The use of mulching films made from non-renewable fossil fuels causes the serious drawback of huge quantities of plastic wastes to be disposed of. Over the last years the growing environmental awareness has prompted researchers to develop a new generation of mulching products starting with raw materials from renewable origin. These materials have to retain their physical and mechanical properties while in use, to be compostable or digestible anaerobically at the end of their life, and to be degradable via micro-organisms into carbon dioxide or methane, water and biomass when integrated directly in the soil. Aim of the research was the development of biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry. Particular attention has been devoted to evaluate the application of such biobased materials in the agricultural practice of mulching. Biobased mulching films were generated in situ by low-pressure spraying of polymeric water dispersion on the soil; the mulches were tested in a Romaine Lettuce Mortarella cultivation inside a greenhouse from November 2013 to January 2014. This paper describes the functionalities of the new bio-based mulching coatings, which were developed and tested in a real scale field cultivation test. During the test in the field, the biodegradable soil mulching materials showed suitable properties for an efficient and profitable use in agriculture. The innovative biodegradable spray coatings lasted in the field up to 2 months. Tests on the lettuce yield and on the properties of the soil under the mulching coatings were carried out. The biodegradable materials could be the environmentally friendly alternatives to synthetic petro-chemical polymers and could contribute to a sustainable agriculture.

Residues of the marine plant posidonia (Posidonia oceanica, PO) beached in tourist zones represent a great environmental, economical, social and hygienic problem in the Mediterranean Basin, in general, and in the Apulia Region in particular, because of the great disturb to the bathers and population, and the high costs that the administrations have to bear for their removal and disposal.In the present paper, Authors determined the heating values of leaves and fibres of PO, the main offshore residues found on beaches, and, meantime, composted those residues with mowing and olive pruning wood. The final composts were characterized for pH, electrical conductivity, elemental composition, dynamic respiration index, phytotoxicity, fluorescence and infrared spectroscopic fingerprints.The aim of the paper was to investigate the composting and energy recovery of PO leaves and fibres in order to suggest alternative solutions to the landfill when offshore residues have to be removed from recreational beaches.The fibrous portion of PO residues showed heating values close to those of other biofuels, thus suggesting a possible utilization as source of energy.At the same time, compost obtained from both PO wastes showed high quality features on condition that the electrical conductivity and Na content are lowered by a correct management of wetting during the composting.

The increasing food demand encourages the overuse of agricultural lands and natural resources that often is not economic, social, and environmentally sustainable. This overuse can lead to the soil sickness, which causes the decline of the soil fertility through the development of soil-borne diseases, the depletion of nutrients, and the loss of soil organic matter. Addition of residual biomasses is a good agricultural practice for improving soil properties and enhancing crop production, in the framework of a sustainable development. The study is performed in a 2 years field experiment using olive pomace residues (OPR), composts from municipal solid wastes (CMW), spent mushroom compost (SMC), and livestock manures based compost (BRX) for the fertilization of the potato crop. The aim of the study is to test the impact of different biomasses available in Apulia region, Italy, on soil fertility and potato growth. The application of BRX shows the highest potato yield in both seasons while OPR, CMW, and SMC significantly increases soil total nitrogen and organic carbon compared to BRX and un-amended plots (CON). All treatments, except SMC, reduce the soil exchangeable K content, therefore, the application of BRX, OPR, and CMW should include the use of K based fertilizer to balance the high crop demand of K. Finally, SMC appears the best compromise for managing soil fertility and obtaining high potato yield.

Posidonia oceanica (L.). Del. is the main marine seagrass endemic of the Mediterranean Sea. From September on, leaves and rhizomes detach off the marine plant and accumulate on beaches in huge amount. Offshore residues represent an environmental, economical, social and hygienic problem because of the great disturb to the bathers and citizens and high costs that the public administrations have to support for managing them. Nowadays, current Italian legislation (D. L. n. 75/2010) allows the use of posidonia residues as raw material for the production of compost even though at a rate of 20% by weight. In an experiment posidonia residues have been used to produce green compost. This was used as a substrate for the cultivation of tomatoes in soilless subirrigation system. Plants grown on compost showed a lower production (18%) compared to perlite: peat (control), but fruits had the same quality characteristics (as dry matter and soluble solids). On the other hand, the same compost represented a viable alternative to peat when used for the production of lettuce transplants. In particular, lettuce seedlings grown on compost showed higher fresh and dry weight of leaves and roots, length and volume of the root system, and leaf area, if compared with those grown on peat alone.

