Perennial crops can deliver a wide range of ecosystem services compared to annual crops. Some of these benefits are achieved by lengthening the growing season, which increases the period of crop water and nutrient uptake, pointing to a potential role for perennial systems to mitigate soil nitrous oxide (N 2 O) emissions. Employing a micrometeorological method, we tested this hypothesis in a 3‐year field experiment with a peren...