The long-term use of high mineral fertilizer rates, aimed at intensifying the plant production, causes the process of soil acidification, resulting in the decrease of the yield of grown plants, due to increased contents of aluminium and manganese and decreased contents of organic matter and basic cations in the soil. In order to eliminate or reduce these harmful effects trials were set up and different materials for the neutralization of acidity and the excess of mobile aluminium were used: bentonite, zeolite, crude phosphates, MgO and CaO. The trial was set up on the pseudogley type of soil with an extremely acid reaction (pH/MKCl about 3.55) and a high content of mobile aluminium (over 37 mg/100 g soil). The obtained results show that the best effect on the decrease of all forms of soil acidity was exerted by the use of the amelioration measure CaO+MgO, with a ratio of 5:1. The application of crude phosphates and zeolite produced the weakest effect. Furthermore, the amelioration measure mentioned reduced mobile aluminium to 1.87 mg/100 g soil, and as regards three more variants (bentonite+CaO and both CaO rates) the content of aluminium was within the limits of successful tolerance for maize (about 10 mg/100 g soil).