Luigi Ledda - Academia.edu (original) (raw)

Papers by Luigi Ledda

The European Green Deal has set a concrete strategic plan to increase farm sustainability. At the... more The European Green Deal has set a concrete strategic plan to increase farm sustainability. At the same time, the current global challenges, due to climate change and fuels and commodity market crisis, combined with the Covid-19 pandemic and the ongoing war in Ukraine, comprise the need for quality food, but also the reduction of negative external effects of agricultural production, with fair remuneration for the farmers. In response, precision agriculture has great potential to contribute to the sustainable development. Precision agriculture is a farming management that provides a holistic system approach to managing the spatial and temporal crop and soil variability within a field to improve the farm’s performance and sustainability. However, farmers are still hesitant to adopt it. On these premises, the study aims to evaluate the impacts of precision agriculture technologies on farm profitability, agronomic and environmental management by farmers adopting (or not) these technologi...

The objective of this study was to assess whether precision photovoltaic irrigation represents a ... more The objective of this study was to assess whether precision photovoltaic irrigation represents a sustainable alternative to traditional systems, where the energy and environmental performances were firstly evaluated through energy and carbon payback times (EPBT and CPBT). The study involved five Photovoltaic Irrigation Systems (PVIS), ranging from 40 to 360 kWp, installed in Spain, Portugal, Morocco and Italy. The results show an average EPBT of 3.3 years and CPBT of 6.3 years, with an energy return on energy invested (EROI) of 9.0. Additionally, the PVIS were able to achieve low emission rates with an average of 77.4 g CO2e per kWh produced. The energy and environmental performance of the PVIS are closely influenced by weather conditions, irrigation requirements and water availability. Moreover, the implementation of precision PVIS allowed improving the irrigation practices, avoiding the exploitation of natural resources and the emissions of large amounts of GHG to the environment.

Italian Journal of Agronomy

Soil-biodegradable mulch films are a promising solution to replace conventional polyethylene-base... more Soil-biodegradable mulch films are a promising solution to replace conventional polyethylene-based mulch films, the use of which has led to negative environmental impacts. Soil-biodegradable mulch films are specifically designed to be incorporated into the soil at the end of the cropping cycle, and are expected to be biodegraded by soil microorganisms. The biodegradability of such products must be tested under laboratory-controlled conditions following international standards, although these can fail to represent real environmental conditions where mulch films are used. The objective of this study was to evaluate the effects of soil refinement on the degradation rates of three different commercial soil-biodegradable mulch films after their incorporation into the soil. The hypotheses were that: (i) soil refinement (i.e., ploughing followed by grubbing) creates more favourable conditions for film biodegradation compared to ploughing alone; and (ii) different mulch films show different...

Agronomy

Crithmum maritimum L., similarly to other halophytes, could be an essential plant in marginal are... more Crithmum maritimum L., similarly to other halophytes, could be an essential plant in marginal areas of the Mediterranean basin; it can grow with low inputs and thus tackle environmental risks of soil erosion and biodiversity caused by climate change. The leaves can be used as food because of their good chemical and nutritional parameters, as a cosmetic product and in medicine. The three treatments studied in the context of organic farming (control without input, irrigated with irrigation water only and fertigated with organic liquid fertilizer diluted in irrigation water) have provided encouraging results; in fact, regardless of the meteorological trend of the two years of experimentation, the production of aerial biomass remained at satisfactory levels and in particular, in the year following the transplantation, the production saw a significant increase in the treatments tested with low inputs (irrigated and fertigated). So, in the second year of production, a low nitrogen input w...

This paper reports outcomes of life cycle assessments (LCAs) of three different oleaginous bioene... more This paper reports outcomes of life cycle assessments (LCAs) of three different oleaginous bioenergy chains (oilseed rape, Ethiopian mustard and cardoon) under Southern Europe conditions. Accurate data on field practices previously collected during a three-year study at two sites were used. The vegetable oil produced by oleaginous seeds was used for power generation in medium-speed diesel engines while the crop residues were used in steam power plants. For each bioenergy chain, the environmental impact related to cultivation, transportation of agricultural products and industrial conversion for power generation was evaluated by calculating cumulative energy demand, acidification potential and global warming potential. For all three bioenergy chains, the results of the LCA study show a considerable saving of primary energy (from 70 to 86 GJ• ha −1) and greenhouse gas emissions (from 4.1 to 5.2 t CO2• ha −1) in comparison to power generation from fossil fuels, although the acidification potential of these bioenergy chains may be twice that of

