Tobacco/garlic intercropping system improve chemical properties by
changing C,N cycling and plant degradation pathway in rhizosphere soil,
thus increase the tobacco plant biomass
Abstract
As the mechanism of the microbe-soil-tobacco interaction remains unclear
and the contribution of tobacco plant growth is still difficult to
predict, the chemical propertie and microbes of soil in tobacco/garlic
intercropping system, the relevance of the soil chemical properties and
the genes involved in C, N cycling and plant degradation (organic matter
turnover) were studied by metagenome sequencing. The results showed that
the intercropping treatment (T)significantly enhanced the content of
organic matter(OM) ,the available nitrogen (AN) , the available
phosphorus(AP) ,the available potassium content(AK), microbe number and
the microbial biomass nitrogen,as well as the activity of urease ,
phosphatase ,invertase compared to monocropping treatment (CK),
Especially the content of OM ,AN,AP,AK increased significantly by
29.46%,19.75%, 10.37%,17.42% in rhizosphere of T treatment than CK
treatment. The content of polyphenol oxidase activity and microbial
biomass carbon significantly decreased in T treatment with by 22.61%
and 9.03% relative to CK treatment. Metagenomic analysis showed that
the relative abundances of genes related to C cycling (ACA,sdhA,sdhB,
sucD, mdh) , N cycling (glnA)and plant degradation (bglX) were higher in
the T treatment than the CK treatment. Compared to the CK treatmen, the
relative abundance of ACA, sdhA, sdhB, sucD,mdh,glnA and bglX were
espectively 26.06%, 39.37%, 48.27%, 32.44%, 57.55%,14.28% and
2.39% higher in the T treatment. The intercropping system changed the
chemical properties as well as the abundance of microbes, and
subsequently regulate genes involved in C, N cycling and plant
degradation, these improved the soil environment and leaded to the
increase of tobacco plant biomass.