Metal accumulation potential, human health risks, and yield attributes of hundred bread wheat genotypes on irrigation with municipal and remediated wastewater

Deciphering integrated soil potential ecological and human health risks attributable to industrial effluents irrigation and wheat consumption

Iron-steel (IS) and textile (T) are among the major polluting industries worldwide which generate large quantities of effluents containing potentially toxic metals (PTMs). Irrigation application of these effluents due to freshwater shortage is a common practice in developing countries. The current research endeavors to investigate potentially toxic metals in IS and T effluents, contamination status and ecological risk assessment of irrigated soils, PTMs accumulation in grains of diverse wheat germplasm and human health risk appraisal. Soil irrigation with effluents significantly enhanced soil nitrate-nitrogen (T, 285.86 mg/kg; IS, 539.70 mg/kg), phosphorus (T, 8.35 mg/kg; IS, 11.44 mg/kg), organic matter (T, 6.05%; IS, 4.48%) and PTMs contents compared to control (C). Enrichment factor and geo-accumulation index revealed substantial contamination trend of PTMs in IS (Ni > Cr > Co > Cd > Pb > Zn > Mn) and T (Co > Cd > Ni > Cu > Cr) treated soils. Potential ecological risk index and modified potential ecological risk index placed T (very high risk) and IS (considerable risk) irrigated soils in respective categories, with highest risk contributions from Cd, Co and Ni. The interactive effects for PTMs accumulation in grains of 30 wheat genotypes were recorded significant. Average PTMs accumulation in grains for the three irrigation treatments was IS > T > C for Zn, Cr, Mn, Pb, Fe, Ni and T > IS > C for Co, Cd, Cu. Multivariate statistical analysis ( principal component analyses) was used to identify the wheat genotypes with higher or lower grain PTMs accumulative potential on effluent irrigation. The genotypes with a lower grain PTMs accumulation and human health risks are recommended for cultivation in agro-systems receiving IS and T effluents, in order to safeguard wheat crop and human health.

Genetic Behavior of Tomato (Solanum lycopersicum L.) Germplasm Governing Heavy Metal Tolerance and Yield Traits under Wastewater Irrigation

Wastewater irrigation is a substitute for surface water scarcity, but traces of heavy metals (HMs) result in deleterious implications for soil, crop productivity, and in humans. Crops presenting HMs tolerance in genetic behavior are important for producing tolerant genotypes cultivated under wastewater irrigation. In the first part of this experiment, the results obtained previously are re-assessed in a hydroponic system and similar patterns and concentrations of HMs are found in different tomato organs. Following this trial, the tomato’s (Solanum lycopersicum L.) genetic basis of traits conferring HMs tolerance and yield are assessed when irrigated with waste or canal water. The North Carolina Mating II analysis illustrate the amount of gene action, nature, and inheritance pattern. Genetic components depict the involvement of non-additive, additive, and maternal genetic effects in HMs tolerance inheritance and yield. A noticeable increase in cumulative additive variance for the number of flowers (11,907.2) and the number of fruits (10,557.9) is recorded for tomato plants irrigated with wastewater, illustrating additive gene action. However, female and male (MSf/MSm) square ratios also show an association with cytoplasmic inheritance. For HMs tolerance, both additive and dominant variances appeared to be significant; cumulative dominance variance (4.83, 16.1, 4.69, 76.95, and 249.37) is higher compared to additive variance (0.18, 2.36, 0.19, −0.27, and 14.14) for nickel (Ni), chromium (Cr), lead (Pb), manganese (Mn), and zinc (Zn), respectively, indicating dominance gene action. The genotype RIOGRANDI accumulated and translocated fewer HMs to the aerial part of the plant compared to CLN-2418A and PB-017906, thus presenting a tolerant tomato genotype according to the hydroponic experiment. This also exhibited a differential pattern of gene action for HMs tolerance, suggesting that genotypes possess significant differences for HMs tolerance.

Sustainable Production of Tomato Plants (Solanum lycopersicum L.) under Low-Quality Irrigation Water as Affected by Bio-Nanofertilizers of Selenium and Copper

Under the global water crisis, utilizing low-quality water sources in agriculture for irrigation has offered an effective solution to address the shortage of water. Using an excess of low-quality water sources may cause serious risks to the environment, which threaten crop safety and human health. Three kinds of irrigation water (0.413, 1.44, and 2.84 dS m−1) were selected under foliar-applied bio-nanofertilizers of selenium (100 mg L−1) and copper (100 mg L−1) in individual and/or combined application. The nanofertilizers were tested on the production of tomato under greenhouse. After harvesting, the quality of tomato yield and soil biology was evaluated. Using saline water for irrigation caused many main features in this study such as increasing the accumulation of salts, soil organic matter, and CaCO3 in soil by 84.6, 32.3, and 18.4%, respectively, compared to control. The highest tomato yield (2.07 kg plant−1) and soluble solids content (9.24%) were recorded after irrigation with low water quality (2.84 dS m−1) and nano-Cu fertilization. The plant enzymatic antioxidants and soil biological activity were decreased in general due to the salinity stress of irrigation water. After 30 days from transplanting, all studied soil biological parameters (soil microbial counts and enzymes) were higher than the same parameters at harvesting (80 days) under different categories of water quality. The values of all soil biological parameters were decreased by increasing water salinity. This study was carried out to answer the question of whether the combined nanofertilizers of selenium and copper can promote tomato production under saline water irrigation. Further investigations are still needed concerning different applied doses of these nanofertilizers.