Driving the Ecological Transition of Agriculture through Voluntary Certification of Environmental Impacts: An Exploratory Literature Review on the Olive-Oil Sector

Human population growth has resulted in increased food consumption, followed by agrifood production intensification. Human activities have a significant impact on the environment, causing, among other things, air and water pollution and biodiversity degradation. In an international context where there is strong concern about environmental issues, it is also necessary to direct food production towards more sustainable models. In this context, the use of frameworks for certifying the environmental footprint of agrifood products can be a lever to promote sustainable production and consumption. The objective of this paper is to explore the opportunities for certifying the environmental footprint of products, focusing in particular on some of the main environmental claims: global warming, water depletion, and biodiversity loss. The olive sector was selected as a case study since it is the major tree crop in the Mediterranean countries, and it has strong impacts on human health and the environment. We employed a literature review in the SCOPUS database and the knowledge of experts in the main environmental certification sectors. The study revealed the possibility of adopting various mitigation strategies and improving environmental performance, while also pursuing certain market objectives related to certified products

Management options influence seasonal CO2 soil emissions in Mediterranean olive ecosystems

Field trials were conducted at traditional Mediterranean olive agro-ecosystems grown at two locations (Italy –IT, Greece –GR). Groves were managed for many years using sustainable (S, cover crops, compost application, mulching of pruning biomass) or conventional (C) practices (e.g., soil tillage, burning of pruning residuals). The IT grove was rainfed (RAIN) while the GR was irrigated (IRR). This study examined the seasonal variation of soil CO2 emission (Rs) to explore the effect of the management options (C, S) on Rs at both sites. The second aim was to test the hypothesis that the seasonal Rs is differentially modulated by soil temperature and moisture, namely that (i) soil moisture limits Rs when it is below the lower limit of the readily available water (RAWLLim) and (ii) soil temperature above a threshold (max_T) reduces Rs even if soil moisture is non limiting. On the whole-season basis, the mean Rs rate at the rainfed site was 2.17 ± 0.06 (SE) at CRAIN and 2.32 ± 0.06 μmol CO2 m−2 s–1 at SRAIN plot, while at the irrigated site Rs was about 3.64 ± 0.11 (CIRR) and 4.05 ± 0.15 μmol CO2 m−2 s–1 (SIRR). The seasonal oscillation of Rs was consistent across locations and partitionable in three periods according to DOY (Day of Year) interval: Phase I (DOY 20–103 –GR; 20–118 -IT), Phase II (DOY 141÷257, GR; 142–257, IT) and Phase III (DOY 291–357, GR; 286–350, -IT). Pooling all the Rs data across sites and managements, max_T was ∼ 20 °C discriminating a differential response of Rs when soil moisture was < or > RAWLLim. These differential modulations exerted by temperature and moisture were integrated into a conditional model developed with a repeated random subsampling cross-validation procedure to effectively (R2 = 0.84) predict Rs. This paper mechanistically describes the interaction of the environment (soil moisture and temperature) and the management options (S, C) under various moisture conditions on Rs and would support carbon flux accounting procedures (e.g., regulating ecosystem services) tailored to the estimation of sink/source capability of traditional olive agro-ecosystem within environmental-friendly agricultural domains

Whole genome scanning of a Mediterranean basin hotspot collection provides new insights into olive tree biodiversity and biology

Olive tree (Olea europaea L. subsp. europaea var. europaea) is one of the most important species of the Mediterranean region and one of the most ancient species domesticated. The availability of whole genome assemblies and annotations of olive tree cultivars and oleaster (O. europaea subsp. europaea var. sylvestris) has contributed to a better understanding of genetic and genomic differences between olive tree cultivars. However, compared to other plant species there is still a lack of genomic resources for olive tree populations that span the entire Mediterranean region. In the present study we developed the most complete genomic variation map and the most comprehensive catalog/resource of molecular variation to date for 89 olive tree genotypes originating from the entire Mediterranean basin, revealing the genetic diversity of this commercially significant crop tree and explaining the divergence/similarity among different variants. Additionally, the monumental ancient tree ‘Throuba Naxos’ was studied to characterize the potential origin or routes of olive tree domestication. Several candidate genes known to be associated with key agronomic traits, including olive oil quality and fruit yield, were uncovered by a selective sweep scan to be under selection pressure on all olive tree chromosomes. To further exploit the genomic and phenotypic resources obtained from the current work, genome-wide association analyses were performed for 23 morphological and two agronomic traits. Significant associations were detected for eight traits that provide valuable candidates for fruit tree breeding and for deeper understanding of olive tree biology.This research was financed by Greek Public Investments Program (PIP) of General Secretariat for Research & Technology (GSRT), under the Emblematic Action ‘The Olive Road’ (project code:2018ΣE01300000). Sebastián Ramos-Onsins is supported by the grant PID2020-119255GB-I00 (MICINN, Spain) and the CERCA Programme/Generalitat de Catalunya and acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centres of Excellence in R&D 2016–2019 and 2020–2023 (SEV-2015-0533, CEX2019-000917) and the European Regional Development Fund (ERDF).The publication of the article in OA mode was financially supported by HEAL-Link.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917).Peer reviewe

Organic olive orchards on sloping land: More than a specialty niche production system?

