ECO-GUARD: Sustainable Seed Enhancement Using Cellulose Nanofiber (CNF) Coatings with Bacillus subtilis from Cotton Stalk Waste"

Pakistan faces a dual environmental crisis: over 5 million tons of cotton stalk waste are burned annually, contributing to severe air pollution and respiratory illnesses, while synthetic polymer seed coatings introduce persistent microplastics into agricultural soils. Additionally, wheat sowing under >40°C field conditions results in poor germination rates of 64-70%. This study presents ECO-GUARD, a sustainable seed enhancement technology that addresses these interconnected challenges through the valorization of cotton stalk waste into cellulose nanofiber (CNF) coatings incorporated with heat-tolerant Bacillus subtilis spores.

CNF was extracted from cotton stalk powder through sequential alkali treatment (NaOH, 70°C), bleaching (H₂O₂, pH 10.5), and acid hydrolysis ( H₂SO₄, 50°C). The resulting 0.5% CNF suspension was formulated with B. subtilis spores (10⁶ CFU/ml), and glycerol plasticizer (3-12%), to create a biodegradable, single-layer seed coating for wheat (Triticum aestivum).

The ECO-GUARD coating is expected to achieve >90% germination under heat stress, increase seedling vigor by 50%, and improve crop yields by 18-28%. The CNF-Bacillus formulation biodegrades completely within 24 days—significantly faster than commercial bioplastics (32-48 days)—eliminating microplastic pollution while releasing organic matter that enriches soil. By transforming agricultural waste into a high-value nanomaterial ($50-100/kg CNF), this circular economy solution simultaneously eliminates crop burning, replaces synthetic polymers, and enhances agricultural productivity under Pakistan's extreme sowing conditions. The technology offers a scalable, environmentally sustainable alternative to conventional seed coatings with demonstrated performance advantages in heat-stressed environments.

Keywords:Cellulose Nanofiber (CNF), Cotton Stalk Waste, Bacillus subtilis, Seed Coating, Sustainable Agriculture, Biodegradable Materials, Wheat Germination, Circular Economy