Pruning Residues Research Articles

Difusión de prácticas de lucha contra la erosión en el olivar de la cuenca del Alto Genil Granadino

Este trabajo analiza el proceso de difusión de prácticas de lucha contra la erosión en el olivar de la provincia de Granada utilizando información de un sondeo a agricultores. Las prácticas más extendidas son el no laboreo y el uso de restos triturados de poda, mientras que otras más tradicionales son minoritarias. Pese a su efectividad contra la erosión y a su inclusión en las exigencias de varios programas agroambientales, el uso de cubiertas vegetales es muy reducido. El motor de los procesos de difusión de las principales prácticas analizadas ha sido la interacción y la comunicación directa entre los agricultores.

Energy valuation of urban pruning residues feasibility assessment

There is consensus that the use of renewable energy must be expanded. More and more restrictions on the use of fossil derived fuels may open the way for an increased consumption of biomass event those so far not perceived as feasible, such some biomass residue. Energy derived from biomass residues may provide even more benefits because it may replace other sources of higher-grade energy while providing proper destination for residues. Biomass from pruning residue has been overlooked as an energy resource due to many limitations. This paper addresses the issue and the means for energy valuation of pruning residues while provides final destination for them. It presents a framework to overcome most of today's challenges across the world. A case study was carried out to determine the main constraints and how they can influence the decision-making process. The variety of urban pruning residues and their rate of generation, handling, storage, logistics, economic and environmental issues, institutional regulations for a small city in Southern Brazil were taken into consideration in the analysis. Pruning residues were sampled in the field, then handled, shredded, dried, specified, stored and burnt in a concurrent woodburning furnace for testing. The diagnostics of the constraints and the lab tests were summarized and organized in a framework that aimed to assess the energy valuation of pruning residues. Results show that with proper assessment tools, projects, biomass analyses and burning technology energy valuation of pruning residues can be feasible.

Utilization of woody pruning residues of apple trees

Utilize agricultural residues from pruning brings many advantages including employment, social and economic benefit, rural development, natural forest protection, increased energy efficiency, and lower costs of raw material for the production of particleboard industry. In this study, the use of wood utilization of pruning residues from apple trees has been investigated by using chipping at the landing chipping methods (LCMs) and farm chipping methods (FCM). These methods were conducted on seven farms, totaling 9.2 ha. A time study was used to estimate operation time and cost. Transportation of chips from the study area to factories was done with semi-trailers, trucks, and pickup trucks. The residue yield was between 1.8 and 2.0 green ton per hectare. The maximum time was related to chipping and the collection of residues and the most delay was mechanical. The residues were collected, chipped, and transported to the particleboard factory at a cost between US$10.18 and US$19.46 per ton, and the profit rate between US$15.5 and US$24.8 per ton depending on chipping methods and secondary transport system. Cost and the total time of LCM were lower than the FCM, and also production rate of LCM was higher than the FCM; therefore, this method was more effective in processing residues from apple trees. Regression techniques showed that in LCM, the effect of diameter and age was significant on residue processing time and in FCM, the effect of diameter, age, residue density, and functional the area was significant in residue processing time.

Tarımsal artıklardan üretilen biyo-briketlerin CO2 emisyonları açısından çevresel etkisi

Aims: This study examined the flue gas emissions of bio-briquettes produced from agricultural residues.Methods and Results: The briquettes were produced from residues of tea (Camellia sinensis) processing plants, pruning residues of persimmon (Diospyros kaki), tomato (Solanum lycopersicum) stalk and pruning residues of peach (Prunus persica) tree. The residues were briquetted using a hydraulic briquetting machine with a horizontal course. Solid cylindrical briquettes were produced under different compression pressures ranging from 40 MPa to 240 MPa, with a moisture content of 10%-12% and having a particle size of 5 mm. Flue gas emissions of bio-briquettes were measured.Conclusions: The results of the study showed that CO2 emissions increased with increase in the briquetting pressures. The lowest CO2 emission was (2.50%) obtained at 120 MPa pressure for the briquettes produced from tomato stalk residues, where the highest was (8.90%) at 240 MPa for the briquettes produced from peach tree pruning.Significance and Impact of the Study: This study deals with the CO2 emission of biomass resulted from residues/wastes from the intensive farming of tea (Camellia sinensis), persimmon (Diospyros kaki), tomato (Solanum lycopersicum) and peach (Prunus persica).

