  as of  the  15th  day of
September, 1992 (the "Agreement"); and

         WHEREAS,  the Shareholders  desire to amend the Agreement to extend the
termination date of the Agreement.

         NOW THEREFORE,  in  consideration  of the mutual promises and covenants
set forth herein, the receipt and adequacy of which is hereby acknowledged,  the
parties to this Amendment mutually agree as follows:

         1.  Amendment.  It is hereby agreed that Section 10 of the Agreement be
deleted in its entirety and replaced with the following:

         "10. Termination. This Restated VTA shall terminate upon the earlier to
occur of the following:

              A.   January 4, 2005; or

              B.   the date on  which  the  Shareholders  unanimously  agree  to
                   terminate this Restated VTA."

         2. Effect.  Except to the extent expressly  provided in this Amendment,
the terms and conditions of the Agreement  shall remain in full force and effect
and shall be binding on the parties hereto.





         Entered into as of the date first above-written.


                                      /s/ S. Lee Kling
                                      ------------------------------------------
                                      S. Lee Kling


                                      /s/ Franklin A. Jacobs
                                      ------------------------------------------
                                      Franklin A. Jacobs


                                      /s/ Robert J. Freeman
                                      ------------------------------------------
                                      Robert J. Freeman


                                      /s/ Sanford Weiss
                                      ------------------------------------------
                                      Sanford Weiss


                                      /s/ Wayne C. Dudley
                                      ------------------------------------------
                                      Wayne C. Dudley


                                      /s/ Dennis C. Dudley
                                      ------------------------------------------
                                      Dennis C. Dudley


                                      /s/ Vicki Jo Harken
                                      ------------------------------------------
                                      Vicki Jo Harken


                                      /s/ Jackie Wildeboer
                                      ------------------------------------------
                                      Jackie Wildeboer


                                      /s/ Stephen L. Kling, Jr.
                                      ------------------------------------------
                                      Stephen L. Kling, Jr.


                                      /s/ Frank Frederick Kling
                                      ------------------------------------------
                                      Frank Frederick Kling


                                      /s/ Lee C. Kling
                                      ------------------------------------------
                                      Lee C. Kling


                                      /s/ Allan B. Kling
                                      ------------------------------------------
                                      Allan B. Kling


                                      TRUSTEES

                                      /s/ Robert J. Freeman, Trustee
                                      ------------------------------------------
                                      Robert J. Freeman, Trustee


                                      /s/ Dennis W. Dudley, Trustee
                                      ------------------------------------------
                                      Dennis W. Dudley, Trustee