Intercropping and low‐rate banded fertilizer to reduce nitrogen leaching in sweet corn

Abstract Water quality can be impacted by agricultural production on coarse‐textured, low organic matter soils where groundwater is shallow. This study investigated the effects of intercropping, decreased nitrogen rate, and precision nitrogen placement as nitrate leaching reduction strategies on sweet corn ( Zea mays L.) yield. Sweet corn was intercropped with winter rye ( Secale cereale L.) and yellow mustard ( Sinapis alba L.) in a randomized complete block design with four replications. The study was conducted in 2024 and 2025. Three intercrop seeding timings were evaluated (seeded at sweet corn seeding, 8 days after sweet corn seeding, and 16 days after sweet corn seeding) compared with non‐intercropped sweet corn, and two fertilizer strategies were tested (standard‐rate broadcast fertilizer application totaling 155 lb N ac −1 and low‐rate banded fertilizer totaling 52 lb N ac −1 ). Sweet corn yield was reduced by 44% and 34% in yellow mustard and winter rye intercrop systems, respectively, when fertilizer was banded at a reduced rate during a high‐leaching risk season. In a season with moderate precipitation, sweet corn yield was similar between fertilization methods. Intercrop germination was sensitive to field and weather conditions. Earlier‐seeded intercrops had more substantial biomass and nitrogen capture than later‐seeded intercrops in both years, with nitrogen uptake up to 31.9 lb N ac −1 in yellow mustard and 19.3 lb N ac −1 in winter rye. Intercropping with nitrogen‐scavenging species seeded at the same time as sweet corn and applying nitrogen in a reduced rate band may be possible without sweet corn yield penalty, but it depends on seasonal precipitation.