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Prediction models were developed to estimate the extent to which the metals Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were taken up by the fruits, the leaves, the stems, and the roots of the okra plant, Abelmoschus esculentus (L.) Moench., grown under greenhouse conditions in soil modified with a spectrum of sewage sludge concentrations: 0, 10, 20, 30, 40, and 50 g/kg. All the metals under investigation, apart from Cd, were more concentrated in the A. esculentus roots than in any other organ. Overall, the sum of the metal concentration (mg/kg) within the varying plant tissues can be ranked in the following order: roots (13,795.5) > leaves (1252.7) > fruits (489.3) > stems (469.6). For five of the metals (i.e., Cd, Co, Fe, Mn, and Pb), the BCF was 1, (i.e., Cr, 1.074; Cu, 1.347; Ni, 1.576; and Zn, 1.031). The metal BCFs were negatively correlated with the pH of the soil and positively correlated with soil OM content. The above-ground tissues exhibited a TF < 1 for all metals, apart from Cd with respect to the leaves (2.003) and the fruits (2.489), and with the exception of Mn in relation to the leaves (1.149). Further positive associations were demonstrated for the concentrations of all the metals in each examined plant tissue and the corresponding soil metal concentration. The tissue uptakes of the nine metals were negatively correlated with soil pH, but positively associated with the OM content in the soil. The generated models showed high performance accuracy; students’ t-tests indicated that any differences between the measured and forecasted concentrations of the nine metals within the four tissue types of A. esculentus failed to reach significance. It can, therefore, be surmised that the prediction models described in the current research form a feasible method with which to determine the safety and risk to human health when cultivating the tested species in soils modified with sewage sludge.

This study aimed to produce an economic and stable biofungicide based on a new effective antagonistic strain (Trichoderma harzianum JF419706) via the exploitation of agro-industrial lignocellulosic residues as carriers for fungal growth to control the root rot diseases of vegetable crops. Trichoderma harzianum JF419706 showed a good resistance to a chemical fungicide with two-fold of the recommended dose. It was able to propagate on corn stovers amended with 20% of date molasses, as a very cheap substrate, up to 2.90 × 1016 CFU/g after 30 days. Formulation of the bioagent on the substrate as a fine powder (FTB) increased the shelf-life up to 8 months with good viability (9.37 × 1011 CFU/g). The bioagent propagated itself in the rhizospheric soil about two-fold of the initial inoculum. Application of the FTB, as a seed treatment, suppressed the root rot disease severity percentage of cucumber, lettuce, and tomato plants to 70.0%, 61.5%, and 53.8%, respectively, from the control. The crop yield increased by 50%, 35%, and 30% in the same order of the three crops. FTB promoted the growth and physiological processes of the plants significantly compared with the control. Our study recommends the application of the FTB as a cost-effective biofungicide and biofertilizer in crop management, singly or as a part of integrated pest management, to ensure the sustainability of green farming and reduce the chemical input in cultural practices.

In calcareous soils, wheat productivity is much lower due to improper nutrient management, especially phosphorus (P). Therefore, this study was conducted to manage P availability from various organic (Control, FYM and Sugar cane straw applied at the rate of 10 ton ha−1) and inorganic (Control, 100% rock phosphate (RP), 50% acidulated RP, 100% acidulated RP, single super phosphate (SSP) and diammonium phosphate (DAP)) sources applied at the rate of 90 kg P2O5 ha−1 in calcareous soil while using wheat as test crop. When averaged across the organic sources, SSP performed better in emergence m−2 (126), tillers m−2 (431), spikes m−2 (419), grains spikes−1 (61), plant height (95.1 cm), 1000-GW (40 g), biological yield (11,023 kg ha−1), grain yield (4022 kg ha−1), phosphorus use efficiency (10.5%), phosphorus in leaves at tillering (2.63 mg kg−1) and anthesis stage (2.50 mg kg−1), soil P at heading (1.73 mg kg−1) and post-harvest stage (1.56 mg kg−1) compared to the rest of the mineral sources. Similarly, among the organic sources, FYM performed better than others for all tested traits. Integration of inorganic P sources with organic manures further improved crop performance and post-harvest soil P content. Therefore, using 10 tons FYM ha−1 in integration to SSP or 100% acidulated RP at the rate of 90 kg P2O5 ha−1 is recommended for ensuring optimum wheat productivity under calcareous soils.

The present study aims to assess the impact of the type of yeast consortium used during bioethanol production from starchy biowastes and to determine the optimal fermentation conditions for enhanced bioethanol production. Three different yeast strains, Saccharomyces cerevisiae,Pichia barkeri, and Candida intermedia were used in mono- and co-cultures with pretreated waste-rice as substrate. The optimization of fermentation conditions i.e., fermentation time, temperature, pH, and inoculum size, was investigated in small-scale batch cultures and subsequently, the optimal conditions were applied for scaling-up and validation of the process in a 7-L fermenter. It was shown that co-culturing of yeasts either in couples or triples significantly enhanced the fermentation efficiency of the process, with ethanol yield reaching 167.80 ± 0.49 g/kg of biowaste during experiments in the fermenter.