Effect Of Bio-organic Fertilizer On Enzyme Activities, Microbial And Nutrients Of Garlic Continuous Cropping Soil

The difference between traditional fertilizer and bio-organic fertilizer was studied bymeasuring the level of soil enzymes, soil microbe, soil nutrients and the nutrient accumulation ofgarlic bulbs in black soil area using field plot experiments. We also studied the improving effects ofthe bio-organic fertilizer on micro ecological environment and garlic quality.The result shows that the activities of soil urase, sucrase, catalase and acid phosphatase in thelate growth stage of garlic in the bio-organic fertilizing group are higher than in the traditionalfertilizing group. The activity of catalase in the late growth stage of garlic was higher than beforesowing. On the contrary, the activities of urase and sucrase were slightly lower. The activity of acidphosphatase was mostly steady during the life cycle of garlic.The activity of soil polyphenoloxidase after garlic harvesting was significantly decreased when bio-organic fertilizing was applied,while increased when traditional fertilizing was applied.The planting years greatly affects the quantity and proportion of soil microbe. The proportionof bacteria, fungi and actinomycetes in soil was seriously imbalanced due to long-term continuousropping of garlic, the quantity of fungi was abnormally higher than bacteria and actinomycetes theleast. The quantity of bacteria and actinomycetes in soil increased after bio-organic fertilizer wasused, especially in long-term continuous ropping soil. Comparing to traditional fertilizer,bio-organic fertilizer effectively controlled the quantity of fungi in soil, as it decreasedsignificantly.Bio-organic fertilizing can apparently improve the content of nitrogen, phosphorus, availablepotassium and available sulfur in soil. It worked even better when appling to45-60yearscontinuous ropping soil. The yield of garlic and the content of nutrients in garlic bulbs improvedgreatly after bio-organic fertilizing. The highest yield came from15years and15-30yearscontinuous ropping. The yield of garlic bulbs was extremely positive correlated to the activity of soil urase, thequantity of bacteria during seeding stage,the content of available nitrogen, available potassium andavailable sulfur in soil,and extremely negative correlated to the activity of soil polyphenol oxidase.It was also significantly negative correlated to the quantity of fungi during seeding stage.To sum up, the bio-organic fertilizing in continuous ropping soil of garlic could efficientlyimprove the microbial ecological environment of soil and the nutrient deficiency. It could alsoimprove the available nutrient content of garlic bulbs and the yield of garlic. This result couldguarantee higher quality and quantity of garlic production and helps solving the degeneration ofqualtity and quantity of crops due to long-term traditional fertilizing.