Effects of Intensifying Food Production

Salination

Building up of salts within the soil

This occurs as flood irrigation is practised

Where the water covers the surface of the land

When water in the field is used up by crops or has evaporated into the atmosphere,the salts in the water are left behind.

As time goes by,salts in the soil build,thus lowering the quality of the soil

Caused in areas where dams are constructed

Eg. Eygpt,Aswan Dam built across Nile River

Results in sediments and minerals trapped in the reservior behind the dam.

When water from the reservoir, is used to irrigate the crops. The salinity of the soil increases.

If the process continues,the salt in the soil would be too high for most of the crops to grow well.

Occurs in arid regions

Eg.dry regions-Syria and Kuwait and coastal areas-India and Libya

Source of irrigation is groundwater and sea water,salinity of soil increases

Waterlogging

Too much water is used in th fields

Causes soil to be saturated with water

Eg. India,where farmers over irrigate the land to wash excess salt from the land to reduce salination

Preventing air and nutrients that the crops need from reaching them

Causing them to wither and die

Leading to a decrease in crop output and food production

Imbalance in soil nutrients

Chemical fertilisers do not supply all the nutients the crop needs

Chemical fertilisers do not add humus to soil

Humus is a organic substance formed by the decomposition of dead plants and animals

This causes the soil to lose its fertility over a long run

Eutrophication in water bodies

Caused by excess fertilisers being washed into nerarby rivers or lakes by rain

This causes rapid growth of algae

Reducing the oxygen supply available for other aquatic life

Leading to the death of many aquatic plants and animals

Water pollution

When excessive peaticides or herbicides are used,they seep into groundwater of dissolve in surface runoff

Th contaminated water eventuallt flows into naerby water bodies cuasing water pollution

Chemicals harm or kill aquatic plants and amimals

Poision people who drink this water

Eg. Dam near Rennes. stopped by public health authorities due to pesticide contamination