What has been the impact of declining harvests and years of drought on african subsistence farmers?

Africans are prone to drought because of their climate condition. Plants do not yield as planned because of poorly nourished soil.  A big part of African land regularly experiences drought. Poverty and unemployment are also a few of the primary impacts in the country and the lack of food to supply the people of Africa is one concern they have to face. 

Answer islamic scholars made advancements in technology, literature, philosophy, mathematics, astronomy, and the arts during this time period;

Magma forms by partial melting of upper mantle and crust. partial melt means that only a fraction of the available material forms a melt, and that the remainder stays solid. the partial melt rises because of its lower density and ascends through he crust. this is so conclusive mean the answer would be magma igneous rocks or balistic magma.