Lead (Pb) toxicity imposed hazardous impacts to agricultural lands, which presents a serious threat to crop productivity, soil health, and ecological sustainability. This study aims to elucidate the synergistic potential of vermicompost and biogas slurry in remediating Pb-stress under controlled conditions. Unlike previous studies that examined these organic inputs individually, this research focuses to explore their potential interactive effects on maize seedlings growth, root structural traits along with root anatomical structures, morphological, and photosynthetic indices. A two-factorial experiment using a completely randomized design with three replicates was conducted, comprising of four Pb levels (0,100,200,300 mg kg soil − 1 ) and four organic amendment application rates (0,4,6,8 tons ha − 1 ). Pb exposure significantly reduced emergence index (-32.14%), decreased final emergence percentage (-25%), and increased mean germination time (+ 9.28%). However, a notable reduction was recorded in root length (-45.53%), root projection area (-69.99%), and lowered root average density (-69.84%) during Pb toxicity. On the other hand, organic amendments mediated structural recovery and strengthening of root architect (enlarged metaxylem vessels, thickened cortex, and well-developed aerenchyma). Pb contamination also retarded maize plant growth by reducing leaf area, shoot dry weight, and root fresh weight up to -52.50%, -55.48%, -42.77% respectively. Photosynthetic pigment content such as Chl. a and carotenoid decreased (-15.76%, -22.87%) under Pb stress whereas increased (+ 15.13%, + 17.76%) with organic amendments treatment. Our findings indicate that integrated use of vermicompost and biogas slurry can sustainably improve plant resilience and soil functionality in contaminated agroecosystems through modulation of root architecture, stimulation of seed germination, and enhancement of photosynthetic performance.
Rehman et al. (Sat,) studied this question.