Mycorrhizas in hill‐country soils

White clover seedlings were inoculated with the indigenous and five introduced strains of mycorrhizal fungi and were planted out into four sterilised hill‐country soils. After 10 weeks' growth, infection with the indigenous mycorrhizal fungi had caused increases in shoot DM over non‐mycorrhizal plants ranging from 130% in Waingaro steepland soil (south aspect) to 3700% in Te Kuiti silt loam. E 3 was more efficient than the indigenous fungi at increasing P uptake and plant growth in Te Kuiti and Mahoenui silt loams. The indigenous fungi in both Waingaro steepland soils were more efficient than all five introduced fungi at stimulating plant growth. The relative efficiencies of the five introduced mycorrhizal fungi were different in each soil. There was no correlation in any soil between the P uptake efficiency of mycorrhizal fungi and the frequency of their hyphal connections between the soil and the root system.