Abstract: We examined the effects of bentonitehumic acid on soil NH₃ volatilization and N₂O emission, nitrogen use efficiency and maize yield on sandy soil in West Liaohe River plain. There were five treatments: CK (no nitrogen and bentonite-humic acid application), B₀ (bentonitehumic acid only, 30 t·hm^-2), N₀ (nitrogen only, 160 t·hm^-2), NB₂ bentonite humic acid, 30 t·hm^-2; nitrogen, 160 t·hm^-2), NB₂ (bentonite humic acid, 60 t·hm^-2; nitrogen, 160 t·hm^-2). Results showed that gaseous nitrogen loss mainly came from NH₃ volatilization, followed by N₂O emission. The dynamics of NH₃ volatilization and N₂O emission during maize growth varied among treatments: the CK and B₀ showed a steady change, but the nitrogen treatments had a rapid increase and dropped down quickly, then remained unchanged. Compared to CK, B₀ had no significant effect on soil gaseous nitrogen loss, but significantly increased maize grain yield (P≤0.05). Addition of bentonite humic acid and nitrogen deceased soil gaseous nitrogen loss, and enhanced nitrogen use efficiency and maize yield and protein content. The NB₂ treatment showed the best performance in reducing gaseous nitrogen loss, but its nitrogen use efficiency and maize yield were lower (P≤0.05) than N₀. NB treatment had the highest nitrogen use efficiency, maize yield and grain protein content, which increased by 21.31%, 8.66% and 40.03% respectively, compared to N₀. In conclusion, addition of bentonite-humic acid on sandy soil could reduce soil gaseous nitrogen loss, increase nitrogen use efficiency and yield of maize, and improve grain quality. Our results provide a new way for improving nitrogen use efficiency and amelioration of sandy soil.

Key words: sediment, sloped apple orchard., polyacrylanide (PAM), dry broadcasting rate, soil nutrients, surface runoff