設大豆、玉米、麥子各所需土地x1、x2、x3（公頃）,牛和雞各飼養(yǎng)x4和x5（只）,根據(jù)題意可以列出下表：

  見下圖點擊可以放大.

目標函數(shù) Max z=175*x1+300*x2+120*x3+400*x4+2*x5;

滿足條件 x1+x2+x3+1.5*x4<=100;

400*x4+3*x5<=15000;

20*x1+35*x2+10*x3+100*x4+0.6*x5<=3500;

50*x1+75*x2+40*x3+50*x4+0.3*x5<=4000;

x4<=32;

x5<=3000;

x1,……,x5>=0 

Lingo程序：

max=175*x1+300*x2+120*x3+400*x4+2*x5;

x1+x2+x3+1.5*x4<=100;

400*x4+3*x5<=15000;

20*x1+35*x2+10*x3+100*x4+0.6*x5<=3500;

50*x1+75*x2+40*x3+50*x4+0.3*x5<=4000;

x4<=32;

x5<=3000;

@gin(x1);@gin(x2);@gin(x3);@gin(x4);@gin(x5);

End

結果如下：

  Global optimal solution found at iteration:            29

  Objective value:                                 20216.00

                       Variable           Value        Reduced Cost

                             X1        0.000000           -175.0000

                             X2        39.00000           -300.0000

                             X3        0.000000           -120.0000

                             X4        21.00000           -400.0000

                             X5        58.00000           -2.000000

                            Row    Slack or Surplus      Dual Price

                              1        20216.00            1.000000

                              2        29.50000            0.000000

                              3        6426.000            0.000000

                              4       0.2000000            0.000000

                              5        7.600000            0.000000

                              6        11.00000            0.000000

                              7        2942.000            0.000000

綜合程序計算結果可以得：

玉米耕種了39公頃,奶牛養(yǎng)了21頭,雞養(yǎng)了58只,并不種植大豆和麥子.由此可以計算出春夏兩季多余的勞動力為7人,經(jīng)計算他們的年凈收入為 2690；而秋冬兩季并沒有多余勞動力.所以該農(nóng)場的年凈收入為 22906.