1,721,018 research outputs found
A new prototype to perform precision treatments of activated steaming to kill weed seed before organic sown vegetable planting
No full textnd saves more herbicide. Is dose response data
in horticulture for the last few decades. Many active ingredients
vailable to implement variable dose treatments? How small
have been banned and researchers are now evaluating different
hould treatment pixels be? The smaller the pixel the greater the
alternative techniques as soil steaming.
prayer costs but the greater the herbicide saving. Map accuracy ay depend on the proportion of the field mapped. How much
The application of precision farming technologies can improve
f the field needs to be surveyed? Answers to these questions
the efficiency of soil steaming, making the treatment “more
re being developed but detailed economic analyses balancing
targeted” to specific purposes, in example weed seedbank
osts and herbicide savings will be needed.
control.
Band steaming is a specific application of precision soil
1. Introduction
steaming which allows to reduce the intra-row weed seed-bank
any weed species demonstrate aggregated distributions, so
and lower labour-intense hand weeding treatments in organic
ppreciable savings in herbicide use can be made by only
farming.
reating weed patches. This is both financially attractive to the
A drawn machine has been built by the University of Pisa and
armer and environmentally beneficial. How patchy are weeds?
has been testing in different sown vegetable crops in different
y own work has indicated that in S. England Alopecurus Italian agricultural contexts
Band-steaming a new solution for seedbank depletion in low competitive vegetables.
No full textWeed competition is a major problem in organic agriculture, because the use of herbicides is prohibited. Vegetable crops are generally the most sensitive from this point of view, especially the sown ones, because they often need plenty of time for emergence. This often implies a large effort for hand weeding in the rows, which are very difficult to be treated physically in a selective way.
Soil steaming could be a possible solution for preventive weed control/weed seedbank depletion in organic/integrated low-competitive vegetable crops, in order to reduce labor time for in-row hand-weeding.
The effect of bioflash system (consisting in the distribution of steam and CaO) on weed seedbank was “exploited” to develop a new machine for “band-steaming”. In this case, steaming is performed just in strips, where the crop will be successively sown. Each strip corresponds to one crop row. The machine is drawn and is equipped with a water tank, a hopper containing the exothermic compound (CaO) and an industrial steam generator providing an outflow of about 1300 kg h-1. The steam generator unit is connected to a 5.10 m wide, PTO-driven rotary cultivator with 12 units. Each unit is connected to a steam pipe and is characterized by the rotating tool and a carter which bears the steaming bar. The tested working speed ranged from 0.2 to 0.5 km h-1. The steam injection is superficial in order to kill the weed seeds till a depth of about 5 cm.
The prototype has been tested on carrot in four organic farms spread throughout Italy. The results are encouraging as the soil temperature peak was about 80 °C and the weed emergence reduction, 10 days after planting, ranged on average from 70% up to over 90%. On average the 50% of labour demand for hand weeding was saved (about 200 h ha-1). However the machine needs to be improved in order to make the steam injection more efficient and this treatment more sustainable (more effective and cheaper)
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
Innovative strategy and machines for non chemical management of weed seed-bank and actual spontaneous flora in turf grass.
No full textWeed management is a major issue not only in agriculture but also in cities and in public and
sport turfs. As a matter of fact, in the latter case an effective control of weed flora is needed in
order to maintain a high quality and functionality of the turf. Actually, weed control in turfs is
performed by means of very high amount of herbicides. This kind of management is very
dangerous as it is connected with very high risks of environment pollution and consequently for
operators and citizens safety and health. In this context, public concern about agrochemical use
in turf is more and more increasing and there is a clear need to define and use alternative and
non chemical methods of weed control in turfs. This paper aims to summarize the main results
achieved by the University of Pisa in about three years of research carried out on the possible
application of thermal weed control in turfs
LPG burners for weed control
Full text linkThis article reports on the results of a study carried out on three prototypes of open flame burners for thermal weed control. Their performance is reported in terms of flame temperature and length, in order to ascertain the best ratio between primary and secondary air, and liquefied petroleum gas (LPG) consumption. To find the best ratio between primary and secondary air, the length and temperature of the flame were recorded for each of the three burners, examined by varying the inlet sections of the primary air and secondary air. The data on temperature and the flame length of each burner were processed using multiple regression analysis. The LPG consumption was determined with one of the burners using 10 different pressures in combination with three nozzles. The data obtained were subjected to non-linear regression using two gaseous outflow models. The various combinations of primary and secondary air inlet sections affected the values of the flame length and temperature. In general, the best combinations of primary and secondary air inlet for flame temperature did not correspond to those for flame length. However, this experiment showed that the inlet of secondary air is critical for the performance of this type of burner, in terms of flame temperature. The fuel consumption trial showed that the model proposed for the gaseous outflow is suitable for describing the values of LPG consumption collected during the trial. © 2015 American Society of Agricultural and Biological Engineers
Development of machines for flaming weed control on hard surfaces
Full text linkWeed control is a major issue not only in agriculture but also on hard surfaces in urban and suburban
contexts. Weeds can cause serious damage to urban structures and are often considered as a sign of neglect. Moreover,
citizens are becoming increasingly aware of environmental pollution and its potential risks for their health.
