Modelagem e quantificação da incerteza espacial do potássio disponível no solo por simulações estocásticas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise geoestatística da variabilidade espacial do acabamento com tingidor em painéis de madeira colada lateralmente

Classical statistical techniques which necessarily assume that all sampling units are random and independent were always used in the timber industry. Geostatistics considers that certain phenomena are characterized by spatial dependence: values of sampling units closer to each other tend to be more similar than values of sampling units farther away. This study aimed to characterize the spatial variability of the finishing (dyer) in the upper and lower surfaces of four edge glued panels by using geostatistical methods using geoR. Semivariograms were constructed for the analysis of spatial dependence. The spherical mathematical model was the best fit to the semivariograms generated, and was done the interpolation of the data (kriging) in samples where the distribution of dyer presents spatial dependence. In the bottom surfaces of two panels where the spatial dependence was detected geostatistical methods characterized a very large spatial variability due to the heterogeneous application of the finishing

Variabilidade espacial dos atributos físicos e químicos em um gleissolo mecânico sob três áreas no município Arari - MA

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Modelagem espacial de áreas de recarga subterrânea em região de afloramento do sistema aquífero guarani (sag), em Brotas/SP

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Variação espacial do grau de trofia e da biomassa fitoplanctônica no reservatório de Itupararanga (São Paulo, Brasil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Calcários albianos de campo petrolífero na Bacia de Campos: fácies, diagênese e modelo deposicional

Pós-graduação em Geologia Regional - IGCE

Cultivo de milho verde em sucessão ao arroz no Vale do Ribeira, SP: subsídios para adoção de zonas de manejo

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Variabilidade de atributos físicos de um latossolo vermelho sob cultivo de cana-de-açúcar

The goal of this paper was to select among the attributes surveyed soil, one with better representation to explain the variability of the technological components of sugar cane. The study was conducted at ETH Eldorado Plant in Rio Brilhante, MS, in the agricultural year 2011/2012, in a Oxisol, which was installed a geostatistical grid for data collection of soil and plant, with 80 sampling points, a 80 ha area. From the standpoint of linear and spatial TCH has been explained as a function of volumetric moisture. The volumetric moisture collected at a depth of 0.00 to 0.20 m, which had values between 0,24 to 0,270 m(3) m(-3), resulted in sites with the highest productivity of sugar cane per hectare from 64 to 70 t ha(-1). To aid future studies aimed at precision agriculture, which will use the same attributes as those of the future works, the values of ranges of spatial dependence to be used should be between 81 and 487 meters.

Mapeamento do fósforo adsorvido por meio da cor e da suscetibilidade magnética do solo

The objective of this work was to evaluate the possibility of mapping adsorbed phosphorus through soil color and magnetic susceptibility. The experiment was done in a 380-ha sugarcane area, which included four types of Oxisols, with different texture and natural fertility. Two hundred and forty-one soil samples were collected at 0.00-0.25-m depth. The soil redness index was calculated from sample values of hue, value, and chroma, obtained with diffuse reflectance spectroscopy. Regression models were adjusted between adsorbed phosphorus and soil magnetic susceptibility or redness index. Data spatial dependence was evaluated with geostatistics. Magnetic susceptibility is significantly correlated to adsorbed phosphorus, which allows it to be used as a component in pedotransfer functions for indirect quantification of soil adsorbed phosphorus. The redness index and the magnetic susceptibility show spatial dependency with adsorbed phosphorus. Soil magnetic susceptibility and redness index, evaluated with diffuse reflectance spectroscopy, can aid in the mapping and identification of areas with different phosphorus adsorption potential.

Simulação sequencial de atributos diagnósticos do solo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mapping of clay, iron oxide and adsorbed phosphate in Oxisols using diffuse reflectance spectroscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Soybean yield in relation to distance from the Itaipu reservoir

Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

Variabilidade espacial de atributos dendrométricas do eucalipto e de um neossolo quartzarênico a partir da aplicação de calcário ou lama de cal + oxyfertil

Pós-graduação em Agronomia - FEIS

Variabilidade no andar com ultrapassagem de obstáculo de idosos com doença de Parkinson

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of CAN-based distributed control system for variable rate technology in agricultural machinery

The number of electronic devices connected to agricultural machinery is increasing to support new agricultural practices tasks related to the Precision Agriculture such as spatial variability mapping and Variable Rate Technology (VRT). The Distributed Control System (DCS) is a suitable solution for decentralization of the data acquisition system and the Controller Area Network (CAN) is the major trend among the embedded communications protocols for agricultural machinery and vehicles. The application of soil correctives is a typical problem in Brazil. The efficiency of this correction process is highly dependent of the inputs way at soil and the occurrence of errors affects directly the agricultural yield. To handle this problem, this paper presents the development of a CAN-based distributed control system for a VRT system of soil corrective in agricultural machinery. The VRT system is composed by a tractor-implement that applies a desired rate of inputs according to the georeferenced prescription map of the farm field to support PA (Precision Agriculture). The performance evaluation of the CAN-based VRT system was done by experimental tests and analyzing the CAN messages transmitted in the operation of the entire system. The results of the control error according to the necessity of agricultural application allow conclude that the developed VRT system is suitable for the agricultural productions reaching an acceptable response time and application error. The CAN-Based DCS solution applied in the VRT system reduced the complexity of the control system, easing the installation and maintenance. The use of VRT system allowed applying only the required inputs, increasing the efficiency operation and minimizing the environmental impact.