1,720,974 research outputs found
Evaluation of mechanical properties of green wood of Italian stone pine (Pinus pinea L.)
No full textItalian stone pine is a very distinct, big size tree developing a characteristic dense, flat-topped or umbrella-shaped head. It is the most widespread species along the roads of the Tuscany coast, with problems due to plant age, to summer and winter drop branches, to stem failure or tree fall and to wide extension of the root system. This study aims to contribute to a better understanding of the biomechanic parameters necessary to support the visual and analytical techniques currently used for tree safety evaluation. Some mature pine trees were chosen in different places of the Tuscany coast and submitted to a classic visual tree assessment. Stem cross sections were cut in correspondence of the instrumental analyses, wood specimens were prepared and compression tests were performed by recording the response in terms of the resistant strain. The MOE values (1.49 - 2.39 GPa) significantly differed from those observed in other species
Agricoltura e legalità: il contributo della meccanica al “Consorzio libera terra”
No full textDa alcuni anni a questa parte l’Università di Pisa in collaborazione con un gruppo di aziende costruttrici di macchine agricole, porta avanti un programma di sperimentazione e di consulenza con le cooperative giovanili che gestiscono le aziende sottratte alla mafia. Esperienza interessante sotto il profilo tecnico, per la vocazione al biologico delle aziende coinvolte, e sotto il profilo etico e civile
Transplanting for conversion to warm season turfgrass.
Get PDFWarm season turfgrass species (like bermudagrass) seem to be very suitable to Mediterranean climate
conditions. They also give an excellent wear resistance to the sport pitches. Transplanting of pre-cultivated
warm season turgrass plants (similar to horticultural nursery) is a promising technique which can be efficiently
used for turf conversion. It is based on the quick ground cover capacity of these species by means of stolons
and rhizomes. Transplanting can be performed both in tilled and untilled soil. A working yard for the
conversion of a professional football pitch was assessed in order to evaluate the performaces.
The transplant was performed with a 4-row mechanical transplanter which had been adjusted to work in the
untilled mowed football pitch. The mechanical transplanter accommodates 4 back-seated operators and 4
walking operators who can manually transplant the plants in case of failure. The working speed of the tractor
was less than 1 km h-1, theoretical working time was about 15 h ha-1, actual working time was 28 h ha-1, thus
the work efficiency was about 0.52. Fuel consumption was about 28 kg ha-1. Such a low efficiency was due to
the difficulty of the operators to remove the plants from the trays and supply the transplanter’s delivery system.
In this concern, an automatic transplanter was modified in order to work in untilled soil within a second specific
trial. This machine had an automatic system for removing the plants from the trays, like the most advanced
robotic transplanters for vegetable crops. Moreover, a specific system for plant deposition in untilled soil was
developed by mounting a double disc in front of the furrowers. Plant deposition was tested and a maximum
variation of 6 cm in the row was assessed with respect to the expected value. This gap is completely in
accordance with this kind of crop
Innovative strategies and machines for physical weed control in organic and integrated vegetable crops
Get PDFWeed control is one of the most serious problems in vegetable crops, limiting cultivated plants correct
development, yields, product quality and farmers income. Therefore, the aim of this work was to set up and
improve innovative strategies and machines for physical (mechanical and thermal) weed control in organic or
“integrated” vegetables production in many important areas of Northern, Central and Southern Italy. Therefore,
on-farm experiments were carried out since 1999 on fresh marketable spinach, processing and fresh market
tomato, cauliflower, savoy cabbage, greenhouse cultivated leaf beet, garlic, chicory, fennel and carrot. These
research activities started are still ongoing. The traditional farm weed management system was always
compared to one or more innovative strategies that were defined according to the characteristics of the
environment (i.e. soil type and conditions, water availability, etc.), typology of cultivation, crop rotation,
expected technical and economical results. The innovative strategies were the combination among preventive
methods (false or stale seed-bed technique), cultural methods (i.e. crop spatial arrangement that was often
adjusted in order to improve operative machines effectiveness) and direct control methods (flaming, precision
hoeing, etc.). Different kinds of specific implement such as flex tine and rolling harrows (patented by the
University of Pisa, patent n. PI/2004/A/000071), and flamers (designed and realized by the University of Pisa)
were used to perform false or stale seed-bed technique. Precision hoes equipped with rigid tools and hoeconformed
rolling harrows, equipped with elastic tines for selective intra-row weed control, were used to
perform post emergence interventions. The use of the innovative weed management systems always resulted
in significant weed abundance reductions (from 70 to 100 %), relevant yield increases, high contractions of
manpower requirement (from 20 to 80 %) and consequent relevant reductions of costs and increases of
farmers gross incomes (from 15 to 75 %) in comparison with those obtained performing the standard systems.
