Remediate Effects On Aluminum Toxicity By Using Four Soil Conditioners In Acid Soils

The problem of soil acidification is very serious in China south, aluminum toxicity caused byacidification is particularly serious. This research choose the oyster shell, dolomite, potassiumfeldspar and Maifanshi as raw material. By collecting soil incubation experiment, exogenous additionof aluminum test and potted plant experiment, we studied the effects of different soil conditioners andapplication rate on the morphology of aluminum in acid soil. Based on the physiological index ofmaize to evaluate the actual improvement effects of different treatments and provide scientific basisfor the application of soil conditioners in acid soil. The results indicated that the four kinds of soilconditioners had obvious effect on improving the acid soil and showed lasting remediate result forsoil pH value and toxicity aluminum. The remediate performance from high to low is dolomite, oystershell, potassium feldspar and Maifanshi. For the biological characteristics of corn, dolomite, feldsparand oyster shell showed marked increase effect, closely followed by Maifanshi. Specific conclusionsare showed as follows:(1) Four kinds of soil conditioners could significantly increase soil pH value. Dolomite showedthe best and longest effect, and the soil pH value continuously increased0.34to1.35units during theculture of70days, followed by oyster shell, potassium feldspar and Maifanshi. There was significantdifference between the different amount of soil conditioners, soil pH value under the applicationamount of0.4%was improved the largest, and maintained increase during incubating.(2) Four kinds of soil conditioners could significantly and persistently reduced the content of soilexchangeable aluminum and toxic aluminum, and the decrease effect was more remarkable with theincrease of application amount. Under the exogenous addition level of240mg/kg and480mg/kg, thesoil exchangeable aluminum content of dolomite treatment decreased with the prolongation of culturetime, which decreased by91.2%and74.7%respectively compared to the control treatment, followedby oyster shell (83.6%and53.7%), potassium feldspar (67.6%and30.3%), Maifanshi (36.9%and26.7%). For the application amount of0.4%,0.2%and0.1%of dolomite, the soil exchangeablealuminum content reduced by99.2%,77.9%and39.7%compared with control treatment.(3) Four kinds of soil conditioners significantly improved the shoot biomass, height, root weightand root length of corn, which increased with the increasing utilization of soil conditioners. The totalbiomass of corn were increased by3.84times,3.60times,3.49times and2.27times under0.2%application levels of dolomite, potassium feldspar, oyster shell and Maifanshi,.The four soil conditioners (oyster shells, dolomite, potassium feldspar and Maifanshi) were firststudied in this paper on the aluminum toxicity of acid soil. The conclusion will provide reference andbasis for the study on the mechanism of aluminum toxicity in acid soils and scientific application ofsoil conditioners.