ABSTRACT
The usage of spatial tools might be helpful in the optimization of decision-making regarding soil management, with technologies that assist in the interpretation of information related to soil fertility. Therefore, the present study evaluated the spatial variability of chemical attributes of the soil under an agroforestry system compared to a native forest in the municipality of Tomé-açu, Eastern Amazon, Brazil. Soil samples were performed at 36 points arranged in a 55 x 55 m grid. The soils were prepared and submitted to analysis in order to determine pH in H2O, exchangeable calcium, magnesium, potassium and aluminium, available phosphorus, potential acidity, organic matter, bases saturation and aluminium saturation. For each soil attribute, the spherical, gaussian and exponential models were adjusted. After the semivariograms fitting, data interpolation for assessment of spatial variability of the variables was performed through ordinary kriging. The spherical and gaussian models were the most efficient models in estimation of soil attributes spatial variability, in most cases. Most of variables presented a regular spatial variability in their respective kriging maps, with some exceptions. In general, the kriging maps can be used, and we can take them as logistical maps for management and intervention practices in order to improve the soil fertility in the study areas. The results principal components indicate the need for integrated management of soil chemical attributes, with localized application of acidity correctors, fertilizers and other types of incomes, using the spatial variability of these fertility variables.
Subject(s)
Soil Chemistry , ForestryABSTRACT
O conhecimento da variabilidade espacial de atributos climáticos e a construção de mapas de krigagem podem auxiliar no manejo adequado de animais confinados em galpões. Portanto, o trabalho teve como objetivos caracterizar a variabilidade espacial do microclima de um galpão do tipo free-stall utilizado para confinamento de bovinos leiteiros empregando a técnica de geoestatística e verificar se as variáveis climáticas encontram-se dentro dos limites de conforto dos animais. Os atributos microclimáticos - temperatura, umidade relativa, velocidade do vento, luminosidade e índice de temperatura e umidade (ITU) - foram amostrados em 152 pontos, em intervalos regulares de 2m, na forma de malha. Por meio dos resultados obtidos, foi possível verificar que o uso da geoestatística possibilitou definir áreas com diferentes variabilidades espaciais para os atributos microclimáticos, definindo áreas específicas no galpão onde a umidade relativa, a temperatura, a velocidade do vento e a luminosidade estão acima do recomendado para o conforto térmico animal. O sistema de climatização utilizado não garantiu a homogeneização do ambiente. Os valores de ITU permaneceram fora da condição de conforto térmico, portanto, a condição de ambiência do galpão possivelmente não propicia conforto aos animais.
The knowledge of the spatial variability of climatic attributes and the build of kriging maps can help livestock management in lodged animals. Therefore, the objective of this research was to characterize the spatial variability of the climatic attributes inside a dairy cow free-stall barn using the technique of geostatistics and to verify if the climatic variables are in agreement with the thermal comfort limits of the animals. The climatic attributes - temperature, relative humidity, wind speed, luminosity and temperature and humidity index (THI) were sampled in 152 points, in regular spacing of 2m, as a grid. According the results, the geostatistical analysis made it possible to find areas with different spatial variability for the climatic variables, showing specifically areas inside the dairy barn where the relative humidity, the temperature, the air velocity and the luminosity were above that the comfort limits for animal housing. The acclimatization system didn't homogenize the environment. The THI values remained above the thermal comfort condition, so, the environment of the barn probably didn't provide comfort for the animals.