Chitosan with Bentonite and Biochar in Ni-Affected Soil Reduces Grain Ni Concentrations, Improves Soil Enzymes and Grain Quality in Lentil

Ecological and human health risks associated with Ni-affected soils are one of the major attention seeking issues nowadays. The current investigation is based on the usage of biochar (BR), chitosan (CN), bentonite (BE), and their mixture to immobilize Ni in a Ni-polluted soil and accordingly contracted Ni distribution in lentil plant parts, improved grain nutritional quality, antioxidant defense system, and soil enzymatic activities. The soil was initially amended with CN, BE, and BR and later lentil was grown in this soil in pots. Results depicted the highest significance of BE+CN treatment in terms of reducing the Ni distribution in the roots, shoots, grain, and DTPA-extractable fractions, relative to control treatment. Contrarily, the BR+CN treatment displayed the minimum oxidative stress and the utmost plant growth, chlorophyll contents in the leaves, relative water content (RWC), micronutrient concentrations, and grain biochemistry. The BR+CN indicated the highest activities of soil enzymes. Based on the results, we recommend BE+CN treatment to reduce the Ni distribution in the lentil plant. Although, improvement in plant growth, grain quality, soil enzymes, and a significant reduction in plant oxidative stress can only be gained with BR+CN.

Automated summary

The study addressed the ecological and human health risks of Ni-affected soils by investigating the use of different amendments to immobilize Ni in polluted soil and improve lentil plant growth and grain quality. The results showed that BE+CN treatment was most effective in reducing Ni distribution in plant parts, while BR+CN treatment was optimal for plant growth, chlorophyll content, nutrient concentrations, and soil enzymatic activities. Recommendations were made for BE+CN treatment to reduce Ni distribution in lentil plants, and for BR+CN treatment for overall improvement in plant growth, grain quality, and reduction in oxidative stress.