Impact of evolutionary populations on soil organic matter characteristics

In Mediterranean areas, agricultural systems have to adapt to an environment presenting few water resources with severe drought events, which are expected to increase in frequency and intensity due to global warming. Therefore, these regions are particularly exposed to climate change and need to implement solutions in order to maintain food production.           
Our objective is to assess the benefits of innovative cropping systems capable to face these constraints. Evolutionary population are mixtures of plants of the same species presenting a high degree of crop genetic diversity needing lower inputs while allowing higher buffering capacities to adapt environmental stress like water shortage. In this study, we investigated the influence that these plants can have on organic matter quality and dynamics and hypothesised that the abilities of the crop to face drought can participate at increasing soil carbon storage in soil.     
We conducted a field experiment with five different evolutionary populations of wheat, i.e. a bread wheat (Monnalisa), an einkorn wheat (Norberto) and 2 evolutionary populations (Furat-Li Rosi, Furat-Floriddia and BIO2), cultivated following four other plants species (Wheat, Pea, Cickpea or Clover) on two different sites in Italy presenting contrasted conditions (hot-summer Mediterranean climate in Roma and humid subtropical climate in Parma). Bulk soil and rhizosphere soils were sampled and C, N contents as well as organic matter functional groups using Mid Infrared Spectroscopy (MIRS) were assessed.  
We observed that the infrared signatures differed between our two sites and depending on the previous cropping species. Evolutionary population of wheat showed different signatures than durum and bread wheat. Our results demonstrate that evolutionary population in particular pedoclimatic conditions can influence the fate of soil organic matter.