The Selhausen site represents the heterogeneous agricultural rural area of the lower Rhine valley. The climate is temperate maritime with a mean annual temperature of 10°C and annual precipitation of 700 mm for the period from 1961 to 2014 (meteorological tower, Forschungszentrum Jülich). The most important crops in the region of Selhausen are sugar beet (beta vulgaris), winter wheat (triticumavesticum), winter barley (hordeum vulgare), maize (zea mays) and rape seed (brassica napus). Only parts of the region are managed as grasslands. The underlying Quaternary sediments are mostly fluvial deposits covered with loess. Major soil types are luvisols and gleyed cambisols, partly with large contents of gravel. The land surface is generally flat with slopes up to 4° in the area of a former channel of the Rur River system. From 2007 to 2010 a first long-term eddy covariance study was conducted within the Selhausen region (measurements can be found at the European fluxes database cluster, ID: DE-Seh). In spring 2011 a new station (50.865°N, 6.447°E, 203m a.s.l.) was equipped with a CSAT3 sonic anemometer and LI7500 gas analyzer. Besides flux measurements and typical climate parameters (radiation, air temperature, air humidity, soil moisture, soil temperature etc.), also the phenological development of the crops and farming activities were recorded. The station fits now the standards of a Level-1 site for the European project ICOS (Integrated Carbon Observation System). As a pan-European long-term research infrastructure ICOS aims at providing harmonized and high-precision scientific data on carbon cycle and greenhouse gas budget and perturbations.