The low fertility of Burundian soils is one of the major constraints limiting crop production. Mineral and organic fertilizers are potential sources of plant nutrients that can contribute to increased crop yields and therefore production. Due to the high cost and the unavailability of mineral fertilizers in time, the use of farm manure or compost is generally the most common mode of fertilization in Burundi because they are available locally. However, few farmers produce sufficient quantities of organic manure and often, its quality is deteriorated following exposure to heat and rain before its use in the field, thus causing a loss of nitrogen by leaching and/or by evaporation.