Innovative films for melon mulching in protected coltivation.

In the last years the growing use of plastic materials in agriculture has created many problems for management and selling off the waste post-use. For a healthy agriculture, research on the adoption of plastic materials that are respectful of the environment are necessary. Therefore, in 1999 and 2000, close to the Experimental Farm “Pantanello” (40°20’N; 16°48’E) in Basilicata region (Southern Italy) a two-year research, with the aim of evaluating the effect of soil solarization, different mulching films and small tunnels on melon (Cucumis melo L. var. reticulatus Naud., cv Baggio), grown in unheated greenhouse during spring-summer period, was carried out. In particular, two innovative mulching films (a photodegradable film and a biodegradable one) were compared with a traditional film (black LDPE 50 mm); all the three films were combined with a crop protection obtained by small tunnels on the mulched rows for the first 60 and 50 days of the growing cycles. Furthermore, half of the greenhouse soil surface had also been previously solarized during 1998 and 1999 summer period. Under photo and biodegradable mulching films, temperatures were rather higher (4-3°C) at 10-30 cm depth with respect to the black LDPE. As for the lifetime of films, the biodegradable one showed clear signs of laceration at about the 40th day from its emplacement; in the solarized soil the reduced weed emergence allowed a better contact of the film with the soil and so a more rapid and complete biodegradation was observed; in the untreated soil, weed competition with the crop and also their high bio-mass under the film lacerated it at several points early on. The photo-degradable film never exhibited its degradation during the two melon crop cycles. Regarding the agronomic traits, the photodegradable film gave the best results in both years, while the biodegradable one showed good yield when it was applied on the solarized soil. Small tunnels improved melon yield by 16 % and 25 %, respectively in the first and second year; yield increase was higher when photodegradable mulching was adopted. Finally soil solarization, thanks to the nematodes control, increased both marketable yield (by 156 % in 1999 and by 268 % in 2000) and fruit quality in terms of flesh soluble solids content: + 2.3 and + 1.7 °Brix, respectively, in the two-year research. The use of these innovative mulching (especially biodegradable one) films is desirbale to reduce the total amount of agricultural plastic wastes.