RESUMO
This study aimed to reveal the trends in soil nutrient (NPK) balances for agricultural land in Albania for the period 1950-2019, through the analysis of the main NPK sources to NPK inputs and outputs. The results showed a large temporal variation in the balances of these nutrients, especially nitrogen. This variability depends mainly on the dynamics of land use change, the amount of chemical fertilizers used, and the number of animals during study period. For all three soil nutrients, negative trends have been observed in their balance sheets. From 1950 to 1990, the negative balance has declined, returning to positive for nitrogen in 1990 and phosphorus between 1970 and 2000, but has increased again in the last two to three decades. For 2019, the deficit for N was -104.8 kg ha1, for P -8.7 kg ha-1, and for K -134.5 kg ha-1, making Albania have the largest deficit of soil nutrients compared to EU and OECD countries. This deficit is mainly due to the application of small amounts of chemical fertilizers. In this context, the increase in crop yields in the last two decades seems to be related more to the improvement of plant production technologies than to the increase in the use of nitrogen and potassium fertilizers. Currently, there appears to be no environmental pressure or potential risk of pollution at nationwide scale. However, this risk may exist at regional and field scales. Therefore, the assessment of soil nutrient balance at these two scales is necessary.
