Corn husk-derived cellulose nanocrystals reinforced multifunctional mulch film for sustainable agriculture

A smart biodegradable mulch film with UV shielding and soil pH sensing was built. • The mulch film has excellent UV barrier properties with a transmittance below 1 %. • The biodegradable mulch film enhances soil moisture and temperature regulation. • The film showed clear color changes across pH 2–13 and in soils of varying pH. • The mulch film biodegraded in soil, losing 56.6 % mass in 50 days. • The film promoted pak choi growth, outperforming LDPE mulch in pots. Current biodegradable mulching films often have insufficient mechanical strength, weak UV protection, and no capacity for soil pH monitoring. We developed a degradable and recyclable multifunctional agricultural film (PSC/An) from polyvinyl alcohol (PVA), sodium lignosulfonate (SL), corn husk-derived cellulose nanocrystals (CNCs), and blueberry anthocyanins (An). The film was fabricated by simple solution casting and integrates mechanical reinforcement, UV shielding, and visual soil-pH sensing. PSC/An showed a tensile strength of 53.6 MPa and UV transmittance below 1 %, indicating effective UV blocking. It also displayed clear color changes over pH 2–13 and in soils with different pH values, enabling direct visual identification of soil acidity/alkalinity. After three dissolution–regeneration cycles, the film retained its mechanical properties, pH responsiveness, and UV-shielding ability. It reached 56.6 % degradation after 50 days of soil burial. In pak choi pots, film mulching increased seed germination to 96.7 % and produced greater plant height, root length, and biomass than the unmulched control and commercial LDPE mulch. This multifunctional film offers a practical design strategy for environmentally friendly, intelligent mulching materials for sustainable agriculture. Download: Download high-res image (116KB) Download: Download full-size image