Chemistry and turnover of naturally occurring resistant organic compounds in soil; In situ analysis of soil components of biological origin; Oxidate coupling of aromatic compounds by ensymes from soil microorganisms; Control of urea transformations in soils; Chemistry and distribution of amino sugars in soils and soil organisms; Biochemistry, ecology, and microbiology of petroleum components in soil; Biological nitrogen fixation; Denitrification; Heavy metals in soil biology and biochemistry; Microbial biomass in soil: measurement and turnover.