Saturday, May 02, 2009

FOOD! mmmm, i like :D

FOOOD is the most diff. lets start with it first!

Developments in food production

  • ·         Irrigation
  • ·         Use of chemicals
  • ·         Genetically modified (GM) food crops

IRRIGATION

Positive

àOvercomes physical limitation (drought)

àEnable more plants to grow healthily, thus increasing output of crop production.

Negative

Salinisation of soil (building of salt in soil)

àtoo much salt in the soil due to continuous cycles of flood irrigation

àlowering quality of soil

Waterlogging

àtoo much water using in the soil

àsoil saturated with water

àplant unable to take in air & nutrients = D I E !

 

USE OF CHEMICAL (fertilizers, pesticides, herbicides)

Negative

Water pollution

àthe chemicals are washed into nearby river when raining or irrigation

àriver water contaminated with chemicals

àharm marines animals or users of the water.

Eutrophication in water bodies

àexcess fertilizers washed into river

àcause rapid growth of algae

àreduces oxygen supply for aquatic plants and animals = D I E !

Imbalance in soil nutrients

à2 or 3 nutrients replenished, not all

àlack of humus

àlose fertility

 

GENETICALLY MODIFIED (GM) FOOD CROPS

Positive

àIncrease income for farmers

àImprove crop resistance to harsh weather conditions, reduces environmental pollution as there is lesser usage of chemicals on crops.

àHigher crop yield

àIncrease food production, solve problem of food shortages

àImprove nutritional value of food, reduce malnutrition

Negative

àloss of biodiversity

àlack of scientific evidence that food is safe for consumption

àmay contain traces of food substances that some people might be allergic to

àreligious concern about the substance used in GM food not permissible to be consumed by people in certain religions

àincrease production results in drop in price$, forcing small scale farmers to be out of job

àpotential environment hazards(“ contamination” of species)

B

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