Environmental Sustainability of Heating Systems Based on Pellets Produced in Mobile and Stationary Plants from Vineyard Pruning Residues

The impact of heat production from vineyard pruning pellets has been evaluated in this paper. The study considers two different systems: the first one based on a mobile pelletizer (PS1) and the second one based on a stationary pellet plant (PS2). The analysis conducted is from “cradle to grave”; the systems under analysis includes pruning harvesting, transport to storage area, pelletization (mobile system or stationary production plant), transport to consumer and combustion. The functional unit selected is 1 MJ of thermal energy produced. The impact assessment calculation methods selected are Eco-Indicator 99 (H) LCA Food V2.103/Europe EI 99 H/A with a midpoint and endpoint approach, and ReCiPe Midpoint (H) V1.10. Considering Life Cycle Assessment results, Eco-indicator shows a total impact of 4.25 and 4.07 mPt for mobile pelletizer and stationary pellet plant, respectively. Considering the three damage categories, PS1 has values of 2.4% (Human Health), 3.8% (Ecosystem Quality) and 17.3% (Resources), more impactful than PS2. Contribution analysis shows that direct emissions are the major damage contributor, followed by wood ash management. From a comparison between the baseline scenario and a scenario with an avoided product (wood ash as a standard potassium fertilizer), PS1 and PS2 with an avoided product approach are 41% and 40% less impactful than in the baseline scenarios. When testing the impact of mobile pelletizer while considering transportation as a factor, a reduction of distance for pellet has been evaluated. Reducing the distance from 100 to 10 km, the total impact of PS1 almost reaches the impact of PS2 with a difference of around 4.6% (Eco-indicator 99 method). The most impactful processes are pellet production, direct emissions and ash management, while a less impactful factor is the electricity consumption. Transportation shows the lowest impact. Considering the ReCiPe impact calculation method with a midpoint approach, the results confirm what was found with Eco-indicator 99; the PS1 shows a slightly higher impact than PS2.

Ohmic Heating Extract of Vine Pruning Residue Has Anti-Colorectal Cancer Activity and Increases Sensitivity to the Chemotherapeutic Drug 5-FU.

Vine pruning residues are by-products of the wine industry that have not received much attention in the past, in spite of being rich in bioactive compounds. In this study, we aimed to test whether an ohmic extract of vine pruning residue (VPE) has anti-colorectal cancer (CRC) properties, and whether responses differ according with cell’s mutation profile. VPE decreased human CRC cell proliferation, accompanied by DNA effects and cell cycle modulation. VPE also increased cell sensitivity to the chemotherapeutic drug 5-FU. Our results suggest that tumors harboring BRAF mutations may be more responsive to VPE than KRAS mutated tumors. These effects of the extract were not completely reproduced by the most abundant constituents tested individually at the concentrations present in the effective dose of VPE. Globally, our results indicate that VPE, a polyphenol enriched extract produced by ohmic heating of vine pruning residue, has anti-colorectal cancer potential, including sensitizing to a chemotherapeutical drug, and its use in functional foods or nutraceuticals could be exploited in personalized anti colorectal cancer dietary strategies. Valorization of this lignocellulosic residue should encourage bio-waste recycling, adding value to this agricultural by-product and promoting the sustainable use of natural resources.

