TY  - JOUR
A1  - Vaidya, Shrijana
A1  - Schmidt, Marten
A1  - Rakowski, Peter
A1  - Bonk, Norbert
A1  - Verch, Gernot
A1  - Augustin, Jürgen
A1  - Sommer, Michael
A1  - Hoffmann, Mathias
T1  - A novel robotic chamber system allowing to accurately and precisely determining spatio-temporal CO2 flux dynamics of heterogeneous croplands
JF  - Agricultural and forest meteorology
N2  - The precise and accurate assessment of carbon dioxide (CO2) exchange is crucial to identify terrestrial carbon (C) sources and sinks and for evaluating their role within the global C budget. The substantial uncertainty in disentangling the management and soil impact on measured CO2 fluxes are largely ignored especially in cropland. The reasons for this lies in the limitation of the widely used eddy covariance as well as manual and automatic chamber systems, which either account for short-term temporal variability or small-scale spatial heterogeneity, but barely both. To address this issue, we developed a novel robotic chamber system allowing for dozens of spatial measurement repetitions, thus enabling CO2 exchange measurements in a sufficient temporal and high small-scale spatial resolution. The system was tested from 08th July to 09th September 2019 at a heterogeneous field (100 m x 16 m), located within the hummocky ground moraine landscape of northeastern Germany (CarboZALF-D). The field is foreseen for a longer-term block trial manipulation experiment extending over three erosion induced soil types and was covered with spring barley. Measured fluxes of nighttime ecosystem respiration (R-eco) and daytime net ecosystem exchange (NEE) showed distinct temporal patterns influenced by crop phenology, weather conditions and management practices. Similarly, we found clear small-scale spatial differences in cumulated (gap-filled) R-eco, gross primary productivity (GPP) and NEE fluxes affected by the three distinct soil types. Additionally, spatial patterns induced by former management practices and characterized by differences in soil pH and nutrition status (P and K) were also revealed between plots within each of the three soil types, which allowed compensating for prior to the foreseen block trial manipulation experiment. The results underline the great potential of the novel robotic chamber system, which not only detects short-term temporal CO2 flux dynamics but also reflects the impact of small-scale spatial heterogeneity.
KW  - Automatic chamber
KW  - Net ecosystem exchange (NEE)
KW  - Gross primary
KW  - productivity (GPP)
KW  - Ecosystem respiration (R-eco)
KW  - Soil erosion
KW  - Soil
KW  - heterogeneity
Y1  - 2021
U6  - https://doi.org/10.1016/j.agrformet.2020.108206
SN  - 0168-1923
SN  - 1873-2240
VL  - 296
PB  - Elsevier
CY  - Amsterdam
ER  -