Phosphate response curves of mycorrhizal and non-mycorrhizal plants

Abstract

Clover plants were grown with or without mycorrhizal fungi in two soils fertilised with superphosphate at rates ranging from 0 to 280 mg P/610 ml pot (equivalent to 0–248 kg P/ha). After 175 days' growth in Dunmore soil, mycorrhizal plants significantly outyielded non-mycorrhizal (control) plants at fertiliser levels up to 200 mg P/pot. Mycorrhizal growth responses were smaller in Waingaro soil, but after 91 days' growth, control and mycorrhizal plants achieved 80% of maximum shoot growth at 125 and 50 mg P/pot respectively. Recovery of phosphate fertiliser was low and ranged from 5 to 20% in Dunmore soil and from 6 to 25% in Waingaro soil.