The results of these on-farm experiments emphasise that physical weed control can be effectively performed
using the innovative machines designed and built at the University of Pisa. These machines can also be easily
adjusted in order to be used in other crops and agricultural contexts.
Moreover, the present versions of the machines, realized as “low-tech” implement in order to be available on
the market at low costs, were recently modified within the RHEA Project, a 7th Framework Programme EU
funded research project, in which an automatic and robotized hoeing-flaming machine able to perform VRA
cross flaming was designed, fully realized and tested obtaining very promising results
Recupero delle terre incolte mediante introduzione di strategie e macchine innovative per la coltivazione biologica dei prodotti tipici nel Comune di Pignone nella Val di Vara.
No full textNon sempre il futuro si nutre di tecnologia e hi-tech, ma il recupero della
tradizione, in particolare della più antica, quella agricola, può essere un
buon viatico per nuove opportunità di sviluppo.
Riportare i giovani (e non solo) alla terra e allo stesso tempo salvare i
campi e i loro tesori dall’abbandono è l’obiettivo che si è posto il progetto
di recupero degli incolti, progetto nel quale il Comune di Pignone ha da
sempre creduto.
Già da diversi anni il nostro territorio si è imposto sullo scenario regionale
come presidio di un’agricoltura di qualità, attenta sia ai prodotti della
terra quanto alle persone che li coltivano. Non a caso a Pignone è attiva
un’Associazione di Produttori o, come meglio amano definirsi, di “Contadini”,
come non è causale che la prima Comunità del cibo di Slow Food della
provincia della Spezia si sia insediata proprio nel nostro Comune.
è in questo continuo sforzo di dare nuova linfa alla custodia del territorio,
anche in funzione di prevenzione del dissesto idrogeologico, che il
recupero degli incolti potrà inserirsi riconoscendo il prezioso contributo
dell’agricoltura per la salvaguardia, il recupero ed il mantenimento di ambiti
di interesse naturalistico, paesaggistico e storico.
Vorremmo, infine, esprimere un doveroso ringraziamento a tutti coloro
che hanno collaborato al progetto, dimostrando con i fatti che la nostra
identità passa anche attraverso l’amore per la nostra terra I Sindaci del Comune di Pignone
Antonio Pellegrotti (2009-2014)
Mara Bertolotto (2014-2019) E' con mio grande piacere che, dopo la pubblicazione del libro intitolato
“Il Centro di Ricerche Agro-Ambientali “Enrico Avanzi”, l’agricoltura per la
prosperità del futuro”, sono oggi a presentare il volume “Recupero delle
terre incolte mediante introduzione di strategie e macchine innovative per
la coltivazione biologica dei prodotti tipici nel Comune di Pignone nella Val
di Vara”, sempre edito dalla Pisa University Press, che racchiude la nuova
esperienza che il gruppo di ricerca del Prof. Andrea Peruzzi ha intrapreso
presso questo piccolo Comune ligure. I “colleghi della meccanica agraria”
del resto sono da moltissimi anni impegnati nella sperimentazione on-farm
e nel trasferimento dell’innovazione tecnologica a basso costo presso le
aziende agricole, con particolare riferimento all’orticoltura biologica ed
all’orticoltura “eroica”. A tale proposito è opportuno ricordare l’esperienza
che ha preceduto l’attività oggetto di questo volume: la sperimentazione
on-farm condotta presso il Comune Ligure di Vessalico, dove l’affiatato e
virtuoso gruppo di agricoltori della Cooperativa “A Resta” ha potuto toccare
con mano e utilizzare un cantiere di meccanizzazione agricola completo ed
innovativo per l’aglio, atto ad effettuare tutte le operazioni colturali, dalla
semina al controllo delle infestanti ed alla raccolta, nel difficile contesto
dell’agricoltura montana tipica dell’Alta Valle Arroscia. Tale esperienza è
stata raccolta in un’altra monografia edita nel 2013 sempre da Pisa University
Press ed a cura del Prof. Andrea Peruzzi.
