Human impact on soil fertility | AQA A-Level Environmental Science Revision | Primrose Kitten

Aeration

Process of introducing air and oxygen into the soil to support aerobic decomposition and increase fertility

Drainage pipe systems

Installed systems in soil to prevent flooding and maintain oxygen levels for aerobic processes

Zero-tillage farming

Method of farming that avoids disrupting soil structure to maintain fertility and stable humus levels e.g. ploughing

Aerobic decomposition

Decomposition process fueled by aerobic respiration using oxygen in the soil

Nitrogen fixation

Biological process where nitrogen from the atmosphere is converted into a usable form

Nitrification

Biological oxidation process that converts ammonia into nitrite then nitrate, increasing soil fertility

Why does crop harvesting reduce fertility?

Crops remove nutrients during growth and store them in their biomass

Inorganic fertilisers

Artificial chemicals made using the Haber process to add a large volume of nutrients directly to the soil

Organic fertilisers

Natural sources of nutrients such as livestock manure, decomposed to release nutrients in smaller amounts

Eutrophication

Excessive richness of nutrients in a body of water, often due to runoff from the land, causing dense plant growth and death of animal life from lack of oxygen

Green manure

Crops grown alongside main crops, ploughed back into the soil to increase organic matter instead of being harvested

Soil biota

Microorganisms and small animals living in the soil, contributing to soil fertility

Leguminous crops

Crops containing nitrogen-fixing bacteria in their root nodules, reducing the need for fertiliser use

Irrigation

Large-scale watering of crops to ensure water availability for nutrient absorption and gas exchange in plants

Stomata

Pores on a plant's leaf for gas exchange, important for photosynthesis and respiration. Also allows water to leave the plant tissue

Drip irrigation

Method of delivering water in small doses to each plant to reduce wastage, runoff and waterlogging

Soil compaction

Reduction of air spaces in the soil due to heavy machinery or high livestock density, decreasing aeration and fertility

Interception

Process where vegetation intercepts and holds precipitation, reducing the volume of water reaching the soil

How does deforestation impact soil fertility

Clearing of trees leading to reduced organic matter, increased water volume reaching the soil, and decreased aeration and fertility