Posidonia (Posidonia oceanica [L.] Delile) is a marine phanerogam endemic of the Mediterranean basin. Senescent plant parts periodically detach from and accumulate along Mediterranean beaches, forcing the coastal municipalities to remove and manage somehow the large amount of beached biomass. In this research, a posidonia based compost (posidonia, 63% by volume - olive tree pruning residues, 21% - green waste, 16%) has been used as growing media component at different ratios (0, 25, 50, 75 and 100%), as a complement to a peat based commercial substrate, for nursery lettuce seedlings production. Growing media with increasing compost percentage showed higher pH, EC, air capacity and nutrients availability, but lower water holding capacity. The overall growth of the seedlings was enhanced by the compost presence in the substrate, with positively evidences for both roots and leaves. Posidonia based compost could represent an interesting alternative to peat as horticultural growing media component.

BACKGROUND: Peat is the main component of growing media but is also a non-renewable resource; therefore European policy strongly encourages the use of peat alternatives such as compost. Posidonia is a Mediterranean seagrass that produces very conspicuous onshore deposits that can be composted. In this study, a commercial green compost and a Posidonia residue-based compost were tested in order to assess their potential use as substitutes or complements to peat. RESULTS: All macro and micro-element concentrations of the substrates were positively and significantly related to the percentage of composts in the growing media. Plant grown on peat showed higher content of P, Ca, K, Na, Cu, Mn, Zn and Fe, and a slightly higher biomass production in comparison to compost-based growing media. In contrast, plants grown on compost-based substrates showed lower uptake of Cd and Cr than peat. CONCLUSION: The results indicate that both composts can be used as a complement to the peat for substrate preparation, especially at a rate of 30%. The Posidonia-based compost showed better productive results in Comparison to the green one. Basil grown on the two compost-based media showed reduced absorption level of potentially toxic metals in comparison to peat.

Posidonia [Posidonia oceanica (L.) Delile] is a marine phanerogam endemic of the Mediterranean Sea that grows all along the coast forming extensive underwater meadows. Senescent posidonia leaves, together with fibers (residues of rhizomes and decomposed leaves), periodically accumulate along Mediterranean beaches, covering vast areas of coast. Removal and disposal of these large volumes of plant biomasses represent a high cost for local administrations. Therefore, in this experiment, beached residues of posidonia were composted with olive pruning and green wastes with the objective to assess the efficacy of posidonia-based compost (63% on a volume basis) as a peat replacement. The compost was then mixed with a peat-based commercial substrate at rates of 0% (C0, pure peat-based commercial substrate tested as control), 25% (C25), 50% (C50), 75% (C75), and 100% (C100, pure posidonia-based compost) v/v. Mixtures were used as growing media to produce lettuce seedlings for transplant. Two lettuce cultivars (8511RZ and Satine) were tested. Main physical and chemical properties of the five growing media, shoot and root fresh and dry weight, leaf area, root morphology, and elemental leaf tissue composition were studied. Growing media containing posidoniabased compost, C25 and C50 in particular, showed good physical properties. Increasing compost proportions in the mixtures resulted in enhanced: 1) availability of macro- and micronutrients in the growing media; and 2) overall growth parameters of lettuce seedlings, in particular for the cultivar Satine. In conclusion, posidonia-based compost shows a considerable potential as a peat substitute in horticultural substrates; posidonia residues are a low-cost renewable material. In growing media for lettuce seedlings production, posidonia-based compost could be used as a complement to peat at a rate of 25% or 50% to obtain optimal physical properties and to limit the negative effects of high B content, which are typical of posidonia residues.