Polymers Use as Mulch Films in Agriculture—A Review of History, Problems and Current Trends

Abstract

The application of mulch films for preserving soil moisture and preventing weed growth has been a part of agricultural practice for decades. Different materials have been used as mulch films, but polyethylene plastic has been considered most effective due to its excellent mechanical strength, low cost and ability to act as a barrier for sunlight and water. However, its use carries a risk of plastic pollution and health hazards, hence new laws have been passed to replace it completely with other materials over the next few years. Research to find out about new biodegradable polymers for this purpose has gained impetus in the past few years, driven by regulations and the United Nations Organization’s Sustainable Development Goals. The primary requisite for these polymers is biodegradability under natural climatic conditions without the production of any toxic residual compounds. Therefore, biodegradable polymers developed from fossil fuels, microorganisms, animals and plants are viable options for using as mulching material. However, the solution is not as simple since each polymer has different mechanical properties and a compromise has to be made in terms of strength, cost and biodegradability of the polymer for its use as mulch film. This review discusses the history of mulching materials, the gradual evolution in the choice of materials, the process of biodegradation of mulch films, the regulations passed regarding material to be used, types of polymers that can be explored as potential mulch films and the future prospects in the area.

Biodegradable High-Molecular-Weight Poly(pentylene adipate-co-terephthalate): Synthesis, Thermo-Mechanical Properties, Microstructures, and Biodegradation

“…3 The PBAT market is expected to increase to $2.7 billion by 2030 from $1.1 billion in 2020, with applications in packaging, consumer durables, and agriculture. 4,5 PBAT is fully degraded in composting environments and meets ASTM tests for biodegradation in soil and aquatic environments. 6−9 In contrast, low-density polyethylene, low-density polyethylene (LDPE), or linear LDPE (LLDPE) is difficult to recycle and has limited biodegradation.…”

“…PBAT is the most widely produced biodegradable polymer . The PBAT market is expected to increase to $2.7 billion by 2030 from $1.1 billion in 2020, with applications in packaging, consumer durables, and agriculture. , PBAT is fully degraded in composting environments and meets ASTM tests for biodegradation in soil and aquatic environments. − In contrast, low-density polyethylene, low-density polyethylene (LDPE), or linear LDPE (LLDPE) is difficult to recycle and has limited biodegradation . However, PBAT-blown films do not fully meet the application requirements due to their lower tensile modulus than polyethylene-blown films (80–95 MPa vs 120–200 MPa) and higher cost.…”

Glufosinate Ammonium-Loaded Halloysite Nanotubes for Slow-Release Weeding Polymer Mulch Films

“…1,2 With the rise of growing white pollution, more and more attention has been paid to degradable plastics. 3,4 As a biodegradable material, poly(butylene adipate-co-terephthalate) (PBAT) is considered to be one of the most promising materials to solve white soil pollution. PBAT is a biodegradable aromatic copolyester with high flexibility that might be a viable replacement for polyolefin-based mulching films.…”

“…Lack of awareness of environmental protection and rapid industrial development have led farmers to increase the use of chemicals such as fertilizers, pesticides, and plastic films, increasing productivity while exacerbating the problem of soil pollution. , With the rise of growing white pollution, more and more attention has been paid to degradable plastics. , As a biodegradable material, poly­(butylene adipate- co -terephthalate) (PBAT) is considered to be one of the most promising materials to solve white soil pollution. PBAT is a biodegradable aromatic copolyester with high flexibility that might be a viable replacement for polyolefin-based mulching films. , Therefore, many researchers have studied and modified PBAT with poly­(lactic acid) (PLA) to prepare mulch film. − However, as the PBAT/PLA film is covered in the field over time, its various properties begin to decline.…”

Effect of beeswax on the physical and mechanical properties of solution cast poly(butylene adipate co-terephthalate)/thermoplastic starch/beeswax films

“…The requirements for films and their testing criteria for mulch applications have been highlighted in EN 17033. 4 Starch is a natural biodegradable polymer composed of amylose and amylopectin, which is mainly found in roots, tubers and seeds. 5 Pure starch has disadvantages like poor mechanical and water barrier properties.…”