Combined effect of Hedysarum coronarium- Medicago sativa intercropping on the agronomic parameters of Brassica napus, biodiversity and health soil under water stress

WAAD BOUSSELMI ¹, Takwa Gritli ¹, Slim ben salah Slim ², Bacem Mnasri ¹

Laboratory of Legumes, Center of Biotechnology of Borj Cedria (CBBC) ¹, Research Unit of-Biodiversity and Resource Development in Mountainous Areas, Higher School of agriculture education of Mateur. ²

Intercropping with forage legumes offers a wide range of additional benefits, such as significantly higher yields compared to single crops and increased activity and diversity of soil microorganisms. The objective of this study is to investigate the impact of Hedysarum coronarium and Medicago sativa intercropping on the agronomic parameters of Brassica napus and the diversity of soil microorganisms associated with the soil and roots under water stress. To investigate the effect of intercropping Hedysarum coronarium and Medicago sativa on the agronomic parameters of Brassica napus, we conducted during two consecutive years, 2022 and 2023 at the Higher School of agriculture education of Mateur in Bizerte, northwest of Tunisia. Agronomic measurements were taken, including production and growth parameters. To study the diversity of microorganisms, rhizosphere, and root samples of Brassica napus were collected and subjected to sequencing using Illumina MiSeq for a metagenomics approach. At the end of this work, in which we studied the impact of intercropping on the morphological aspect of rapeseed cultivation, we found that: The behavior of Brassica napus intercropping is improved; the growth of Brassica napus is optimized throughout the cycle compared to that obtained in Brassica napus only. This is explained by the fact that Brassica napus can benefit very quickly from an additional source of nitrogen. The optimal condition of the associated Brassica napus in winter output is important to improve grain productivity. Metagenomic analysis showed that the bacterial communities in the roots and rhizosphere of Brassica napus between 2022 and 2023 highlights notable differences and trends. Temporal shifts suggest year-specific environmental factors influencing microbial communities. In conclusion, intercropping is a powerful way to promote a more diversified beneficial bacterial community necessary for rapeseed growth, thus allowing significantly higher yields. Keywords: Intercropping, Brassica napus, Hedysarum coronarium, Medicago sativa. Illumina Miseq.

Main author career stage: PhD student

Contribution type: Poster

First choice session: 2. Ecology

Second choice session: 6. Plants, Fungi and Society