| Abstrakt: |
In April 1959 an aircraft was used for the first time in Britain to broadcast fertilizers on to an existing forest crop. This operation was the culmination of investigations over the previous 8 years into the causes of slow growth of spruce plantations (Piceaspp.) over appreciable areas of soils derived from Culm Measures, notably at Wilsey Down forest, Cornwall, and Halwill forest, Devon. At these sites, many plantations dating from the early 1930's are almost completely ‘checked’, having failed to close canopy in up to 30 years. Recent experiments have suggested that nutrient deficiencies are largely responsible for the failure, and in 1957–9 the trials were extended to include exercises in the use of tractor-mounted equipment and aircraft for spreading fertilizers on a practical forest scale. The paper provides a short review of the site problems and experiment results at Wilsey Down, together with an account of the larger-scale fertilizer-spreading operations. |
