Effect of organic agronomic techniques and packaging on the quality of lamb's lettuce.

BACKGROUND: This research focused on the effect of organic production systems on initial quality and postharvest performance of lamb's lettuce leaves stored in air or under modified atmosphere at refrigerated temperature. Different strategies of organic soil fertility management were compared under the same environmental conditions: (i) a simplified organic production system based on organic commercial fertilizers to recover crop uptake (SB); (ii) an organic production system based on organic matter amendment mainly supplied by animal manure (AM); and (iii) an organic production system based on organic matter amendment supplied by green waste compost (AC). Fully developed lamb's lettuce leaves were harvested and then packed into perforated bags (control in AIR) or in modified atmosphere packaging (MAP) and stored at 4 °C. RESULTS: At harvest, the yield of lamb's lettuce in the AM and AC systems was higher than that in SB. Phenol and dehydroascorbic acid accumulation was observed in the system with the lowest initial supply of organic amendment (SB). Regarding the effect of packaging, AIR conditions maintained the initial quality attributes for a longer period than MAP, which developed off-odours above the threshold of acceptability at 11 days, irrespective of the production system used. CONCLUSION: In general, the initial differences among the production systems were minimal during the postharvest storage. As for the tested packaging systems, AIR successfully maintained the initial quality attributes for a longer period than the MAP. © 2018 Society of Chemical Industry.

Integration of behavioral tests and biochemical biomarkers of terrestrial isopod Porcellio scaber (Isopoda, Crustacea) is a promising methodology for testing environmental safety of chars.

We investigated how different carbonized materials, or chars (olive mill pomace biochar (BC) and urban greens pruning residues hydrochar (HC)) affect an important member of soil fauna, the terrestrial isopod Porcellio scaber. The selection behavior of isopods towards chars after a 48 h exposure was studied in (i) soil-char amended tests with single and multiple choices, and (ii) tests with chars offered as pure material. Finally, we exposed the isopods to char-amended soils for a period of 14 days to follow the effect on food consumption, body mass and activities of enzymes that are commonly altered upon stressor exposure (acetylcholinesterase, AChE, and glutathione S-transferase, GST). We showed that isopods are able to select between char amended and un-amended soil and different forms of char amendments: a clear preference for BC, and avoidance of HC were evidenced. The preferences remained the same when the chars were sterilized leading to the conclusion that initial microorganism composition was not the reason for selection, but selection was governed by other chars' physico-chemical properties. It remains to be elucidated which of these properties were the dominant reason for the selection. We also showed that isopods intentionally use BC as food at a similar rate to alder leaves. Medium-term exposure to HC resulted in adverse effects on isopods because it led to reduced feeding and growth, in addition to increasing GST activity, although no alterations in AChE activity were found. We suggest that behavioral tests with P. scaber could be used as a fast, reliable and economically feasible screening method for determining the safety of chars for the soil environment. Results represent significant contribution in the field of char toxicity testing, highlighting the importance of tests with isopods as important members of soil meso fauna, with the aim of influencing environmental policies and quality standards.

Organic vs. organic - soil arthropods as bioindicators of ecological sustainability in greenhouse system experiment under Mediterranean conditions.

Organic greenhouse (OGH) production is characterized by different systems and agricultural practices with diverse environmental impact. Soil arthropods are widely used as bioindicators of ecological sustainability in open field studies, while there is a lack of research on organic production for protected systems. This study assessed the soil arthropod abundance and diversity over a 2-year crop rotation in three systems of OGH production in the Mediterranean. The systems under assessment differed in soil fertility management: SUBST - a simplified system of organic production, based on an input substitution approach (use of guano and organic liquid fertilizers), AGROCOM - soil fertility mainly based on compost application and agroecological services crops (ASC) cultivation (tailored use of cover crops) as part of crop rotation, and AGROMAN - animal manure and ASC cultivation as part of crop rotation. Monitoring of soil fauna was performed by using pitfall traps and seven taxa were considered: Carabidae, Staphylinidae, Araneae, Opiliones, Isopoda, Myriapoda, and Collembola. Results demonstrated high potential of ASC cultivation as a technique for beneficial soil arthropod conservation in OGH conditions. SUBST system was dominated by Collembola in all crops, while AGROMAN and AGROCOM had more balanced relative abundance of Isopoda, Staphylinidae, and Aranea. Opiliones and Myriapoda were more affected by season, while Carabidae were poorly represented in the whole monitoring period. Despite the fact that all three production systems are in accordance with the European Union regulation on organic farming, findings of this study displayed significant differences among them and confirmed the suitability of soil arthropods as bioindicators in protected systems of organic farming.