The relationship between soils, land use potential and physiographic units on three bedrock types in N.E. Scotland
In N.E. Scotland, the upland areas have been surveyed and classified into land facets by a number of workers. The present project attempts to evaluate the physiographic approach for land use potential and to compare the relationships between soils and physiography on the three bedrocks, granitic, metamorphic and basic rocks, in N.E. Scotland involving three areas: 1. Bennachie area: the studies were restricted to sites whose soils are derived from granitic rock. 2. Clashindarroch and Strathdon areas: the study dealt with sites whose soils are derived from metamorphic and basic rocks. Physiographic subdivision of the terrain in terms of facets was made using air photos. Eight major facets on each bedrock area were identified, involving 99, 77 and 49 sampling plots on granitic, metamorphic and basic rock types respectively. To obtain more information on the variation between physiographic units, steep and moderate slope facets were grouped together and called similar grouped facets (S.G.F.s) giving a total number of 36 facets. Ground surveys were made field data collected and sample plots established to study site and soil characteristics in the field and the laboratory. Statistical analyses of the data, using ANOVA to test the variation within and between individual facets (I.F.) and S.G.F. facets on the three bedrocks were added to validate the findings. The physiographic system has been evaluated according to topographic soil profile and soil chemical factors. The facets were significantly ranked according to the means of the variables. The results show that the physiographic system is reasonably efficient because most variables were effectively partitioned by facets. The larger facets (S.G.F.) proved to be more homogeneous and suitable than the over-defined I.F. facets, in areas of varied topographic features and more useful in reconnaissance mapping. The system was not very reliable in characterizing soil nutrient status. The results show that soil and site information can be extended to neighbouring areas and it provides a basis of land use planning and soil management.