Paracetamol removal by Kon-Tiki kiln-derived biochar and activated carbons

Biochar was obtained from Eucalyptus pruning residues with a non-conventional device named Kon-Tiki kiln. The average heat of combustion of the biochar, 27.3 MJ kg−1, was higher than that of Eucalyptus wood, 17.8 MJ kg−1. Activation with CO2 was performed by varying the activation time from 0 to 60 minutes. The activated carbons (ACs) and the carbon precursor have been characterised and tested for paracetamol removal in the liquid phase, studied in both kinetic and equilibrium aspects. ACs presented an increase in BET area (up to 845 m2/g), total pore volume and microporosity with the activation time. The pseudo-second order model was the one that best fitted the experimental data. Elimination of paracetamol was much faster when using ACs, 5 h, than when using the biochar, 3 days. However, pollutant removal was greater than 95 % for all materials, which is a promising result for low-cost biochars in a difficult economic context. All the adsorption equilibrium experiments exhibited multilayer behaviour, showing values up to 98 mg g−1 for the maximum monolayer-adsorption capacity.

Valorization of Olive Pruning Residues through Bioconversion into Edible Mushroom Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm. (1871) of Improved Nutritional Value.

In several Mediterranean countries, olive pruning residues (OLPRs) are abandoned or burned leading to several environmental problems. Valorization of these agrowastes could be a challenge for the primary decomposer Pleurotus ostreatus, turning them into edible biomass. The OLPR was used alone (OLPR), or in mixtures with wheat straw (WS : OLPR 1 : 3 v/v and WS : OLPR 3 : 1 v/v). Mycelial colonization was hastened by 3.7 days in WS : OLPR 1 : 3 (v/v). Yields were comparable to control (WS) in WS : OLPR 3 : 1 (v/v). Organic matter loss decreased with increasing proportions of OLPR in substrates. The nutritional value of mushrooms was improved by lower fat and sodium contents, in WS : OLPR 1 : 3 (v/v) and WS : OLPR 3 : 1 (v/v), and higher total protein, crude fiber, iron, and total carbohydrates contents in WS : OLPR 3 : 1 (v/v), compared with those of control. Polyunsaturated fatty acids, mainly linoleic acid, were the most abundant in mushrooms. Monounsaturated fatty acids increased in mushrooms of the substrates containing OLPR. A good predictive model of partial least square regression analysis showed different relationships of mushroom palmitic, oleic, linolenic, palmitoleic, and stearic acids with substrate composition. Findings suggested the use of OLPR as a supplement to commercial wheat straw and as a tool to reduce the negative impacts of their hazardous disposal on the environment.

Estimation of the quantity and availability of forestry residue for bioenergy production in China

Forestry residue is an important lignocellulosic feedstock for bioenergy production. This study estimated the potential forestry residue production (PFRP) in 31 provincial regions in mainland China. The PFRP increased from 220.48 million tons (Mt) in 2007 to 257.44 Mt in 2016. The average annual PFRP between 2014 and 2016 was 254.69 Mt, which comprised 228.01 Mt of wood residue, 22.86 Mt of bamboo residue, and 3.82 Mt of herbaceous fruit plant residue. For the wood residue, forest pruning residue accounted for 43.34% (98.83 Mt), while wood logging residue and wood bucking residue accounted for 16.39% (37.37 Mt) and 18.73% (42.72 Mt), respectively. Bamboo residue was composed of 21.26 Mt of bamboo processing residue and 1.60 Mt of waste bamboo. Guangxi, Yunnan and Fujian had the highest potential forestry residue from 17.88 – 32.66 Mt among 31 provinces from 2014 to 2016. Wood residue production in southern provinces was higher than that in northern provinces, and all bamboo residue and herbaceous fruit plant residue were produced in southern China. The annual PFRP distribution density ranged from 0.66 t km−2 in Qinghai to 181.43 t km−2 in Hainan, and increased from southeast to northeast China. The annual collectable forestry residue was estimated at 71.97±7.4 Mt, which amounted to a bio-electricity potential of 130.77±13.38 TWh.

