In Tunisia, climate change impacts that lead to the degradation of soil resources are considered to be a major limiting factor on socio-economic development. These impacts are exacerbated by the intensive plowing and cultivation practices used by Tunisian farmers, which expedite the depletion of soil organic matter (SOM), leading to changes in the physio-chemical properties of soil and consequently promoting soil erosion. In fact, the decrease in soil organic carbon (SOC) stocks affects soil’s fertility and the ability to regulate climate change. The objective of this study, which was conducted in Le Krib in the Siliana region of northwestern Tunisia, was to evaluate the effects of two cropping systems, consisting of durum wheat (Triticum aestivum) and oats (Avena sativa), and two types of tillage, no-till (NT) and mouldboard plowing (MP), on different soil aggregate classes (>2000 µm, 2000–250 µm, 250–180 µm, 180–53 µm and <53 µm) and soil physio-chemical properties, as well as the resulting effects on the carbon and nitrogen concentrations in these aggregates. The results showed that the carbon content of all soil aggregate classes was influenced by interactions between the previous crop and tillage regime. The clay-silt fraction had higher carbon concentrations under no-till and mouldboard plowing management. Furthermore, the previous crop and tillage type and their interactions had significant effects on nitrogen concentrations in micro-aggregates. The highest nitrogen concentrations (2846.6 ppm) were found in micro-aggregates in soils where the previous crop was durum wheat and mouldboard plowing was used, while the lowest concentrations (1297 ppm) were obtained in soils where the previous crop was oats and mouldboard plowing was used.

The aim of this study was the mycorrhizae inoculation effect on production and mineral nutrition of snap bean variety under low phosphorus intake. The experiment was a randomized block design with four treatments: a non-mycorrhizal control, two mycorrhizal strains: Piriformospora indica (Piri), Glomus intraradice (Glomus), and their combined inoculation Piri + Glomus; using ten replicates per treatment. A comparative trial of different treatments on plant growth, yield parameters, mineral absorption and mycorrhizae colonization frequency was conducted in the greenhouse under controlled conditions using autoclaved soil-sand-vermiculite substrate. The inoculation with Piri and co-inoculation with Piri + Glomus significantly increased aerial dry biomass (p ≤ 0.01) and highly increased root dry biomass (p ≤ 0.001). Mycorrhizal snap bean plants showed a significantly higher number of pods, pods dry weight, dry weight of seeds per plant, and percentage of mycorrhizal colonization than non-mycorrhizal plants. Mycorrhizae inoculation increased significantly nitrogen and phosphorus uptake that the inoculation with Piri increased N uptake in roots by 187% and P uptake by 200% compared to the non-inoculated plants. For cations leave incorporation, Piri significantly enhanced Ca²⁺ by 100%, Mg²⁺ by 110% and NH₄ ⁺ by 175% relative to the non-mycorrhizal plants. While mycorrhizal inoculation doesn’t have a significant effect on K⁺ nutrition. In conclusion, snap bean Contender variety seedling inoculated with Piri proved to be most effective by improving plant growth, mineral nutrition and yield production under low phosphorus uptake.