Effects Of Inoculation AMF On Soil Phosphorus Forms And Crop Responses Under Different P Levels In Abandoned Coal Mining Area

To screen the highest efficiency of arbuscular mycorrhizal fungi(AMF)on soil P availability and determine the reasonable amount of fertilizer P addition,a pot experiment was conducted to study the effects of inoculation with three species of AMF alone and its combination,including Glomus intraradices,(G.i),Glomus mosseae(G.m),and Glomus etunicatum(G.e),respectively and the combination of three species of AMF,on soil phosphorus(P)forms and maize biomass.The soil was collected from an abandoned coal mining soil of JinShanPo,located in LianFu Town,JieXiu City,ShanXi Province.Theresults showed that:(1)Both the two factors and its interaction of different P levels and inoculation of AMF had significant effect on the infection of AMF to maize root.The effect of AMF inoculation on maize root infection was different depended on the species of AMF.Of the inoculation AMF treatment,the combination of three species(3G)had the highest effect on root colonization and infection density in.maize,while the highest abundance of AMF was observed in inoculation with G.m alone.Effect of maize infection varied with Phosphorus levels.The highest effect was observed at the level of 25 mg/kg P on the infection density,root colonization,and the abundance of AMF in maize,with 10.09%,51.63%and 4.50%respectively.(2)The growth of maize was closely related to the level of phosphorus and with or without AMF inoculation,the maize aboveground biomass and total biomass had the maximum values at 50mg/kg phosphorus levels(8.58g and 14.65g),which significantly increased by 63.12%and 56.35%,respectively relative to those of no P addition treatment whereas the underground biomass of maize achieved the maximum value(6.76g)at 25 mg/kg P level,which was 64.47%higher than that without P addition treatment.Of AMF treatment,the inoculation with G.m alone had the maximum values on aboveground biomass and total biomass of maize(8.37g,14.75g)with 37.66%and 30.30%increase than those of G.e inoculation alone,and with 39.97%and 36.07%increase than no AMF treatment.(3)Of the tested two factors,inoculation with AMF and P levels and the interaction of them had significant effects on the content of soil Olsen-P and alkaline phosphatase activity,as well as the uptake of P in maize in this experiment.At 50mg/kg P level,soil Olsen-P content,alkaline phosphatase activity and the P uptake of maize had the largest values with 37.61mg/kg,1.08mg·g-1·24h-1 and 6.78mg/kg,respectively.The inoculation with G.m treatment achieved the highest values on soil alkaline phosphatase activity,Olsen-P content and the P uptake of maize,which increased by 14.16%、15.01%and 11.21%,compared with the inoculation with 3G combination,and increased by 41.03%、29.92%and 29.24%relative to no AMF treatment.(4)Soil P content in Hedley forms except for residual P was varied with the addition of P levels with an increase first then having a decreasing trend.Soil H2O-Pi,H2O-Po,NaHCO3-Pi and NaHCO3-Po had the highest values at P level of 50 mg/kg with 18.95mg/kg,7.53mg/kg,70.72mg/kg,31.82mg/kg,respectively,which were 2.34,1.94,5.31,and 2.27 times higher than those of no P addition treatment,but inoculating G.e.alone had the highest value on soil H2O-Pi(14.92mg/kg)and NaHC03-Pi(37.87mg/kg)at the P level of 25mg/kg.(5)To summarize,the combination of inoculating G.m at 25mg/kg P level was the most efficient,economical,and the optimal treatment to reclaim the abandoned JinShanPo coal-mining soil in this area.