Study On Biological Effect Of Bacterial Manure Application Of Various Maize Varieties In Cd Contaminated Soil

The pot culture experiment was carried out to study the effect of different bacterial manure application of various maize varieties (Changyul6, Jindan56and Dazheng2) and remediation efficiency in1mg/kg Cd contaminated soil, in order to investigate whether the bacterial manure application has an effect on phytoremediation efficiency. The results showed that:(1) Under Cd (lmg·kg-1) stress, application of bacterial manure promoted the growth of maize at seeding stage. The bacterial manure application improved the plant height in maize at seeding stage from3.78%to31.99%. The treatment of Changhyu variety with200g/pot bacterial manure application showed the highest plant height. Maize with bacterial manure application had higher fresh weight than that without bacterial manure, and the increase rate of fresh weight ranged from23.64%-66.50%. The treatment of Jindan variety with100g/pot bacterial manure application showed the highest fresh weight.(2)Compared with CK, bacterial manure application improved the chlorophyll content and enhanced the net photosynthetic rate. In all treatment, the treatment of Dazheng variety with100g/pot bacterial manure showed the highest chlorophyll content, and the treatment of Dazheng variety with50g/pot bacterial manure application showed the net photosynthetic rate. The ability of photosynthetic capacity with Dazheng variety was very significantly higher than Changyu variety and Jingdan variety.(3) Application of bacterial manure improved the antioxidant enzyme activity (CAT activity. SOD activity and POD activity) of maize at seeding stage, and the increase rate of CAT activity ranged from2.08%-62.52%, the increase rate of SOD activity ranged from1.20%-30.50%, the increase rate of POD activity ranged from1.72%-15.43%. The promote effect of antioxidant enzyme activity with Jingdan variety was very significantly higher than Changyu variety and Dazheng variety.(4) Application of bacterial manure promoted the plant height and stem diameter of maize at mature stage, promoted the growth of maize, improved rate ranged from0.37%-25.00%. Bacterial manure application improved the Cd accumulation of maize, bacterial manure could accelerate the transfer of cadium to plants, and effectively reduce the Cd content in soil. The results indicate that combination of suitable bacterial manure application rate with suitable varieties of maize was possibly an efficient choice for enhancing remediation of soils contaminated. Changyu variety generally worked better than DZ and JD varieties, and the economic optimum application bacterial manure rate was100g/pot. The fertilizer application was possibly one of the efficient ways to enhance the efficiency of soil phytoremediation.Application of bacterial manure improved the Cd accumulation of maize from4.44%to36.07%. The treatment of Changhyu variety with100g/pot bacterial manure application showed the highest Cd accumulation in maize and the lowest Cd content in soil..(5) Compared with CK, application of bacterial manure improved the soil enzyme activity include alkaline phosphatase activity, catalase activity, sucrase activity and urease activity. The treatment of Jindan variety with200g/pot bacterial manure application showed the highest alkaline phosphatase activity. The treatment of Changyu variety with50g/pot bacterial manure application showed the highest catalase activity, and sucrase activity. The treatment of Jindan variety with50g/pot bacterial manure application showed the highest urease activity.(6) Under Cd (lmg-kg1) stress, most of Cd was existed in residual species. Application of bacterial manure reduced the organic-bound species and residual species, and improved the exchangeable and carbonated-bound species. The reason might be that bacterial manure changed the adsorption capacity of different Cd forms with soil.