Straw return in a rice-wheat rotation can boost crop yield and reduce nitrate nitrogen leaching. Returning all straw (TS) increased soil organic matter and decreased nitrate leaching at certain depths. Both half straw return (HS) and TS outperformed conventional methods in reducing nitrate leaching in the wheat season. The increase in crop yield and soil aggregation from straw return helps lower nitrate levels in the soil. This study shows that total straw return has the potential to improve crop yield, soil quality, and reduce nitrate pollution in the Ningxia irrigation district.