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Quantifying the emissions of the three main biogenic greenhouse gases (GHGs), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), from agroecosystems is crucial. In this study continuous measurements of N2O, and CH4 emissions from potato and pea crops in southwest British Columbia, Canada were made using the eddy‐covariance (EC) technique. Flux footprint analysis, coupled with EC and manual nonsteady state chamber measurements, was used to address the spatial heterogeneity resulting from the field edge at the study site. Flux footprint corrections had a larger effect on N2O fluxes than CO2 fluxes because of a more pronounced difference in N2O fluxes between the crop and edge areas. After flux footprint corrections, the potato and pea crops were both weak CO2 sinks with annual net ecosystem exchange values of −57 ± 9 and −97 ± 16 g C m−2 yr−1, respectively. However, after taking carbon (C) export via crop harvest and C import via seeding into account, the potato crop shifted to being a moderate C source of 284 ± 55 g C m−2 yr−1, while the pea crop became near C neutral, sequestering only 30 ± 26 g C m−2 yr−1. Annual GHG balances, quantified by converting N2O and CH4 to CO2 equivalents as pulse emissions using respective global warming potentials on a 100‐year timescale, were 417 ± 88 and 152 ± 106 g CO2e m−2 yr−1 for the potato and pea crops, respectively, with N2O contributing the largest proportion to annual total GHG balances and outweighing the CO2 uptake from the atmosphere. Plain Language Summary: To better mitigate climate change, quantifying the emissions of the three main biogenic greenhouse gases (GHGs), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), from agroecosystems is critical. Therefore, in this study we made continuous half‐hourly measurements of CO2, N2O, and CH4 emissions from potato and pea crops in southwest British Columbia, Canada using micrometeorological instrumentation installed at the field edge. To correct for the effects of the field edge on the micrometeorological measurements, we used supplementary chamber measurements and a footprint model. This enabled us to estimate the actual GHG budgets of the study crop areas. The correction had a larger effect on N2O fluxes than CO2 fluxes because of a more pronounced difference in N2O fluxes between the crop and edge areas. Both crops sequestered CO2 on an annual basis. However, after taking carbon (C) export via crop harvest and C import via seeding into account, the potato crop shifted to being a moderate C source while the pea crop became near C neutral. Even though CH4 emissions were low, substantial N2O emissions outweighed the CO2 uptake from the atmosphere by both crops, resulting in both being GHG sources. Key Points: Combining eddy‐covariance and flux‐chamber data with flux analysis allowed estimation of actual greenhouse gas fluxes from crop fieldsIncluding export (harvesting) and import (seeding), peas were near carbon neutral while potatoes were a moderate carbon sourceFor both potato and pea crops, nitrous oxide contributed the largest proportion of the annual total greenhouse gas emissions [ABSTRACT FROM AUTHOR]

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