Carbon dioxide exchange in maize and soybeans

Abstract.

Carbon dioxide exchange was measured concurrently in irrigated maize and irrigated soybean fields using eddy covariance. The adjacent study sites, located at Mead, Nebraska, are large production fields, one-quarter section in size (65 ha). These sites are equipped with center-pivot irrigation systems. Our presentation will include a comparative examination of carbon dioxide fluxes in these two key agricultural ecosystems. We will address the following questions: What are the seasonal distributions of GPP (gross primary productivity)? What are the seasonal distributions of ecosystem respiration? What are the key biophysical factors which control the daytime CO2 uptake and nighttime CO2 release?