Effect of mineral NPK fertilization, farmyard manure application and liming on the exchangeable and extractable aluminium content in the soil was studied in a long-term experiment at Łyczyn. Nitrogen fertilization increased the content of exchangeable and extractable aluminium in soil. Phosphorus fertlization, manuring and liming decreased the content of exchangeable and extractable aluminium in soil. Potasium fertilization did not affect the content of exchangeable and extractable aluminium in soil. The content of exchangeable aluminium (Al-KCl) was strongly correlated with the content of extractable aluminium (Al-CaCl2).