Four samples of \soils\". Leaf mould (left), is produced by the decomposition in bulk of fallen autumn leaves. It is high in humus content, but lackin

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Four samples of \soils\". Leaf mould (left), is produced by the decomposition in bulk of fallen autumn leaves. It is high in humus content, but lacking in plant nutrients. Turf loam ( left of centre) is produced by stacking cut turves from pasture or grassland, and leaving them to decay for 6 months or more. It has a well balanced mineral content of mostly small particles, the largest being sand grains. It also has 2-7% by bulk of humus from the original grass. Garden soil (left of centre) is very variable in composition depending on geology and horticultural practice. This sample, from Norfolk UK, contains many small stones compared to the turf loam ( also made in Norfolk ). Peat (right) is produced by the slow anaerobic decomposition of bog mosses. It has a high humus content and low mineral content, and contains few plant nutrients."

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Size: 5212px × 3468px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
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Keywords: biological, biology, botanical, botany, content, garden, humus, leaf, loam, mineral, mould, nutrients, peat, plant, soil, turf