Carbon exchange of a maize crop in southern Italy

The study was conducted in an irrigated agricultural system in Borgo Cioffi (SA) on a maize crop. Measures of CO2, H2O and energy fluxes using the eddy covariance technique were carried out throughout the crop cycle. The gaps in the historical series of net ecosystem exchange (NEE) were filled performing nonlinear regressions: the relationship between respiration and temperature described by the Q10 exponential function was used to fill the nighttime gaps; the relationship between incoming PAR and NEE, described by the Michaelis-Menten equation, was used to fill daytime gaps. Diurnal total ecosystem respiration used for gross primary production (GPP) calculation was evaluated extrapolating the sensitivity of NEE to temperature found for nighttime conditions. The final crop production was inferior to the expectations mostly due to the inadequate water supply so that cumulative carbon uptake was 426 g C m-2.