Specific and varietal differences in sodium and potassium in grasses

Marked differences in sodium content between and within species were maintained in primary and recovery growth throughout the growing season. There was a general, though rather loose inverse relationship between Na and K content. The species studied (in descending order of Na) were : Lolium perenne, Dactylis glomerata, L. multiflorum, Festuca arundinacea, F. pratensis, Phleum pratense. Nitrogen raised the Na content whether applied as nitrate of soda, sulphate of ammonia or Nitro‐Chalk, but the effect was much less marked in P. pratense.