4,721 research outputs found
Principal components in the study of soil and plant properties in precision coffee farming
ArticleIn this work, a principal component analysis was performed to evaluate the possibility
of discarding obsolete soil and plant variables in a coffee field to eliminate redundant and
difficult-to-measure information in precision coffee farming. This work was conducted at Brejão
Farm in Três Pontas, Minas Gerais, Brazil, in a coffee field planted with 22 ha of Topázio cultivar.
The evaluated variables were the yield, plant height, crown diameter, fruit maturation index,
degree of fruit maturation, leafing, soil pH, available phosphorus (P), remaining phosphorus
(Prem), available potassium (K), exchangeable calcium (Ca2+), exchangeable magnesium
(Mg2+), exchangeable acidity (Al3+), potential acidity (H + Al), aluminium saturation (N(Al)),
potential CEC (CECp), actual CEC (CECa), sum of bases (SB), base saturation (BS) and organic
matter (OM). The data were evaluated by a principal component analysis, which generated 20
components. Of these, 7 representing 88.98% of the data variation were chosen. The variables
were discarded based on the preservation of the variables with the greatest coefficients in absolute
values corresponding to the first component, followed by the variable with the second highest
absolute value corresponding to the second principal component. Based on the results, the
variables V, OM, fruit maturity index, plant height, yield, leafing and P were selected. The other
variables were discarded
Measurements relationship among compost bedded pack barn farms in six European countries during the winter and spring season
Geostatistics applied to evaluation of thermal conditions and noise in compost dairy barns with different ventilation systems
ArticleThe objective of this work was to evaluate the spatial distribution of thermal
conditions and bed variables in compost dairy barns with different ventilation systems, through
the technique of geostatistics. The experiment was conducted in April 2017, in farms located in
Madre de Deus, Minas Gerais, Brazil. Three facilities were evaluated with different ventilation
systems: natural (NV); mechanical of low volume and high speed (LVHS); and mechanical of
high volume and low speed (HVLS). The interior of the premises was divided into 40 meshes
equidistant points, in which air temperature, relative humidity and air speed were manually
collected. Geostatistics technique was used to assess the spatial dependence of the variables.
The results showed the occurrence of dependence and spatial variability of the variables
evaluated. Based on thermal comfort indexes, it was concluded that dairy cows were under
stress conditions during the hottest hours of the day in the three animal facilities evaluated. The
results obtained allow us to understand that the thermal environment is more influenced by the
ventilation system adopted
Behavioural and physiological responses of rabbits
ArticleThe profitability of a rabbit farming system must consider the thermal environment
that the animal will be exposed during the productive period. The goal of this study was to
evaluate the physiological responses and behaviours of 26 New Zealand rabbits during seven
days of their lives at three times a day. The experiment was carried out in rabbit house in the
Federal University of Lavras at Lavras, Brazil. To characterize the thermal environment sensors
were used to measure the dry bulb temperature and relative humidity at 48 points inside the rabbit
house, at 6:00 a.m., 12:00 a.m. and 6:00 p.m. In addition, the temperature and humidity index
(THI) was calculated. The respiratory rate and the superficial temperature of the rabbits' ears were
measured. Behaviour evaluations were monitored in punctual record, with duration of two
min/cage. Later an ethogram was made with the main behaviours identified. Similar data of
behaviour and data of physiological responses were identified by using Ward’s method of cluster
analysis. It was observed the period of 6 a.m. showed more comfortable conditions of THI values
than the others analysed. Besides, physiological responses presented better values at 6:00 a.m. in
comparison to 12:00 and 6:00 p.m. Furthermore, in general, a similar behaviour was observed in
the rabbits at 12:00 and 6:00 p.m., while at 6:00 a.m. was different. But rabbits demonstrated to
be more comfortable at 6 a.m. maybe because at this time environment conditions were better
than the rest of the day. Besides, it can be observed that rabbits were more active in sunrise and
sunset than in the rest of the day
Spatial variability of litter temperature, relative air humidity and skin temperature of chicks in a commercial broiler house
ArticleThe thermal environment inside a broiler house has a great influence on animal welfare
and productivity during the production phase. Among the importance of the chicken litter is the
function of absorbing moisture, provide thermal insulation and provide a soft surface for broilers.
