The phosphate response of eight Mediterranean annual and perennial legumes

摘要

The growth response of eight Mediterranean type legumes to phosphate (P) fertiliser additions was measured in pots of a low P fixing Manawatu sandy loam known to be deficient in P. The yield ofMedicago polymorpha, M. intertexta, M. truncatula, Trifolium subterraneum and T. vesiculosumwas increased two to three fold by P addition; responses were near maximum at 50#x2013;80 mg P per pot. Yield ofVida dasycarpawas also doubled, but smaller plants especially required less P (approx. 20 mg P per pot) for near maximum growth.Lotus pedunculatusestablished more slowly than the other legumes and showed a four#x2013;fold increase in growth which continued up to the highest levels of applied P. Ornithopus sativus did not show statistically significant growth increases with added P, although the data suggest that there may be a small response at the lowest levels of applied P,particularly as the plants become older. Foliar P levels of all species were higher in older plants and increased with addition of P.O. sativushad the highest foliar P content over the range of applied P, but especially at zero and low P inputs.