Interpreting soil CO2 transport and production in oasis cotton field, central Asia

Abstract

In order to explore soil profile CO₂ transport and production, values of vertical soil profile CO₂ concentration, moisture and temperature were measured continuously during whole cotton growing season in oasis cotton field of Aksu National Experimental Station of Oasis Farmland Ecosystem, central Asia. Simultaneously, soil CO₂ efflux was measured by chamber system to assess the deducing result by Fick’s first law. In our experiment, soil CO₂ effluxes were determined by two related intimately methods. Soil CO₂ releasing at 0–20 cm depth was calculated by gas transport equation and was found to be closely related to soil CO₂ efflux. However, mean values of soil CO₂ production at 0–20 cm depth were less than those of soil CO₂ efflux during the whole cotton growing season. Moreover, there were some negative values of CO₂ production at 0–20 cm depth found during the experimental period.