Organic material e.g leaf litter

• Anchorage for roots
• supply of water
• supply of oxygen
• Protection against of temperature and pH
• supply of mineral nutrients

Physical:

• Mechanical barriers ( e.g high bulk density)
• Absence of cracks
• Shortage of oxygen due to waterlogging
• dryness
• temperature are too high or too low

Chemical:

• High aluminium concentration, low pH
• Low nutrient supply
• Phytotoxic chemicals in anaerobic soil

High mineral content, Intermediate drainage, Intermediate water holding capacity (~25%), Intermediate air spaces (~15%), Highest biota, Good mix potential to hold organic matters, Highest productivity in balanced soil

Limited mineral content, Poor drainage, Highest water holding capacity (~40%), Lowest air spaces (~10%), Little space for biota, Low potential to hold organic matters, Waterlogged crops above

Moderate mineral content, Highest drainage, Low water holding capacity (~10%), Highest air spaces (~40%), Space to live for biota, High potential to hold organic matters, Low productivity in pure sand

Benefits:

• a large number of data can be shown on one graph
• Groupings are easily recognizable (loams)
• Dominant characteristics can be shown
• Classification can be drawn up

complex ecosystem forming a habitat for many animals and plants

soils are made up of four main components:

• mineral particles mainfly from underlying rocks
• organic remains that have come from plants and animals
• water within spaces between soil grains
• air also within soil grains

translocation (movement of soil particles in suspension)

leaching (minerals dissolved in water through soil

• strongly leached (ash coloured horizon, as in podzol)
• weakly bleached (light brown horizon, as in earth brown)

The process of organic matter transformation into stable humus

Involves the accumulation of complex organic compounds, leading to the dark colouration and improved water-holding capacity of soil

The process of organic matter breakdown by microorganisms, resulting in the
release of carbon dioxide, water, and nutrients

Involves the conversion of complex organic compounds into simpler forms

The physical and chemical processes that break down rocks and minerals into
smaller particles, contribute to soil formation

Includes physical weathering (mechanical breakdown) and chemical weathering (alteration of minerals through chemical reactions)

The cycling of nutrients within the soil-plant system, involving uptake, assimilation,
release, and recycling of elements like nitrogen, phosphorus, potassium

ensures the availability and redistribution of essential nutrients for plant growth

The decomposition of the chemical compounds in organic matter. The nutrients in those compounds are released in soluble inorganic forms that may be available to plants

Example: The conversion of organic nitrogen compounds into inorganic forms, particularly ammonium (NH4 ) and nitrate (NO )

It occurs through microbial activity, release nitrogen for plant uptake and contribute to the nutrient pool in the soil

Soil is formed from the weathering of rocks in the lithosphere. Minerals from these rocks become part of the soil, providing nutrients for plants.

The soil supports plant growth by supplying nutrients and water. In return, plants and animals contribute organic matter to the soil when they decompose.

Soil exchanges gases with the atmosphere, such as releasing carbon dioxide during respiration of organisms and absorbing oxygen.

Water from precipitation or groundwater interacts with soil, aiding in nutrient absorption by plants and influencing soil moisture levels, which affects its structure and fertility.