Mycorrhizas in hill country soils

Indigenous mycorrhizal fungi quickly infected oversown white clover in Waingaro steepland (hill country) soil throughout the year, except in late winter when the rate was reduced as the soils became waterlogged. Infection rates and growth responses in Dunmore silt loam were determined for three grasses and three legumes infected with the indigenous and two other mycorrhizal fungi and grown in the field and in sterilised soil in the glasshouse. Mycorrhizal infection rates were slower and dependence on infection for growth and P uptake was usually less in Lotus and in grasses than in clovers. Of the fungi tested, Gigaspora margarita was the most efficient at stimulating growth of grasses and white clover, but was less efficient than the indigenous fungi at stimulating red clover growth. Mycorrhizal infection greatly stimulated legume nodulation.