Residual effects of tobacco biochar along with different fixing agents on stabilization of trace elements in multi-metal contaminated soils.

The residual effect of tobacco biochar (TB ≥ 500°C) mono and co-application with Ca-hydroxide (CH), Ca-bentonite (CB) and natural zeolite (NZ) on the bio-availability of trace elements TE(s) in alkaline soils has not been deeply studied yet. A pot study that had earlier been investigated TB mono and blended with CH, CB and NZ on the immobilization of Pb, Cu Cd, and Zn by Chinese cabbage. Maize crop in the rotation was selected as test plant to assess the residual impact of amendments on stabilization of Pb, Cu Cd, and Zn in mine polluted (M-P), smelter heavily and low polluted (S-HP and S-LP, respectively) soils. The obtained results showed that stabilization of Pb, Cd, Cu and Zn reached 63.84% with TB + CB, 61.19% with TB + CH, 83.31% with TB + CH and 35.27% with TB + CH for M-P soil, 36.46% with TB + NZ, 38.46% with TB + NZ, 19.40% with TB + CH and 62.43% with TB + CH for S-LP soil, 52.94% TB + NZ, 57.65% with TB + NZ, 52.94% with TB + NZ, and 28.44% with TB + CH for S-LP soil. Conversely, TB + CH and TB alone had mobilized Pb and Zn up to 19.29% and 34.96% in M-P soil. The mobility of Zn reached 8.38% with TB + CB and 66.03% with TB for S-HP and S-LP soils. The uptake and accumulation of Pb, Cd, Cu and Zn in shoot and root were reduced in three polluted soils. Overall, the combination of TB along with CH, CB and NZ has been proven to be effective in Pb, Cd, Cu and Zn polluted mine/smelter soils restoration.

Effect of pre-storage removal of different parts of the scape top on the biochemical changes of two garlic cultivars during controlled atmosphere storage.

BACKGROUND: This study highlights the effect of removing different plant parts on the biochemical changes in the garlic scape of cultivars G064 and G025 during controlled atmosphere storage (O2 = 2%-5%, CO2 = 3%-6%) at temperature = 0 ± 0.5 °C, Relative Humidity (RH) RH = 85%-95%, for 168 day. Total polyphenols (TP), total flavonoids (TF), the concentration of allicin, ethylene production and the antioxidant potential were evaluated and analyzed by using four different assays. Statistically significant differences were observed between different treatments. RESULTS: Total polyphenols, allicin concentration, and ethylene production were the highest in G064, while the total flavonoid concentration was the highest in G025. Removing the top resulted in the highest levels of total polyphenols, total flavonoids, allicin, and ethylene in both cultivars. The antioxidant capacity was also significantly higher when the top was removed than with other treatments in both cultivars. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity (HRSC), ferric ion reducing antioxidant power (FRAP) and metal-chelating capacity (MCC) were higher in cultivar G064 compared to G025. CONCLUSION: Overall, the results suggest that the removing the tops of the scapes of G025 and G064 is the best treatment to maintain these biochemical changes. © 2018 Society of Chemical Industry.