The main challenge of the agricultural sector is to develop new ecological technologies that increase the yields and the tolerance of crops to abiotic constraints, especially in arid areas. The objective of this study was to test the potential roles of biofertilizers, namely, arbuscular mycorrhizal fungi (AMF), a native AMF consortium (AMF₁) and an exotic AMF strain (AMF₂); plant growth-promoting rhizobacteria (PGPR); and compost (comp), applied separately or in combination, in improving the tolerance of date palm vitroplants to salt stress. Plants were grown under non-stressed (0 mM NaCl) or stressed conditions (120 and 240 mM NaCl). Salt stress negatively affected growth and physiological parameters. However, biofertilizers used alone or in combination increased these traits in either the presence or absence of salinity. The two tripartite combinations PGPR+AMF1+Comp and PGPR+AMF2+Comp efficiently increased plant height compared to the controls, with respective enhancements of 47% and 48% under non-stressed conditions (0 mM), 44% and 43% under 120 mM NaCl and 42% and 41% under 240 mM NaCl. Moreover, under 240 mM NaCl level, the PGPR, AMF1+Comp and PGPR+AMF1+Comp treatments improved the shoot dry weight by 128%, 122% and 113% respectively compared to the stressed control plants submitted to 240 mM NaCl. The tripartite combinations PGPR+AMF₁/AMF₂+Comp improved salt stress tolerance of plants by increasing plant growth, accumulation of osmotic adjustment compounds and antioxidant enzyme activity compared to control plants and the other treatments.

Winter wheat is an important cereal consumed worldwide. However, current management practices involving chemical fertilizers, irrigation, and intensive tillage may have negative impacts on the environment. Conservation agriculture is often presented as a sustainable alternative to maintain wheat production, favoring the beneficial microbiome. Here, we evaluated the impact of different water regimes (rainfed and irrigated), fertilization levels (half and full fertilization), and tillage practices (occasional tillage and no-tillage) on wheat performance, microbial activity, and rhizosphere- and root-associated microbial communities of four winter wheat genotypes (Antequera, Allez-y, Apache, and Cellule) grown in a field experiment. Wheat performance (i.e., yield, plant nitrogen concentrations, and total nitrogen uptake) was mainly affected by irrigation, fertilization, and genotype, whereas microbial activity (i.e., protease and alkaline phosphatase activities) was affected by irrigation. Amplicon sequencing data revealed that habitat (rhizosphere vs. root) was the main factor shaping microbial communities and confirmed that the selection of endophytic microbial communities takes place thanks to specific plant–microbiome interactions. Among the experimental factors applied, the interaction of irrigation and tillage influenced rhizosphere- and root-associated microbiomes. The findings presented in this work make it possible to link agricultural practices to microbial communities, paving the way for better monitoring of these microorganisms in the context of agroecosystem sustainability.