Arbuscular mycorrhizal fungal communities and Rhizophagus irregularis populations shift in response to short term ploughing and fertilisation in a buffer strip.. Running tittle: Shift of AMF communities under short term agricultural practices.

We studied the short-term effects of soil physical disturbance by ploughing and nitrogen and phosphate fertilisation on arbuscular mycorrhizal fungal (AMF) communities and on intraspecific populations of Rhizophagus irregularis in a buffer strip surrounded by arable fields. Pre-grown Plantago lanceolata plantlets were transplanted into fertilized and/or ploughed experimental plots. After three months, the glomeromycotan communities in the roots of these trap plants were analysed using 454 pyrosequencing of a fragment of the RNA polymerase II gene (RPB1). Intraspecific populations of Rhizophagus irregularis were studied by restriction fragment length polymorphism (RFLP) analysis of the mitochondrial large ribosomal subunit gene (mtLSU). Soil disturbance significantly increased diversity of species Molecular Taxa (MTs) and altered community structure, while fertilisation alone had no significant effect, unless coupled with ploughing. At the population level, the expected shift from genotypes of Rhizophagus irregularis typically found in grasslands to those usually found in arable sites was only partially observed. In conclusion, in the short term physical soil disturbance, as well as nitrogen fertilisation when coupled with physical soil disturbance, affected AMF community and to a smaller extent population composition.