CO2, CH4 and N2O fluxes in a Nordic agricultural field growing barley intercropped with undersown species

This package contains data from an experimental site in southern Finland, where barley was cultivated either as a monoculture or intercropped with 1 to 8 undersown species. After the barley harvest, the undersown species remained in the field and served as a cover crop until tillage in the following spring. The field, located in Helsinki (60°13'29.4"N, 25°01'12.7"E), is classified as coarse mineral soil. Manual chamber flux measurements included NEE, TER, N₂O, and CH₄, and were conducted over a two-year period from May 2020 to May 2022.