Soil net nitrogen mineralization and leaching under <i>Miscanthus</i> × <i>giganteus</i> and <i>Zea mays</i>

Abstract The winter fallow period common in annual cropping systems leaves soils vulnerable to erosion and nutrient loss, especially nitrogen (N) leaching. This vulnerability can be mitigated with perennial crops that have living roots the ground year‐round. mechanisms, magnitude, consistency which retain N are not clear. We used an experiment test whether a crop, miscanthus ( Miscanthus × giganteus Greef et Deu.), would leach less than continuous maize Zea mays L.) how soil net mineralization (N min ) may explain observed leaching under varied environment management conditions. included three crossed factors: (1) system (maize, juvenile = 1–2 years old, mature 3–4 old); (2) fertilization (0 224 kg ha −1 ); (3) (four site‐years at two locations Iowa, USA, differed climate fertility). measured cycling dynamics, including: inorganic (ammonium + nitrate), situ , leaching, crop uptake, calculated use efficiency. There were many complex interactions among factors. On average, cumulative was 111% greater maize, but as matured, there no difference between maize. decreased by 42% 88% compared (with without fertilization, respectively). Across all treatments, relationship suggesting other mechanisms regulating Overall, shows promise tool reduce losses areas dominated row‐crops.