Chemical and microbial properties of semiarid tropical soils of short-term fallows in Burkina Faso, West Africa

In the soudano-sahelian zone of Burkina Faso, the short-term fallow effect on the soil chemical and microbial properties was evaluated. In four farm experiments, two types of fallows were compared with cultivated fields: a natural vegetation fallow and a fallow enriched with Andropogon gayanus. After 5 to 7 years of experiments, soil chemical and microbial characteristics were determined in laboratory for 0-10 cm soil depth. Soil organic carbon (+64%), nitrogen (+35%), microbial biomass (+76%), basal respiration (+141%), and beta-glucosidase activity (+86%) were significantly higher in fallows plots than in cultivated fields. The metabolic quotient was not significantly different on fallows compared to the cropped plots. Also, no significant difference was highlighted between natural vegetation fallows and the A. gayanus-enriched one.