Effects Of Fertilization And Planting Years On Vegetabke Quality And Soil Microbes

Vegetable plays an important role in our diet structure，its yield and quality areinfluenced by fertilization levels and types, planting years of vegetable field and so on. Withthe increase of planting years, the soil environmental quality will be changed, the applicationfor special bio-organic compound fertilizer could reduce the amount of fertilizer，meanwhile，improve the soil biological characteristic. This paper investigated the impacts of differentfertilizer levels and types on soil environmental quality by indoor simulated experiment. Thesoil of different vegetable planting years were collected on some fixed-point in Shaanxiprovince. The response of soil environmental to those influencing factors was main based onsoil physic-chemical properties, vegetable quality，soil enzyme activities and microbialfunctional diversity. The main results were summarized as follows.1. There was a significant effect on soil microbial communities functional diversity ofdifferent fertilizer application. Under the condition of the two fertilization levels，soilmicrobial carbon source utilization was improved enormously after applying bio-organiccompound fertilizer, and higher when the fertilization level was0.3g N/kg soil. Bio-organiccompound fertilizer and organic-inorganic compound fertilizer could increase the soildiversity and richness index, the amount of dominant species, meanwhile, reduce theuniformity. Fertilization reduced the utilization of amino acids carbon source utilization in soilmicrobial ability, and the main use of carbohydrates source microbial species level wereraised. After application special bio-organic compound fertilizer， the utilization ofcarbohydrates, amino acids, carboxylic acids were significantly higher than other treatments.2. There was a significant effect on soil enzyme activities of different fertilizerapplication. The application of bio-organic compound fertilizer could improve soil hydrolyseand oxido-reductase activities in different degree. When the fertilization level was0.3g N/kg soil, the activities of FDA and catalase in soil were enhanced by special bio-organiccompound fertilizer, and significantly higher than the application of organic inorganicfertilizer treatment which the fertilization levels was0.6g N/kg soil.3. Under the condition of the two fertilization levels, bio-organic compound fertilizer,organic inorganic fertilizer and inorganic fertilizer could significantly improved the content ofsoil available minerals, compared with the control. At the same time, soil available mineralsof special bio-compound fertilizer were the highest，except the nitrate nitrogen under0.3g N/kg soil fertilizer level. Bio-organic compound fertilizer had the best effect on reduced theaccumulation of malondialdehyde in pakchoi, when compared with control and the otherfertilization treatments. The application of bio-organic compound fertilizer and organicinorganic fertilizer could increase the content of vitamin C and decrease the content of nitrate,and the effect would be better in reducing the amount of using fertilizer.4. The10-year-old vegetable soil had the highest microbial carbon utilization efficiencyand had a signification activation of average well color development (AWCD) and Shannon,Simpson, McIntosh indexes compared to other years. The main use of carbon sources werechanged with different planting years, respectively for polymers, carbohydrates andcarboxylic acid. Principal component analysis demonstrated that carbon utilization by soilmicrobial communities changed in different planting years. The10-year-old soil treatmentwas located in the positive direction of the first principal component，and distinguish fromother planting years, the main carbon sources which played differentiation were carbohydrateand amino acids.5. Soil urease, FDA hydrolase, nitrate reductase and catalase activities increased withdifferent planting years, while soil dehydrogenase activity increased at first and thendecreased. The effect on the activities of soil invertase, alkaline phosphatase andpolyphenoloxidase in the10-year-old vegetable field were the strongest. Vegetable field soilEC, total nitrogen, total phosphorus, available nutrient and organic matter content increased atfirst and then decreased with the different planting years. Vegetable planting decreased thesoil pH.