Soil Fertility | AQA A-Level Environmental Science Revision | Primrose Kitten

Role of soil

Essential for plant growth in natural and agroecosystems, also a habitat for organisms.

Soil Profile

Unique to an area due to climate, properties of original rocks/minerals, time, and relief.

Soil Fertility

Ability to support crop growth and productivity, highly affected by soil texture.

Soil Texture

Proportions of sand, silt, and clay, impacting soil fertility characteristics.

Sand Soil characteristics

Has large air spaces, best drainage rate, but may lead to nutrient loss.

Clay Soil characteristics

Smallest particle, small air spaces, prone to waterlogging, lower temperature.

Importance of soil water content

Affects soil fertility, essential for plant growth, but too much can lead to waterlogging.

Which soils are best at draining?

Impacts water conditions, sandy soils drain quickly, clay soils prone to waterlogging.

Which soils have lower temperatures?

Clay soils have lower temperature due to high water retention, impacting biota enzymes.

Denitrification

Process occurring in anaerobic conditions, removes nitrates from the soil and lowers fertility.

Anaerobic Soil

Soil lacking oxygen, inhibiting nitrification and increasing denitrification, reducing fertility.

Soil Compaction

Method impacting air space size, affecting root penetration and fertility. Caused by use of heavy machinery and trampling by livestock

Nitrification

Process that produces inorganic nitrates in the soil, increasing soil fertility

Aeration

The volume of oxygen in the soil

Root Penetration

Impacted by soil texture, influencing plant anchoring and dead organic matter, affecting fertility.

Cation Adsorption

Affected by clay soil texture, immobilizing cations as they adsorb onto the clay surface, increasing fertility

Humus

Result of decomposition, increases soil fertility.

Soil Structure

Formation of aggregates impacting aeration, drainage, and root penetration, affecting fertility.

Crumb Peds

Round, small soil aggregates with high aeration, good drainage, and high fertility.

Platy Peds

Long, flat soil aggregates reducing aeration, drainage, and fertility.

Soil pH

Impacts nutrient availability, root hair cell membranes, and nutrient solubility, affecting fertility.

Soil Depth

Influences water levels, root networks, and plant support, impacting fertility.