Crops require good sunshine and a certain temperature in order to grow. Image credit mg.co.za

ZIMSEC O Level Geography Notes:Agriculture:Farming as a system:Farm Inputs: Sunshine and Temperature

Sunshine

  • It refers to cloud free days experienced in an area.
  • The number of days with sunshine decreases as latitude increases towards the poles.
  • Sunshine is important in farming because it is required in the germination of plants.
  • It also enables crops to flower to produce the seeds which will be harvested as crops.
  • It is also required to dry the harvest otherwise when stored with a lot of moisture content, they develop mildew and rot.

Temperature

  • Plants will not grow below 6°C or above 48°C.
  • In cold areas, crop production can only be done under glass houses (incubators).
  • In winter seasons, crops that cannot tolerate frost have to be protected by the burning of coal in pots as well as irrigating them in the evening or dawn to reduce the risk of frost.
  • Examples of crops that require cool temperatures are rubber and palm oil. These will only thrive at a minimum temperature of 24° C.
  • Other crops will tolerate quite high temperatures even with little moisture, these are called drought resistant crops.
  • Examples are millet, rapoko and sorghum.
  • The temperature factor has led to the sub division of crops into: tropical and temperate crops.
  • Tropical crops are crops requiring warm weather for their growth and development, examples are maize and banana.
  • Temperate crops refers to crops that grow in the cooler climates in the world, examples are oats, barley, rye and millet.
  • Temperature is also important in animal husbandry as it determines whether open grazing or pen feeding must be undertaken in an area.
  • It also controls the type and breed of livestock to keep in an area depending on the adaptation of such livestock to the environment.
  • The temperature input together with rainfall, are used to sub-divide a region or country into natural or agro-ecological regions.
  • Temperature and sunshine determine growing seasons in seasonally humid climates.

Rainfall

  • The water may be used directly in what is called dryland farming.
  • It may also be drawn from rivers and underground aquifers or stored in dams and lakes to be used for crop production and animal husbandry through irrigation.
  • Its shortage has created a nomadic way of life in arid and semi-arid environments.
  • Some crops require large amounts of this natural input such as tea, rice; while others are tolerate of only small proportions for examples sorghum and millet.
  • Under certain climates, both total annual amount and seasonal distribution determine a farmer’s calendar and the crops to grow and the animals to keep.

To access more topics go to the O Level Geography Notes page