Angela Libutti

Impact of the reusing of food manufacturing wastewater for irrigation in a closed system on the microbiological quality of the food crops

In order to evaluate if the reuse of food industry treated wastewater is compatible for irrigation of food crops, without increased health risk, in the present study a cropping system, in which ground water and treated wastewater were used for irrigation of tomato and broccoli, during consecutive crop seasons was monitored. Water, crop environment and final products were monitored for microbial indicators and pathogenic bacteria, by conventional and molecular methods. The microbial quality of the irrigation waters influenced sporadically the presence of microbial indicators in soil. No water sample was found positive for pathogenic bacteria, independently from the source. Salmonella spp. and Listeria monocytogenes were detected in soil samples, independently from the irrigation water source. No pathogen was found to contaminate tomato plants, while Listeria monocytogenes and E. coli O157:H7 were detected on broccoli plant, but when final produce were harvested, no pathogen was detected on edible part. The level of microbial indicators and detection of pathogenic bacteria in field and plant was not dependent upon wastewater used. Our results, suggest that reuse of food industry wastewater for irrigation of agricultural crop can be applied without significant increase of potential health risk related to microbial quality.

Biochar application to peat based growing media for nursery production of broccoli seedlings

Conservation agriculture (CA) can improve sustainable rice production. This work evaluated the effect of different CA practices on rice agronomic system. A four-year experiment (2013-2016) was carried out in Crescentino (VC), North-West Italy, comparing three tillage managements (sod dry seeding, sod wet seeding and ploughing), combined with three N fertilisation levels (0-110160 kg N ha) and two straw management (straw retained and removed). Yield and yield components were influenced by both tillage practices and N fertilisation, but not by straw management. Sod seeding reduced grain yield of about 16% with respect to ploughing, because of the lower panicle density and higher sterility. Rice responded to N fertilisation, but the higher sterility limited the positive effect at high N rates. Moreover, in sod seeding, high N supply increased Apparent Recovery (AR). Straw retention improved soil quality, increasing soil organic carbon concentration.