Radiometric properties of biodegradable films for horticultural protected cultivation

The use of low-density polyethylene plastic films for soil mulching and greenhouse covering has been increasing significantly in the world. In order to overcome the environmental pollution due to the huge consumption of plastics and to the consequent waste production, innovative biodegradable materials have been introduced to replace traditional plastic films. Biodegradable films can be disposed directly in the soil or in composting plant. Biodegradable films are innovative materials, as a consequence their physical properties must be evaluated in order to assess if they meet the agricultural requirements. In the present research the radiometric properties of innovative biodegradable starch based films were tested in laboratory and during experimental field tests. The biodegradable films were used as low tunnel covering and mulching films in a melon cultivation in Southern Italy. Two black biodegradable and one transparent mulching film were used in combination with two biodegradable films for low tunnel covering. Low density polyethylene films were used for comparison too. Radiometric tests carried out by means of spectrophotometers on the biodegradable films for low tunnel covering showed values of the solar transmissivity coefficient between 86 and 87% and values of the long wave infrared coefficient ranging from 10 to 16%. The yield of melon obtained using biodegradable films was comparable with the yield obtained using LDPE films, especially using the black mulching film rather than transparent mulching films.