Flaming represents a concrete alternative to herbicide applications on hard urban surfaces. Flaming can also be a
good alternative to mechanical means (e.g., string trimmers) which can seriously damage surfaces because they are too
intense and in any case are often not effective. The aim of this work is to describe LPG fed flaming machines designed and
built at the University of Pisa, Italy. Liquefied Petroleum Gas (LPG) is a flammable mixture of hydrocarbon gases–
propane and butane. Four different machines were developed and tested in four different urban and sub-urban contexts. A
small backpack flamer equipped with a manual lance was tested on a stonewall, a trolley machine with a manual lance
was used to clean the base of ornamental trees, a self-propelled machine was tested in a railway station, and a mounted
machine was used in a suburban cycle way. Flaming was compared to the ordinary weed control systems such as using
herbicides or mowing.
The results showed that flaming can be both less expensive and more effective (on average less that 1 € m-2 year-1
maintaining weed cover below 5% to 6%) than the ordinary treatments in urban areas. Flaming was more effective than
mowing in the suburban area but much more expensive, thus an integrated approach would be advisable in this context.
Future research should be devoted to improving the efficiency of the treatment, using for example, new burners with
secondary air and precision agriculture technologies
Design and full realization of physical weed control (PWC) automated machine within the RHEA project
Full text linkCurrently precision agriculture can rely on modern technologies that allow to design and realize
operative machines provided with perception systems, in order to perform precise and
targeted treatments. The ultimate objective of this synergy consists in reducing the use of
agrochemicals and energy, enhancing the sustainability of agricultural practices. In this regard,
the RHEA project funded by EU, aims to develop a fleet of etherogenous autonomous
robot units in order to perform precise treatments related to crop protection in different scenarios.
In this paper is reported the design and the development of an automatic machines able to
perform, at the same time, mechanical and thermal weed control on maize is described and
discussed. The equipment will be coupled to an autonomous ground mobile unit equipped
with a row and a weed detection systems. The operative machines was designed to remove
weeds mechanically from the inter-row spaces of the crop and perform selective and targeted
cross flaming, in the rows of the crop. The precision of the treatment is ensured by specific
vision based perception system for weed detection and crop row detection. Mechanical
treatment (inter-row cultivation) will be performed in a continuous way, even without weed
presence. The machine is provided with a guidance system managed by a crop row detection
system in order to avoid damaging the maize plants with the rigid tools used for mechanical
weed removal. On the contrary cross flaming on the rows of the crop is actuated only if
weed patches are detected. The thermal weed control is applied by mean of couples of rod
burners LPG fed, able to treat a 25 cm wide strips with the crop row in the middle. The biological
selectivity is ensured by maize high tolerance and weeds sensitivity to flame exposure
for few tenths of seconds. Moreover, the LPG working pressure can be adjusted according to
the level of weed cover detected by the weed detection system:
- no treatment, if weed cover is near to 0 %;
- low LPG working pressure, if weed cover is lower than 25%;
- high LPG working pressure, if weed cover is higher than 25%.
Each unit for thermal weed control is provided with an ignition system able to properly swich
on the burners at the selected LPG working pressure. This ignition system enables to avoid
the use of pilot light, often adopted in the conventional “low-tech” flaming machines. This fact
is very important for the overall safety of the system, since the implement is coupled with an
unmanned ground mobile unit
Sensor based LPG management system for application of precision flaming.
No full textModern technologies allow to design and
implementing autonomous robotic weed control system, suitable
to perform treatments according to a precision farming
management. The RHEA European project fits in this branch of
research with the aim of project and provide a fleet of different
autonomous robot units in order to perform precise and targeted
treatments related to crops protection, allowing to lower
agrochemical, energy and hand labour input. In this work is
described the LPG feeding system of an autonomous robotic
ground mobile unit designed to perform thermal and mechanical
weed-control treatment on maize
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