NITRATE ASSIMILATION BY SOIL MICROÖRGANISMS IN RELATION TO AVAILABLE ENERGY SUPPLY
THE INFLUENCE OF MANURES AND ORGANIC RESIDUES ON PLANT GROWTH
PRODUCTION OF NODULES ON DIFFERENT PARTS OF THE ROOT SYSTEMS OF ALFALFA PLANTS GROWING IN SOILS OF DIFFERENT REACTION
SOIL PHOSPHORUS STUDIES : I. THE COLORIMETRIC DETERMINATION OF ORGANIC AND INORGANIC PHOSPHORUS IN SOIL EXTRACTS AND THE SOIL SOLUTION
SOIL PHOSPHORUS STUDIES : II. THE CONCENTRATION OF ORGANIC AND INORGANIC PHOSPHORUS IN THE SOIL SOLUTION AND SOIL EXTRACTS AND THE AVAILIBILITY OF THE ORGANIC PHOSPHORUS TO PLANTS
SOIL PHOSPHORUS STUDIES : III. PLANT GROWTH AND THE ABSORPTION OF PHOSPHORUS FROM CULTURE SOLUTIONS OF DIFFERENT PHOSPHATE CONCENTRATIONS
THE DELAYED EFFECT OF LIMING