Growing season carbon dioxide exchange in flooded non-mulching and non-flooded mulching cotton.

There is much interest in the role that agricultural practices might play in sequestering carbon to help offset rising atmospheric CO₂ concentrations. However, limited information exists regarding the potential for increased carbon sequestration of different management strategies. The objective of this study was to quantify and contrast carbon dioxide exchange in traditional non-mulching with flooding irrigation (TF) and plastic film mulching with drip irrigation (PM) cotton (Gossypium hirsutum L.) fields in northwest China. Net primary productivity (NPP), soil heterotrophic respiration (R(h)) and net ecosystem productivity (NEP) were measured during the growing seasons in 2009 and 2010. As compared with TF, PM significantly increased the aboveground and belowground biomass and the NPP (340 g C m⁻² season⁻¹) of cotton, and decreased the R(h) (89 g C m⁻² season⁻¹) (p