Eugenio Cavallo

Performance and energy efficiency of alternative comminution principles: Chipping versus grinding

Abstract Comminution is a critical process in biomass supply chains and can be conducted with either chippers or grinders. These machines use different work tools(knives and hammers, respectively) and are applied to different feedstock types, but few studies are available on the inherent differences between the two technologies. A versatile grinder, alternatively equipped with hammers and knives, was studied to investigate the effect of tool type on machine productivity, fuel consumption, and product quality.The machine was powered by an agricultural tractor rigged with a flow meter, a torque meter, and shaft revolution meter for determining fuel consumption, power output, and engine speed. Three different feedstock types were processed: discarded pallets, solid logs, and residues from park maintenance, the latter consisting of branches from ornamental tree and shrub species. Depending on feedstock type, the knife configuration was 30–80% (average 50%) more productive than the hammer configuration and required 15–30% (average 24%) less energy per unit of product. Fuel consumption per dry ton was 30–75% (average 52%) higher for the hammer configuration. That held true for all feedstock types. Product quality was better for the knife configuration, except for park maintenance residues. In general, hammers should be limited to product with severe contamination that prevents the efficient use of knives.

Strategic management implications for the adoption of technological innovations in agricultural tractor: the role of scale factors and environmental attitude

Technological innovations in agricultural tractors have revolutionised farming, increased labour productivity and reduced operators hazards. The purpose of this paper is to analyse the relation between agricultural tractors’ technological innovations and farm size, as well as users’ attitude on environmental impact of agricultural tractors according to their age and years of activity in the farm. Results, concerning Italy, highlight that high technological innovations of tractors are associated to larger farms, which are managed professionally by more efficient and sophisticated agricultural machineries. Empirical evidence also shows that the older the tractor adopters are and the longer they have been working in agriculture, the higher is their commitment to environment protection and safe working conditions. These results could be important for critical strategic management implications to spur technological innovation in agricultural tractors that better satisfy farmers needs and to support the fruitful adoption of innovations for an efficient and safe modern agriculture.

Perceptions of Tilt Angles of an Agricultural Tractor

ABSTRACT A tractor stability simulator has been developed to help study tractor operators’ perceptions of angles when the simulator is tilted to the side. The simulator is a trailer-mounted tractor cab equipped with hydraulic lift that can tilt the tractor cabin up to 30 degrees. This paper summarizes data from 82 participants who sat in the simulator while it was tilted. Demographic variables, estimates of tilt angles, and measured tilt angles were collected. The effects of age, gender, tractor driving experience, and frequency of operation on the estimated and measured tilt angles were analyzed. The results showed that about 50% of the participants reported estimations of side tilt angles within ±5 degrees of the actual angles, and nearly the same percentage overestimated the actual side tilt angles. Only a small percentage underestimated the angles. Older, more experienced, and male participants set higher limits on the actual angle at which they felt uncomfortable and would not drive.

Evaluation of Erosion Intensity and Some of Its Consequences in Vineyards from Two Hilly Environments Under a Mediterranean Type of Climate, Italy

Giuseppe Corti1, Eugenio Cavallo2, Stefania Cocco1, Marcella Biddoccu2, Giorgia Brecciaroli1 and Alberto Agnelli3 1Dipartimento di Scienze Ambientali e delle Produzioni Vegetali, Facoltà di Agraria. Università Politecnica delle Marche, Ancona; 2Istituto per le Macchine Agricole e Movimento Terra, Consiglio Nazionale delle Ricerche, Torino; 3Dipartimento di Scienze Agrarie ed Ambientali, Facoltà di Agraria. Università degli Studi di Perugia, Perugia; Italy

Attitudes towards mechanized Cut-to-Length technology among logging contractors in Northern Italy

Abstract While motor-manual short-wood harvesting still dominates Italian forest operations, there is a growing interest to introduce mechanization in order to reduce logging costs and increase work safety and comfort. Against this background, a survey was conducted for determining the attitudes of North Italian logging contractors towards mechanized Cut-to-Length (CTL) technology and to evaluate the potential of machine simulators when introducing mechanized harvesting for prospective users. A total of 90 persons were interviewed, after they tested a forwarder simulator; 74 interviews were valid and accepted into the study for statistical analysis. This sample was younger and contained a larger proportion of employers compared with the overall population of North Italian logging contractors. Respondents are aware of the significant potential of mechanized CTL technology, and of its notable safety benefit. People working with firewood seem to be keener than the others. The main obstacles to the expansion of mechanized CTL technology in Italy are financial, rather than technical. Harvester manufacturers trying to increase their sales in Italy may want to focus on simplified low-cost machines, suitable for application to general purpose prime movers and especially designed for firewood contractors. They should also target younger contractors, who are more familiar with computer technology. Forest machine simulators can help introducing CTL technology to Italy, but one needs to think about new ways to deploy them.

Safety signs on agricultural machinery: Pictorials do not always successfully convey their messages to target users

This study investigated the extent to which a sample of Italian users comprehended safety pictorials used on agricultural machinery. A questionnaire with 12 safety pictorials was administered to 248 users of agricultural machinery. For each of the pictorials, the participants were asked to select the most appropriate description of four written choices. The investigated safety pictorials were, in general, not well comprehended. Two different classes of participants were identified, each with a different level of comprehension. The participants with better comprehension were characterized by the regular use of agricultural machinery and frequent previous exposure to pictorials. The need for training courses focusing on safety pictorials and their meanings, as well as the need for improvement to the pictorials themselves to make them more easily comprehended, is discussed.

