Using eddy covariance flux measurements, gross primary production (GPP) and ecosystem respiration (Re) of irrigated maize and soybean fields were quantified and examined in terms of relevant controlling variables. Even though the peak green leaf area index (GLAI) of the maize and soybean canopies was comparable (about 5.8 m2 m−2), the maize GLAI increased more rapidly during… More
Carbon dioxide exchange was quantified in maize–soybean agroecosystems employing year-round tower eddy covariance flux systems and measurements of soil C stocks, CO2fluxes from the soil surface, plant biomass, and litter decomposition. Measurements were made in three cropping systems: (a) irrigated continuous maize, (b) irrigated maize–soybean rotation, and (c) rainfed maize–soybean rotation during 2001–2004. Because of… More
Field experiments were conducted to determine optimal time during the day for N2O flux determination and to evaluate the effects of wheel traffic and soil parameters on N2O fluxes following urea ammonium nitrate (UAN) injection and summer UAN fertigations. The experiments were located on silty clay loam soils under no-till irrigated continuous corn of eastern… More
The AmeriFlux QA/QC Tech Team is currently concluding the 2014 site visit season. 8 site visits have been completed and 1 more is scheduled. This season, the team visited 4 sites for the first time (US-Dia, US-Cpk, US-Ha2, US-Myb).