Plant Growth, Yields and Fruit Quality of Processing Tomato (Solanum lycopersicon L.) as Affected by the Combination of Biodegradable Mulching and Digestate

In order to improve environmental sustainability of tomato cultivation and the quality of the harvested fruits, we tested (a) the digestate from anaerobic fermentation of buffalo slurries as partial replacing of NP fertilizers and (b) the biodegradable mulching to improve the nutrients and water availability for crop and to control weeds. In 2017&ndash
2018, a private farm of Campania region hosted a trial with four treatments deriving from the combination of two experimental factors: (1) fertilization strategy (standard farm NPK fertilization vs. digestate combined with reduced rates of NP fertilizers)
(2) soil mulching (biodegradable mulching vs. no mulching). We measured fresh and dry aboveground biomass (fruits and stem + leaves), yields, fruits quality. Results pointed out: (1) combination of digestate with reduced rates of NP fertilizers did not decrease yields compared to complete mineral fertilization
(2) yields were improved in 2017 by synergic effects of soil mulching and combination of digestate and reduced rates of NP fertilizers
(3) in both the years, digestate combined with reduced rates of NP fertilizers and soil mulching determined the significant improving of fruits quality parameters interesting the processing industry, namely, fruit color, and firmness, total soluble solids, titratable acidity while antioxidant activity, contents of ascorbic acid, polyphenols, flavonoids, and lycopene showed responses variable with year or cultivar.