Effects Of Planting Plants On Soil Microbial Species After A Slope Hill To A Terrace Landform

Land remediation can destroy soil structure and ecosystem,leading to a decrease in soil quality.As a sensitive ecological indicator,soil microorganisms can quickly respond to changes in the surrounding environment.Previous researches are mostly focused on the impact of land consolidation on the ecological environment in the project area,however,there are none or few studies on influence characteristics and mechanism of planting on soil microbial communities after land consolidation.In this study,corn,soybeans and apple trees were planted to study the characteristics of the effect of planting on soil characteristics and microbial communities after the conversion of a hillslope to a terrace landform.Redundancy analysis was used to analyze the relationships between both soil characteristics and microbial dominant species and diversity characteristics.Then,the effect of planting on improving soil microbial communities and diversity after the conversion of a hillslope to a terrace landform was exploreed.The main results are as follows:(1)Planting plants has a significant(p < 0.05)effect on soil mechanical composition.The soil total carbon and organic carbon content and p H value were significantly(p < 0.05)different from those under the control.Soil C/N and available phosphorus and soluble salt contents were significantly(p < 0.05)lower than those under the control.Generally,soil total nitrogen,available nitrogen,and available potassium contents were significantly(p < 0.05)higher than those under the control.(2)The OTUs ACE and Shannon indexs for bacterial community were significantly(p< 0.05)lower than those under the control.The OTUs,and ACE index for fungal community were significantly(p < 0.05)different from those under the control,and the Shannon index was significantly(p < 0.05)higher than those under the control.The OTUs and ACE,Simpson,and Shannon diversity indexs for ammoxidizing bacteria(AOB)and ammoxidation archaea(AOA)communities increased significantly(p < 0.05)compared to those under the control.(3)Proteobacteria was the predominant flora in soil bacteria and AOB communities.Ascomycota was dominant in fungal community.Thaumarchaeota was only one detected in AOA community.Planting corn and apple trees increased the relative abundance of somedominant bacteria such as Rhizobiales and Sordariales but reduced the relative abundance of some dominant bacteria such as Sphingomonadales and Hypocreales.Soil microbial communities showed significant differences(p < 0.05)at the dominant genus.The soil AOB and AOA communities structure gradually changed to singularity.(4)There were significant(p < 0.05)positive correlations between soil nitrogen content and the diversity of soil bacteria,AOB,and AOA communities.There was a strong negative correlation between available phosphorus and fungal diversity.Soil available phosphorus has a significant(p < 0.05)effect on the bacterial dominant genus.Soil total carbon was a main factor on the composition of fungal community and the dominant genera in AOA community.Soil nitrogen content is the main factor affecting the composition of AOB species dominant genus.(5)In general,the plant types and planting years after the conversion of a hillslope to a terrace landform had significant(p < 0.05)effects on soil microbial community structure and diversity.Soybeans after land consolidation might be the preferred plant type to improve soil physical,chemical,and biological characteristics.