The Impact of Nitrogen fertilizer and Irrigation with Piggery Wastewater on Nitrogen Mineralization

DU Zhenjie; LI Ping; CUI Erping; QIAO Dongmei; LIANG Zhijie; QI Xuebin

doi:10.13522/j.cnki.ggps.2017.12.009

Abstract：Nitrogen input into soil influences nitrogen cycling and is closely related to nitrogen use efficiency.A laboratory experiment was conducted in this paper to investigate the change in ammonium nitrogen(NH+4-N),ni-trate nitrogen(NO-3-N)and total nitrogen(TN)in soil samples(0,7,14,21,28,35 and 42 days)irrigated by pig-gery wastewater and clean water(running water)under conditions that the nitrogen input in all treatments were the same and that the nitrogen input in each treatment was set at a high level and a low level.The results showed that TN and NH+4-N gradually decreased over time under different treatments,while NO-3-N increased.At the end of the incubation,the content of TN,NH+4-N and NO-3-N in high N treatment was higher than those at low N treat-ment. The maximum TN content was in CKH treatment (clean water with high nitrogen), while the maximum contents of NH+4-N and NO-3-N were both in the PWH treatment(irrigating with piggery wastewater plus high ni-trogen application).There was a significant difference in cumulative mineralized nitrogen among different treat-ments (P<0.05).The results also demonstrated that nitrogen input impacted cumulative mineralized nitrogen in two ways,and the cumulative mineralized nitrogen was the highest in the PWH treatment with a value of 59.69 mg/kg.The nitrogen mineralization rate decreased with the incubation time,and the nitrogen mineralization rate under piggery wastewater treatments were significantly higher than that under clean water treatments despite their different nitrogen managements.It is not difficult to conclude that the PWH treatment has the greatest nitro-gen supplying capacity,due to the high microbial biomass and enzyme activity of nitrogen mineralization.