Changes to Ecosystems (ii) Intensive Farming

• High yield crop variety - monoculture
• Fertilisers - more nutrients such as nitrogen, phosphate and potassium
• Herbicides - reduce competition
• Pesticides - Reducing 'predation'
• Fungicide - Reducing disease

The growth of a single species over a large area -  a single crop ecosystem

• It increases the yield of a crop which in turn increases the amount of profit the farmer makes
• A monoculture will grow to the same height and be ready to harvest at the same time meaning farmers can use large machines, eg combine harvesters, to make harvesting crops easier and faster

• Monocultures are very unstable and so are highly susseptible to: disease caused by bacteria, fungi and viruses, attacks from pests (weeds, insects and animals), soil erosion and adverse weather conditions
• A monoculture will be genetically identical so if attacked by disease the whole crop could be wiped out if there is no natural resistance present
• It reduces the nutrient levels in the soil, as less organic material is reincorporated into the soil (as the crops are sold and not allowed to decompose in the fields) so the nutrients that were previously in the soil are not being replaced

Hedgerows and fences are taken down to make larger fields so heavy machinery can navigate them easily.  This causes soil erosion as they hegrows is no longer present to act as a windbreaker.  Biodiversity decreases with the removal of herdgerows because there is less habitats and shelters for organisms. 

• Manure
• Composts