EN
In reported studies the observations on rye cultivated in continuous cropping were contrasted with the impact of continuous cropping of rye on the content of biologically active organic substances in soil. In soils under continuous cropping of rye, increased concentrations of various phenolic acids were found. These compounds are known as plant growth inhibitors. The negative effects of continuous cropping were manifested by lower seed sprouting and root growth. The investigations dealt with seasonal changes in contents of free and bound amino acids, and amino acids bound to humic acids. The varying concentrations of amino acids bound in humic acids extracted from the soils under both, crop rotation and continuous rye cropping were observed. Soils were fertilized with NPK and manure. Special attention was put on amino acids, like ß-alanine, proline, citrulline and free sulfuric amino acids that play an important role in physiological and biochemical processes in soils.