PROBLEM TO BE SOLVED: To provide a fertilizing work machine capable of adjusting a fertilizing quantity according to conditions of each of farm field partitions.SOLUTION: A fertilizing work machine is constituted by having a soil characteristic measuring device detecting the soil characteristic of a farm field such as the depth and the fertilizer concentration of the farm field, a fertilizing quantity calculating device calculating a fertilizing quantity by adjusting an initial set value according to the soil characteristic detected by the soil characteristic measuring device, and a fertilizing device supplying the farm field with fertilizer of the amount according to the fertilizing quantity calculated by the fertilizing quantity calculating device in a travelling vehicle body capable of travelling on the farm field, and further has a fertilizing standard value calculating means calculating a fertilizing standard value from the soil characteristic detected by the soil characteristic measuring device while the travelling vehicle body travels in a predetermined zone in the farm field, and is constituted so as to calculate the fertilizing quantity of the fertilizing device the fertilizing quantity calculating device from the soil characteristic detected by the soil characteristic measuring device according to the travelling after that making the fertilizing standard value the initial set value of the farm field.
