No abstract

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.

No abstract

Adaptation can be a key factor that will shape the future severity of climate change impacts on food production. The objective of this study was to assess the suitability of an agro-ecological approach based on various techniques as potential adaptation strategy in organic horticultural systems. A long-term field experiment was set up in Southern Italy, combining: (i) appropriate soil surface shaping; (ii) cash crop rotation; (iii) agro-ecological service crops (ASC) introduction as living mulch and complementary crops; (iv) tailored organic fertilization; and (v) alternative tillage strategies. In this paper, the first two-year results on cauliflower (Brassica oleracea L.) and tomato (Solanum lycopersicum L.) crops, as well as energy consumptions through the Energy Analysis (EA) method are reported. Due to the climatic conditions that occurred, which were characterized by the absence of extreme climatic events (particularly rainfall), it was not possible to verify if the designed experimental device was able to mitigate the impact of climate change, whereas the EA indicated that total energy inputs were lower when ASC are introduced in cropping systems.

Horticultural farms are faced with the problem of disposing of huge amounts of agricultural by-products whose management requires sustainable solutions. Composting means to recycle organic waste to make compost—a high agronomic value product—able to positively affect soil quality: A good occasion to switch definitively from a conventional agriculture to an organic one. Nevertheless, composting can have negative direct/indirect environmental impacts. The aim of this research was to assess the sustainability of a windrow composting system, able to treat agricultural green waste of different typology (“light” and “heavy” with dry matter below or above 10%, respectively). Environmental impacts, energy consumptions, and production costs of all composting stages were evaluated by Life Cycle Assessment. Results show that the production of 1 ton of compost caused CO2eq emissions ranging from 199 to 250 kg and required between 1500 and 2000 MJ of energy; costs ranged between 98 and 162 euro, nevertheless lesser than the commercial green compost. The raw material typology affected significantly the composting process making compost based on “heavy” materials the most sustainable. These findings underline the need to spread this low technology process, easy to apply, especially in organic farms, and to promote the agronomic use of compost.