The skin temperature is an important physiological parameter to quantify the thermal comfort of
animals, its variations may occur as a function of thermal variables. So, the aim of this work was
to analyse the magnitude and spatial variability of chicken litter temperature and relative humidity
of the air and to correlate them with the spatial distribution of chicks’ skin surface temperature
throughout the broiler house during the 7th, 14th and 21st days of the chicks’ life, using
geostatistical techniques. The experiment was performed in a commercial broiler house located
in the western mesoregion of Minas Gerais, Brazil, where 28,000 male Cobb chicks were housed.
The heating system consisted of an industrial indirect-fired biomass furnace. The heated air was
inflated by an AC motor, 2,206 W of power, 1,725 RPM. Geostatistical techniques were used
through semivariogram analysis and isochore maps were generated through data interpolation by
kriging. The semivariogram was fitted by the restricted maximum likelihood method. The used
mathematical model was the spherical one. After fitting the semivariograms, the data were
interpolated by ordinary kriging. The semivariograms along with the isochore maps allowed
identifying the non-uniformity of spatial distribution of the broiler litter temperature throughout
the broiler house for 3 days of chicks’ life. It was observed that skin surface presented a positive
correlation with the litter temperature and a negative correlation with the air humidity. The
semivariograms along with the isochore maps allowed identifying the non-uniformity of spatial
distribution of the litter temperature, air humidity and skin temperature of chicks throughout the
broiler aviary for the three days. In addition, the use of geostatistics and distribution maps made
possible to identify different environmental conditions in regions inside the broiler house that
may harm the development of chicks
Spatial variability of soil fertility attributes and productivity in a coffee crop farm
ArticleCoffee cultivation is of great importance to Brazilian agribusiness, as coffee occupies
extensive production areas and is one of the most exported Brazilian products. To maintain coffee
production numbers, productive techniques must be adopted that optimize productive system use.
The objective of this work was to apply geostatistical techniques in the evaluation of soil fertility
attributes to construct maps of variability in soil fertility parameters and the productivity of a
coffee crop in the municipality of Monte Carmelo, Minas Gerais (MG), Brazil. The work was
developed with coffee of the cultivar Mundo Novo 379/19, and 19 sample points were
georeferenced in Universal Transverse Mercator coordinates. Spatial dependence of the fertility
and productivity parameters was analysed via classic semivariogram fitting and interpolation by
ordinary kriging using the statistical computer system, R. All parameters evaluated showed high
degrees of spatial dependence. The attribute values varied along the sampling points, except for
the sodium (Na) contents, which had similar values in all samplings. The studied parameters
ranged from 80 to 200 metres. It is conclusion, the use of productivity maps linked to soil
chemical attributes can be useful for determining the occurrence of variable productivity rates
throughout the area, allowing the adoption of corrective practices for subsequent crops and thus
making the maps very useful tools for producers
Evaluation of the physical properties of bedding materials for dairy cattle using fuzzy clustering analysis
Design and construction of a low-cost remotely piloted aircraft for precision agriculture applications
ArticleThis study aimed to construct a low cost RPA capable of recording georeferenced
images. For the construction of the prototype of a quadcopter type RPA, only essential materials
were used to allow stable flight. A maximum total weight of 2 kg was stipulated, including frame
weight, electronic components, motors and cameras. The aircraft was programmed using a
low-cost microcontroller widely used in prototyping and automation research. An electronic
circuit board is designed to facilitate the connection of the microcontroller with the other
components of the design. Specific software was used for flight control. The prototype was built
successfully, being able to lift stable and controllable flight. However, we still need to acquire
equipment and programming components capable of enabling autonomous images and flights.
The final cost of the RPA was on average 772.81 to $ 1,288.00
Teores de zinco em solo em função da fonte e forma de aplicação na cultura da soja em Sete Lagoas, MG.
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