| The study adopted the organic and inorganic compound fertilizer, manure and straw compostfertilizer to improve soil fertility and soil microbial communities. A field experiment(The experimentstarted in wheat season2010) was carried out on Dezhou farmland which sets6treatments, namelywere CK (no fertilizer), CF (NPK), OF (70%NPK+organic fertilizer3000kg/hm2), FS (NPK+straw+straw-decomposing inoculant150kg/hm2), OI1(Organic inorganic compound fertilizer11800kg/hm2),OI2(Organic inorganic compound fertilizer23600kg/hm2). Based on the surface layer soil samples ofwheat and corn harvest in2012and2013, the thesis systematically analyzed the reactions of microbialecology changes to different fertilization. Main research results were shown as follows：1. Effects of different fertiling treatments on soil properties and production shown: Soil organicmatter, Total N, available K, and available P in all fertilization treatments are higher than no fertilizertreatment. The indexes in FS and OF treatment are significantly higher than CF treatment, besides,organic and inorganic fertilizer treatment have little difference with that of CF. Available K, available Pwere obviously promoted by the FS, OF and OI2treatment. In all kinds of fertilization treatments pHwas slightly decreased, that was to say, pH of CF treatment was lower than that of CK, and soil pH ofFS and OF treatment were lower than that of CF. The order of total nutrient content was FS> OF> OI2>OI1> CF> CK. It could be seen from the wheat and corn production changes that in2012and2013,wheat and corn production in CF treatment increased49.04%,37.92%,23.12%and30.96%than thatof CK. The wheat production in OF and FS treatment is2%-9%higher than CF treatment, and there isno significant difference in the production of organic and inorganic fertilizer treatment (OI1and OI2)with CF treatment. In all kinds of treatments the production in FS treatment was the highest in wheatand corn season.2. The dynamic changes of enzyme activities during the growth period of corn2013demonstratesthat fertilization could increase the activity of the three enzymes, which showed strong regularity: Peakof the soil catalase activity appeared at jointing stage of corn，while the peaks of soil cellulase andurease activity appeared in large bell of corn. The activities of the three enzymes were all higher in FSthan that of others during the whole corn growth period. The analysis of soil nutrients and yieldsreflected that FS and OF treatment achieve the best result, OI2、OI1and CF treatment followedrespectively, and the CK was the last. Significant positive correlation was found between the yields andthe soil available nutrients, as well as the enzyme activity in peak and large bell of corn season2013.3. Microbial quantity: in wheat season and corn season, the microbial quantity in all kinds offertilization treatments was higher than that of CK, and the microbial quantity in FS and OF treatmentare better than other treatment. PCR-DGGE result showed that, there were small changes and high similarity in soil bacteriaduring2012and2013, which showed no special bands. But, fungi had obvious changes in DGGE. CKtreatment contains fungi bands most, CF treatment came second, and other fertilizer treatments bandsfollowing. Special band appeared in fungi, the Pseudogymnoascus, is psychrotrophs producing cellulase.Coprophilous, takes animals (especially herbivores) manure as growth substrate and has decomposedmanure capabilities.4. Biolog-Eco results indicated that the average well color development (AWCD), microbialspecies richness index(H), evenness index(E) were different in various fertilization treatment. Theactivities in all kinds of treatments were significantly higher than that of CK.Among that, the FS and OFtreatment were the highest. The comprehensive primary component values of wheat and corn harvestshow that FS and OF treatment was positive, and others’ treatments were negative in all the season. Theprincipal component analysis (PCA) showed that, CK and CF, OF and FS, OI1and OI2were similar incarbon source utilization. Four PCA maps revealed that, FS and OF treatment located on PC1and PC2positive side, while CK and CF treatment located on PC1and PC2negative side, and OI1and OI2located on PC1negative side and PC2positive side respectively. It showed that there are similarities indifferent fertilizer treatments and the trend of microbial functional changes has similarity in2-yearsfertilizer treatment.5. The results of454sequencing indicated that the fungi OTUs covered97.71%-99.34%of the soilfungi, including Ascomycota, Basidiomycota, Chytridiomycota, zygomycetes, Glomeromycota, andothers. The Ascomycota was the highest abundance in soil. The fungal diversity index (Chao1) and theevenness index (ACE) in CK were the highest, while the lowest in OI2. The Chao1and ACE in FS, OFand OI1were lower. In the meantime, the index of CF was closer to that of CK. By hierarchicalclustering of the genetic relationship of the soil fungus, we found that the OI1and OI2had close geneticrelationship, while FS、OF and CF had closer genetic relationship, but not the CK.6. The results of Illumina sequencing indicated that OTUs cover the68.4%-72.1%of the soilbacteria and archaea. Proteobacteria was the largest phyla in bacteria, which covered28.4%-30.80%inthe soil samples of different kinds of fertilization, and each fertilizer treatment in dealing withindividual flora was different from the other one. Crenarchaeota, Actinobacteria, Firmicutes,Proteobacteria bacterial abundance in CK are significantly lower than other fertilizations, whileVerrucomicrobia, Acidobacteria, Gemmatimonadetes, Bacteroides and Planctomycetes had higherproportions than other fertilizers. OP11was not found in CK and FS, and OD1is not in OI1. Both ofthem were anaerobic bacteria, and they had very low proportions in all microbial community. Thehierarchical clustering of genetic relationship of soil fungus indicated that OI2and FS, CK and CF, OI1and OF had close genetic relationship. |
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