The unmanaged waste disposal, coupled with the increased industrialization and urbanization, has aggravated the problem of heavy metal contamination in the environment, especially in the agricultural soils. In view of this, the present study was planned to evaluate the effectiveness of zinc (Zn) in the amelioration of cadmium (Cd) toxicity in plants, thereby sustaining the crop productivity in near future. The experiment was performed in two parts. The first part focused on calculating the EC50 (half-effective concentration) of Cd, for which the potted experimental plants (Amaranthus cruentus L.) were treated with different doses of Cd (10, 20, 30, 40, and 50 mgL(-1)). In the second part, the EC50 Cd dose was combined with different Zn doses (100, 200, 300, 400, and 500 mgL(-1)) and the effect of Zn supplementation on Cd exposed plants was studied by evaluating the response of different biochemical, physiological and yield parameters. The EC50 Cd dose was calculated to be 26.5 mgL(-1). Plant yield increased significantly with reduced Zn dosages. Biochemical parameters improved more than physiological parameters after Zn treatment in Cd-stressed plants. At higher Zn doses, its toxic effects exacerbate Cd toxicity. The study indicates that Zn partially decreases Cd toxicity in Amaranthus plants. The results suggest that 300 mgL(-1) Zn dose was sufficient to bring about maximum recorded mitigation of Cd toxicity. However, since the synergistic effects of high doses of Zn with Cd cannot be ruled out, the selection of the applied Zn dose should be carefully selected.

Red clay soil in Guilin, characterized by a large pore ratio, high liquid-plastic limit, and high shrinkage, necessitates effective stabilization methods due to the region's seasonal flooding. This study employed enzyme-induced carbonate precipitation technology in conjunction with MgO and lignin fiber to stabilize the soil. The study aimed to elucidate the solidification mechanism of red clay and assess the effects of admixture dosage and curing age on unconfined compressive strength, carbonate formation, liquid-plastic limit, and fine particle content. The findings indicated that MgO significantly enhanced the unconfined compressive strength through a synergistic effect. The mineralization process of EICP technology facilitated CO2 production, promoting the carbonation of MgO, which, in turn, established an alkaline environment that further increased carbonate formation. The damage to the specimen was in the form of brittle damage. Conversely, conversely, the inclusion of lignin fibers enhanced the ductility of the soil matrix. The fibers interlaced within the soil matrix, preventing contraction and cracking under external forces and inhibiting the propagation of small fissures into larger ones, leading to plastic deformation. The dosage of MgO played a crucial role in the strength of stabilized red clay. At lower dosages, strength gains were primarily due to increased carbonate content, while higher dosages reduced water content, increasing inter-particle friction and soil densification. As strength increased, clay content decreased, and specific gravity rose.

Drylands are limited by water and nutrients and exposed to high solar radiation, which result in sparse vegetation cover, soil erosion, and subsequent land degradation. Land degradation affects human wellbeing, causing health and environmental problems, migrations and increasing socio-economic instability worldwide. The restoration of degraded drylands by induced biocrusts has recently gained increased scientific interest. However, harsh environmental conditions can slow down biocrust development. Thus, it is necessary to investigate and develop methods for the mitigation of harsh environmental factors. This survey and assessment reviews studies on environmental barriers to biocrust development and technological achievements in the acceleration of artificially induced biocrust development through the mitigation of harsh environmental conditions. Climatic conditions, and soil and inoculum properties have been identified as major factors that influence the acceleration of biocrust development and which should be considered when dryland restoration is planned. Activities such as watering, shading, soil stabilization and fertilization, as well as further measures for the survival of the cyanobacterial inoculum have promoted biocrust establishment. The restoration of degraded substrates requires the alignment of amelioration techniques with environmental conditions and inoculum requirements. This study has also identified the need for further optimization of watering and shading technologies, better understanding of the importance of soil properties in biocrust growth, as well as further studies on the most appropriate inoculum type and techniques for mass cultivation and application at field scale. The proposal of a multifunctional solution is proposed that could contribute to the restoration of land and cleaner air and water, by providing an inoculum and suitable microsite environmental conditions for the accelerated establishment of viable biocrusts leading to further development, survival, and to the succession to higher organisms under a wide range of environmental conditions.