生化抑制剂组合与施肥模式对黄泥田稻季氨挥发的影响

为探讨生化抑制剂组合与施肥模式对黄泥田稻季氨挥发的影响,采用二因素随机区组设计,研究生化抑制剂组合N-丁基硫代磷酰三胺(NBPT)、N-丙基硫代磷酰三胺(NPPT)和2-氯-6-(三氯甲基)吡啶(CP)]与施肥模式(一次性和分次施肥)互作对黄泥田稻季氨(NH3)挥发动态变化的影响。结果表明:黄泥田稻季NH3挥发损失主要集中于施肥后1周,峰值发生在第1~3 d。生化抑制剂组合与施肥模式对黄泥田稻季NH3挥发损失量的效应显著。尿素分次施用处理稻季NH3挥发净损失率较一次性施用处理显著降低24.6%。不同施肥模式下,硝化抑制剂CP处理显著提高田面水NH+4-N峰值和NH3挥发速率峰值,增加稻田NH3挥发损失量;脲酶抑制剂NBPT/NPPT或配施CP处理明显延缓尿素水解,降低NH3挥发速率峰值,减少稻田NH3挥发损失量。新型脲酶抑制剂NPPT单独施用及与CP配施的稻田NH3挥发动态变化与NBPT相似。相关性分析表明,稻田NH3挥发速率与田面水NH+4-N浓度和pH值呈显著正相关,而与气温、土温和土壤相对湿度无显著相关性。总之,生化抑制剂组合与适宜的运筹相结合更能有效减少黄泥田稻季NH3挥发损失。

Effects of combined biochemical inhibitors and fertilization models on ammonia volatilization in yellow clayey paddy field

Ammonia(NH₃) volatilization is one of the main pathways of nitrogen(N) fertilizer loss in rice production. This study was conducted to investigate the interaction effects of biochemical inhibitor combinations and fertilization models(one-off and three-time fertilizations) on ammonia(NH₃) volatilization during the rice growing season in yellow clayey field using two-factor randomized block design. The results showed that NH₃ volatilization loss mainly occurred within one week after fertilization during the rice growing season, and peaked within 1-3 days. Both biochemical inhibitor combinations and fertilization models had significant effects on the loss of NH₃ volatilization. The three-time urea fertilization treatment significantly reduced the net NH₃ volatilization loss rate by 24.6% than that of one-off urea fertilization treatment during the rice growing season. The addition of nitrification inhibitor CP significantly increased the peak value of NH₄⁺-N concentration in surface water and NH₃ volatilization rate, and thus enhanced NH₃ volatilization loss under different fertilization modes. Combined with(or without) CP, the addition of urease inhibitor NBPT/NPPT significantly inhibited urea hydrolysis, and reduced the peak value of NH₃ volatilization rate, and thus mitigated NH₃ volatilization loss. The addition of new urease inhibitor NPPT alone(or combined with CP) had a similar trend of dynamic change of NH₃ volatilization to that of NBPT. Correlation analysis showed that NH₃ volatilization rate from paddy fields had a significant positive correlation with NH₄⁺-N concentration and pH in surface water rather than air temperature, soil temperature, and soil relative moisture. In conclusion, biochemical inhibitors combined with appropriate management can more effectively reduce NH₃ volatilization loss during the rice growing season from yellow clayey fields.