Experimental and simulated data for crop and grassland production and carbon-nitrogen fluxes

<p dir="ltr">Multi-year datasets from field experiments and simulations at five agricultural sites in the Northern Hemisphere were developed for three cropland sites in Ottawa (Canada), Grignon (France) and Delhi (India) and two grassland sites at Laqueuille (France) and Easter Bush (UK). The cropland sites have rotations with wheat, triticale, maize, rapeseed, soybean, phacelia and rice, as well as periods of bare fallow. Cattle (Laqueuille) or mixed cattle and sheep (Easter Bush) graze in the two grassland sites. Field data were collected between 2003 and 2012 for three to eight years, including grain yield/above‐ground net primary productivity, nitrous oxide emissions, carbon fluxes (gross primary production, net ecosystem exchange, ecosystem respiration), together with daily weather data (solar radiation, maximum and minimum temperatures, precipitation, wind speed, relative humidity, vapour pressure), soil properties, and records of crop and grassland management. Simulated outputs are from 23 models: 11 crop models, eight grassland models and four models simulating both systems.</p>