Bowen Ratio Energy Balance Measurement of Carbon Dioxide (CO2) Fluxes of No-Till and Conventional Tillage Agriculture in Lesotho

Global food demand requires that soils be used intensively for agriculture, but how these soils are managed greatly impacts soil fluxes of carbon dioxide (CO₂). Soil management practices can cause carbon to be either sequestered or emitted, with corresponding uncertain influence on atmospheric CO₂ concentrations. The situation is further complicated by the lack of CO₂ flux measurements for African subsistence farms. For widespread application in remote areas, a simple experimental methodology is desired. As a first step, the present study investigated the use of Bowen Ratio Energy Balance (BREB) instrumentation to measure the energy balance and CO₂ fluxes of two contrasting crop management systems, till and no-till, in the lowlands within the mountains of Lesotho. Two BREB micrometeorological systems were established on 100-m by 100-m sites, both planted with maize (Zea mays) but under either conventional (plow, disk-disk) or no-till soil mangement systems. The results demonstrate that with careful maintenance of the instruments by appropriately trained local personnel, the BREB approach offers substantial benefits in measuring real time changes in agroecosystem CO₂ flux. The periods where the two treatments could be compared indicated greater CO₂ sequestration over the no-till treatments during both the growing and non-growing seasons.

This article was published openly thanks to the University of Tennessee Open Publishing Support Fund.

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