Effects of Phosphorus Fertilizer Application On the Community Structure of AMF Infected In Soybean Roots.

In generally, it is well known that if the content of phosphorus in field soil became high, the infection rate of AMF was lower. But, it is not clear that the high phosphoric acid concentration in soil effect AMF community structure or not. We clarified that effects of phosphoric fertilizer application on AMF community structure in which was infected in soybean roots. The field experiment was carried out in 3 fields. Three fields are located in Fujisawa and Hiratsuka city, Kanagawa in Japan. Soil types of the fields are andosol (Fujisawa) and gray lowland soil (Hiratsuka). Used phosphoric fertilizer in this experiment was super phosphate, and application rate was 0kg(P0 plot), 100kg(P1 plot) and 200kg(P2 plot) per ha. Soybean seeds (variety: Enrei) sowed in May 10 or 16, 2007. And sampling date was July 26th, 2007. When amount of super phosphate application increased, the available phosphorus content in field soil rose and infection rate of AMF lowered in all field. But, the difference of phosphorus content and dry matter weight of soybean shoot was not between plots. The number of AMF OUT in P0 plot soybean roots was 17, 11 and 8, respectively and that beamed 15, ‚W and ‚V in P2 plots, respectively. The composition of AMF OTU that was infected in soybean roots was different between P0 plot and P2 plot. Concretely, there were two types of OTU in which the composition proportion decreasediScu2,Glo2, 9 and 11jor increasediGlo8, 10,12 and 13jat P2 plots. However, there was hardly a difference on the diversity index and evenness index of the AMF in P0 and P2 plots. From the above fact, it was considered that the application of phosphoric fertilizer was affected in the AMF composition, but not be affected in the diversity of AMF in soybean roots.