Autohydrolysis pretreatment of castor plant pruning residues to enhance enzymatic digestibility and bioethanol production

Castor plant is used commonly for oil extraction and biodiesel synthesis. However, the residues during pruning are not being used effectively. These residues have the potential to be used as feedstock to produce bioethanol and other by-products. The present work assessed the eco-friendly autohydrolysis pretreatment of castor plant pruning residues at different severity factors (R0), applying a range of temperatures from 100 °C to 200 °C. The hydrolysis of pretreated solids was carried out using a commercial cellulases complex at different solid and enzyme loadings. The enzymatic hydrolysate with a higher glucose concentration was further subjected to fermentation using Saccharomyces cerevisiae ATCC 4126. The results showed an efficient xylan hydrolysis (77.5%) and a preservation of glucan up to 83% in the solids pretreated at an R0 of 5.78. The enzymatic hydrolysis of the pretreated solids at an R0 of 5.78 showed a glucose release of 2.9-fold higher than non-pretreated material. In the hydrolysate fermentation, a maximum ethanol production of 50.5 g/L was achieved (equivalent to 6.4% v/v), corresponding to a conversion efficiency of 98% and a biomass-to-ethanol conversion yield of 93.0 g of ethanol per kilogram of feedstock.

Cellulose nanocrystals from blueberry pruning residues isolated by ionic liquids and TEMPO-oxidation combined with mechanical disintegration

In the last years, Chile has increased the production of blueberries; consequently, a large number of lignocellulosic residues derived from the harvesting and pruning are being generated. These residues are commonly burned, therefore increasing CO2 emissions. This study focuses on the extraction of two added-value products from blueberry pruning residues (BPRs), cellulose nanocrystals (CNC-IL) isolated using ionic liquid (IL) 1-ethyl-3-methylimidazolium [emim][Cl], and carboxylated nanocellulose (TOCNC), isolated with (2,2,6,6-tetramethylpiperidine-1-yl) oxyl or TEMPO reagent combined with a mechanical disintegration process. These products were characterized by zeta potential (ζ), FTIR, XRD, TGA, AFM, and conductometric titration. Results show oval-shaped CNC-IL particles with lengths of 46.1 ± 9.3 nm; meanwhile, TOCNC were rod-like shaped particles, with lengths of 120.3 ± 30.6 nm. These BPRs showed a promising potential to produce cellulose nanocrystals (CNCs) with different surface properties, opening a new alternative for the production of cellulose nanomaterials (CNMs) with promising applications in colloidal formulations, coatings, among others.

CN diatomic emission for N determination by LIBS

The determination of N is an important demand for several sectors and the analytical features of laser-induced breakdown spectroscopy (LIBS) are very attractive to accomplish this task. In this work, a novel proposal for nitrogen determination was explored considering molecular diatomic emission lines of CN measured by LIBS. As a proof of concept, a method was developed to determine N in biochar-based fertilizers, a highly recalcitrant matrix. The fertilizers were prepared from biochar of eucalyptus pruning residues, peanut skin and fibers of banana tree and the calibration standards were prepared by matrix matching using eucalyptus biochar. Diatomic emission signals of CN at 388.3 nm showed high correlation with the levels of N in standards and samples, suggesting the molecular emission of CN is little affected by the matrix effect. The developed method is accurate since the N levels determined in the samples do not differ statistically from the expected level, with a 95% confidence level. Furthermore, the method using molecular emission is simple and highlights the potential of LIBS for N determination in complex matrices (e.g. biochar).

