Variabilidade espacial da resistência à penetração em solo cultivado com cana-de-açúcar sob colheita mecanizada com tráfego controlado

• Autor(a) principal: Silva, Josévaldo Ribeiro
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/15570
• topic: Geoestatística; Saccharum oficcinarum L.; Compactação; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

The cultivation of sugarcane (Saccharum oficcinarum L.) is one of the main activities of the primary sector in the northeast of Brazil. This crop always received high advances in technology, thus the harvesting way changed, being realized in the mechanized way. Despite the benefits of the mechanized harvesting, an intense trafficability of the sugarcane harvesters, can cause compaction by eminently changing the physical properties of the soil. The controlled traffic is being used increasingly as a way to mitigate the negative effects resulted from trafficability. Based on that, the objectives of the present study were: I) evaluate the spatial variability of soil mechanical resistance to penetration in areas cultivated with sugarcane under different times of mechanized cuttingss with controlled traffic; II) evaluate the quality of physical properties of the soil in the first and third cuttings cultivated with sugarcane under mechanized harvesting with controlled traffic. The experiment was carried out at the Santa Emília II Farm, belonging to the Miriri Alimentos and Bioenergia S/A mill, located in the municipality of Rio Tinto (PB). Two commercial areas of sugarcane were selected, respectly, first (PC) and third (TC) mechanized cuttings under controlled traffic in a Alfisil. The samples collection were taken in plots of 100 x 100 m, under a sampling grid of 20 x 20 m, contemplating wheel tracks and planting row, each crossing point of the sampling grid were georeferenced, and measured the mechanical resistance to penetration with the aid of an impact penetrometer at the layer of 0-0.6 meter, the deformed and undisturbed sample collection was performed at the layers of 0-0.1 and 0.1-0.2 meters for analysis of the following variables: Texture, Dispersed clay in water , degree of flocculation,bulky bulk density, macroporosity, microporosity, total porosity, hydraulic conductivity, field capacity, permanent wilting point and available water. The resistance data were submitted to geostatistical analysis with generation of semivariograms and maps of isolines, the remaining variables were performed in a complete randomized scheme and were submitted to analysis of variance and the Tukey test (p <0.05). The mechanical resistance of the soil to the penetration presented a high and very high spatial dependence in both, the wheel tracks and planting row, were observed spherical, exponential and Gaussian models, besides the presence of pure nugget effect. The highest values of resistance to penetration were observed between the planting row, more specifically in the third cutting area, a result that was expected, given the high intensity of traffic. Higher ranges were observed in the third cutting area, with a decrease in the depth. The data of texture, dispersed clay and flocculation degree were not, in their total, altered with the time of harvest, as data seen, without significant difference for the position and collected areas. The bulk density presented higher values in the wheel tracks position, with increase of the area from the first to the third cut, in contrast, the macroporosity had a decrease. The other variables did not present significant difference. Controlled traffic was efficient in mitigating negative effects in the planting row, avoiding the increase of resistance to penetration and negative changes in the quality of physical properties.