Effects of soil salinity on nodulation and growth of invasive and native Prosopis seedlings in arid deserts

Abstract Soil salinity is a major environmental stressor that significantly affects nodule formation and the growth of both exotic and native plant species. This study investigates the effects of soil salinity and the canopy cover of Prosopis juliflora on the physico-chemical properties of soil and the nodulation and growth of two exotic (P. juliflora and P. pallida) and one native (P. cineraria) Prosopis species in the arid deserts of the UAE. The results reveal significant variations in soil nutrient content and physical properties under and away from the canopies in both salty and non-salty habitats. Soils under the P. juliflora canopy, particularly in non-salty habitats, exhibited higher levels of essential nutrients and improved physical conditions compared to soils away from the canopy. These favorable conditions led to enhanced nodule formation and biomass production. Prosopis juliflora and P. pallida showed superior growth and nodulation compared to P. cineraria, suggesting a better adaptation to the modified soil environment under the P. juliflora canopy. Despite the study finding that soil salinity negatively impacted soil microbial communities, nutrient availability, and plant growth, P. juliflora demonstrated high salinity tolerance. It maintained robust nodulation and growth, indicating its potential for invading and even rehabilitating degraded saline lands. These findings underscore the importance of canopy cover in mitigating salinity, enhancing soil fertility, and supporting plant growth. The study provides valuable insights into the invasive ability of different Prosopis species, and ecosystem management in arid regions.