Effect of biochar on alleviation of cadmium toxicity in wheat (Triticum aestivum L.) grown on Cd-contaminated saline soil

Abstract

Soil degradation by salinity and accumulation of trace elements such as cadmium (Cd) in the soils are expected to become one of the most critical issues hindering sustainable production and feeding the increasing population. Biochar (BC) has been known to protect the plants against soil salinity and heavy metal stress. A soil culture study was performed to evaluate the effect of BC on wheat (Triticum aestivum L.) growth, biomass, and reducing Cd and sodium (Na) uptake grown in Cd-contaminated saline soil under ambient conditions. Soil salinity decreased the plant growth, biomass, grain yield, chlorophyll contents, and gas exchange parameters and caused oxidative stress in plants compared with Cd stress alone. Salt stress increased Cd and Na uptake and reduced the potassium (K) and zinc (Zn) uptake by plants. AB-DTPA-extractable Cd and soil electrical conductivity (ECe) increased under salt stress compared to the soil without NaCl stress. Biochar application improved the plant growth and reduced the Cd and Na uptake except in plants treated with higher BC and salt stress (5.0% BC + 50 mM NaCl). Biochar application reduced the oxidative stress in plants and modified the antioxidant enzyme activities, and reduced the bioavailable Cd under salt stress. The positive effects of BC under lower salt stress while the negative effects of BC under higher BC and salt levels indicated that BC doses should be used with great care in higher soil salinity levels simultaneously contaminated with Cd to avoid the negative effects of BC on growth and metal uptake.

Alleviation of aluminum and cadmium toxicity by biochar and its potential toxicity to sorghum

“…As discussed previously, the decrease in aluminum and cadmium toxicity by different mechanisms owing to the addition of biochar explains the higher yields of dry matter by sorghum seedlings in the BS and BB treatments. Other authors working with wheat (Abbas et al, 2017), rice (Rizwan et al, 2016), and sorghum (Soudek et al, 2016) found higher dry matter yield and lower Cd concentrations in seedlings grown in treatments with biochar, consistent with the results obtained in this study. As discussed previously, the decrease in aluminum and cadmium toxicity by different mechanisms owing to the addition of biochar explains the higher yields of dry matter by sorghum seedlings in the BS and BB treatments.…”

ACC Deaminase Producing PGPR Bacillus amyloliquefaciens and Agrobacterium fabrum along with Biochar Improve Wheat Productivity under Drought Stress

“…Novak et al [79] and Lehmann et al [80] also observed a significant improvement in water holding capacity of soil where BC was applied. The greater surface area and pore spaces of BC facilitate the retention of water when used in soil [33,[79][80][81]. According to Singh et al [76], the organic carbon in BC significantly facilitates PGPR for improvement in their growth.…”

Comparison of Monovalent and Divalent Ions Removal from Aqueous Solutions Using Agricultural Waste Biochars Prepared at Different Temperatures—Experimental and Model Study

“…It involved the formation of solids with PO 4 3− , CO 3 2− , Cl − or SO 4 2− either on the surface or in the solution during the adsorption process. Zhou et al [45] reported the surface precipitations for divalent metals on biochar obtained at 400 • C. Between the surfaces of the biochar and cations (Cu, Zn, Pb and Ag), there was an electrostatic attraction during the heavy metal adsorption process [46]. The variable surface charge (Q) measured for the used solids came mainly from negative surface groups.…”