Microbial Characteristics Of The Calcareous Purple Soil Affected By Different Hedgerows

In this paper, we studied the effect of hedgerows, including Vetiveria zizanioides hedgerow, Amorpha fruticosa hedgerow and hedgerow-free soil in the slope farmland at Ziyang, on the amount of the three sorts of microbes, capacity of soil ammonification and soil nitrification, together with PCR-DGGE methods, were employed to evaluate the differences among three treatments. The results are as follows:(1) Hedgerows planted in the slope farmland can increase the number of the three microbes effeetively.Compared with the control,the number of bacteria and actinomyeetes of Amorpha fruticosa hedgerow are more,it's up to 6.79x105 cfu-g-1 and 1.57×105 cfu-g-1,respeetively.To the fungi, the number of Vetiveria zizanioides is 3.61×102 cfu·g-1,it's greater than that of Amorpha fruticosa treatment and control.(2) The amount of soil ammonification in both Vetiveria zizanioides and Amorpha fruticosa are much higher than that in control.Compared with the control, in the Sampling points 1-3,Vetiveria zizanioides increase the amount to 300.46%; while Amorpha fruticosa increase the amount to 201.72%% in the Sampling points 3-4.However,the soil nitrification of Vetiveria zizanioides and Amorpha fruticosa treats are lower than that of the control, Compared with the control, in the Sampling points 1-3,Vetiveria zizanioides reduce the amount of 65.16%; while Amorpha fruticosa rduce the amount of 47.82% in the Sampling points 3-4.Overall,the amount of ammonification of Vetiveria zizanioides is higher than that of Vetiveria zizanioides, but the amount of nitrification is on the contrary.(3) Total bacterial genomic DNA is extracted for PCR-DGGE profile. The analysis of the profiles showed indigent types of bacterial communities, which indicate that the soil bacteria are not very diversy. The DNA sequences of 12 main bands are analyzed and the most representative bacterium are belonged to acidobacteria, Sphingobacteria, Chloroflexi,betaproteobacteria and uncultured bacteria.(4) In the PCR-DGGE analysis of Ammonia-oxidizing bacteria (AOB), the profiles show indigent types of AOB communities, which indicate that the AOB of the soil samples are not very diversy. The DNA sequences of 11 main bands are analyzed and all of the representative AOB are belonged to Nitrosospira,there is no Nitrosomonas.(5)For the Fungi DGGE profile, there are a great deal of bands with high brightness, which show great variation among different treatment. The DNA sequences of 17 main bands are analyzed and the phylogenic tree is constructed, the results suggest that these fungi mainly distributed in the 10 phylogenetic branches.(6)For the arbuscular mycorrhizal fungi(AMF)DGGE profile, there are lots of bands with high brightness, which show great variation among different treatment. The DNA sequences of 17 main bands are analyzed and the phylogenic tree is constructed, the results suggest that all of the AMF belongd to Glomus.most of them are Glomus mossea and Glomus caledonium, and a small amount is Glomus clarum,in addition,there are some AMF uncultured embodied in NCBI.