聚天门冬氨酸/盐对水稻田面水氮素变化及养分利用的影响

Effects of polyaspartic-acid/salt on nitrogen loss from paddy surface water and nutrients utilization

为探究聚天门冬氨酸/盐(PASP)对稻田氮素流失及水稻养分利用的调控作用,本研究以普通聚天门冬氨酸钙/锌盐和改性聚天门冬氨酸钙/锌盐为供试材料,在干旱棚条件下,通过水稻桶栽试验研究了PASP对水稻田面水氮浓度变化和水稻生长、氮磷钾养分吸收及土壤养分的影响。结果表明,与常规尿素对照处理相比,各聚天门冬氨酸/盐处理降低了田面水氮素浓度,尤其在施肥后第3 d和第5 d,铵态氮和硝态氮浓度显著降低了16.8%~44.7%和20.4%~42.8%。聚天门冬氨酸/盐的施用有利于水稻生长及产量提高,水稻株高、有效穗数、秸秆产量和籽粒产量以及氮、磷、钾养分吸收量均表现出增加趋势,其中改性聚天门冬氨酸钙盐处理显著增加了水稻株高(12.0%)、有效穗数(13.8%)、秸秆产量(9.26%)及籽粒氮含量(8.32%),氮肥表观利用率提高了8.4%,但差异不显著。聚天门冬氨酸/盐处理土壤氮含量也有所增加,尤其是NH4^+-N含量显著增加,但土壤有效磷和速效钾含量受影响不大。综合水稻产量、养分吸收利用以及田面水氮素流失风险,改性聚天门冬氨酸/盐处理效果优于普通聚天门冬氨酸/盐,且改性聚天门冬氨酸钙盐处理最好。田间应用效果有待进一步验证。

To investigate the effects of polyaspartic-acid/salt(PASP)on paddy nitrogen(N)loss and nutrients utilization,PASP-Ca/Zn and modified PASP-Ca/Zn were used for pot experiments conducted in a rainproof tank.We evaluated the impacts of PASP on N concentrations in surface water,rice growth and its N,P,K uptake,and soil nutrients.The results showed that PASP treatments decreased NH4^+-N,NO3^--N,and TN concentrations of surface water,with 16.8%~44.7%lower NH4^--N and 20.4%~42.8%lower NO3^--N in PASP than the control in day3 d and 5 d after fertilization,respectively.Addition of PASP promoted rice growth and yield;modified PASP-Ca/Zn significantly increased rice height(12.0%),productive tillers(13.8%),straw yield(9.26%),and grain N concentration(8.32%),with 8.4%higher N use efficiency.NH+4-N concentrations in paddy soil were significantly increased by 28.4%~62.2%in PASP treatments compared to the control,whereas no significant difference in soil available P and K was observed.Considering rice yield,nutrients utilization,and N loss risk of surface water,modified PASP-Ca/Zn was more effective than PASP-Ca/Zn.In this study,modified PASP-Ca treatment was evaluated to be the best,with grain yield 9.21%greater and NH4^+-N of the surface water 44.7%lower than the control.However,PASP application effects need to be verified further by field experiments.