Answer:
Mansa Musa developed cities like Timbuktu and Gao into important cultural centers. He also brought architects from the Middle East and across Africa to design new buildings for his cities. Mansa Musa turned the kingdom of Mali into a sophisticated center of learning in the Islamic world.
Increase of crops due to new innovations with the farming technique is one that comes to mind, not very sure about other factors though, sorry
In preparation for a nuclear attack in 1950-60s