Sprayers mounted on tractors or other vehicles, or self-propelled are produced for spraying liquid fertilizers. They are resistant to corrosion and ensure proper spray coverage (required volumes and droplets of liquid). Modern sprayers are equipped with a control system, ensuring high uniformity of spray both lengthwise and crosswise (keeping the constant rate - automatic change of pressure, constant pressure on whole spray boom, actual control of sprayer operating parameters, remote control from tractor cab). The approximate analysis of fertilizing technology costs proved that the cost of solid fertilizers spread, which amounts to 5-12 PLN·ha⁻¹, is less than the spraying cost which varies from 10 to 17 PLN·ha⁻¹. Also the cost of whole technology for solid fertilizer treatments, which amounting to from 10 to 15 PLN·ha⁻¹, is less than that for liquid fertilizing technology, which is 11-21 PLN·ha⁻¹. However, during liquid fertilizing of leaves the plant protection can be simultaneously done. Machines used for liquid fertilizing can also be employed in plant protection.