Patterns for Pea-Rhizobium symbiosis efficiency response to pedological and varietal variations in Tunisia

Abstract Pedological constrains and varietal recommendations are serious causes of Pea-Rhizobium symbiosis efficiency deviations in Tunisia limiting pea crop adaptation to varying environments. In order to explore variation patterns of this symbiosis in contrasting soils and varieties and appreciate its contribution to plant adaptation, nine locations with potential pea crop vocation are prospected for collection of soils. Two pea varieties with different cycle length are randomly sown on triplicate irrigated containers and placed on natural condition during two seasons. The results have shown that soil fertility is mostly low and highly variable. It is mainly affected by high active limestone content and pH or by salinity. The studied factors (Soil type, Variety) have presented highly significant effect on native rhizobia efficiency, pea root nodulation, shoot and root biomass production, and shoot nitrogen accumulation (p