Effects Of Different Fertilization Treatments On Soil Biological Properties And Yield Of Camellia Oleifera Forest

Camellia oleifera.Abel is an important woody oil species in China,which has great cultivation value and exert as excellent breeding germplasm.The soil microbial community structure reflect the change of soil quality and is thus considered to be one of the most potential sensitive biological indicators.At present,researches on the biodiversity in soil involved in C.oleifera forestland are relatively few,whereas the traditional culture methods are unable to outline the community diversity and structural characteristics of soil microorganisms.Therefore,it is necessary to study the soil microbial diversity in C.oleifera forestland by using molecular technology on genetic level.In this study,in order to explore the soil dominant microbial community in C.oleifera forestland,high-throughput sequencing was used to analyze the soil microbial community structure and diversity in C.oleifera forestland applied with different fertilizers,and the differences between soil chemical properties and microbial community structure of C.oleifera forest were compared,which may provide theoretical basis for scientific and rational fertilization as well as the application of C.oleifera organic fertilizer.The main findings are as follows:1.The soil chemical properties in different fertilizer treatments were significantly different;water-soluble organic carbon,total nitrogen,alkali-hydrolyzed nitrogen,available potassium,calcium,magnesium and zinc in the of C.oleifera specific organic fertilizer treatment(SF)were significantly higher than those in the municipal general fertilizer(GF)and control(CK).Nitrate,ammonia nitrogen,total phosphorus,available phosphorus and organic matter increased after fertilizer application,however,there were no significance among these treatments.These results indicated that fertilizer could significantly improved the soil nutrient conditions in C.oleifera forestland.2.The dominant bacteria phyla of soil bacteria in C oleifera forestland under different fertilizer treatments were composed of Actinobacteria,Chloroflexi,Proteobacteria,Acidobacteriota and Firmicutes;The fungal dominant fungi phyla were Ascomycota,Basidiomycota,unclassified_k_Fungi,and Mortierrellomycota.This study showed that there were significant differences between the microbial community in the SF,GF and CK in C.oleifera forestland soil.3.The richness and evenness index(Sobs?Ace?Chao)of bacterial diversity among all the treatments showed a trend of GF>CK>SF,and the Shannon diversity index exerted a variation trend of GF>CK>SF,but the difference was not significant(p<0.05).The order of the three indexes of fungal richness and evenness was CK>GF>SF,and GF>CK>SF in Shannon index.The highest level in four diversity indexes of bacteria and fungi were found in the SF treatment.4.Under different fertilizer treatments,soil chemical factors including available nitrogen,available phosphorus,organic matter,water-soluble organic carbon had great influence on bacterial community,whereas soil properties including available phosphorus and total phosphorus had great influence on fungal community.There was a great positive correlation between total nitrogen,total phosphorus,available potassium,water soluble organic carbon and the fungal community in the SF treatment.5.The yield of C.oleifera fruit was significantly increased after fertilizer treatments,among which,the yield improvement of C.oleifera SF was the best,compared with that of GF,with the highest yield per plant increased by 13.95%,and the oil yield of fresh fruit increased by 2.99%.In conclusion,this study showed that there are significant differences in soil chemical properties,microbial community structure and yield of C.oleifera under different fertilizer treatments,and the relationship between microbial community structure and diversity and related nutrient elements is different.The relationship between bacterial dominant community and phosphorus is closer,while fungi and potassium are more closely related.Therefore,the research and improvement of special organic fertilizer should be considered as the key problem in the future.