脱硫废弃物改良宁夏盐渍化土壤对细菌和氨氧化微生物丰度的影响

为探明脱硫废弃物改良盐渍化土壤对微生物群落的影响效果,在2009~2010年,采用田间试验,施用不同量的脱硫废弃物(0、0.74、1.49、2.25、3.00 kg·m-2),研究了脱硫废弃物对盐渍化土壤细菌、氨氧化细菌和氨氧化古菌的影响。试验结果表明:0~20 cm土层,Ca2+和NO-3-N含量随着施用量增加而增加;土壤p H值、电导率值显著下降。实时荧光定量PCR(q PCR)分析结果表明,微生物丰度随着脱硫废弃物的施用发生变化,但这种变化并不与脱硫废弃物的施用量呈线性关系。在0~20 cm土壤层,施脱硫废弃物使得细菌16S rRNA基因拷贝数处理组显著高于对照组。氨氧化古菌与氨氧化细菌基因拷贝数在T2和T4处理高于其它处理。20~40 cm土层各处理间微生物群落没有显著变化,或没有出现规律的变化趋势。因此,脱硫废弃物增加了土壤细菌和氨氧化功能基因丰度,且对上层土壤影响更为显著。本研究中施用脱硫废弃物1.49 kg·m-2(T2)是引起细菌和氨氧化功能基因丰度增加的施用量。

Influence of flue gas desulphurization by products on abundance of soil bacteria,ammonia oxidizing microorganisms in saline soil in Ningxia province

To investigate the effect of flue gas desulphurization by products on saline soil microbial communities,a field experiment with five different levels of flue gas desulphurization by products (FGDB) gradient,which were 0,0.74,1.49,2.25,3.00 kg·m-2 respectively,was performed to examine the effect of FGDB on the soil bacteria,ammonia oxidizing bacteria and ammonia oxidizing archaea in 2009 and 2010.The results indicated that FGDB addition resulted in an increase in Ca2+ and NO-3-N and a decrease in pH and electrical conductivity.The results of real time quantitative PCR showed that the abundance of microbial community composition differed with different FGDB gradient but was non linear.Total bacterial 16S rRNA gene copy numbers were significantly higher in FGDB treatments than control.The abundance of ammonia oxidizing archaea (AOA) and ammonia oxidizing bacterial (AOB) in T2 and T4 treatments was higher than other treatments.There were no significant differences at 20~40 cm depth for microbial community.The addition of 1.49 kg·m-2 was a threshold value for improving soil bacterial and functional gene abundance.The effects of FGDB on soil microbial community were more effective in top soil than deeper depth.