Five organicSloping and Mountainous Olive Plantation ProductionSystems (SMOPS) have been studied in four olive-producing areas in four European countries (Spain, Italy, Greece and Portugal). Results indicate that these SMOPS provide ecological, economic and social benefits to the regions in which they are located, although most of these benefits are not strictly limited to the organicproductionsystems. Erosion control and organic matter balance remain significant issues in four of the SMOPS and we suggest that subsidy support should be conditional on the implementation of additional soil and water conservation measures that should be provided with specific funding. Most of the SMOPS will remain dependent on a similar level of support in order for oliveproduction to remain economically feasible. The lower profitability compared to non-organicoliveproductionsystems suggests that there is limited scope for expansion of organicoliveproduction, although in the study areas where there is little such production, such as Western Crete (Greece) and Basilicata–Salerno (Italy) the scope remains great. The analysis of the reasons for the beneficial effects of olive cultivation in the areas studied indicates that in most cases soil management techniques adopted in or recommended for organicproductionsystems could provide similar benefits in other productionsystems as well

Nutrient dynamics, soil properties and microbiological aspects in an irrigated olive orchard managed with five different management systems involving soil tillage, cover crops and compost

The aim of the present study was to determine the short-term effects (three years) of four sustainable management systems including different carbon inputs (compost, pruning residues and cover crops, applied solely or combined) on the mineral content of soil, olive trees and weeds, on some specific groups of soil microorganisms, and on weed mycorrhizal colonization in an olive orchard compared to a conventional system involving soil tillage and only mineral forms of fertilizers. The study was performed between 2013 and 2015 in a 40-year-old olive plantation. The results showed that soil organic matter, as well as main macro- and micronutrients, were markedly improved following three years of increased biomass inputs. Data related to the mycorrhizal colonization of spontaneous weed flora and to actinobacteria, Azotobacter and proteolytic bacteria suggest favourable effects on soil biology and agro-ecosystem complexity. Sowing a mixture of winter cover crops for three successive years also contributed to soil enrichment in biological as well as mineral nutrient aspects. Adoption of the sustainable management here applied practices is in complete agreement with the European policy on the transition from a linear to a circular economy and would provide significant benefits for rural stakeholders and ecosystems in the long term

Effect of different sustainable orchard management strategies on soil properties, nutrient uptake and soil microbiological aspects in an olive orchard

The short-term (three years) effects of four sustainable orchard management schemes were evaluated in an experimental olive orchard in Crete, Greece, in terms of mineral content of soil and trees, soil microbial populations and mycorrhizal colonization. The study was performed between 2013 and 2015 in a forty-year-old olive plantation (Olea europaea L., cv. Kalamata). The orchard management schemes included: a) compost application (COMP), b) recycling of pruning material (PRUN), c) a mixed (legumes and Avena sativa) cover crop (COVER), d) combination of a, b and c (ALL), and e) control (CON), with no application of organic material and maintenance of weed-free orchard. Although alteration of basic soil properties including increase of organic matter and water and nutrient holding capacity are slow processes that require several years to be achieved, some positive effects were recorded during the first 3 years of application. Soil organic matter, was significantly increased in ALL treatment as compared to single-factor treatments, where differentiation from control was still not clear. Nitrate-N availability was higher in COMP and ALL treatments, while sole application of PRUN treatment seemed to act negatively in N availability as compared to control. Phosphorus availability was also increased in COMP and ALL treatments, while ALL treatment resulted in higher N and P content in olive tree leaves. A positive effect on mycorrhizal colonization was recorded in ALL treatment, while all sustainable schemes seemed to favor the populations of azotobacters and actinomycetes, as compared to the control. The adoption of the sustainable management schemes applied during this study, is in complete agreement with the European policy on the transition from a linear to a circular economy and could provide significant benefits for rural stakeholders and ecosystems in the long term

Self-incompatibility and pollination relationships for four Greek olive cultivars

