Effect of sustainable soil and crop management on humus changes

Organic matter is one of the most important factors for saving clay soils from their degradation. In order to increase the amount of organic matter in the soil and to improve its quality applying different practices of soil and crop management, complex researches on a glacial lacustrine clay loam on silty clay (Gleyic Cambisol) were made in Joniskelis Research Station of the Lithuanian Institute of Agriculture. It was assessed, that increasing the area of longer vegetation wintering crops in the heavy soil had a positive influence to the amount of organic carbon and humic acids and degree of humification. Application of sustainable soil tillage systems especially in blends with organic manure determined the reduction of organic substances mineralization and increased the amount of humus and fulvic acids.