The phosphate response of eight Mediterranean annual and perennial legumes

Abstract

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 of Medicago polymorpha, M. intertexta, M. truncatula, Trifolium subterraneum and T. vesiculosum was increased two to three fold by P addition; responses were near maximum at 50–80 mg P per pot. Yield of Vida dasycarpa was also doubled, but smaller plants especially required less P (approx. 20 mg P per pot) for near maximum growth. Lotus pedunculatus established more slowly than the other legumes and showed a four–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. sativus had the highest foliar P content over the range of applied P, but especially at zero and low P inputs.

Keywords:

• phosphate
• annuals
• feed legumes
• controlled environment
• phosphorus efficiency
• Medicago spp.
• Trifolium spp.
• Vicia dasycarpa
• Lotus pedunculatus
• Ornithopus sativus
• phosphorus (nutrient)
• crop yields