Characterization of cadmium adsorption on two cost-effective biochars for water treatment

The objective of this study was to characterize the cadmium (Cd) adsorption behavior on biochar derived from grape and apple pruning residues (GPR and APR, respectively). Consequently, batch experiments were carried out with increasing levels of initial Cd concentration (0 to 200 mg L−1) under different shaking times (0 to 240 min) and temperatures (10, 20, 30, and 40 °C). The adsorption of Cd on the biochars was well fitted to the Elovich kinetics and Freundlich sorption model. The maximum Cd sorption capacities of 57 mg g−1 and 49 mg g−1 were calculated for GPR and APR biochars, respectively, indicating the higher sorption capacity of GPR in comparison with the APR biochar. The sorption energy parameter (E) of Dubinin–Radushkevich isotherm (4.37 and 4.05 kJ mol−1) and negative Gibbs free energy (∆G) values (− 15 to − 19 kJ mol−1) revealed the physical adsorption and spontaneous of Cd adsorption on the biochars, respectively. The entropy (ΔS) and change in enthalpy (ΔH) were found to be 1.57 J mol−1 K−1 and 0.22 kJ mol−1 for GPR biochar and 1.50 J mol−1 K−1 and 0.21 kJ mol−1 for APR biochar, reflecting an affinity of Cd on the biochars and endothermic nature of Cd adsorption reaction. This study demonstrated the feasibility of the biochars derived from grape and apple pruning residues to be as a potential low-cost adsorbent for Cd removal from aquatic systems. Furthermore, the adsorption procedure involving kinetic time and temperature effects were optimized to achieve the maximum Cd sorption on the adsorbent. Adsorption mostly took place within 20 and 40 min for GPR and APR biochar, respectively, while the optimum temperature was 40 °C.

Life-Cycle Assessment of the Use of Peach Pruning Residues for Electricity Generation

Biomass residues from permanent crops might be an alternative fuel for energy generation in a local market with limited transport distances. Moreover, as activities related to CO2 reduction are of special attention in the European Union (EU), sustainable use of resources plays an important role in climate change mitigation. In this paper, a life-cycle assessment (LCA) of the integrated value chain from peach pruning residues for electricity generation is presented and compared with the common practice including the mulching process of the pruned biomass in an orchard. It was shown that biomass harvesting, chipping and its delivery to a power plant—the Pruning-to-Energy (PtE) scenario—is feasible from an environmental point of view. The total global warming potential (GWP) of this value chain was 200 kg CO2 eq.·ha−1 (or 27 kg CO2 eq.·GJ−1). In turn, the mulching and leaving of the pruned biomass in an orchard—the pruning-to-soil (PtS) scenario—is characterized by a CO2 equivalent of 2360 kg·ha−1. Other impact categories showed a lower environmental impact for the PtE scenario as well. When considering the Spanish electricity-mix instead of coal-based electricity, the PtS scenario score better in most impact categories, but the GWP for the PtE scenario remains lower.

Circular Economy Model: Insights from a Case Study in South Italy

This study aims to analyze the economic and environmental sustainability of a case study of an energy power plant that produces electricity from pruning residues of olive groves from nine municipalities in southern Italy. To assess the economic sustainability of the agro-energetic chain, the profitability and efficiency ratios are calculated. Moreover, the GHG emissions of the agro-energetic pruning supply chain due to both the pruning collection at the field level, and their combustion for energy production at the power plant, are calculated. To put together the environmental and economic evaluations, the ecoefficiency ratio was calculated to measure the value added per 1Mg of GHG emitted into the atmosphere. The findings show the whole agro-energetic chain, namely the power plant and the collection company have both a good return on owner’s equity (ROE) ratio (15.89% and 31.48%, respectively) and ROI ratio (4.34% and 6.14% respectively). Moreover, the power plant’s ecoefficiency ratio (2.64€ per 1Mg of GHG) is slightly lower than harvest firm one (2.91€ per 1Mg of GHG). The findings could be useful to develop new business models based on the circular economy concept. In fact, the business model proposed could push entrepreneurs towards new income opportunities, at the same time, helping local farms and reducing the environmental impacts.