Agronomy, 2022

Proximal soil sensors are receiving strong attention from several disciplinary fields, and this h... more Proximal soil sensors are receiving strong attention from several disciplinary fields, and this has led to a rise in their availability in the market in the last two decades. The aim of this work was to validate agronomically a zone management delineation procedure from electromagnetic induction (EMI) maps applied to two different rainfed durum wheat fields. The k-means algorithm was applied based on the gap statistic index for the identification of the optimal number of management zones and their positions. Traditional statistical analysis was performed to detect significant differences in soil characteristics and crop response of each management zones. The procedure showed the presence of two management zones at both two sites under analysis, and it was agronomically validated by the significant difference in soil texture (+24.17%), bulk density (+6.46%), organic matter (+39.29%), organic carbon (+39.4%), total carbonates (+25.34%), total nitrogen (+30.14%), protein (+1.50%) and y...

Agronomy for Sustainable Development, 2021

Globe artichoke is one of the most intensively cultivated horticultural species in Mediterranean ... more Globe artichoke is one of the most intensively cultivated horticultural species in Mediterranean regions. In this context, sustainable agronomic management is a requisite to increase the soil carbon content, making the artichoke cultivation system more resilient to climate change. A 10-year experiment was considered to forecast the influence on soil C dynamic of three globe artichoke managements: monoculture with dry crop residues incorporation (conventional monoculture), monoculture with the inclusion of a cover crop (alternative monoculture), and rotation with cauliflower plus cover crop (biannual rotation). During the 2006–2016 period, total soil organic carbon content and plant C inputs to soil were measured. RothC model was used to predict the effect on the soil C stock and C sequestration potential in 20 years of the three managements tested in the field, plus a hypothetical conventional scenario with no residues’ incorporation (no residues). Plant C inputs increased according to the number of crops in rotation in each system, resulting 25% lower in conventional monoculture with respect to biannual rotation, whereas the C stock change was significantly higher (p < 0.01) in conventional and alternative monoculture (+ 7.57 and 7.14 t C ha-1) compared to biannual rotation (-1.03 t C ha-1). In the 20-year predictions, all the systems had a positive C balance. The soil organic carbon change (t C ha-1) for the future climate was + 7.2 for alternative monoculture and + 0.6 for monoculture with residues removals. For the first time, in this study, we clearly shown in the long term and in a climate change perspective that an improper crop residues management might lead to a loss of soil fertility in intensively cultivated horticultural soils under Mediterranean climate. The adoption of biannual rotation with cauliflower needs to be evaluated carefully because it proved to be less efficient in terms of C sequestration potential.

Ecological Indicators, 2020

The knowledge about land management effects on soil capacity to store carbon is necessary to plan... more The knowledge about land management effects on soil capacity to store carbon is necessary to planning effective strategies by managers and decision-makers. In this study we analyzed the land use change (LUC) effects on soil organic carbon stocks (SOC-S) for long term in the Sardinia region-Italy (Mediterranean area). Throughout the 20th century, the studied area has undergone different LUC. The first LUC was in 1938, from forest to agricultural land under three different uses: vineyards, hay crop and pasture, later (1966) some of this agricultural land were abandoned to seminatural ecosystem (second LUC). The different LUC affected to SOC-S causing decarbonization, carbonization and recarbonization processes along the soil profile. The different land uses studied chronologically were: i) natural forest-cork oak forest (Cof), ii) tilled vineyard (Tv), iii) no tilled grassed vineyard (Ntgv), iv) hay crop (Hc), v) pasture-silvopastoral and silvoarable practices (P), and vi) former vineyard-vineyards abandoned and naturally revegetated (Fv). The first LUC (Cof to Tv, Ntgv, Hc and P) caused 5.1% and 37.5% reduction on SOC-S for Tv and Ntgv (soil decarbonization), however, the SOC-S increased 47.1% and 51.3% for Hc and P respectively (soil carbonization). The second LUC (Tv and Ntgv to Fv) increased the SOC-S on average 66.3% (soil recarbonization). In general, these effects were observed principally in depth. This study shows the importance of land use and LUC with respect to SOC-S, and that the human action can degrade and/or regenerate the soil, affecting to soil functions. Consequently, is necessity to promote good environmental practices to improve the soil functions and to reduce the greenhouse gases (ecosystem services). On the presumption that the SOC sequestration through of agricultural management can reduced the atmospheric CO 2 concentration (4p1000 target in the XXI Conference of the Parties-Paris, 2015). Therefore, the soils regeneration via carbonization and/or recarbonization is an opportunity to prevent the climate change.

