Photodegradable mulching films

Mulching films have a long-established usage in farming practice, because of their advantages  

prevention of evaporation to keep the humidity level as constant as possible  

Mulching films also have applications in glasshouses and cloches. Traditional mulching presents some serious drawbacks, such as  

It must be removed from the field after harvest, a very time and moneyconsuming operation. 

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The results agree with the trends seen in the tests of previous years. The preripening treatment may become unnecessary with the use of photodegradable mulching films. The use of plastic mulch causes a remarkable increase in marketable fruit as well as the length of the ripening stage and uniformity of... 

Production of photodegradable mulch films with carefully controlled lifetimes (cf section 8.5). 

EniChem Agricultura (Italy) has developed photodegradable mulch films (Greenplast ) with very precise induction times, which totally disappears into the soil. Photodegradable mulch films are suitable for the following crops watermelons and miscellaneous vegetables (sweet peppers, aubergines. 

The wide application of photodegradable mulch films is still limited by the following factors ... 

Carbonyl-modified polymers photodegrade too rapidly to be useful in mulching films which normally have to retain their integrity for several months before photodegrading. 

Rolland [22] proposed a photodegrading agent comprising E/CO and certain heavy metal salts to enhance the degradability of polyethylene articles such as disposable packaging and mulch film, especially those made from linear resins. 

Category (b) applications, however, use photodegradability primarily to save the cost of collecting and disposing of conventional materials when their useful lives are over. Examples here include mulch film, temporary covers for storing grain, and netting to protect crops from birds [3]. E/CO resins for these uses would probably require modification of the conventional available resins to provide finite induction times to allow the primary function of the products to proceed. 

Fig. 8.3. Photodegradation clear films (a) (MDPS) soil sterilization by solar heating (strawberry) and (b) mulching of Italian vegetable marrow by photodegradable black film (LDPE) [2344]. (MDPS=medium density polystyrene LDPE=low density polyethylene.)...

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