生化抑制剂组合与施肥模式对黄泥田稻季田面水及渗漏液氮素动态变化的影响

Effects of Combined Biochemical Inhibitors and Fertilization Models on Nitrogen Dynamics in Surface Water and Leachate from Yellow Clayey Paddy Field

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)毗呢(CP))与施肥模式(一次性施肥和分次施肥)互作对黄泥田稻季田面水和渗漏液氮(N)素浓度动态变化特征的影响。结果表明,黄泥田稻季田面水和渗漏液中N素形态分别以NHJ-N和NO,-N为主。基肥施用后,稻田田面水中NH;-N和总氮(TN)浓度于第1天达到峰值后降低,第6天分别降为峰值的57.9%~ 69.1%、41.9%~59.0%(一次性施肥)和29.9%~60.7%、60.9%~ 69.7%份次施肥);稻田渗漏液中NO;-N和TN浓度于第1 ~3天达到峰值后降低,第6天分别降为峰值的51.4%~ 56.5%、56.6%~ 61.6%(一次性施肥)和45.3%~ 57.5%、51.1%~59.6%(分次施肥)。不同施肥模式下,硝化抑制剂CP会提高田面水NH4^+-N浓度,而脉酶抑制剂NBPT/NPPT或配施CP有效抑制脉酶活性,降低田面水NH4^+-N峰值;CP显著降低渗漏液NO3^--N浓度,且CP或配施NBPT/NPPT有效抑制硝化作用,降低渗漏液NO3^--N峰值。新型服酶抑制剂NPPT单独施用及与CP配施的稻田田面水和渗漏液N素浓度动态变化特征与NBPT相似。总之,生化抑制剂与适宜的氮肥运筹相结合更能有效延缓黄泥田中尿素水解,抑制硝化作用,减少N素径流和渗漏损失。

An experiment was conducted to study the interaction effects of biochemical inhibitor combinations (N?(n-butyl) thiophosphoric triamide (NBPT), N-(n-propyl) thiophosphoric tri amide (NPPT) and 2-chloro-6-(trichloromethyl) pyridine (CP)) and fertilization models (one-ofF and three-time fertilization) on nitrogen (N) dynamic change characteristics in the surface water and leachate from yellow clayey paddy field using two factor randomized block design. The results showed that N losses of surface water and leachate from yellow clayey paddy field were given priority to NH4^+-N and NO3^--N, respectively. The peak values of NH4^+-N and TN concentrations in the surface water from paddy field appeared within one day after basal application, and then decreased by 57.9%- 69.1% and 41.9%- 59.0%(one-off), 29.9%- 60.7% and 60.9%- 69.7%(three-time) till the 6th day, respectively. The peak values ofNO3^--N and TN concentrations in the leachates from paddy field appeared within 1 - 3 days after basal application, and then decreased by 51.4%- 56.5% and 56.6%- 61.6%(one-off), 45.3%- 57.5% and 51.1%- 59.6%(three-time) till the 6th day, respectively. Under different fertilization modes, CP increased NH4^+-N concentration of surface water, and NBPT/NPPT or combined with CP effectively inhibited the activity of urease, and reduced the peak value of NH4^+-N in the surface water. On the other hand, CP significantly decreased NO3^--N concentration of the leachate, and CP or combined with NBPT/NPPT effectively inhibited nitrification, and reduced the peak value of NO3^--N in the leachate. Application of a new urease inhibitor NPPT alone or combined with CP had the same effect on N dynamic change characteristics in the surface water and leachate from paddy field with NBPT. In conclusion, the integration and optimization of fertilization technique and combined inhibitors application can more effectively delay urea hydrolysis, inhibit nitrification, and reduce the runoff and leakage loss of N in yellow clayey paddy field.