Division of the tropics can be made according to rainfall.
What are the 3 main divisions:
Division is according to the number of humid months:
- Humid climates have 7 or more wet months – 9 is very humid
- Semi-Humid (wet & dry) have 4.5-7 wet months
- Semi-arid have 2-4.5 wet months
In which ways can the tropical farming systems can be classified?
- By components: all crops, all livestock or a mixture of the two
- By lifestyle: settled, nomadic or semi-nomadic
- By inputs: Labour intensive or Capital Intensive
- By land use: Very intensive (full planting as often as possible) or land extensive ( fallow land or few livestock grazing a large area)
- By output: Subsistence, surplus or cash cropping
List three difficulties of tropical soils
- Low level of natural potential fertility due to sudden and heavy rainstorms leaching the nutrients from the soil to below root level
- Tropical soils typically have a low level of organic material because the humidity makes the matter break down rapidly when it is moist
- The soil cab have poor structure (especially very sandy) which will not stand up to intensive cultivation and is prone to water and wind erosion
What is bush fallowing?
- The cropped area for each year is systematically changed round a given area so all the land is equally used. Some of the land will need 3 years rest before cropping again, sandy soil may need 20 years or more rest.
What is zero grazing?
- Zero grazing is the practice whereby grass or fodder is cut and bought to the animals which are enclosed or tethered rather than be allowed freedon to graze.
Define wet rice cultivation.
- Wet rice system cultivation is where the land is flooded using irrigation and the crop is grown in wet soils from the time of transplanting seedlings until the harvest. This is a technique specific to paddy rice and is not commonly used for any other crops. It is popular inSouth-East Asia
List the three main types of tropical perennial crops
- Perennial field crops: short term 1-3 years, sugar cane, sisal, pineapple
- Shrub crops: tea, coffee
- Tree crops: long term, rubber, cocoa, oil palm, coconuts
What is multi-storey cropping?
- This is the planting of several crops that differ in height, root development and light requirements. Multi-storey mimics the tropical rainforest allowing a more efficient use of solar energy, water and soil nutrients.
What are the three main types of grazing systems in the tropics
- Nomadic: the owners and families have no permanent place of residence and practice no cultivation
- Semi-Nomadic: the owners have a permanent place of residence and practice some cultivation, but usually travel long periods of the year with their herds
- Ranching: the livestock land and water are organized within one unit. Stationery animal husbandry is organized according to commercial principals
Written by Fiona Johnson
For more answers to questions on farming in Africa and the tropics, click here.