Exploring the benefits of biochar over other organic amendments for reducing of metal toxicity in Withania somnifera

Abstract

Biochar is considered as a good metal sequester and ameliorates the metal toxicity and uptake in plants. However, its effectiveness over other organic amendments is not well discussed. The aim of this study is to compare the biochar amendments alleviating the levels of Pb and Cd in Withania somnifera L. Dunal with other organic manure. Farmyard manure, vermicompost, and biochar were applied in the field spiked with highly available Pb and Cd. Metal bioavailability and accumulation, plant growth and plant physiology, antioxidant enzymes and metabolite content of W. somnifera along with soil properties were evaluated in all treatments. Study indicates that the application of organic manures significantly alleviated the metal levels (33-72%) in the plant in comparison with control. The herbage yield was significantly higher (33-69%) under different organic manures as compared to the metal treatments. Secondary metabolite contents and antioxidant enzymes were higher in metal treatments in comparison with control. Organic manures were not only able to restrain the Pb and Cd in soil but also enhanced the soil microbial activities. Results indicate that biochar amendments were more promising than farmyard manure and vermicompost due to the presence of more stable carbon in biochar and more alleviation in metal uptake. In addition, net profit in the cultivation of W. somnifera was higher for biochar amendments (50% higher) compared to control. The study recommended that biochar could be a better option for commercial and safer production of W. somnifera.

Biochar production: A sustainable solution for crop residue burning and related environmental issues

“…Mohan et al, 48 demonstrated that rice husk and corn stover biochar can be used for carbon sequestration and soil amendments. Amelioration of different types of soils (metal‐contaminated, sandy loam, and soils affected with mine wastes) by biochar prepared from distilled waste was demonstrated in various studies 14‐16,21‐23,33,49 . These studies indicate that biochar improved the soil chemical and biological quality, reduced nutrient leaching, improved nutrient use efficiency of the plant, enhanced plant growth, and restrict the uptake of contaminants.…”

“…In India, where lots of residues burn yearly, biochar production could be a sensible tool for combating the increase in atmospheric CO 2 and for sustainable agricultural development. The application of biochar has also been demonstrated to improve nutrient cycling in the short term 11 with the enhancement of biomass production 12‐16 . Moreover, biochar application in restoration of desertified 17 and secondary salinized land 18‐20 and acidic mine soil 21‐23 encountered the challenges of problematic soils.…”

“…Biochar also has liming properties that curtailed the cost of chemicals used for neutralizing the acidic soils 21,23 . In stressed soil, biochar improvement in soil fertility and crop productivity biochar 15,16,23 further curtailed the remediation cost of these lands and generate extra revenue from barren lands.…”

Effect of biochar on soil microbial community, dissipation and uptake of chlorpyrifos and atrazine

“…For the experiment, the soil was taken from fallow land of an experimental form of CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, India (26° 48′ 0″ N, 80° 54′ 0″ E) at a depth of 0-15 cm. The distilled waste of Mentha arvensis was used to produce biochar according to previously reported conditions (Nigam et al 2019). Fine powdered and sieved (2-mm particle size) soil and biochar were used for the experiment.…”

“…Over the last two decades, biochar produced by incomplete combustion of biomass has been considered a promising option for immobilizing the pollutants in the soil due to its porous structure and surface properties (Zhou et al 2021). The application of biochar displayed a beneficial effect on its fertility and soil biological activities and improved the growth of plants (Nigam et al 2019;Jain et al 2020;Singh et al 2022b;. Song et al (2023) in his review demonstrated that biochar has high adsorption potential and can accelerate the pesticide degradation of soil and mitigate its uptake in the plantings.…”