18 / 2021-05-24 15:53:58

EVALUATION OF HYDROPHOBIC LIGNOCELLULOSE NANOFIBRILS AS AGRICULTURAL MULCH FILMS AND SPRAY COATINGS

Agricultural waste stalks,compostable,mulching,films,soil coatings,biodegradation,sustainable development goal

The 2015 United Nation General Assembly adoption of Agenda 2030 for sustainable development especially SDG 2 of ‘zero hunger’ has led to recent increase in agricultural crop production occasioned by the need to serve the ever-growing human population. This has also given rise to the use of various plasticulture techniques to improve crop yields. These techniques leave lots of plastic debris in the soil after crop harvesting contributing to environmental pollution, soil degradation and incur more cost for its removal. This practice though has short-term agronomic benefits, but its long-term effects neglect the principle of food security and sustainable agricultural systems enshrined in SDG 2. It is important to note that direct sources of these plastic debris in agricultural soils include, plastic mulch films, greenhouse materials and soil conditioners like polyurethane foam and polystyrene flake. Plastic mulch films has been quoted to contribute most of the 2-3 million tons of plastics used annually in agriculture. This increased level of plasticulture recently practiced has increased volume of waste plastics in the soil and consequently decreased productivity in arable lands with the concomitant health and environmental hazards poised.

This work designed based on the second sustainable development goal of ensuring more productive and less wasteful agriculture systems demonstrated a facile way of producing compostable mulch films and coatings. The mulch films were fabricated from waste agricultural stalks converted to lignocellulose nanofibrils (LCNFs) through a mechanochemical action which also involves addition of Methyltrimethoxysilane to make the LCNFs hydrophobic (Figure 1). The 63µm films formed by casting for both LCNFs showed excellent ability to shield UV-B and UV-A rays (below 300 nm) and a paper-like tensile strength of about 16 MPa. With its good thermal properties of withstanding above 150 oC before deterioration and low water vapour permeation of less than 3.41x10-08 g/m.h.Pa, it is believed that improvement of its elongation at break which lags at less than 11 % will make the films excellent for mulching. However, the LCNFs concentrate sprayed as coating on the soil showed good adhesion to the soil topography and ability for crops to grow through it (Figure 2).