IMPORTANCE OF BIOFFERTLIZATION VIA RHIZOBIA STRAIN ON PEA (PISUM SATIVUM L.) PRODUCTION IN A STRESSED EDAPHO-CLIMATIC ENVIRONMENT, IN TUNISIA

Pea (Pisum sativum L.) is a nutritious leguminous rich source of protein. It plays an important role in crop rotation and contributes efficiently to soil fertility. Despite these nutritional, symbiotic and agronomic characteristics, pea cultivation areas are in regression and yield remain low. Abiotic and biotic constraints as well as the optimization of symbiotic nitrogen fixation are the main factors affecting the pea crop development. This work aimed to study the effects of inoculation with rhizobia having high potential solubilization of inorganic phosphorus on pea production under edapho-climatic stress conditions. Inoculation with rhizobia and phosphorus fertilization trials were performed in vitro at the laboratory and in vivo in fields at two experimental stations for three successive crop seasons characterized by contrasted precipitations regimes. The inoculation with both selected strains of Rhizobium (TAC and 12362) increased significantly the biomass nodular and improved the phosphorus content and phosphorus use efficiency (PUE) of pea plants. The phosphorus application induced symbiosis efficiency and increased nodulation and biomass production of pea. Regardless of the treatment, a highly significant effect of the season and site on the variability of pea production was recorded. Inoculation with rhizobia could substitute nitrogen and phosphorus chemical fertilizers for economic, ecological and sustainable agriculture.