生化抑制剂组合与施肥模式对黄泥田稻季氨挥发的影响

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

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。

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 NH＋4-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 NH＋4-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.