Mulches/mulching degradation

Synthetic spun fabrics these materials may also be sold as "landscape fabrics" or occasionally "geotextiles," for long-term weed control. They allow water to permeate through them into the soil, but can degrade where exposed to the sun, so cover with a loose mulch to protect them from the light. 

Depending on the crop and the specific enviromnental requirements of the region (e.g., EU compared to Asia), different compounds have to be developed to achieve these requirements. For example, in Europe more than 8 weeks of intact performance of the mulch film is required. Limited UV-stability, different degradation speeds and the different mechanical properties of the individual polymers have to be considered in the formulation development. 

Gilead D (1995) The disposal of mulching films after use. In Scott G, Gilead D (eds) Degradable polymers principles and applications. Chapman Hall, London, chap 10... 

Ecoflex is also found in agricultural films such as cover sheeting and mulch film. The film can be ploughed into the field and is degraded in the soil after use. 

Alternative uses of EEB have been investigated and results have shown that they are suitable as a mulching material for oil palm. The EFB are fibrous in nature and have a high moisture content (about 60%). The application of EFB in the interrows of palm avenues has been shown to improve oil palm growth and yield performance. When applied onto the soil surface, the EFB undergoes a degradation process that will yield organic matter and slowly release plant nutrients for crop uptake. 

Several years ago, Princeton Polymer Labs. contracted with a client to develop a degradable agricultural mulch film. A first generation additive system was developed and some 12,000 sq. ft. of polyethylene film containing the additive was tried out in 14 states in the U.S.A. Both black and clear films... 

A second generation, and far more effective photo-degrading additive system was later developed and extensive indoor and outdoor testing was done. With such an effective system it was obvious that its use could go much further than just agricultural mulch films. 

Realistic uses for Degradable Plastics include those applications where materials are used outdoors for a limited time only and it is not economically desirable to collect the residual materials after use. Examples are agricultural mulch, films and cordage, twine, etc. Another application is that of packaging which is stored and used indoors and discarded outdoors, in other words litter for which manual collection is not practicable. 

Ecoten LDPE embrittled in 2210 hrs in the Weather-Ometer and 11 months outdoors. This sample of Ecoten does not appear to be a satisfactory Degradable Plastic because of the high level of Ti02 added to the film. Clear Ecoten film without the titanium dioxide pigment was tested outdoors in Israel as agricultural mulch and found to embrittle in less than four months ( ). 

A good example of a class of materials with specific stability and degradability criteria are mulch films for corn production as seen in Fig. 1. They should protect the crops at the beginning of the season but be brittle enough... 

---