This study examined the effect of sulfur, ethylenediaminetetraacetic acid (EDTA), olive mill wastewater (OMW), and their mixtures in remediating metal-polluted soils by implementing both leaching trials and a greenhouse experiment with sunflower (Helianthus annuus). In the leaching study, soils were subjected to five discharge volumes (V1–V5). EDTA significantly improved metal mobility of Cd (221.4) mg·kg⁻¹ in V2, Pb (340.8) mg·kg⁻¹ in V3, and Zn (1.01) mg·kg⁻¹ in V3, while OMW moderately mobilized Cd and Mn. However, sulfur mitigated leaching by buffering soil pH and metal immobilization. Mixed treatments revealed moderate leaching behavior. EDTA lowered soil pH (5.3) and raised EC (1763) µS/cm, while sulfur maintained stable chemical environments. In the greenhouse experiment, amendments significantly influenced biomass and metal uptake. Sunflower roots accumulated the highest Cd under sulfur (733.5) mg·kg⁻¹ and Mn under EDTA (743.3) mg·kg⁻¹. EDTA restricted Cd translocation (TF = 0), while OMW enhanced Cr movement to shoots (TF = 17.6). EDTA also reduced Cd bioavailability, whereas OMW raised Pb and Mn availability. Overall, EDTA improved metal solubility for potential removal and sulfur in stabilized metals, while OMW acted as a moderate mobilizer. Sunflower demonstrated selective metal uptake, indicating its potential in phytoremediation strategies tailored to specific contaminants.

Soil contamination with heavy metals (HMs) poses a significant environmental threat. Phytoremediation, a sustainable and eco-friendly emerging bioremediation approach, utilizes plants to remove, immobilize, or stabilize soil contaminants. This study examines the interactive effects of sulfur (S), ethylenediaminetetraacetic acid (EDTA), and olive mill wastewater (OMW) on HM uptake and the growth of maize (Zea mays L.) and mustard (Brassica juncea). Mustard exhibited superior dry matter (DM) yield (2.4 g/pot with 5% OMW), nutrient uptake, and tolerance to metal toxicity. The translocation factor (TF) and bioaccumulation factor (BF) for maize and mustard plants vary significantly with different treatments. For maize, the S 2T/ha treatment achieved the highest TF and BF for cadmium (Cd), while 5% OMW led to maximum chromium (Cr) and manganese (Mn) uptake. In mustard, 5% OMW treatment resulted in the greatest bioconcentration factor (BCF) for cadmium (Cd), lead (Pb), and zinc (Zn), whereas sulfur application yielded the highest TF for Cd. The 5% OMW treatment overall enhanced HM uptake most significantly. Lower sulfur application rate (1 ton/hectare) increased the availability Cd and Pb, boosting plant growth and nutrient uptake. For instance, 1 ton/hectare of sulfur elevated Cd availability to 24.102 mg·kg⁻¹ in maize and 58.705 mg·kg⁻¹ in mustard. EDTA treatments further improved metal bioavailability, increasing Cd levels in maize (10.09 mg·kg⁻¹) and mustard (7.78 mg·kg⁻¹). Mustard’s superior tolerance and nutrient efficiency identify it as a promising candidate for phytoremediation of HM-contaminated soils in arid regions. Innovative treatments with sulfur, EDTA, and olive mill wastewater significantly enhance soil decontamination and plant growth.

Degraded non-cracking soils (locally known as Naga’a) are widespread in semi-arid regions of Sudan and are characterized by severe compaction, low organic matter, poor water retention, and limited crop productivity. Sustainable rehabilitation strategies for these soils remain underexplored. This study evaluated the potential of farmyard manure compost (FYM) as a soil amendment to improve physicochemical properties, soil water retention, and sorghum (Sorghum bicolor L.) performance in degraded Naga’a soil. Aerobic composting of FYM was conducted for two months under controlled moisture and C/N ratio conditions, producing a mature compost with enhanced organic carbon, nitrogen, and water-holding capacity. A pot experiment was conducted using five rates (0, 5, 10, 15, and 20 t ha⁻¹) of the produced compost alongside a mineral NPK treatment, assigned in a randomized complete block design. Compost application significantly (p ≤ 0.05) increased soil organic carbon, total nitrogen, total phosphorus, saturation percentage, and water-holding capacity compared with the control and NPK treatments. The highest compost rate (20 t ha⁻¹) improved soil water-holding capacity by approximately 20% and organic carbon by over 90% relative to the control. Sorghum dry matter production and plant nutrient uptake (N, P, K, and Ca) increased significantly with compost rate, while total seasonal irrigation water requirements declined. Water productivity improved progressively with compost addition, reaching a maximum increase of 60.5% at 20 t ha⁻¹ compared to the control. Overall, FYM proved effective in restoring soil functional properties, enhancing water-use efficiency, and improving sorghum growth. The results highlight the valorization of FYM as a sustainable, low-cost strategy for rehabilitating degraded non-cracking soils in arid and semi-arid environments.