Interactions of nitrogen and phosphorus on mycorrhizal development and shoot growth of Eucalyptus globulus (Labill.) seedlings inoculated with two different mycorrhizal fungi
Mason, Philip A.; Ingleby, Kevin; Munro, Robert C.; Wilson, Julia; Ibrahim, Kamal. 2000 Interactions of nitrogen and phosphorus on mycorrhizal development and shoot growth of Eucalyptus globulus (Labill.) seedlings inoculated with two different mycorrhizal fungi. Forest Ecology and Management, 128 (3). 259-268. 10.1016/S0378-1127(99)00154-1Full text not available from this repository.
A number of investigations have demonstrated that balanced fertilizer applications can improve shoot growth of E. globulus plantations. Similar information on the impact of balanced N + P fertilizers on mycorrhizal development is lacking. This study was thus undertaken to determine the combinations of N and P which promote greatest mycorrhizal development and growth of seedlings of E. globulus. The overall objective was to generate information which might be translated into protocols for improved nursery and plantation management. Factorial combinations of two ectomycorrhizal fungi (Hydnangeum carneum Wall. apud Klotz. and Laccaria fraterna (Cooke and Mass.) Peg.) and eight fertilizer regimes containing different combinations of nitrogen (N) and phosphorus (P) were applied to Eucalyptus globulus seedlings. The four concentrations of nitrogen in the solutions ranged from 62.5 up to 250 mg l(-1) while those of phosphorus were 10 and 25 mg l(-1). Plants were harvested 12 weeks after inoculation. When given the lower P regime (10 mg l(-1) P), increasing amounts of applied N resulted in increasing percentages of infected roots, irrespective of fungal inoculant. Maximum colonization, including frequency of mycorrhizal branching, was observed at 250 mg l(-1) N/10 mg l(-1) P, with no indication that mycorrhizal infection had peaked. For seedlings given the higher P (25 mg l(-1)) concentration, increasing amounts of nitrogen tended to decrease per cent root infection. Seedlings given 25 mg l(-1) P grew larger (leaf, stem and shoot dry weight) with increasing concentrations of nitrogen. Those that were given the lower P concentration responded less to N. With the exception of leaf number, a strong positive relationship was found between seedling growth variables and percentage mycorrhizal infection at 10 mg l(-1) P. No such relationship was found at 25 mg l(-1) P. The implications of these findings for the development of a balanced N:P fertilizer regime in eucalypt nurseries and plantations are discussed.
|Programmes:||CEH Programmes pre-2009 publications > Other|
|CEH Sections:||_ Biosystems Management|
|Additional Keywords:||Eucalyptus globulus, Hydnangium carneum, Laccaria fraterna, nitrogen, phosphorus, mycorrhizal development, shootgrowth|
|NORA Subject Terms:||Agriculture and Soil Science
Biology and Microbiology
|Date made live:||16 May 2012 09:32|
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