Plantation agriculture was the major cause of increased slave trade in east Africa. By 1840, slaves were heavily used in clove plantations in Zanzibar and Pemba. The slaves had to provide for both themselves and their masters.
In early 19th century, the Arabs and the Swahili started growing grains like semeseme and millet. Slaves spent long working hours on such plantations under the supervision of slave overseers.
Plantation slavery was intensively practiced around Malindi, where there were large tracts of farmland. In Mombasa, cultivation of coconuts was preferred as farms there were smaller. Coconuts required less rain while their yields were higher.
The Mijikenda traded with the Arabs in ivory, cattle and grains. Arabs prevented the Mijikenda from owning the rich coastal farmland.
Slaves often tried to escape from plantations due to their bad working conditions. They were grouped into different classes and were not equal.
Those slaves that ran away were employed by rich Arabs and the Swahili to fight against the Sultan‟s government. Those that remained behind became more stubborn and did not work as hard as they were required. They disobeyed orders and refused to accept their masters‟ culture.
Because of this, there were efforts to improve their conditions.
However, the coming of colonialism ended the use of slaves in the plantations.