Seasonal changes in the performance of a catch crop for mitigating diffuse agricultural pollution

An in situ technology for mitigating diffuse agricultural pollution using catch crops was developed for simultaneously preventing nitrate groundwater pollution, reducing nitrous oxide (N₂O) gas emissions, and removing salts from the topsoil. Seasonal changes in the performance of a catch crop were investigated using lysimeters in a full-scale greenhouse experiment with 50 d cultivation of dent corn. Catch crop cultivation significantly reduced the leached mineral nitrogen by 89-91% in summer, 87-89% in spring, and 61-82% in winter, and it also significantly reduced the N₂O emission by 68-84% in summer. The amounts of nitrogen uptake by the catch crop were remarkably higher than those of leached nitrogen and N₂O emission in each season. Catch crop cultivation is a promising technology for mitigating diffuse agricultural pollution.