Human influences on the environment 1

Demands of humans on the environment

Food

Materials

Fuel

Space

Waste materials

How to control soil ions

By adding fertiliser to add extra minerals

How to control soil structure

By ploughing fields to add more oxygen into the soil

How to control soil ph

By adding lime to increase uptake of mineral ions

How to control carbon dioxide , light and heat

By making a glasshouse

How to make soil more acidic

By adding peat

How to make soil more alkaline

By adding lime

How do glasshouses and improve yield

Short wavelength infrared radiation enters the glasshouse and is re-radiated as longer wavelengths which cannot escape the glasshouse. This heats up the glasshouse

Heaters in glasshouse may produce CO2

Fodder

food that you create to feed animals

How is nitrogen lost on a farm

When crops and livestock are sold, the nitrogen from their proteins is lost from the ecosystem

Inorganic fertiliser

carefully formulated fertiliser

Organic fertiliser (does not improve soil structure)

Farmyard manure

Usage of legume crop to increase crop yield

Legumes contain nitrogen fixing bacteria which convert nitrogen gas into ammonia for plants. The legumes are ploughed back into the soil

Pests

Organisms that reduce the yield of crop

Ways pests harm yield

Reduce growth by damaging leaves

Affect the appearance of a crop

Herbicides

Kill plant pests

Insecticides

Kill insects

Fungicides

Kill fungi

Mollusicides

Kill snails and slugs

Problems with pesticides

Pest may develop resistance through natural selection

Cause environmental damage

How do pests cause environmental damage

They are slow to decompose

Bioaccumulate in organisms

Become more concentrate along food chains through bio magnification