Magnesium in forage plants I. Magnesium contents of different species and strains as affected by season and soil treatment

Individual herbage species were grown in pots and their magnesium contents studied throughout the growing season. The effects of treatments with sulphate of ammonia, superphosphate and calcined magnesite were also investigated. 2. Of the grasses studied timothy was consistently the lowest in magnesium content, the rye-grasses and cocksfoot being appreciably higher and similar. The clover species had higher magnesium contents than the grasses, especially in the spring. 3. The magnesium contents of the grass species were lowest in spring and showed a marked increase as the season advanced. The corresponding increases in clover magnesium content were considerably smaller. 4. The effects of sulphate of ammonia and superphosphate were slight increases in magnesium contents, but the calcined magnesite resulted in major increases in magnesium contents of both grasses and clovers.