Brown Earths 1(a) Zonal soils are influenced more by the biome they are found in rather than by the parent material. (b) Zonal soil of a coniferous forest is a podzol. Deciduous woodland is a Brown earth. (c) Interzonal soils are more influenced by local factors e.g. parent material, drainage etc.. Azonal soils are immature soils, which have not had enough time to develop horizons e.g. recent glacial deposits, volcanic soils and river alluvium deposits.

Brown Earths 2(b) Podzols are produced in cold wet environments, where precipitation exceeds evapotranspiration leaching occurs of minerals from the surface to the lower layers creating an iron pan. The Ao horizon forms because of decaying plant matter either pines or cones or dead heather shoots. The cold climate means organic matter decays slowly to form an acidic mor humus. Brown earth’s form in temperature climates, because of warmer temperatures, organic matter decays quicker creating a mull humus, which is less acidic than mor. The horizons are well mixed due to the action of earthworms. The closer balance between precipitation and evaporation causes less leaching.

Brown Earths (d) (i) Podzols have more clearly defined horizons due to lack of organisms to mix up the layers. (ii) Brown earth's are more suited to farming as the soils are less acidic and have a higher organic content to feed the growing crops. (iii) An iron pan is more likely to develop in a podzol soil due to precipitation exceeding evapotranspiration, this encourages minerals to be leached downwards creating an iron pan in the B horizon.