• Energy Research

In the Mediterranean area, using organic fertilizers is crucial to maintaining and increasing soil fertility and crop productivity since soil organic matter is being progressively depleted due to climate change effects. Therefore, the aim of this study was to compare two different organic fertilizers (MC1 without and MC2 with an inoculum of selected microorganisms), applied at 100% and 50% doses, with mineral fertilization and an unfertilized control: (i) by assessing the agronomic performance of fennel crop; and (ii) by investigating environmental and economic sustainability, through GHG emissions determination, carbon efficiency, and cost analysis. The results of the MC2 were comparable to the mineral fertilization for crop growing parameters (plants and roots dry weights) and marketable yield, irrespective of the amount applied (50–100%), likely due to the inoculum of selected microorganisms. These may have favored the soil microbial activity, the nutrient availability, and better synchronization of N mineralization with fennel N demand with respect to MC1 (with a higher C/N ratio). The MC2 also achieved lower costs than the other treatments. The highest GHG emission value was found in the mineral fertilization treatment, while the lowest was recorded in the unfertilized control treatment. The two organic treatments at 100% were the most carbon-efficient systems because of the highest carbon stocks/output, considering the difference between C stocked/output and the C loss/input emitted.

Brassicaceae are promising oil feedstock for cultivation in centralsouthern Italy. Therefore, a two-year investigation on Brassica carinata A. Braun (cv. CT 204) was carried out in three sites of Apulia region [Site 1, Alberobello - Murgia foreland; Site 2, Troia (Foggia) - Daunian sub-Apennines; Site 3, Monteroni (Lecce) - Area of Salento], and in one site of Basilicata region (Site 4, Hill of Matera). The aim was to identify site-specific management practices [by comparing minimum vs conventional tillage, low sowing density vs high sowing density; different levels of nitrogen (N) supply and organic fertilisers] in the four different marginal areas, to achieve optimum yield performance for biodiesel prospective production. The crop showed a good adaptability in the study sites, and the highest N level positively influenced the yield performance in Sites 1, 2 and 3. Moreover, the reduction of mechanical operations (minimum tillage) did not negatively influence crop production and seed oil content. The highest density of sowing tested determined the best crop performance in Site 3, particularly showing the maximum seed oil content with the lowest N supply. Finally, in Site 4 the compost mixed with mineral N fertiliser as well as the sewage sludge from urban wastewater determined productive results comparable to those obtained with mineral fertiliser, evidencing that organic fertilisers could (partially or completely) substitute the mineral one for this crop in the study site. On the whole, seed yield and oil content showed a potential for biodiesel production of Brassica carinata cultivated with site-specific agronomic techniques in four different marginal areas of Southern Italy, suggesting it can be likely achieved the crop environmental adaptation.

The Circular Economy concept implies the re-design of existing production systems in agriculture, by promoting agricultural waste recycling. In an organic zucchini—lettuce rotation, two different agroecological tools were considered: biofertilizer and presence or absence of green manure (GM+ and GM−). In particular, we compared: (i) anaerobic digestate from cattle manure, co-composted with vegetable wastes, with the presence of GM (AD GM+); (ii) olive pomace compost, re-composted, with the presence of GM (OWC GM+); (iii) municipal waste compost with GM (MWC GM+); (iv) municipal waste compost without GM (MWC GM−). These materials were tested with a commercial organic fertilizer without GM (COF GM−) as a positive control. The objectives were: (i) assessing the environmental sustainability of biofertilizers through carbon footprint analysis by greenhouse gas—GHG—emissions; (ii) evaluating the agronomic performance on the vegetable rotation, by energy output assessment. The total carbon emissions of biofertilizers production was 63.9 and 67.0 kg of CO2 eq Mg−1 for AD and OWC, respectively. The co-composting and re-composting processes emitted 31.4 and 8.4 kg CO2 per Mg of compost, respectively. In AD the ventilation phase of composting accounted for 37.2% of total emissions. The total CO2 emission values for the two-crop cycles were the highest in COF GM− and the lowest in OWC GM+, due to different fertilizer sources. On the average of the treatments, the input that induced the highest CO2 emission was irrigation (37.9%). The energy output assessment for zucchini and lettuce highlighted similar performance for all the treatments. Our findings demonstrated the validity of the tested processes to recycle agro-industrial wastes, and the potential of agroecological practices (GM) to mitigate GHG emissions.

