Published online by Cambridge University Press: 27 March 2009
The effect of P applications and native vesicular-arbuscular mycorrhiza (VAM) on the growth and P nutrition of red clover plants was studied in two acid hill soils with similar edaphic characteristics.
Mycorrhizal and non-mycorrhizal plants were compared under sterilized soil conditions. Plant growth increased on P addition in both soils, but the effect of mycorrhiza in improving drymatter production and P uptake was significant only in one of the soils. Fourteen and twenty-five mg/kg Olsen-P were needed in this soil to obtain the same yields by mycorrhizal and non-mycorrhizal plants, respectively. Results are explained in terms of a different effectiveness of the two fungal populations, and the possible effect of the soil sterilization process on percentage VAM infection is discussed.