Reducing interflow nitrogen loss from hillslope cropland in a purple soil hilly region in southwestern China

Interflow related nitrogen (N) loss from hillslope cropland is a global issue of concern. Field experiments were carried out in purple soil to study how to reduce interflow related N loss by substituting organic fertilizers for mineral fertilizers. Study conditions were engineered where identical amounts of N were applied to four different fertilization regimes: N fertilizer only, mineral fertilizers (MF), mineral fertilizers with livestock manure (MFL), and mineral fertilizers with crop straw (MFS). Results showed that total MFL and MFS interflow N loss decreased by 44.1 and 36.9 %, respectively, compared to the MF fertilization regime, using identical amounts of N. Furthermore, crop yields for the MFL and MFS fertilization regimes were higher compared to the MF fertilization regime. These findings can result in an important new means in controlling interflow N loss from hillslope cropland by substituting organic fertilizers for a port of mineral fertilizers, using identical amounts of organic fertilizer.