Effects Of Aspergillus Niger Fermentation Liquid On Phosphorus Reutilization And Growth Of Wheat Seedling In Calcareous Soil

In order to study the effects of Aspergillus niger fermentation liquid with threedifferent dilution ratio （They are50,100and150,those treatments could be definedas T50,T100and T200）on the growth of wheat in calcareous soil, we potted Xiaoyan22(Triticum aestivum) wheat seedlings under four different soil conditions:addedbroth which was diluted50,100,200times respectively(T50,T100and T200), and addedwater (CK).Compared the three kinds of fermented liquid concentration on somebiochemical (Chlorophyll content, Nitrate reductase activity and root activity) andphysiological characteristics(root length, phosphorus content of plants and biomass)of Wheat with the control group, we chosed the most proper concentration offermentation liquid. Then studied the influence of this concentration of fermentationbroth on available phosphorus content change in calcareous soils planted withwheat.By the means of HPLC and Mo-Sb colorimetry, we explored the effect ofAspergillus niger broth on insoluble phosphorus reusing in calcareous soil and thegrowth of wheat, the results were as follows:1Aspergillus niger fermented in corn starch medium for72h,the product ismixed natural organic acid mainly contained citric acid.The main carbon source usedfor fermentation was reducing sugars;and with medium pH descended theAspergillus niger mycelium dry weight was increased,When the organic acidproduction reached a maximum value,cell growth reached the top.The total acidproduction rate in200ml of the fermentation medium was128.4mg.2The broth was diluted100times(T100) increased the total content ofchlorophyll in wheat; promoted Nitrate reductase activity both in leaves and roots ofwheat; significantly (P <0.05); total phosphorus content of wheat seedling increased61%and ground-biomass accumulation increased21%. The Aspergillus nigerfermentation broth diluted to100times (T100) for watering was the most suitableconcentration.After using this concentration of fermentation liquid, soil availablephosphorus content increased by122%,soil total P–content declined more than the control group; the wheat total phosphorus content increased36.3%more than thecontrol;It also had an obvious inhibitory effect on the wheat root phosphate enzymeactivity. The results of correlation analysis showed that: Afte the application offermentation liquid, soil available phosphorus content and the phosphatase activitysecretion by wheat root and soil,had a significant negative correlation at0.01level,compared to the control group, the relationship between those were enhanced. Soiltotal phosphorus and available phosphorus content also had an significant negativecorrelation at0.01level.