Comparing Carbon Dioxide (CO2) Flux Between No-Till and Conventional Tillage Agriculture in Lesotho, Africa.

Soil management practices can either sequester or emit carbon (C).  Feeding 7 billion people mandates that soils be used intensively for food production, but how these soils are managed greatly impacts soil flux/efflux of carbon dioxide (CO₂).  However the lack of CO₂ flux measurements on African subsistence farms makes it difficult to estimate C sequestration rates on small farmer’s fields.  This study was conducted to measure the energy balance and CO₂ flux of two contrasting crop management systems in the Senqu valley region of Lesotho.  The potential of no-till to increase soil C sequestration in Lesotho, Southern Africa, was assessed using Bowen Ratio Energy Balance (BREB) data collected over a 1.5 year period, comparing CO₂ flux between till and no-till treatments.  Two BREB systems were established on two 100-m by 100-m sites, both planted with corn (zea mays) but under either conventional (plow, disk-disk) or no-till soil management systems.  This study collected data to add to the knowledge of the effects of specific agricultural management practices on soil C sequestration in sub-Saharan Africa, using a BREB micrometeorology method to collect CO₂ flux and other environmental data over shorter time periods.  The present study verified the applicability of BREB measurement methods to study CO₂ sequestration at remote agricultural locations.  The results of this study indicate no-till management practices in Lesotho emit less CO₂ than conventional tillage.