<PAGE>

                                  EXHIBIT 10(j)

                            LINDSAY MANUFACTURING CO.
                         MANAGEMENT INCENTIVE PLAN (MIP)
                                 2004 Plan Year

Purpose

         The purpose of the Management Incentive Plan (the "Plan") is to:

                  -        Encourage performance consistent with the Company's
                           business strategy

                  -        Focus on near-term performance results as well as
                           progress toward the achievement of long-term
                           objectives

                  -        Strengthen the link between performance and pay by
                           delivering awards based on measurable corporate and
                           individual goals.

Definitions

         The terms used in this Plan have the meanings set forth below.

         A.       "Company" shall mean Lindsay Manufacturing Co.

         B.       "Compensation Committee" shall mean the Compensation Committee
                  of the Company's Board of Directors.

         C.       "Financial Performance Component" shall mean the portion of a
                  Participant's Plan award that is based on the Company's and
                  specific Market financial performance as defined in Section
                  7B.

         D.       "Individual Performance Component" shall mean the portion of a
                  Participant's Plan award that is based on a Participant's
                  performance relative to individual objectives established in
                  accordance with Section 7C.

         E.       "Named Executive Officers" shall mean the executives of the
                  Company listed in the Executive Compensation section of the
                  Company's Proxy Statement.

         F.       "Participant" shall mean a key employee eligible for awards
                  under the terms outlined in Section 4 of this Plan.

         G.       "Plan" shall mean Lindsay Manufacturing Co. Management
                  Incentive Plan.

Effective Date

         The Plan shall be effective as of September 1, 2003 and will be in
         effect for the 2004 bonus year. The 2004 bonus year is defined as
         September 1, 2003 through August 31, 2004.

Eligibility for Participation

         A.       Participation in the Plan is limited to individuals in
                  positions which have significant responsibility for and impact
                  on the Company's corporate performance.

         B.       Only the Chief Executive Officer and those employees in grades
                  E through G are eligible to be considered for participation in
                  the Plan.

<PAGE>

         C.       Participation in the Plan does not guarantee or entitle any
                  employee to participate in any bonus plan enacted in the
                  future. Participation in the Plan at any target bonus level
                  does not guarantee or entitle any employee to be eligible to
                  participate at any similar target bonus level in any bonus
                  plan which may be enacted in the future.

Enrollment in the Plan

         A.       Initial Enrollment

                  At the beginning of the Plan year, each Participant must be
                  enrolled in the Plan subject to the approvals and eligibility
                  criteria set forth in Sections 4 and 6. The enrollment process
                  is as follows:

                  i.       Plan Participants will participate in the Plan at the
                           standard target percent per grade level as listed in
                           Section 6.

                  ii.      The Company's Chief Executive Officer will review the
                           participant list and projected bonus costs of
                           enrolled employees with the Compensation Committee.
                           The Compensation Committee provides final approval on
                           the aggregate potential cost of the Plan.

         B.       Mid-year Enrollment

                     When hiring or promoting employees during the Plan year who
                     may be eligible for participation in the Plan, the
                     following procedures must be followed:

                     i.    Prior to the commencement of the recruiting or
                           promotion process, the hiring manager consults with
                           Human Resources to determine the position's
                           eligibility for participation in the Plan and the
                           recommended target bonus amount.

                     ii.   Offer letters indicating bonus Plan participation and
                           target bonus award opportunities to new hires and/or
                           promoted employees must be reviewed by the CEO or, in
                           the case of a Named Executive Officer, by the
                           Compensation Committee. Target bonus recommendations
                           must be approved before communication to a
                           prospective Participant. Generally, employees hired
                           or promoted during the fourth quarter 2004 are not
                           eligible to participate in the 2004 Plan.

Determination of Target Payout Levels

         A.       Incentive awards will be calculated as a percentage of the
                  Participant's actual base salary received during the Plan
                  year. While award amounts will vary based on the range of
                  award opportunity and an assessment of individual performance
                  results, the target award opportunities for each grade level
                  are shown below:

<TABLE>
<CAPTION>
GRADE        TARGET % OF SALARY
<S>          <C>
 CEO                 60%
  G                  35%
  F                  25%
  E                  15%
</TABLE>

                     i.    Actual participation is subject to approval by the
                           CEO, or in the case of a Named Executive Officer, by
                           the Compensation Committee. Actual participation is
                           based on an assessment of the individual's position
                           impact on the organization.

                     ii.   Standard target percents per grade level should be
                           followed for all Plan Participants.

