Soil as Reservoir of Essential Elements

Soil Supplies Minerals Through Weathering

Most of the mineral nutrients a plant needs become available in the first place because rock weathers and breaks down over time, releasing dissolved ions and inorganic salts into the soil. This is precisely why the whole subject of absorbing these elements is called 'mineral nutrition' — the minerals plants take up ultimately trace back to rock and soil minerals being broken down.

Soil Does More Than Just Supply Minerals

Soil is a genuinely complex mixture, and its role for a plant goes well beyond being a source of dissolved nutrients. It also:

• harbours nitrogen-fixing bacteria and countless other soil microbes that plants depend on,
• holds water that the plant's roots can draw on,
• supplies air (oxygen) to the roots, which need it for respiration, and
• physically anchors the plant in place.

Why Farmers Add Fertilisers …