Abstract To improve the quality of tobacco cultivation, effect of different potassium levels on nitrogenous metabolism, nitrogen bacteria and nitrogen archaea bacteria communities in rhizosphere was syudied by means of high-throughput sequencing and spectrophotometric method. Specific results are followed. First, at the growth period with increasing amounts of potassium, the relative abundance of denitrifying bacteria and nitrate reducing bacteria decreased while the ability of reducing nitric nitrogen decreased. Second, available nitrogen was higher and increased by 20.9% than control when N:K2O=1:2.1. Third, the quality of tobacco which was revealed by chemical ingredient was higher when N:K2O=1:2.1. Fourth, at later maturing period, the nicotine was out of suitable range while sugar and potassium were below, which resulted in decreased upper leaves quality. But at the same time, total nitrogen decreased at N:K2O=1:3.5-4.2, along with urease activity. These results showed that different potassium levels affected not only community structure of nitrogen bacteria and nitrogen archaea, but also nitrogen availability and enzyme activity, which further resulted in changes of leaf quality and quantity. It was suggested that N:K2O=1:2.1(236.25kg K2O per hectare) could be applied to increase nitrogen utilization in soil, and dressing potassium fertilizer after topping would be required to altere rhizosphere condition and improve leaf quality.
WENG Zebin, PENG Shiwen, WANG Shumin, HE Dongdong, ZHENG Guojian, XU Chensheng, CAI Haiyang, LIU Hong, CHEN Zhihou. Effect of different potassium levels on nitrogen metabolism, nitrogen bacteria and nitrogen archaea bacteria communities in rhizosphere of tobacco plant[J]. Acta Tabacaria Sinica, 2018, 24(2): 39-47.