Food Research International, 2021

Full bibliographic details must be given when referring to, or quoting from full items including ... more Full bibliographic details must be given when referring to, or quoting from full items including the author's name, the title of the work, publication details where relevant (place, publisher, date), pagination, and for theses or dissertations the awarding institution, the degree type awarded, and the date of the award.

Energies, 2020

The energy consumption of sheep milk cooling systems (MCSs) was quantified in this study to provi... more The energy consumption of sheep milk cooling systems (MCSs) was quantified in this study to provide original information filling a literature gap on the impact of sheep milk cooling on the energy and economic balance in dairy farms. Performance and energy monitoring tests were conducted simultaneously on 22 MCSs in Sardinia (Italy). The results determined the cooling time as a function of the performance class and number of milkings. The Energy Utilization Index (EUI) was applied to measure the energy required to cool down the milk and estimate the incidence on its price. The average EUI was 1.76 kWh 100 L−1 for two-milkings and 2.43 kWh 100 L−1 for four-milkings MCSs, whereas the CO2 emissions ranged from 998 to 1378 g CO2 100 L−1 for two- and four-milkings MCSs, respectively. The estimated energy consumption for the storage of refrigerated sheep milk was 0.12 kWh 100 L−1. The malfunctioning MCSs averagely consumed 31% more energy than regular systems. The energy cost for cooling a...

Sustainability, 2018

The oilseed rape conventional system can be moved to a more sustainable one by reducing herbicide... more The oilseed rape conventional system can be moved to a more sustainable one by reducing herbicide application whilst ensuring at the same time effective weed control, maintaining oilseed rape yield, and quality and increasing profitability. Over three growing season periods, two field experiments at two different Southern Italy locations were carried out. In both sites, a conventional weed-control management system (recommended label dose), four alternative low-herbicide treatments, and an untreated control were compared. We monitored weeds and crop response to herbicide treatments, and calculated the net economic return, within site and year, for each treatment. In experiment 1, a half dose of herbicide did not show any significant difference in seed yield with respect to conventional treatment in two of three growing seasons. In experiment 2, compared with the conventional system, weedy control and the lowest applied herbicide dose treatment (25% of the recommended label dose) did not underline significant differences with regard to yield level. Net returns from the half dose of metazachlor herbicide were not significantly lower than net returns from conventional treatment in experiment 1 (on a three-year average 748 vs. 812 € ha −1 , respectively). Our findings suggest that the herbicide dose might be cut by at least 50% in order not to jeopardize negative effects on production and economic performances.

European Journal of Agronomy, 2019

Biomass production helps address the worldwide energy demand. However, some controversial issues ... more Biomass production helps address the worldwide energy demand. However, some controversial issues have been identified such as the possible conflict between the goal of increasing vegetable biomass and food production and the need to limit environmental impacts. In Mediterranean region, where the supply of some natural resources appears significantly limited (e.g., water) and the competition for land is higher than it was in the past, the objective of evaluating environmental burdens at a regional scale represents an important issue, especially if the assessment considers the farmer scope of increasing productivity. Using a Life Cycle Assessment (LCA) "from cradle to field gate" approach, this paper aims to evaluate land-based environmental sustainability related to four energy crop options. We carried out a LCA differentiating between annual and perennial species and between irrigated (giant reed and sorghum) and rainfed crops (cardoon and milk thistle) to determine their performances and impacts within the same context. The findings suggest that irrigated crops generate larger impacts on the environment than rainfed species and that annual crops (both irrigated and rainfed) are more damaging than the respective perennial crops. The damages were expressed in Ecopoints, where one Ecopoint corresponds to one thousandth of the annual overall environmental burden of an average European inhabitant. Ecopoints for sorghum, giant reed, milk thistle and cardoon are equal to 361, 288, 146, and 138, respectively. Except for irrigation, fertilizers were found to be the input with the largest effect, accounting for 37% (giant reed) to 75% (cardoon) of the environmental burden on the system. The results do not suggest the presence of a winning crop optioni.e., a crop that shows the best environmental performances everywhere and in all categoriessince regional environmental burdens are simultaneously related to different factors (e.g., land allocation, crop productivity, and degree of practice intensification) that drive farmer choice. Finally, following a dynamic and innovative perspective, we evaluated the trade-off between productivity and environmental burden for each crop simulating an increasing product variation. We found that environmental burdens would increase more proportionally than crop yields done. Especially the latter finding provides interesting suggestions on energy cropping system integration within agricultural planning under stressed natural resource conditions. 1. Introduction Biomass energy supply is greatly interwoven with the controversial dilemma among food, energy and the environment (Tilman et al., 2009) that in turn has remarkable repercussions in terms of land availability and biomass potential (Thrän et al., 2010; Harvey and Pilgrim, 2011; Popp et al., 2014). Biomass production triggers competition for natural resource use-especially for land and waterassuming its strategic relevance to farmers and policy makers in a given territory (Johansson, 2013; Bonsch et al., 2016; Robledo-Abad et al., 2016; Rosillo-Calle, 2016). For example, a crucial issue is identifying what type of lands should be used for energy crops to mitigate the food-energy-environment controversy and, as a consequence, improve the sustainability of biomass production (Allen et al., 2014; Lewis and Kelly, 2014; Mehmood et al., 2017). Indeed, a sustainable land-use choice for energy crop cultivation may involve both agricultural land-use intensification