Sustainability of agricultural practices is one of the most important issues in organic agriculture and its assessment is crucial. To this aim, evaluating the balance between the energy inputs and outputs in crop rotations could be a valuable tool. Therefore, we compared different management strategies in a four-year organic cropping system, by estimating the energy balance of crop production. Two different living mulches with no-till (B1) and green manure (B2) were compared with a cropping system without cover crop (B3), performing both energy analysis and energy balance. Energy parameters were also evaluated. The energy input of fertilizers and water was more than 55% of the total energy required by the cropping systems, suggesting that these agronomic practices should be tailored by farmers to decrease total energy inputs. The potential energy output was significantly higher in the B1 than the B2 and B3 cropping systems (20% and 54%, respectively). Results indicated that B1 and B2 could enhance the energy outputs without negatively affecting the energy consumption, since these cropping systems also showed higher energy efficiency. The introduction of the cover crop as living mulch combined with no-till could be a powerful tool to enhance systems sustainability, without compromising the crop yields.

The implementation of agroecology principles within organic farming research is a crux to redesign sustainable agri-food systems. To govern this transition, the local research demand should be addressed by direct engagement of all stakeholders in the research process. The first step is the involvement of farmers and technicians, with the aim of restoring their decision-making role, switching governance to local scale. The co-design/co-management of Long-Term Experiments (LTEs) can be crucial to govern the above-described transition through networking and participatory activities. In this study, we report the experience of co-designing a new LTE in Southern Italy by local actors and scientists. Through a participatory action research methodology, an LTE was considered as a biophysical component of an agroecological living lab, a public–private environment aimed to design a local food system. The setup of parallel field trials in satellite farms stands for the other biophysical component, whereas the stakeholder platform represents the social one. Through definition of common objectives, a step-by-step process is presented, which highlights the interest of local organic actors to share ideas and perspectives for the territory, pointing out the inclusion of end-users (the consumers) in the process to complete the transition to sustainable food systems.

Organic agriculture is perceived as environmentally sustainable, but, under its umbrella, different production systems exist ranging from simplified organic productions to well diversified systems with a full implementation of agro-ecological approaches. Among several developed tools for agriculture sustainability assessment, multi-criteria models are increasingly gaining importance. In this study, we evaluated the use of the multi-criteria DEXi-BIOrt tool, coupled with data from long-term experiments, for the sustainability assessment of different organic vegetable production scenarios. These scenarios were applied in two Italian areas: the Adriatic coast of Marche Region and the Metaponto plan of Basilicata Region. Despite the presence of some critical issues, DEXI-BIOrt proved to be a valid tool for the sustainability evaluation of organic vegetable productions. In both areas, the most sustainable scenarios resulted the well diversified organic systems characterized by proper rotations, inclusion of agro-ecological service crops, cultivation of local and different cultivars, and presence of short supply chain mechanisms. Conversely, the implementation of the simplified organic substitution scenarios does not guarantee a suitable level of sustainability. The findings of this study could support decision makers in the implementation of appropriate measures for enhancing organic production sustainability in the framework of post-2020 Common Agricultural Policy.

Horticultural crops produce huge amounts of wastes due to the large difference between total and marketable yields, and plant residues. The biological stabilization and sanitization of these organic materials directly on-farm through a simple technique such as composting may be a feasible and sustainable management strategy. The objectives of this research were to (i) estimate the sustainability and the energy impact of the on-farm composting process; (ii) to evaluate the agronomic performance and sustainability of the compost application, compared to a commercial organic fertilizer; and (iii) to identify the management and environmental hotspots. To accomplish these aims, a composting process was set up and monitored using the organic wastes and residues produced in the experimental farm. The compost produced was compared to a commercial organic fertilizer in combination with the use of cover crops in the rotation, in a two-year pepper cultivation. All processes were assessed using an energy analysis and a carbon stocks and emissions evaluation. Our findings point out that the composting process on-farm was environmentally sustainable in terms of energy consumption and carbon emissions and produced a good quality fertilizer. The use of this compost determined the best agronomic performance, especially when it was combined with other agro-ecological techniques. The yield values were slightly higher and statistically comparable with the commercial fertilizer ones. Moreover, the treatments that included the compost were most energy efficient and showed the best compromise between C emissions and C stocks.