Community or organisms: tree, bacterias, fungi, earthworms, decomposers, other soil organisms, faeces

Bacteria fix atmospheric nitrogen converting into a usable form for plant roots

Mycorrhizal fungi on tree roots take up soil nutrients and pass them directly to the tree

Decomposers break down litter releasing nutrients into the soil

Soil organisms help to mix the soil improving its structure

Climate and land use change may accelerate the above factors

Loss of structure, soil crusting, surface sealing and compaction

Caused by compaction through heavy machine or animal and cultivation in wet weather

Soil crusting and compaction ;- increase runoff, decrease the infiltration of water into soil, inhibit plant growth and leave the surface bare

The greater the % of tree removed, the less interception occurs, the more soil compaction by raindrop impact, increase soil erosion potential

Overgrazing ;- Grazing of natural pastures at stocking intensities above the livestock carrying capacity

Reduce interception, increase raindrop impact and soil erosion

Increase soil compaction, less infiltration, soil becomes impermeable

Requires removal of vegetation for construction and heavy machinery, compacting soil surface

Lead to soil exhaustion, reduce availability of certain nutrients

Large areas of surface soil are washed away during heaving rain (can include landslide)

Channels develop on hillsides following rainfall. Over time they get deeper and deeper

Drier soils have the top layers consistently removed

type of erosion: surface, gully, rill and runnel erosion (sink hole)

Found in marine derived sediments, coastal location

Hot arid areas where capillary action bring salts to the upper part of soil

Removal of vegetation in dry land farming

The spread of desert-like conditions into previously green areas causing a long-term decline in biological productivity

Caused by climate change and/or by destructive use of the land

Reduced soil cover through grazing or preparing soil for planting increase wind and water erosion

Reducing soil nutrient and damaging soil structure

Caused by municipal and industrial waste, oil spills, excessive use of fertilisers, herbicides and insecticides or release of radioactive materials and by airborne pollutants

Use of fertilizer alter soil’s chemical composition + increase nutrient runoff

Use pesticides / herbicides → increase amount of dangerous toxins → in the long run make soil too toxic for further agricultural use (toxification)

Goal: maximize the yield of crops to achieve economies of scale.

Why people consume? = It's mass produced, so it's cheaper

Case Study - Commercial farming in East Anglia, UK

It's an area of intensive arable farming, with large open fields and heavy use of agricultural chemicals.

Impact: The previously fertile soil is much depleted and requires further use of fertilizers for commercial crops to be grown successfully.

Options for soil conservation:

• avoid inappropriate weather conditions (e.g. heavy rain) for ploughing and harvesting
• add organic matter to the soil to increase water retention
• add clay to the soil to improve soil cohesion
• practise crop rotation so that soils do not become exhausted (this is less common now due to specialization in farming)
• use wind breaks to reduce the risk of wind erosion
• use cover crops to protect the soil in winter
• mulching - plough in the remains of the previous season's crop to improve nutrient retention in the soil
• leave some land fallow so that it can improve its fertility.

Large amount of chemical and energy input is required

More holistic approach to farming by relying on ecological processes, biodiversity & cycles adapted to local conditions

• Sustainable
• Grow range of crops, improve biodiversity. Makes farm less susceptible to pests, less pesticide required
• Rely on more natural fertilizer. e.g. manure, compost
• Less use of machinery

But why is small-scale farms declining?

• Don't produce large amounts of food
• More expensive compared to mass-produced harvests
• Limit of fund compared to commercial
• Struggle to get products to market place

Deforestation for oil palm plantation