关键词: 平邑甜茶, 连作障碍, SNB-86菌肥, 土壤酶活性

Abstract:

A biocontrol bacteria SNB-86 isolated from apple continuous cropping soil by confrontation method was identified as Bacillus subtilis. The biofertilizer was prepared by solid-state fermentation using SNB-86，and pot experiment was carried out with apple continuous soil potted Malus hupehensis Rehd. seedlings as the material. Four treatments were set：continuous cropping soil（control），continuous cropping soil fumigated with methyl bromide，biofertilizer carrier and SNB-86 biofertilizer treated soil in pot. The results showed that bioorganic fertilizer SNB-86 significantly increased 171.5% fresh weight and 142.3% dry weight of M. hupehensis seedlings，respectively. The M. hupehensis seedling height increased 97.9% and 25.3% in SNB-86 biofertilizer treated group than that in continuous cropping soil and biofertilizer carrier groups，respectively. The M. hupehensis seedling basal diameter increased 57.6% and 6.2% in SNB-86 biofertilizer treated group than that in continuous cropping soil and biofertilizer carrier groups，respectively. The growth of M. hupehensis seedling in SNB-86 biofertilizer treated group was not good as that in continuous cropping soil fumigated with methyl bromide group. Compared with continuous cropping soil，the number of soil bacteria and actinomycetes in biofertilizer carrier and SNB-86 biofertilizer treated groups increased. The number of soil fungi in SNB-86 biofertilizer treated group decreased significantly to 32.3% of continuous cropping soil，while biofertilizer carrier treatment had less influence on the number of fungi in continuous cropping soil，only 10% lower than that of the continuous cropping soil group. But bromomethane fumigation significantly reduced the number of microbes in soil，resulting in lower soil enzyme activity than continuous cropping soil group. The activities of sucrase，urease，catalase and neutral phosphatase were significantly increased by SNB-86 biofertilizer treatment and biofertilizer carrier treatment. The effect of SNB-86 biofertilizer treatment was most obvious，followed by biofertilizer carrier treatment. While the activities of sucrase，urease，catalase and neutral phosphatase in continuous cropping soil fumigated with methyl bromide were significantly decreased，respectively compared with that in continuous cropping soil group. It is concluded that SNB-86 biofertilizer can significantly promote the growth of M. hupehensis seedlings，increase the activity of soil enzymes，reduce the number of culturable fungi in the soil，and alleviate the obstacle of apple continuous cropping.

Key words: Malus hupehensis, replant disease, SNB-86 fertilizer, soil enzyme activity