         B.       If a Participant's Plan target award opportunity (Target % of
                  Salary as set forth above) changes due to promotion into a
                  grade level with a higher target bonus, the Participant's
                  bonus will be calculated based on his or her actual

<PAGE>

                  salary during the Plan year and a weighted average bonus
                  percentage. The weighted average bonus percentage will reflect
                  the portion of the Plan year spent in each grade level (e.g.,
                  seven months at 15% and five months at 25%). In evaluating the
                  performance of Participants who change positions during the
                  Plan year, consideration will be given to the length of time
                  and results in each position. Actual award decisions will be
                  made by the CEO or, in the case of a Named Executive Officer,
                  by the Compensation Committee. Generally, fourth quarter
                  promotions will not result in an increase in a Participant's
                  target award opportunity.

         C.       Examples of various award calculations are included with this
                  Plan document as Attachment A.

         D.       The CEO will review and approve award recommendations for all
                  employees other than Named Executive Officers prior to payout.
                  Final approval authority for all payments (except for award
                  payments to the Named Executive Officers) rests with the CEO.
                  Individual award payments for all Participants (except the
                  Named Executive Officers) may be adjusted at any time and for
                  any reason at the discretion of the CEO.

         E.       The Compensation Committee will determine the award payments
                  to the Named Executive Officers.

         F.       Award payments will be calculated on an annual basis and paid
                  in accordance with the Company's normal payroll cycle.
                  Payments will be made during the first quarter following the
                  Plan year. The payment date may be changed at any time and for
                  any reason at the discretion of the CEO, or in the case of a
                  Named Executive Officer, with approval of the Compensation
                  Committee.

Basis of Awards

         A.       Measurable performance objectives for each Plan Participant
                  will be established at the beginning of the Plan year (or at
                  mid-year for mid-year hires or newly eligible employees). In
                  2004, consideration will be given to:

                     i.    Financial Performance Component: Company and Market
                           financial performance vs. Plan performance objectives
                           in accordance with Section 7B.

                     ii.   Individual Performance Component: Participant's
                           performance relative to individual goals established
                           in accordance with Section 7C.

                     iii.  Individual and Financial Performance Components will
                           be added to reach a Participant's total bonus. The
                           relative weighting will vary by grade in accordance
                           with the following schedule:

<TABLE>
<CAPTION>
                  Financial          Individual
Grade            Performance        Performance
<S>              <C>                <C>
 CEO                 80%                20%
  G                  80%                20%
  F                  65%                35%
  E                  50%                50%
</TABLE>

         B.       At the beginning of the Plan year, the objectives for the
                  Financial Performance Component are identified and approved by
                  the Compensation Committee.

                     i.    Recommended award amounts may range from 0 - 200% of
                           the Financial Performance Component of the
                           Participant's target award, based on performance.

                     ii.   Percentages between the threshold, target, and
                           maximum award will be interpolated.

<PAGE>

                  iii.     In the event of an acquisition, revenue and operating
                           income resulting from the acquisition will be
                           excluded from award payout calculations, unless

                           (a) the CEO or Compensation Committee suggests a
                               modification to the objectives under the
                               Financial Performance Component that would
                               incorporate revenue and income generated as a
                               result of the acquisition, and

                           (b) The Compensation Committee approves the
                  modification.

         C.       The Individual Performance Component will be based on written
                  objectives set annually for Participants by their supervisors
                  and approved by the CEO or, in the case of a Named Executive
                  Officer, by the Compensation Committee. Objectives will be
                  based on the Participant's position and may be financial,
                  operational or strategic.

                     i.    Objectives under the Individual Performance Component
                           may be linked to team-based goals, if appropriate

                     ii.   Examples of appropriate objectives under the
                           Individual Performance Component include:

                           -        Safety

                           -        Customer Service

                           -        Market Share

                           -        On-time Delivery

                           -        Cost Reduction

                           -        Product Development

                     iii.  Recommended award amounts may range from 0% - 200% of
                           the target amount under the Individual Performance
                           Component. Recommended award amounts will be based on
                           an assessment of the individual's performance
                           relative to objectives established under the
                           Individual Performance Component, in accordance with
                           the following guidelines:

<TABLE>
<CAPTION>
                                                      PAYOUT
           INDIVIDUAL                       (AS % OF TARGET INDIVIDUAL
           PERFORMANCE                        PERFORMANCE COMPONENT)
<S>                                         <C>
    Does not meet objectives                             0%
      Meets some objectives                             50%
      Meets most objectives                             75%
      Meets all objectives                             100%
       Exceeds objectives                              150%
Significantly exceeds objectives                       200%
</TABLE>

                  iv.      The "Payout (as % of Target Individual Performance
                           Component)" represents the payout relative to target
                           award for the Individual Performance Component of the
                           Plan.

