Factors Limiting Plant Growth on High-Level Blanket Peat: II. Nitrogen and Phosphate in the First Year of Growth

Abstract

Measurement was made of one season''s growth of the two species, Molinia caerulea. grown from cuttings and Dactvlis glomerata grown from seed. Spaced plants were grown at high-level (blanket peat) and at sea-level (drained raised bog), they were treated with ammonium sulphate and calcium dihydrogen phosphate separately and in combination. The Dactvlis plots received lime. A positive growth response to nitrogen only was obtained with Dactylis at the high-level site. No response was detected using phosphate and no interaction between nitrogen and phosphate was found. Very little growth occurred in Dactylis with nitrogen only at sea-level, phosphate was essential for growth however and there was a positive interaction between nitrogen and phosphate. There were no significant responses to nutrient treatment by Molinia at either site. Chemical analyses of the plant material confirmed that the applied nutrients had been taken up. Analyses of the peats indicated that the total phosphate concentration in the high-level peat was higher than at the sea-level site.