Il Centro di Ricerche Agro-Ambientali “Enrico Avanzi” conferma quindi
la sua volontà di essere sempre vicino alle problematiche reali del mondo
agricolo ed ascoltare e confrontarsi con tutti coloro che sono interessati a
sostenere l’innovazione, facendo ricerca applicata ed allo stesso tempo trasferendo
tecnologia, come testimoniato dalla lunga lista di progetti, di cui
è stato promotore, finalizzati proprio a tale obiettivo. Al riguardo credo che
sia doveroso chiudere questa breve presentazione ricordando che il volume,
assieme a molti altri, sarà gratuitamente scaricabile come pdf dal sito
del Centro “Enrico Avanzi”, affinché la divulgazione dei suoi contenuti sia
quanto più vasta, rapida e capillare. Non resta che augurare a tutti gli studenti,
gli agricoltori, i tecnici, gli operatori del settore, o più semplicemente
10 Recupero delle terre incolte
i simpatizzanti e i curiosi, una buona lettura, nella speranza che da questa
pubblicazione possa arrivare a tutti, almeno in parte, la grande passione
che spinge da sempre i ricercatori del Centro di Ricerche Agro-Ambientali
“Enrico Avanzi” a svolgere il proprio lavoro.
Direttore del
Centro di Ricerche Agro-Ambientali “Enrico Avanzi”
Prof. Marco Mazzoncin
Design of an automatic machine for variable rate application of flame weeding on maize.
Get PDFAn automatic operative machine for variable rate application (VRA) of flame weeding on maize was designed and built at the University of Pisa within the European Project “Robot fleets for Highly Effective Agriculture and forestry management” (RHEA). The machine was
designed to conduct non-selective mechanical weed control between the crop rows and site-specific VRA of flaming in the intra row space.
Flame weeding is applied by a pair of burners liquefied petroleum gas (LPG) fed, which work cross to the row, and is activated automatically only in presence of weeds. The machine was coupled with an autonomous tractor equipped with an optical sensor for real-time row crop and weed detection. Specific hardware and software provide information about the weed cover percentage detected and send these data to the operative machine. The LPG dose that has to be applied is chosen in real-time between two doses identified in the calibration phase to be effective on weed cover percentages lower or higher than 25%. In the case of 0% weed cover, burners are switched off. The burners ignition system was designed to be almost instantaneous in order to minimize all delays, which elapse between weed detection and the presence of the flame in the area that have to be treated. The almost instantaneous burners ignition system allows also to avoid the use of a pilot flame, which would be switched on for all the effective working time of the machine. The operative machine is equipped with and automatic steering system, which according to directional movement of two metallic wheels, allows maintaining the same trajectory of the autonomous tractor, and avoiding the accidental damage of the crop. A study aimed to find the optimal LPG doses for an effective weed control and which not lead to yield losses, as a consequence of damages occurred to maize plants treated at different development stages, was conducted in 2012 and 2013 at the experimental farm of the University of Pisa. Maize and weeds response to the application of five LPG doses was evaluated in terms of yield, weed density after the application and weed dry biomass at harvest. The optimal LPG doses estimated were useful for the automatic operative machine calibration. The site-specific VRA of flaming and the use of an almost instantaneous burners ignition system allow to reduce the LPG consumption compared to a continuous application and the presence of the pilot flame during turning, leading to a reduction
of costs for the thermal weed management of heat-tolerant crops. The operative machine represent a new technology for precision agriculture, which if integrated with a proper perception system, independent from the autonomous tractor for the receiving of information needed for the automatic regulation of the LPG dose, could work coupled with a common tractor
Thermal weed control on horizontal and vertical surfaces in archaeological sites as an alternative to herbicides
Get PDFFlaming could be an alternative weed management at archaeological sites because it controls
a wide range of weed species without inducting future resistance. The aim of this study was to
test the weed control efficiency of flaming on various horizontal and vertical surfaces of
archaeological buildings. Working times and costs were recorded. Flaming performances were
compared to the normal herbicide treatments and mowing. Results showed that repeated
flaming reduced weed cover by 100%. Working times and total costs decreased by increasing
the number of applications over time. This is because the repeated flaming applications deplete
the weed root stocks, thus keeping the mortar between the stones or bricks and the building
materials free from weeds and their seeds for a long time. The method involved zero toxicity
for humans and animals, thus providing safe accessibility to the archaeological buildings and
visitor pathways. The application of flaming did not cause any damage or change of colour to
the treated materials, although specific, multidisciplinary studies on this subject will have to be
conducted in the next future, in order to exclude any negative effect on the remains. The results
of these studies showed that flaming is a viable alternative for controlling weeds growing on
archaeological surfaces
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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