Soil Types & Structure

Aug 20

2 min read

Explore the work of people investigating, documenting and teaching about plants, ecosystems and environmental change.

Shanti Plants - The Earth Provides

Natural-light cross-section of garden soil with leaf litter, dark topsoil, mineral subsoil, fine roots, stones and soil structure, with small samples of sandy, loamy and clay-rich soil below. — A cross-section of healthy garden soil showing surface litter, dark organic-rich topsoil, deeper mineral layers, fine roots and natural soil structure, with separate examples of sandy, loamy and clay-rich soils in the foreground.

Soil is more than loose mineral particles. Its texture, aggregates, pore spaces, organic matter, water, air and living organisms interact to control how roots grow and how water and nutrients move. Two soils with similar texture can behave differently because their structure, compaction, salt level or organic matter differs.

What This Index Covers

This index covers soil texture and horizons, aggregates and pores, bulk density and compaction, infiltration and drainage, water-holding capacity, erosion risk and the role of organic matter. It supports observation and testing; it does not classify a soil reliably from colour or a single hand test alone.

Browse Resources

Browse the resource areas currently organised under this index. Links can be added as reviewed articles and records are published.

Texture - Comparing the proportions and behaviour of sand, silt and clay.

Structure and aggregation - Understanding crumbs, blocks, plates and other arrangements of particles.

Pores, air and water - Seeing how pore size affects drainage, oxygen and storage.

Compaction - Recognising restricted roots, hard layers and poor infiltration.

Organic matter - Understanding its contribution to aggregation, water and nutrient cycling.

Erosion and surface condition - Reading crusting, runoff, bare ground and sediment movement.

Read First

Before using these resources for identification, growing, harvesting, conservation, community work or other practical decisions, read:

Texture Is Not the Same as Structure

Drainage, Waterlogging & Root Oxygen

Soil Disturbance, Compaction & Erosion

Coverage and Evidence

Soil properties vary across short distances and with depth. A surface sample cannot describe the whole root zone, and a jar or ribbon test provides an estimate rather than a laboratory classification. Interpret observations with landform, recent weather, management history and plant response. Avoid promising that one amendment will permanently change a soil's inherent texture.

The Earth's Resource Map and Learn library are being built progressively. Indexed means that a topic or resource can be connected to its identity, source and broad context; it does not mean that every claim has been verified or localised. Evidence is assessed claim by claim. Where information is missing, uncertain, restricted or location-dependent, that limitation should remain visible.

Last Reviewed

19 August 2026

This date records review of this index-page copy and its resource structure. Individual articles, records, laws, project details and evidence may have different publication and review dates.