Development and characterization of biobased sprayable mulches

Polyethylene plastic mulch (PPM) films have been employed in high-value and specialty crop production as a physical barrier to weed growth since the 1950s. Over the last decade, due to the environmental problems associated with PPM, biodegradable plastic mulch (BPM) films have started to replace PPM films. However, concerns have arisen regarding the control of BPM film deposition, removal, and decomposition. Bio-based and biodegradable sprayable mulches are a promising substitute for BPM films. A series of biobased sprayable mulches (BSM) were developed using locally available biomaterials, including starch, protein, lignin, and chicken feather waste. Optimum BSM film-forming conditions of protein, starch, lignin, and glycerol mixtures were determined by evaluating different ratios. Keratin was isolated from chicken feathers by dissolving the feathers in a 1 M NaOH solution. The BSM film-forming solutions were physicochemically analyzed (pH, TDS, conductivity), transferred to petri dishes, and dried at 40 °C for 24 h. The dried BSM films were peeled from the petri dishes for mechanical testing, imaging, water absorption testing, and measuring mass loss percentage in water. BSM-12 exhibited the highest tensile strength (23 kPa), with an elongation at break of 15.39 % and a Young’s modulus of 230 kPa. Finally, BSM-5 and BSM-12 film-forming solutions were suggested to assess their effectiveness in weed suppression and their impact on plant growth because of their higher tensile strength and elongation at break. • Developed biobased sprayable mulches using keratin, starch, and other local biomaterials. • Corn starch > 4 % increased filler interaction, reducing the strength of the sprayable mulch films. • BSM-5 and BSM-12 showed superior tensile strength, flexibility, and biodegradability. • Demonstrated potential of circular waste valorization for sustainable agricultural mulching solutions.