Evaluation of newly reclaimed areas in Saudi Arabia for cultivation of the leguminous crop Phaseolus vulgaris under sewage sludge amendment

Native desert plants have the potential for phytoremediation of phytotoxic metals in urban cities: implications for cities sustainability in arid environments

Arid regions can benefit from using native desert plants, which require minimal freshwater and can aid in remediating soil phytotoxic metals (PTMs) from traffic emissions. In this study, we assessed the ability of three native desert plants-Pennisetum divisum, Tetraena qatarensis, and Brassica tournefortii-to accumulate phytotoxic metals (PTMs) in their different plant organs, including leaves, stems, and roots/rhizomes. The PTMs were analyzed in soil and plant samples collected from Dubai, United Arab Emirates (UAE). The results indicated significantly higher levels of PTMs on the soil surface than the subsurface layer. Brassica exhibited the highest concentrations of Fe and Zn, measuring 566.7 and 262.8 mg kg-1, respectively, while Tetraena accumulated the highest concentration of Sr (1676.9 mg kg-1) in their stems. In contrast, Pennisetum recorded the lowest concentration of Sr (21.0 mg kg-1), while Tetraena exhibited the lowest concentrations of Fe and Zn (22.5 and 30.1 mg kg-1) in their leaves. The roots of Pennisetum, Brassica, and Tetraena demonstrated the potential to accumulate Zn from the soil, with concentration factors (CF) of 1.75, 1.09, and 1.09, respectively. Moreover, Brassica exhibited the highest CF for Sr, measuring 2.34. Pennisetum, however, could not translocate PTMs from its rhizomes to other plant organs, as indicated by a translocation factor (TF) of 1. In contrast, Brassica effectively translocated the studied PTMs from its roots to the stem and leaves (except for Sr in the leaves). Furthermore, Pennisetum exclusively absorbed Zn from the soil into its leaves and stems, with an enrichment factor (EF) greater than 1. Brassica showed the ability to uptake the studied PTMs in its stem and leaves (except for Fe), while Tetraena primarily absorbed Sr and Zn into its stems. Based on the CF and TF results, Pennisetum appears to be a suitable species for phytostabilization of both Fe and Zn, while Brassica is well-suited for Sr and Zn polluted soils. Tetraena shows potential for Zn phytoremediation. These findings suggest that these plants are suitable for PTMs phytoextraction. Furthermore, based on the EF results, these plants can efficiently sequester PTMs.

The use of photosynthetic pigments and SPAD can help in the selection of bean genotypes under fertilization organic and mineral

The common bean is cultivated in all regions of the country, representing a product of great economic and social importance. In order to ensure food security in the world, it is necessary to create alternatives to reduce the dependence on fertilizers and seeds, and in this context, organic agriculture is a sustainable alternative to ensure it. Therefore, it becomes necessary to adapt rapid methods to monitor plant nutrition in real-time. The reflectance index determined by SPAD and pigment determination can be a sustainable alternative to identify genotypes in different fertilizations (organic × mineral fertilizer). The research hypothesis is to monitor nutritional management through pigment levels and reflectance index in common bean cultivars and their adaptation into different types of fertilization (organic × mineral fertilizer). Therefore, the objective of the research was to evaluate the common bean genotypes of the type carioca, in different fertilizations (organic × mineral fertilizer), and their effects on photosynthetic pigments, and the relationship between SPAD reflectance index and productivity. The experimental design used was a 2 × 7 factorial in randomized blocks with four replications: The first factor was the fertilization (organic × mineral fertilizer)and the second were the 7 genotypes (UFU-1; UFU-2; UFU-3; UFU-4; UFU-5; UFU-6 UFU-7), with UFU-1 being a hybrid obtained between genotypes UFU-4 and UFU-7; UFU-2 and UFU-3 were commercial genotypes; and UFU-4, UFU-5, UFU-6 and UFU-7 were genotypes from the UFU germplasm bank, located in the city of Monte Carmelo, Brazil. Evaluations were carried out for the agronomic characteristics of the plants, which were: height, number of branches, length and volume of roots, dry matter, leaf area index, number of flowers, number of pods, number of seeds per pod, 100 seed weight, and productivity of the genotypes. The results were compared with chlorophyll content and SPAD reflectance index, and the genotypes showed distinct behavior for each fertilization (organic × mineral fertilizer). The genotypes recommended for the organic fertilizer were UFU-2, UFU-6, and UFU-7, which showed higher productivity. For themineral fertilizer, the best-adapted genotype was UFU-4, with a higher productive yield. In conclusion, we can affirm that the highest chlorophyll and SPAD indices can help select common bean genotypes with higher productivity and adaptation within the organic fertilizer being this the main focus of this research. However, the other variables carried out during this research also demonstrated to have significant effects, so they could be analyzed individually and could offer valuable information in the selection of the best-adapted genotypes.

Safety assessment and sustainability of consuming eggplant (Solanum melongena L.) grown in wastewater-contaminated agricultural soils

Vegetables cultivated on contaminated agricultural soils are being consumed by the public, and consequently cause serious health concerns due to contaminants' dietary intake. The current study examines the safety and sustainability of eating eggplant (Solanum melongena) by looking into the possibility of heavy metals translocation from polluted soils to the edible sections, as well as the health hazards that come with it. Soil and eggplant samples were taken from three contaminated and other three uncontaminated farms to estimate their chemical constituents and plant growth properties. Based on the pollution load index data, the contaminated soils were highly polluted with Fe, Cu, Pb, and Zn; and relatively polluted with Cr, Mn, Cd, Mn, Co, and V. Under contamination stress, the fresh biomass, dry biomass, and production of eggplant were significantly reduced by 41.2, 44.6, and 52.1%, respectively. Likewise, chlorophyll a and b were significantly reduced from 1.51 to 0.69 mg g⁻¹ and 1.36 to 0.64 mg g⁻¹, respectively. The uncontaminated plant shoots had the highest quantities of N, P, and proteins (1.98, 2.08, and 12.40%, respectively), while the roots of the same plants had the highest K content (44.70 mg kg⁻¹). Because eggplant maintained most tested heavy elements (excluding Zn and Pb) in the root, it is a good candidate for these metals' phytostabilization. However, it had the potential to translocate Mn and Zn to its shoot and Pb, Cr, Mn, and Zn to the edible fruits indicating its possibility to be a phytoextractor and accumulator of these metals. Cd, Cu, Ni, Pb, Mn, and Co quantity in the edible sections of eggplant grown in contaminated soils exceeded the permissible level for normal plants, posing health hazards to adults and children. For safety issues and food sustainability, our investigation strongly recommends avoiding, possibly, the cultivation of eggplant in contaminated agricultural lands due to their toxic effects even in the long run.