Comparison of the technical and economic performances of two different shredders on pomegranate pruning residues

Aim of study: The study aimed to examine the technical and economic performances of two different shredders for three windrow densities of pomegranate residues.Area of study: The study was conducted in the Serik District of Antalya Province, Turkey.Material and methods: Two different pruning residue shredders driven by tractor power take off (PTO) were used. Machine‑I has pick‑up, shredding, screen units. Machine‑II only has a shredding unit. The experiment was conducted at windrow densities of 1.49, 2.10, and 2.41 kg/m2 in a pomegranate orchard; the study used a completely randomized split‐plot design with two treatments and three replications.Main results: The power values for the increasing windrow densities were 8.00, 11.73, and 18.47 kW/m for Machine-I and 5.08, 5.68, and 6.48 kW/m for Machine-II. Moreover, the average particle length of 68.6 mm shredded by Machine‑I was approximately 20 mm smaller than that of Machine‑II. The minimum unit energy value of Machine-II was 2.53 kWh/t at the maximum windrow density of 2.41 kg/m2. This value for Machine-I was 5.58 kWh/t at the medium windrow density of 2.10 kg/m2. The lowest unit cost for Machine-I and Machine-II was calculated as 27.2-7.1 US$/t (at medium density) and 16.8-3.5 US$/t (at maximum density), respectively.Research highlights: The appropriate windrow densities for Machine-I and Machine-II were different in terms of energy requirements and total unit cost. Machine-I is more effective at consistently chopping the residues than Machine-II, but it requires more energy and a higher unit cost.

Production of pellets from pruning residues and determination of pelleting physical properties

ABSTRACT Turkey is among the leading countries in fruit production. Every year important amounts of pruning residues emerge from orchards. These residues have significant energy potential. There is a lack of study on the physical properties of pellet production from different orchard residues. Assessment of these residues is of enormous significance for the environment and economy. Pelleting is one of the methods of evaluating these low-density residues. Particle size and moisture content are the most important factors affecting pellet quality. The aim of this study is to evaluate the pruning residues such as olive, vineyard and pomegranate as biofuels. For this, pruning residues were pelleted in a pellet machine. Different moisture contents (10-12% and 14-16%) and three different particle sizes (2, 4 and 6 mm) were used in the experiments. The physical properties of pellets such as particle density, bulk density, durability, tensile strength and absorption resistance were defined. Besides, energy consumption values and pellet production capacity were measured. At the end of the experiments, depending on the material properties and moisture content, average pelleting machine pellet production capacity was measured as 23–83 kgh−1 and cylindrical pellets with an average diameter of 6 mm were produced. The particle density and bulk density of pellets were between 981–1338 kgm−3 and 521–793 kgm−3, respectively, and pellet densities were decreased with increasing moisture content. In addition, the relation between physical properties was analyzed by using the analysis of variance (ANOVA) method using by IBM SPSS 17 software.

Machine Performance and Hog Fuel Quality Evaluation in Olive Tree Pruning Harvesting Conducted Using a Towed Shredder on Flat and Hilly Fields

Pruning residues from olive groves represent an important biomass source. Until now, the management of pruning residue has generally represented a disposal problem rather than an opportunity for additional revenue. The main problem is the lack of a well-organized pruning biomass supply chain. In particular, harvesting is a key stage that influences the product quality, the type of logistics chain, and the economic sustainability of the pruning supply chain. The aim of the present paper was the evaluation of the machine performance of the Facma Comby TR200 towed shredder. The harvesting tests took place in Agios Konstantinos, Fthiotida, Central Greece. Two different experimental fields were used for the evaluation of this harvesting system; these fields were characterized by different slopes to check the convenience of using such a towed shredder on both hilly slopes and flat terrains. Analysis was conducted focusing on both the work productivity and costs. Moreover, an evaluation of the obtained hog fuel quality was performed. The Facma Comby TR200 showed good work performances on both flat (2.60 tdm·h−1) and hilly (2.74 tdm·h−1) land, even if a consistent influence of the pruning biomass yield on the work performances was reported. The biomass quality could be consistently improved by modifying the pick-up systems to avoid the collection of inert materials (soil and rocks). In fact, the analysis showed a high ash content in the comminuted material (4% dry basis). Finally, the economic aspects of this study’s results were in line with those reported in the literature. The applied harvesting system showed a cost equal to 29.88 and 16.59 €·tfm−1 on flat and hilly land, respectively.