The present three-year study aimed to (1) determine the number of flowers per inflorescence, (2) determine the proportion of hermaphrodite flowers and (3) investigate the genetic and environmental components of self-incompatibility through controlled pollination trials, followed by microscopic observation of in vivo pollen tube growth for olive cultivars 'Koroneiki','Kalamata','Mastoidis' and 'Amygdalolia'. Significant differences between cultivars and years were observed for number of flowers/inflorescence and hermaphrodite flowers percentage. The highest number of flowers was observed for 'Kalamata' panicles followed by 'Koroneiki', whereas the lower numbers were for 'Mastoidis' and 'Amygdalolia'. The highest percentage of hermaphrodite flowers was observed for 'Koroneiki', followed by 'Kalamata' while lower levels were counted for 'Mastoidis' and 'Amygdalolia'. 'Koroneiki' showed a noteworthy capability (3.6-8.7% of hermaphrodite flowers) to set fruit through self pollination. Lower fruit set rates were counted for 'Mastoidis' (1.7-2.6%) and 'Amygdalolia' (0.5-2.4%). The lowest level of fruit set was observed for 'Kalamata' (0.4-2%). In the case of cross pollination, the highest fruit set rates were observed for 'Koroneiki', intermediate rates were counted for 'Mastoidis', followed by 'Amygdalolia', and the lowest levels of fruit set were counted for 'Kalamata'. In the framework of the sporophytic SI system, we attributed R2R4 to 'Mastoidis' and 'Kalamata', R1R2 to 'Amygdalolia' and R4R6 to 'Koroneiki'. Based on the results of these experiments, recommendations were released on cross pollination requirements and combinations with compatible cultivars for setting up new olive orchards to ensure high fruit sets and adequate yields

Growth, photosynthesis and pollen performance in saline water treated olive plants under high temperature

© G.C. Koubouris et al., 2015. Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl)] on physiological and reproductive functions of cultivars Koroneiki and Amphissis in a closed hydroponic system. Shoot growth was markedly reduced in high salinity dose in Amphissis (−81%) and Koroneiki (−75%). The photosynthetic rate was significantly reduced at 120 mM NaCl for both cultivars, as well as chlorophyll and carotenoids content (43% and 44%, respectively). The Na+ content in all plant parts increased in both salinity doses especially in Amphissis while K concentration decreased for both cultivars. Inflorescences in Amphissis were severely damaged due to salinity. Consequently, pollen sampling and in vitro germination study was only feasible for Koroneiki. Indeed, Koroneiki pollen germination was reduced at 60 mM NaCl (−42%) and at 120 mM NaCl (−88%). Pollen tube length was also reduced by 15% and 28% for the middle and high salinity dose, respectively. The results of the present study indicate that Amphissis is more sensitive in high salinity doses compared to Koroneiki and that reproductive functions are severely affected by salinity

Growth, photosynthesis and pollen performance in saline water treated olive plants under high temperature

© G.C. Koubouris et al., 2015. Olive cultivation in hot arid areas is hindered by the scarcity of irrigation water. The exploitation of saline water has been proposed as a solution to partially cover plant water demands. This paper presents the effects of salinity [0, 60 and 120 mM sodium chloride (NaCl)] on physiological and reproductive functions of cultivars Koroneiki and Amphissis in a closed hydroponic system. Shoot growth was markedly reduced in high salinity dose in Amphissis (−81%) and Koroneiki (−75%). The photosynthetic rate was significantly reduced at 120 mM NaCl for both cultivars, as well as chlorophyll and carotenoids content (43% and 44%, respectively). The Na+ content in all plant parts increased in both salinity doses especially in Amphissis while K concentration decreased for both cultivars. Inflorescences in Amphissis were severely damaged due to salinity. Consequently, pollen sampling and in vitro germination study was only feasible for Koroneiki. Indeed, Koroneiki pollen germination was reduced at 60 mM NaCl (−42%) and at 120 mM NaCl (−88%). Pollen tube length was also reduced by 15% and 28% for the middle and high salinity dose, respectively. The results of the present study indicate that Amphissis is more sensitive in high salinity doses compared to Koroneiki and that reproductive functions are severely affected by salinity

Sustainable Agricultural Practices for Improving Soil Carbon and Nitrogen Content in Relation to Water Availability – An Adapted Approach to Mediterranean Olive Groves

<p>A field experiment was conducted in an irrigated olive orchard to determine the effects of an orchard management system consisting of increased carbon input management on spatial distribution (tree inter-row/in-row, soil depth 0–10/10–20 cm) of nitrogen and carbon in the soil as well as on some microbial properties in relation to water availability. The experiment consisted of 12 blocks (each with 4 trees covering 200 m² of land), uniform olive tree canopy size and natural vegetation, used as replications (three per treatment) in a split plot design for the following four treatments: a) spreading of olive mill compost on the soil without soil tillage, b) spreading of chopped pruning residue on the soil without soil tillage, c) combination of b + c, and d) control which received no organic materials and soil was kept free of weeds with frequent tillage and herbicide sprays. Increased soil organic matter content (SOM) (up to +80%), NO₃ N (up to +194%), and NH₄ N (up to +37%) by carbon inputs were observed in soil layer 0–10 cm. Irrigation enhanced SOM, NH₄ N, and electrical conductivity (EC) while it favored NO₃ N increase by carbon inputs. All microbial properties (Soil Basal Microbial Respiration, Soil Microbial Biomass Carbon, and Metabolic quotient) were significantly higher at 0–10 cm in comparison to 10–20 cm depth. This study suggests good agricultural management practices for optimized soil organic carbon (SOC) storage adapted to the typical Mediterranean agroecosystems.</p