Zanzibar consists of two main Islands Unguja and Pemba, the islands are located at 390E and between latitude 50S and 60S, with a total area of 2,332 km2 (Unguja 1,464 km2 and Pemba 868 km2). The current population estimated to be 1.2 million with the growth rate of 3%.
Four major seasons
There are four major seasons: the long rains (Masika) from the end of March to mid May cool season (Kipupwe) with intermittent showers from June to August; the short rains (Vuli) from the end of September until December, and the dry spell (Kaskazi) which start soon after short rains to the onset of long rains. The average annual rainfall is about 1,700 mm for Unguja and 1,800 mm for Pemba.The temperature is also typically equatorial with very little variation between the seasons. The mean annual maximum temperature is 30.30C for Unguja and 29.30C for Pemba; the minimum is 23.50C and 21.10C, respectively.
Zanzibar has deeper and richer soils on the western side and soils become shallower towards the eastern side. The karst coral country of Unguja is mainly found in the Eastern and Southern parts, but patches of this rocky plateau found at several levels to the West and Southwest of the island. The semi coral rag areamake the clear distinct between the coral rag and plantation areas which havedeep soils in western part of Zanzibar.
Coral ragarea in Zanzibar lie on the Eastern part of both two island of Unguja andPemba. Roughly quarter of Pemba and 60% of Unguja consist of this type of land which in natural state covered byvegetation, the tree complex of which varies in different area.
Agriculture = 70 percent of the total labour force
Agriculture employs approximately 70 percent of the total labour force in Zanzibar. In addition to being a source of income, the agriculture sector has a direct contribution to the food security, nutrition and health status of thepeople and an indirect impact on many other aspects of livelihood. Majority of farmers in Zanzibar are subsistence; traditionally they grow at least three crops in different associations in order to avoid risks and uncertainties, the intercropping of perennials, tree crops and annual food crops being the common.
The common crops grown in Zanzibar including; a wide range of tropical fruits and vegetables,including banana, mango, coconut, citrus (oranges, lemons andtangerines), pineapples, papaya, rambutan, avocado, passion fruits, guava,Carrabolla, durian, tomato, amaranths, eggplant, okra, cucumber, watermelon and pumpkin. The food crops are cassava, rice, cowpeas, maize,sweet potato, pigeon pea, yams, cocoyam and spices include chillies, black pepper,cinnamon, and cardamom, ginger, nutmeg, tumeric and lemon grass.
The coral rag area supports livelihood of about 35 percent of the total population of Zanzibar. The common activities of local community arefood and cash crop production, livestock keeping, hunting, lime making,collecting honey, fishing and sea weed farming. This area also is known for the supply of wood products which include fire wood,charcoal, building poles and medicine for tradition healing.
Shifting cultivation is the dominant agriculture system in coral rag areas. The practice simply involves slashing of the bushes and burning the debris during the dry season, few days before the rains, traditionally the cultivation is carried out for about 3 to 5 year and resting period of the land is 10 to 15 years. This system becomes unsustainable interms of fertility improvement due to high rate of deforestation and reducedfallow during shifting cultivation practice. Parallel with traditional land use, coral rag are threaten with tourist industry and construction of hotels which highly dominated in the Northeast and Northwest coasts of the island.
Traditionally shifting cultivation has been performed as a communal activity. All farmers has been cultivating in the same area by growing different crops for several years until when the land showsigns of fertility reduction, then they shift together to another place. When they come back to the first place it take decades and find the forest is wellmature. This practice helps the farmer to protect their crops from wild animals. The system now has change each farmer cultivate his land on his own.
Agriculture & environment in coral rag areas
Due to scarcity of arable land for expansion, agriculture directly affect environment in coral rag areas. It was estimated that about 500 ha ofcoral rag forest are cleared annually for cultivation The situation contributes to increasing frequency of cutting down trees, which affect cultivation in thecoral areas where by crop growing in these areas depend highly in organicmatter. The soil in coral rag areacontain significantly higher nutrient levels than soils in deep soil region. The higher nutrient level is associated with maturity of the forest to nourish the land during fallowing period.