Skip to main navigation menu Skip to main content Skip to site footer

EFFECT OF BIODEGRADABLE MULCH FILM DECOMPOSITION RATE ON ROOT-ZONE MICROCLIMATE AND YIELD FORMATION IN CUCURBIT CROPS UNDER ARID CONDITIONS

Abstract

 Plastic film residues accumulating in agricultural soils represent a significant environmental challenge worldwide, driving demand for biodegradable alternatives. This three-year field study evaluated five commercially available biodegradable mulch films (polylactic acid [PLA], polyhydroxyalkanoate [PHA], thermoplastic starch [TPS], starch-polybutylene adipate terephthalate blend [PBAT], and paper-based mulch) against a conventional low-density polyethylene (LDPE) control on watermelon (Citrullus lanatus cv. 'Crimson Sweet') and cantaloupe (Cucumis melo cv. 'Topmark') plantations in Uzbekistan (40°51′N, 68°43′E). Key microclimate variables root-zone temperature at 5, 15, and 25 cm depths, volumetric soil water content (SWC), and CO₂ flux from soil surface were monitored continuously. Tensile strength degradation kinetics were modelled using a modified Avrami equation. Results showed that PBAT blend films maintained structural integrity for 85–92 days post-installation, matching the critical crop establishment period (65–70 days), while TPS films degraded prematurely within 38–42 days under field UV exposure. Root-zone temperature in PBAT plots was 2.9°C higher than in LDPE plots at 5 cm depth due to increased CO₂ flux from microbial film decomposition. Watermelon marketable yield in PBAT plots reached 41.3 t ha⁻¹, surpassing LDPE (38.6 t ha⁻¹) by 7.0%, with no statistically significant residue detected at harvest (p = 0.08). These findings provide quantitative design criteria degradation half-life, thickness-to-tensile-strength ratio, and UV stabilizer concentration for biodegradable mulch films optimized for arid Central Asian growing conditions.

Keywords

biodegradable mulch, PBAT, PLA, degradation kinetics, root-zone temperature, cucurbits, arid agriculture, CO₂ flux, tensile strength, Avrami model.

PDF

References

  1. OECD. (2022). Plastics in Agriculture: Sources, Fates, and Impacts. OECD Publishing, Paris. https://doi.org/10.1787/e1163e2b-en
  2. Ministry of Agriculture, Republic of Uzbekistan. (2023). Annual Report on Agricultural Inputs Consumption. Tashkent: MAR Statistical Division. 112 p.
  3. Sintim, H.Y., Bandopadhyay, S., English, M.E., et al. (2019). Impacts of biodegradable plastic mulch on soil health. Agriculture, Ecosystems & Environment, 273, 36–49.
  4. Ghimire, S., Wszelaki, A.L., Moore, J.C., et al. (2018). The use of biodegradable mulches in lieu of polyethylene in fresh-market tomato production. HortScience, 53(3), 288–294.
  5. Moreno, M.M., Moreno, A., Mancebo, I. (2009). Comparison of different mulch materials in a pepper (Capsicum annuum L.) crop. Spanish Journal of Agricultural Research, 7(3), 54–60.
  6. Kyrikou, I., Briassoulis, D. (2007). Biodegradation of agricultural plastic films: a critical review. Journal of Polymers and the Environment, 15(2), 125–150.
  7. Mochizuki, M. (2010). Synthesis, properties, and structure of poly(lactic acid). In: Auras R. et al. (eds.) Poly(Lactic Acid). Wiley, pp. 17–29.
  8. Brodhagen, M., Peyron, M., Miles, C., Inglis, D.A. (2015). Fate of soil-applied bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Polymer Degradation and Stability, 114, 46–56.
  9. Sintim, H.Y., Bary, A.I., Hayes, D.G., et al. (2020). Release of micro- and nanoplastic fragments from soil-incorporated conventional- and biodegradable-mulch films. Environmental Science & Technology, 54(20), 12828–12839.
  10. Moreno, M.M., Moreno, A. (2008). Effect of different biodegradable and polyethylene mulches on soil properties and production in a long-term experiment. Scientia Horticulturae, 117(2), 49–56.
  11. Briassoulis, D., Dejean, C. (2010). Critical review of norms and standards for biodegradable agricultural plastics. Journal of Polymers and the Environment, 18(3), 384–400.
  12. Morales, M.A., Aranaz, I., Guitart, M., et al. (2022). Modelling UV-induced degradation kinetics of starch-PBAT blend films in Mediterranean field conditions. Polymer Testing, 108, 107498.
  13. Li, C., Moore-Kucera, J., Miles, C., et al. (2014). Effects of biodegradable mulch on soil quality. Applied Soil Ecology, 79, 59–69.
  14. Bandopadhyay, S., Martin-Closas, L., Pelacho, A.M., DeBruyn, J.M. (2018). Biodegradable plastic mulch films: impacts on soil microbial communities and ecosystem functions. Frontiers in Microbiology, 9, 819.
  15. Miles, C., Wallace, R., Wszelaki, A., et al. (2012). Deterioration of potentially biodegradable alternatives to black polyethylene mulch in three tomato production regions. HortScience, 47(9), 1270–1277.

Downloads

Download data is not yet available.