盐胁迫对设施土壤微生物量碳氮和酶活性的影响

Effect of Salt Stress on Carbon and Nitrogen of Microbial Biomass and Activity of Enzyme in Greenhouse Soil

采用室内恒温培养法,以合肥地区的黄褐土为研究对象,研究了盐分对土壤微生物量碳、氮和土壤酶活性的影响。试验设置了4个不同盐分(0.3%,0.6%,0.9%,1.2%)处理和对照处理,在25℃恒温培养箱中培养了75d,分别在15,30,45,60,75d取样分析。结果表明,随着盐分浓度的升高,微生物量碳、氮显著降低,其中培养45d时盐分的抑制作用最为明显,相对于空白处理,1.2%处理的微生物量碳、氮抑制率分别为65.62%和57.68%;盐胁迫对土壤酶活性的抑制作用明显,盐分浓度越高,土壤酶活性越低。对脲酶、蛋白酶、碱性磷酸酶和纤维素酶的抑制作用相对较大,培养75d的1.2%处理的纤维素酶活性抑制率为62.20%。土壤微生物量碳、氮与土壤酶之间均有很高的线性相关性。

An indoor thermostatic incubation experiment was carried out to investigate the effect of salt stress on microbial biomass carbon and nitrogen content and enzyme activity of yellow cinnamon soil in Hefei area.In this experiment,a control treatment（CK）and 4salt stress treatments with different salt contents（0.3%,0.6%,0.9% and 1.2%）were set up,which were incubated for 75 dunder 25 ℃in greenhouse.Soil samples were collected separately on the 15 th,30th,45 th,60th and 75 th day of incubation and then analyzed.The results showed that with the increasing salt concentration,soil microbial biomass C and N content decreased,and the negative effects of salt stress was the most significant on the 45 th day of incubation.Treatment D（salt content：1.2%）reduced soil microbial biomass C and N by 65.62% and57.68%,respectively,compared to CK treatment.Salt stress had significant inhibitory effect on soil enzyme activity,with the activities of enzymes decreasing with the increasing salt content of experimental soil.The inhibitory effect of salt stress was more significant on urease,protease,alkaline phosphatase and cellulose.On the 75 th day of incubation,treatment D（salt content：1.2%）reduced cellulose activity by 62.20%,compared to CK treatment.Correlation analysis indicated that soil microbial biomass C and N were highly linear with the activities of soil enzymes at the same level of salt stress.