Changes in Employment Status

         A.       Under most circumstances, Participants who cease to be
                  employees of the Company during the Plan year or after the
                  Plan year but prior to the date of actual payment will receive
                  no award. Only active employees on the date that the bonus is
                  paid will be eligible to receive an award. Any exceptions will
                  require the approval of the CEO, or in the case of a Named
                  Executive Officer, the Compensation Committee.

<PAGE>

         B.       In the event that a Participant transfers out of an eligible
                  position into an ineligible position within the Company, the
                  employee may be eligible for a prorated bonus award based upon
                  the approval of the CEO, or in the case of a Named Executive
                  Officer, the Compensation Committee.

         C.       In all cases awards will be calculated and paid according to
                  the provisions in Sections 6 and 7 of this Plan document.

Administration

         A.       General authority for Plan administration and responsibility
                  for ongoing Plan administration will rest with the
                  Compensation Committee of the Company's Board of Directors.
                  The Compensation Committee has sole authority for decisions
                  regarding interpretation of the terms of this Plan.

         B.       The Company reserves the right to amend or change the Plan in
                  whole or in part at any time during the Plan year. Amendments
                  to the Plan require the approval of the Compensation
                  Committee.

         C.       Participation in the Plan does not constitute a contract of
                  employment nor a contractual agreement of payment. It shall
                  not affect the right of the Company to discharge, transfer, or
                  change the position of a Participant. The Plan shall not be
                  construed to limit or prevent the Company from adopting or
                  changing, from time to time, any rules, standards or
                  procedures affecting the Participant's employment with the
                  Company or any Company affiliate, including those which affect
                  bonus payouts.

         D.       If any provision of this Plan is found to be illegal, invalid
                  or unenforceable under present or future laws, that provision
                  shall be severed from the Plan. If such a provision is
                  severed, this Plan shall be construed and enforced as if the
                  severed provision had never been part of it and the remaining
                  provisions of this Plan shall remain in full force and effect
                  and shall not be affected by the severed provisions or by its
                  severance from this Plan. In place of any severed provision
                  there shall be added automatically as part of this Plan a
                  provision as similar in terms to the severed provision as may
                  be possible and be legal, valid and enforceable.

         E.       This is not an ERISA plan. This is a bonus program.

<PAGE>

                                  ATTACHMENT A
                          AWARD CALCULATION GUIDELINES

The following examples are to be used as guidelines in calculating bonus awards
at the end of the 2004 Plan year. Managers should use their discretion in
calculating actual bonus awards and may consider exceptions to the calculations
below when necessary. Any such exceptions must be fully documented and are
subject to review and approval by the Chief Executive Officer, or in the case of
a Named Executive Officer, the Compensation Committee.

<TABLE>
<CAPTION>
                                                                                               Target
                                                                                               Award
                                                                                              -------
<S>                                                        <C>                                <C>
Full Year Participation
-     September 1 - August 31                                   15%
-     Target award opportunity:                            $75,000
-     Actual base salary received:                         $75,000 * 15% =                    $11,250
-     Plan target award calculation:

Partial Year Participation
-     February 15 - August 31
-     Target award opportunity:                                 25%
-     Actual base salary received
      (for partial year employment):                       $61,250
-    Plan target award calculation:                        $61,250 * 25% =                    $15,312

Mid-year Promotion
-     March 1 promotion
-     Actual base salary received:                         $94,000
-     Target award opportunity at beginning of year:            15%
-     Target award opportunity upon promotion:                  25%
-     Months from September 1 - March 1:                   6 months
-     Months from March 1 - August 31:                     6 months
-     Weighted average target award calculation:           ((15% * 6 months) + (25% * 6
                                                           months)) / 12 months = 20.0%
-     Plan target award calculation:                       $94,000 * 20.0%                    $18,800
</TABLE>