Agricultural chemicals and waste management

Operation and calibration of the fertiliser spreader

The basis for the effectiveness of the fertilisers used is the accuracy of their application. Fertiliser spreader manufacturers have developed spreading tables for their equipment, in which they instruct how to optimally set up the spreader to achieve the planned spreading rate (kg/ha), at an assumed driving speed and at a specified spreading width.

Using these tables, carry out a fertiliser spreading test under field conditions:

  • aggregate the mounted spreader on the tractor’s 3-point linkage,
  • level the spreader,
  • ensure technical efficiency and, if necessary, replace defective parts in accordance with the manufacturer’s recommendations,
  • connect the spreader to a drive source and a functioning hydraulic system,
  • use the settings proposed by the spreader manufacturer according to the type of fertiliser and test the settings of the spreading elements so as to achieve the lowest possible spreading coefficient of variation,
  • check the settings regularly so that the fertiliser application rate does not vary,
  • calibrate the equipment according to the instructions if the spreader has a calibration system,
  • record all maintenance and calibration work,
  • clean the spreader regularly during and after work,
  • close the lid of the tank during stoppages if fertiliser is in it,
  • take care of the condition of the spreader in accordance with the instructions.

The setting of the spreader depends on the physical properties of the fertilisers, in particular: the size of the granules, their flowability and bulk density. Therefore, it is necessary to:

  • it is essential to read the operating instructions, paying particular attention to the recommendations for settings and calibration,
  • set up the spreader according to the equipment manufacturer’s tables, bearing in mind that fertilisers from different manufacturers may have different physical properties; this should be stated on the packaging,
  • carefully measure out the amount of fertiliser before each fertilisation,
  • test the spreading on the field test kit before starting the application.

Examples of fertiliser spreader calibrations can be seen on the following websites:

Properly spreading fertilisers on the land to be cultivated involves:

  • maintaining a proper driving path,
  • refraining from spreading fertilisers in strong winds,
  • keeping in mind that at high humidity some fertilisers absorb moisture and change their parameters,
  • spreading at a constant speed – variations in spreading speed can have a marked effect on the uniformity of fertilisation,
  • keeping in mind that field irregularities, especially at higher speeds, can lead to uneven fertiliser spreading,
  • checking the height of the spreaders on an ongoing basis and correct as necessary in accordance with the operating instructions.

After use, place the spreader on a flat, firm surface, preferably in a covered area. It is essential to clean the spreader discs, metering openings and sliders. Carry out all maintenance work after washing the spreader. Inspect connections and components, retighten loose screw connections, replace worn or damaged parts. Replenish any corrosion protection coating before leaving the spreader for a prolonged period.