The DRC is the third largest country in Africa after Sudan and Algeria. It stretches from the Atlantic to the east African rift plateau. It includes the major part of the Congo River basin. Crossed by the equator, it has a warm and humid climate in the region of the river basin, and drier and cooler in the south. The DRC counts 64 million of inhabitants.
The study takes place in the province of South Kivu. The Kivu provinces lie in the East of DR Congo, bordering Rwanda, Burundi, Uganda and a small part of Tanzania. The largest part of the area falls into the humid zone. With a bimodal pattern observed in the rainfall, Kivu has two growing seasons per year: the long season (A season) ranges from mid-september to mid-january and the short season (B season) ranges from mid-february to mid-june. South Kivu can be divided into three parts with different climate: east is mountainous with fresh temperatures, Shabunda and Mwenga, located in the center and south west of the province are subject to an equatorial climate with heavy rainfalls and Ruzizi plain is subject to a dry tropical climate with lower rainfall. The soils in Kivu are generally of relatively high-fertility of recent volcanic origin. However, high population density has led to continuous cropping with little or no external input to maintain soil fertility (Lunze et al. 2011).