The Influence Of Combined Application Of Short Rotation And Fungus Fertilizer On The Soil Environment Of Apple Replanted Orchard And Physiological Characteristics Of Malus Hupehensis Rehd. Seedlings

The experiment was investigated in the Nation Apple Experiment Center of Shandong Agricultural University from March 2014 to October 2015. The influence of combined application of one year short rotation and fungus fertilizer on the soil environment of 25 years apple replanted orchard and physiological characteristics of Malus hupehensis Rehd. seedlings was studied under pot condition. The effect and action mechanism of this comprehensive measures on apple replant disease was investigated. The main results were as follows.1. Short term rotation of different crops could increase the number of soil bacteria and actinomycetes, reduced the number of soil fungi. Shallot rotation could significantly increase the number of bacteria and reduced the number of fungi in the soil, which increased by 167.97% and decreased by 54.61% compared with the continuous cropping. The number of actinomycetes with shallot rotation was significantly higher than the other treatments, increased by 50.94% compared with continuous cropping. After a year of short rotation, shallot rotation treatment significantly improved bacteria/fungi ratio, which was 6.06 times of continuous cropping.2. Shannon index and Margalef index could be improved after short term rotation, Simpson index could be reduced. The Shannon index and Margalef index of the fallow treatment increased most significantly, which were 1.05 and 1.17 times of the continuous cropping. From PCA for T-RFLP patterns and Cluster analysis of T-RFLP patterns we could see that the effect of shallot rotation on soil fungal community structure was the biggest, which significantly changed the soil fungal community structure.3. Short term rotation significantly increased soil enzyme activity in continuous cropping soil. Compared to the control, the urease activity in the rotation of peanut, shallot, fallow and green grass respectively increased by 63.64%, 100.91%, 33.33% and 157.58%, the catalase activity respectively increased by 9.71%, 16.95%, 7.24% and 19.43%, the invertase activity respectively increased by 27.71%, 47.30%, 18.07% and 23.29%, the neutral phosphatase activity respectively increased by 91.67%, 51.11%, 63.78% and 37.78%.4. Compared to control, the number of bacteria and actinomycetes of fallow, natural grass, rotating peanut and rotating shallot combined with fungus fertilizer were significantly increased. The number of bacteria respectively increased by 86.82%, 126.28%, 110.50% and 189.42%, the number of actinomycetes respectively increased by 110.28%, 98.50%, 83.81% and 107.32. The results of T-RFLP showed that the treatment of short rotation and fungus fertilizer changed the fungal community of apple replanted orchard. The simpson index of soil was improved but shannon index, pielou index and margalef index were reduced significantly. It had the most significantly increase in plant biomass of M. hupehensis Rehd in the treatment of rotating shallot combined with fungus fertilizer.5. The combination of short rotation and fungus fertilizer could significantly increase the biomass of seedlings of Malus hupehensis Rehd. Compared to control, the plant fresh weight of fallowing and microbial fertilizer, natural grasses and microbial fertilizer, peanut rotation and microbial fertilizer, shallot rotation and microbial fertilizer respectively increased by 184.19%, 93.68%, 117.55% and 186.32%, the plant dry weight respectively increased by 205.17%, 99.22%, 131.01% and 205.94%, the plant height respectively increased by 70.68%, 38.68%, 44.00% and 58.68%, the rhizome roughness respectively increased by 34.14%, 16.59%, 27.07% and 33.17%.6. The treatment of shallot rotation and fungus fertilizer had the best index of the morphology of fine root of all. Compared with the control, total fine root length, total fine root surarea, total fine root volume and fine root tip number increased by 147.21%, 225.87%, 298.46% and 331.29% respectively. Rotating shallot add fertilizer also significantly increased root respiration rate, which increased by 131.02% than that of continuous cropping. Compared to the control, the SOD activity of fallowing and microbial fertilizer, natural grasses and microbial fertilizer, peanut rotation and microbial fertilizer, shallot rotation and microbial fertilizer increased by 43.70%, 47.97%, 39.51% and 46.22% respectively, the POD activity respectively increased by 97.13%, 51.29%, 93.97% and 110.49%. CAT activities of fallowing and shallot rotation were significantly higher than the other treatments, increased by 233.53% and 158.96% than continuous cropping respectively.7. Shallot root extract could inhibit the growth of Fusarium. The inhibitory rate of the root extracts and the extracts from the stems of green shallot was 37.84% and 22.42% respectively, and there was a significant difference between them. Therefore, shallot rotation can reduce the number of harmful fungi in the replant soil, thereby reducing the occurrence probability of apple replant disease.