Is new olive farming sustainable? A spatial comparison of productive and environmental performances between traditional and new olive orchards with the model OliveCan

Olive (Olea europaea L.) is a widely spread tree species in the Mediterranean. In the last decades, olive farming has known major management changes with high economic and environmental impacts. The fast track expansion of this modern olive farming in these recent years casts doubts on the sustainability of such important tree plantation across the Mediterranean. In this work, we performed a spatial modelling analysis to investigate the implications of climate variability and farming management on the productivity and environmental performances of olive orchards around the Mediterranean. Implementation of this research is based on the use of OliveCan; a process-based model able to illustrate responses of water and carbon balances to weather variables, soil characteristics and management techniques enabling the comprehension of olive orchard dynamics under heterogeneous conditions of climate and agricultural practices. Four main intensification levels were adopted to reflect the main olive grove types from traditional to new intensive plantations: low density LD (100 trees ha−1), medium density MD (200 trees ha−1), high density HD (400 trees ha−1) and super high density SHD (1650 trees ha−1). Managements tested were intensification, water supply (rainfed, deficit and full irrigated) and the fate of pruning residues (exported or left on the soil). Two cases studies in two of the main Mediterranean olive-growing regions with contrasting environmental conditions, Tuscany and Jaen regions, focused on mitigation alternative managements for carbon sequestration. Results showed that olive orchards responses in terms of yield and Net Ecosystem Productivity (NEP) vary along with climatic conditions. Water supply was the main driver with a production function that varies for different atmospheric demands. Application of deficit irrigation proved to boost water use efficiency. Besides, intensification from LD to SHD, presented the greatest improvements, 28–73% for yield and 50–100% for NEP. The C sequestration potential of olive orchards was confirmed. In fact, soil organic carbon (SOC) increased continuously over 400 years of simulation, reaching a state of equilibrium. Moreover, intensification and irrigation improved total carbon sequestration. Management of incorporating pruning residues in the soil increased SOC of 10.5 t C ha−1 for Tuscany and 10.8 t C ha−1 for Jaen. Findings of this research enabled the identification of the main drivers influencing the productive and environmental performance of olive groves in the different Mediterranean sub-climates. Impacts of management innovations on olive farming sustainability were also quantified which may help improve production systems for a more sustainable olive cultivation.

Analysis of the Work Productivity and Costs of a Stationary Chipper Applied to the Harvesting of Olive Tree Pruning for Bio-Energy Production

Pruning residues could represent an important biomass resources for energy production. Only in Italy it has been estimated that an annual quantity of biomass of over 2600 kt of dry matter could be obtained from olive residues. Several machines developed for pruning harvesting are available in the market, most of which are tractor-driven, while limited knowledge is available on performance, quality of work and costs of harvesting logistics based on stationary chippers. The aim of the present paper is to analyze machine performance of a forestry stationary chipper applied to pruning harvesting for what concerns work productivity, quality of the comminuted product and harvesting operating costs. This system is actually applied by Fiusis Company, an Italian enterprise which manages a biomass power plant exclusively powered by olive trees’ pruning residues, and it has never been analyzed in literature. The results obtained showed consistent work productivity, which resulted the highest ever found in olive pruning harvesting systems and equal to 5.23 ± 0.81 tdm·h−1. This high work productivity allowed also to obtain a little economic gain from a matter, which is actually considered a problem for olive groves’ owners and not a potential source of income. In particular, the use of a stationary chipper seemed very efficient in olive groves with a consistent amount of wooden residues to be processed and with big branches not harvestable by the most common towed pruning harvester. In addition, the stationary chipper has the advantage of avoiding the preliminary raking operation, which results in reduced costs for the farmer.