Machinery-related perceived risks and safety attitudes in senior Swedish farmers

ABSTRACT Objectives: To perform an ergonomic analysis of work and machinery-related risks in a group of Swedish older farmers, investigating farmers’ attitudes and perceptions about: 1) health status and work motivation, 2) physical and cognitive workload and difficulties in the interaction with machinery and technological innovations, and 3) risks and safety practices. Methods: Nine Swedish male farmers aged 65+ were administered a semi-structured interview and a questionnaire. Results: Participants perceived themselves as being in good health and considered farming as a good proxy of their health status. They reported an increased physical workload but did not describe any cognitive workload. Technology was reported to have low usability, and thus its benefits cannot be fully exploited. Older farmers acknowledged the existence of “new risks” related to the aging process and mainly referred to the common sense and previous experience as the best safety practices. Conclusion: Multilevel interventions focused on the capabilities and limits of the older farmers should be developed, involving both training activities and design solutions for the machinery that can support older farmers’ health and safety.

Perception of side rollover hazards in a Pennsylvania rural population while operating an all-terrain vehicle (ATV)

BACKGROUND All-terrain vehicles (ATVs) are unstable on steep and rough terrain, and thus, rollover is the most common accident which can result in a high rate of fatal outcomes, with higher rates for young and male drivers. OBJECTIVE This paper investigates the ability of rural Pennsylvania ATV drivers to correctly evaluate slopes, and the mean slope angle at which the most and least conservative drivers indicate a beginning of concern of a roll-over. METHOD The study was conducted using a simulator, a commercial ATV firmly fixed on an hydraulically-lifted platform. As the platform was being raised, participants were asked to report when they became uncomfortable and then when they would not drive across a slope at such an angle. The difference between the reported and the actual angles in both conditions were analyzed. RESULTS Fifty-five individuals, mostly male and younger than 20 years, participated in riding on the simulator. Between 1/3 and 1/4 of the participants correctly estimated the angle while approximately 2/3 of participants overestimated the angles at which they felt they would be uncomfortable and they would not drive across. Participants began to feel uncomfortable at 15.9±5.7 degrees and became so uncomfortable that they felt they would not drive at 22.7±3.7 degrees. CONCLUSIONS Overestimation of lateral roll angles is the most common result. This is in favor of safety when drivers are informed about a slope limit ATVs should not be operated on.

Relationship between runoff and soil losses with rainfall characteristics and long-term soil management practices in a hilly vineyard (Piedmont, NW Italy)

Abstract Runoff and soil losses caused by natural rainfall events were monitored over a 10-year observation period in three experimental vineyard plots located in Alto Monferrato, a vine-growing area in Piedmont (NW Italy). The plots are characterized by a slope of about 15% and a soil classified as Typic Ustorthents, fine-loamy, mixed, calcareous, mesic. Each of them was managed with a different inter-row soil management practice: conventional tillage (CT), reduced tillage (RT) and controlled grass cover (GC), respectively. The rainfall characteristics, runoff discharge and concentration of soil in the water were measured. More than 150 rainfall events producing runoff and 63 erosive events were recorded. The data set was elaborated to investigate the relationships between runoff and soil losses with rainfall amount, duration and intensity, and to evaluate the effects of soil management methods. The amounts of water and soil that ran off the vineyard in the study period varied according to the season, rainfall characteristics and soil surface conditions. The highest soil losses were observed for tilled plots, with values of 111.5 and 207.7 Mg ha−1 in the CT and RT plots, and only 25.6 Mg ha−1 for GC treatment. The worst soil management practice was found to be the RT, whereas the GC was able to reduce soil lost from inter-rows in every season of the year, reaching the best effectiveness in summer (reduction greater than 90%). In addition, GC reduced runoff by 35% compared with the CT plot, showing a greater performance in summer and losing efficacy in autumn. A lower runoff reduction of 11% was observed in RT.

Pelletization of composted swine manure solid fraction with different organic co-formulates: effect of pellet physical properties on rotating spreader distribution patterns

IntroductionIn Europe, because of the high production levels of livestock farming in general and pig farming in particular, animal waste management has become increasingly important to comply with the required lowering of livestock farming environmental pressure. Usually manures undergo solid/liquid separation, which generates one clarified liquid fraction and one nutrient-rich solid fraction suitable for in farm composting (both raw and in mixture with other bulking agents). This can be used to produce soil amendments, whose management can be further improved by pelletization that, against technological and environmental advantages, has the disadvantage of requiring a quite high energy input.ResultsFour different pelleted organic fertilizer formulations made of swine manure solid fraction (SMSF) composted both by itself and with sawdust (SMSF-SD), wood chips (SMSF-WC) and wheat straw were tested to highlight differences in physico-chemical and land distribution features. They were compared with two pelleted organic fertilizers ordinarily available at retailers. Results show that, as far as physical and chemical features are concerned, the greatest difference from the reference products used in this study is found in pellet size distribution after spreading since the disintegrating action of the rotating vanes does not affect the tested formulation with the same intensity as the commercial products. Distribution tests showed that SMSF-SD was the formulation with better longitudinal and transverse distribution, while SMSF was the one showing good transverse but poor longitudinal distribution.ConclusionsIn farm pelletizing of SMSF composted with different organic waste materials as co-formulates can turn into organic fertilizer formulations comparable with pelleted organic fertilizers ordinarily available at retailers. SMSF-WC was the formulation with the best resistance to fragmentation induced by spreader vanes. SMSF-SD was the formulation showing better longitudinal and transverse distribution, while SMSF showed good transverse but poor longitudinal distribution. These promising results enhance the importance of co-composting as a way to increase livestock farming sustainability and produce better manure compost for wider agricultural uses.