The Science of the total environment, Jan 27, 2018

The setting up of innovative irrigation water management might contribute to the mitigation of ne... more The setting up of innovative irrigation water management might contribute to the mitigation of negative issues related to climate change. Our hypothesis was that globe artichoke irrigated with a traditionally drip system could be converted to an innovative water management system based on precision irrigation techniques and on evaporative cooling application in order to improve crop physiological status with positive impacts on earliness, total heads yield and water saving. Over two experiments carried out at plot- and field-scale, two irrigation management systems, differing in type and application time, were compared: (i) conventional, and (ii) canopy-cooling. Plant physiological status at a weekly sampling interval and the head atrophy incidence (as the ratio of the total primary heads collected) were monitored. We also recorded and determined heads production, and yield components. In both experiments, throughout the application period of evaporative cooling (three months), cano...

The Science of the total environment, 2017

Soil quality is mainly studied from the chemical and physical point of view, whereas soil biochem... more Soil quality is mainly studied from the chemical and physical point of view, whereas soil biochemical and microbiological parameters are relatively more scarcely explored to assess the effect of management practices. This study aimed to evaluate soil organic carbon (SOC) and its pools; soil microbial activity parameters; and the Biological Fertility Index (BFI), in six land uses characteristics of the Mediterranean basin in north-eastern Sardinia. These land uses differed in management intensity and consisted of: tilled vineyard (TV), no tilled grassed vineyard (GV), former vineyards (FV), hay crop and pasture (HC and PA), cork oak forest (CO). Significant differences among ecosystems were found in most cases in (SOC), the related pools (total extractable carbon, humic and fulvic acids, not humified, not extractable), humification parameters (degree, rate and index of humification), and soil microbial activity (microbial carbon, respiration, metabolic quotient, and mineralization qu...

Solar Energy, 2017

This study introduces a novel algorithm to estimate the cumulated global radiation inside photovo... more This study introduces a novel algorithm to estimate the cumulated global radiation inside photovoltaic (PV) greenhouses at the desired time interval. The direct and diffuse radiation were calculated on several observations points (OPs) inside the PV greenhouse. The PV panels were assimilated to polygons that can overlap the sun path seen from a specific OP. The algorithm was tested in a greenhouse with 50% PV cover ratio on the roof. The results were showed as the percentage ratio of the cumulated yearly global radiation with and without PV array on the roof (GGR), and used to draw maps of light distribution on different canopy heights (from 0.0 to 2.0 m). The maps displayed the variability of the light distribution and the most adversely affected zones inside the PV greenhouse. The yearly GGR increased with the canopy height on the zones under the plastic cover (GGR from 59% at 0.0 m to 73% at 2.0 m), and decreased under the PV cover (GGR from 57% at 0.0 m to 40% at 2.0 m). Most zones close to the side walls and the gable walls were the least affected by shading on all canopy heights. The different light distribution on the canopy heights showed that the incident solar energy on the crop changes consistently, according to the growth stage of the plants. The algorithm can be applied to several PV greenhouse types and may provide a decision support tool for the identification of the most suitable plant species, based on their light requirements.