The nursing of Sitka spruce - 2. Nitrogen-fixing species.

  • Niall OCarroll Research Branch, Forest and Wildlife Service, Sidmonton Place, Bray, Co. Wicklow, Republic of Ireland.
Keywords: Legume, nitrogen fixing, Sitka spruce, nursing effect, furze, lupin, broom, alder, Picea sitchensis, silviculture.


Three experiments covering the use of common broom, two species of lupin and two species of alder as aids in the establishment of Sitka spruce crops are described. One experiment was begun in 1961 and the others in 1964. Of the species tested common broom and tree lupin showed most promise. Broom when young is susceptible to destruction by hares, and tree lupin dies after about 5 years. A combination of tree lupin and broom has resulted in a satisfactorily growing crop of Sitka spruce after 20 years. Establishment of tree lupin is improved by ground limestone and by intensive cultivation, but the long-term benefit of tree lupin alone to a tree crop has not been established. It is suggested that further work is required to investigate the use of a shrubby or dwarf species of alder and also into the use of the native dwarf furze as nurses for Sitka spruce.
How to Cite
OCarroll, N. (1982) “The nursing of Sitka spruce - 2. Nitrogen-fixing species.”, Irish Forestry. Available at: (Accessed: 28June2022).

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