Effects Of Chinese Onion And Malus Hupehensis Rehd. Seedling Mixed Cropping On Replanted Soil Environment

Effects of Chinese onion and Malus hupehensis Rehd. Seedling mixed cropping on the environment of soil microorganism and physiological characteristics of Malus hupehensis Rehd. seedlings were investigated in pot experiments from February 2014 to November 2015. Tests were started in research center of apple engineering technology, school of horticulture science, Shandong agricultural university. The experiments included four kinds of treatments: apple replant(CK), methyl bromide sterilization(T1), lime nitrogen sterilization(T2) and mixed Chinese onion(T3). The results of the research were introduced as follows:1. Chinese onion and tree mixed cropping enhanced the physiological characteristics of Malus hupehensis Rehd. In July, August and September, the three treatments of methyl bromide sterilization, lime nitrogen sterilization and mixed chinese onion increased the plant height, ground diameter, fresh weight and dry weight of Malushupehensis Rehd. compared with apple replant. The physiological characteristics of Malus hupehensis Rehd. were showed in order as follows: methyl bromide>lime nitrogen>mixed chinese onion>apple replant. The plant height with chinese onion and tree mixed cropping increased by 67.26%, 42.33% and 47.89% respectively compared with the control group in July, August and September. The ground diameter increased by 18.83%, 67.28% and 22.20% respectively compared with the control group. The fresh weight increased by 100.24%, 263.14% and 46.48% respectively compared with control group and the dry weight increased by 189.17%, 198.84% and 95.45% compared with the control group.2. Chinese onion and tree mixed cropping significantly improved the root respiration rate of Malus hupehensis Rehd. In July, August and September, methyl bromide sterilization, lime nitrogen sterilization and mixed chinese onion increased the root respiration rate compared with apple replant. The root respiration rate of Malus hupehensis Rehd. was showed in order as follows: methyl bromide>mixed chinese onion>lime nitrogen>apple replant. The root respiration rate with methyl bromide sterilization increased by 143.09%, 83.15% and 66.13% respectively compared with the control group. Lime nitrogen sterilization increased by 68.22%, 49.54% and 14.54% respectively compared with the control group and mixed chinese onion increased the root respiration rate by 96.29%, 58.02% and 19.68% compared with the control group.3. Chinese onion and tree mixed cropping exhibited higher activities of antioxidant enzymes including superoxide dismutase(SOD), catalase(CAT) and peroxidase(POD). In July, August and September, methyl bromide sterilization, lime nitrogen sterilization and mixed chinese onion increased antioxidant enzymes compared with apple replant. The activities of antioxidant enzymes were showed in order as follows: methyl bromide>mixed chinese onion>lime nitrogen>apple replant. The superoxide dismutase(SOD) with mixed chinese onion increased by 19.79%, 174.18% and 92.29% respectively compared with the control group in July, August and September. Peroxidase(POD) increased by 301.14%, 579.27% and 380.96% compared with the control group and catalase(CAT) increased by 148.83%, 141.48% and 92.96% compared with the control group.4. Chinese onion and tree mixed cropping significantly increased the activity of soil enzymes which included uerase, invetase, phosphatase and catalase. In July, August and September, mixed chinese onion increased the uerase by 202.33%, 35.96% and 19.81% respectively compared with control group. Invetase increased by 28.21%, 12.00% and 127.66% respectively compared with control group. Phosphatase increased by 2.12%, 12.45% and 35.22% respectively compared with control group and catalase increased by 75.00%, 90.00% and 21.43% respectively compared with control group.5. Compared with the control group, the quantity of soil bacteria and actinomycete were increased and the quantity of soil fungi were decreased. In July, August and September, the quantity of soil bacteria were showed in order as follows: mixed chinese onion>lime nitrogen>methyl bromide>apple replant. Mixed chinese onion increased the quantity of soil bacteria by 282.93%, 144.19% and 200.00%. The quantity of soil fungi were showed in order as follows: methyl bromide<mixed chinese onion<lime nitrogen<apple replant. Mixed chinese onion decreased the quantity of soil fungi by 45.19%, 79.03% and 59.38% respectively compared with control group.6. Chinese onion and tree mixed cropping had an obviously effect on fungal community. The margalef index, shannon index and pielou index increased by 48.38%, 23.16%, 8.44% respectively and simpson index decreased by 43.04% significantly. The number of Fusarium oxysporum was reduced significantly compared with the control group.7. With the change of time, the content of total phenolic acids was declined in the earlier days and then raised when prolonging storage time. The content of phenolic acids was least in August compared with the other two months. Apple replant had higher content of phenolic acids compared with the other three treaments. Apple replant had higher content of Gallic acid, Chlorogenic acid, Catechin, Benzoic acid and Phlorizin. In a word, Chinese onion tree mixed cropping had less content of phenolic acids compared with apple replant and it had least content of phenolic acids in August.