Paper Details

Abstract

Lead (Pb) is a highly toxic heavy metal that severely impairs plant growth by disrupting key physiological and biochemical processes, including photosynthesis, respiration, and enzymatic activity. The application of soil amendments that enhance metal immobilization and improve plant resilience represents a promising strategy for mitigating Pb toxicity. In this context, hydroxyethyl cellulose (HEC), a hydrophilic polymer known for improving soil moisture retention and nutrient availability, and nitrilotriacetic acid–chelated biochar (NTA-BC), recognized for its metal-complexing capacity and nutrient retention, were evaluated individually and in combination for their effectiveness in alleviating Pb stress in maize. A pot experiment was conducted using a completely randomized design with six treatments: 0HEC+0NTA-BC, 5HEC+0NTA-BC, 10HEC+0NTA-BC, 0HEC+0.75NTA-BC, 5HEC+0.75NTA-BC, and 10HEC+0.75NTA-BC, applied under two Pb regimes (0 and 600 mg kg⁻¹ soil) with four replications. Lead stress markedly reduced maize growth, biomass accumulation, and photosynthetic performance. However, the combined application of HEC and NTA-BC significantly mitigated these adverse effects, with the 10HEC+0.75NTA-BC treatment exhibiting the most pronounced improvement under Pb stress. This treatment increased shoot length (26.73%), shoot fresh weight (13.26%), shoot dry weight (56.74%), root length (51.88%), root fresh weight (64.51%), and root dry weight (81.29%) relative to the Pb-stressed control. Moreover, chlorophyll a, chlorophyll b, and total chlorophyll contents were increased by 10.65%, 10.90%, and 12.60%, respectively, indicating enhanced photosynthetic efficiency. Enhanced leaf nitrogen, phosphorus, and potassium concentrations further confirmed improved nutrient uptake and metabolic functioning. Overall, the synergistic application of HEC and NTA-chelated biochar effectively alleviated Pb-induced toxicity, enhanced plant growth, and improved physiological performance in maize. The use of 10HEC+0.75NTA-BC is therefore recommended as a sustainable soil amendment for improving crop productivity in Pb-contaminated soils

To Cite This Article