THE RESPONSE OF MYCORRHIZAL AND NONMYCORRHIZAL ROOTED CUTTINGS OF HEATHER (CALLUNA VULGARIS (L.) HULL) TO VARIATIONS IN NUTRIENT AND WATER REGIMES

SummaryRooted cuttings of heather showed their best dry matter production in drained regimes with a frequent addition of nutrients. Mycorrhizal plants generally showed a decreased production when compared with equivalent non‐mycorrhizal plants, except on drained regimes low in nutrients where the mycorrhizal plants grew better. Concentrations of nitrogen in the shoot and potassium and phosphorus in the root were higher in mycorrhizal than in non‐mycorrhizal plants, effects most marked in well‐drained regimes with the minimum addition of nutrients. In general, alterations in nutrient and water regimes had more significant effects on dry matter production than did the presence or absence of mycorrhiza. It is concluded that mycorrhizal infection may have a beneficial effect in freely drained, infertile, soils that are characteristic of well‐developed heathland.