Effects Of Tillage On Soil Fungi Diversity In Maize Field

The diversity of soil fungi in 13 maize fields treated by subsoiling tillage and strew returning treatment were studied used the method of dilution plate and straw tissue colonization in 13 Chinese provinces from 2010 to 2015.At the same time,the fungi were identified by morphological identification,and the main results of this study are as follows:1.Compared with the conventional rotary tillage,the non-pathogenic,pathogens and beneficial fungl in the deep plowing soil were increased year by year.The number of non-pathogens was the highest,followed by pathogens,and the number of beneficial fungl was the least.The vertical distribution of non-pathogenic,pathogens and beneficial fungi by subsoiling tillage in maize fields soil is 0-10cm>10-20cm>20-30cm.(H ’-2.9662),and the distribution of non-pathogenic,pathogens and beneficial fungl during the growth period of maize is tassel>jointing>pre-sowing.The highest Diversity index and the highest Evenness index was Nanning test station of Guangxi(H ’= 2.9662;J = 1.0698),the highest Richness index was Taonan test station of Jilin(R = 5.7727).and the similarity index of soil fungi was between 0.1578 and 0.7273.2.The colony density of non-pathogens,pathogens and beneficial fungus under straw returning treatment was much higher than that of rotary tillage,and the number increased year by year.The colony density and increment of non-pathogenic were the highest,and the colony density of pathogens and beneficial fungus was similar,and the increase of colony density of beneficial fungl was greater than that of pathogens.The density of colony decreased from the sowing period to the jointing period,and increased from the jointing period to the tassel period.The highest Diversity index and the highest Richness index was Mianyang test station of Sichuan(H ’-4.7921;R = 5.3640),the highest Evenness index was Taonan test station of Jilin(J = 1.3912).and the similarity index is between 0.0435 and 0.5556.3.A total of 1971 strains of fungi were isolated and identified from 12 soil samples of maize field by subsoiling tillage,and 52 strains were classified as non-spore groups.The other 1919 fungi belonged to 41 generas,including 6 genera of Zygomycota,accounting for 9.49%,3 genera of Ascomycete,accounting for 1.78%,34 species of asexual fungi,accounting for 86.10%.The dominant species of soil fungi in maize field of subsoiling tillage were Fusarium,Penicillium,Trichoderma and Aspergillus,respectively.The isolation frequency of Fusarium was 15.98%,the separation frequency of Penicillium was 15.93%,the separation frequency of Trichoderma was 15.83%,and the frequency of Aspergillus was 12.94%.A total of 1824 strains of fungi were isolated and identified from 6 soil samples of maize field by strew returning treatment,and 45 strains were classified as non-spore groups.The other 1779 fungi belonged to 39 genera,including 6 genera of Zygomycota,accounting for 9.65%,3 genera of Ascomycete,accounting for 2.30%,34 species of asexual fungi,accounting for 85.58%.The dominant species of soil fungi in maize field of strew returning treatment were Trichoderma,Fusarium,Aspergillus and Penicillium,respectively.The isolation frequency of Fusarium was 15.35%,the separation frequency of Penicillium was 12.86%,the separation frequency of Trichoderma was 15.63%,and the frequency of Aspergillus was 13.53%.