R ESU M OObjetivou-se, neste trabalho, avaliar as propriedades físicas de três classes de solo cultivadas com cana-deaçúcar em sistema de colheita mecanizada na região de Mato Grosso do Sul. O local de estudo pertence à Usina Eldorado, Grupo ETH Bioenergia S/A, localizada no município de Rio Brilhante, MS. A amostragem em cada área experimental foi realizada a partir de uma malha, com 180 m de comprimento e 145,6 m de largura, totalizando 90 pontos em forma de grade, com 9 colunas e 10 linhas, onde foram coletadas amostras de estrutura indeformada nas camadas de 0-0,2 m e 0,2-0,4 m de profundidade nas entrelinhas da cultura. Após coleta, as amostras foram processadas para determinação da densidade do solo (DS), porosidade total (PT) e umidade do solo () para interpretação dos dados. A palhada deixada sobre superfície auxiliou na mantença de bom nível de matéria orgânica, corroborando na formação, agregação e estabilidade de poros, impedindo o aumento da densidade. A redução da porosidade total e consecutivo aumento na densidade do solo, principalmente na profundidade de 0,2-0,4 m, indicam compactação nesta camada, justificada pelo intenso tráfego de veículos e ausência de revolvimento do solo. Palavras-chave:Saccharum officinarum, densidade do solo, geoestatística, estabilidade de agregados Physical properties of three classes of soils cultivated with sugarcane in mechanized harvesting A B ST R A C T The aim of this study was to evaluate the physical properties of three soils cultivated with sugarcane mechanized harvest system in the region of Mato Grosso do Sul The study site belongs to the Plant Eldorado, ETH Bioenergy Group S/A, located in Rio Brilhante, MS. The sampling in each experimental area was made from a grid with 180 m long and 145.6 m wide, totaling 90 points in a grid form, with nine columns and 10 rows, where samples were collected in undisturbed layers of 0-0.2 m and 0.2-0.4 m deep in the rows. After collection, samples were processed for determination of soil bulk density (BD), total porosity (TP) and soil moisture () for data interpretation. Crop residues left on surface helped to maintain good level of organic matter, supporting the formation, aggregation and stability of pores, preventing the increase in density. The reduction in total porosity and consecutive increase in density, especially in the 0.2-0.4 m, indicating compaction of this layer, justified by the intense traffic of vehicles and lack of soil disturbance.

ABSTRACT:The aim of this study was to characterize the spatial variability of soil bulk density (Bd), soil moisture content (θ) and total porosity (Tp) in two management systems of sugarcane harvesting, with or without burning, in a Haplustox soil, in the 0-0.20 m layer. The study area is located in Rio Brilhante, state of Mato Grosso do Sul, Brazil, in Eldorado Sugar Mill. The plots have presented 180 m length, and 145.6 m width, totaling 90 points distributed in the form of a grid of nine rows by ten columns, with points spaced 20 m from its neighbor. Soil samples were collected at 0-0.20 m layer in 2007/2008 and 2008/2009 crops. The harvest with burning system had a higher density compared to mechanized harvest, in the two study periods. The moisture content as well as the porosity increased proportionally with the decrease of the density of the harvest burning system compared to the mechanized. KEYWORDS: mechanized harvesting, bulk density, Saccharum spp. VARIABILIDADE ESPACIAL DAS PROPRIEDADES FÍSICAS DO SOLO EM DOIS

When deposited on land the vinasse can promote improvement in fertility, however, often fertilizer application occurs in areas considered homogeneous, without taking into account the variability of the soil. The objective of this study was to evaluate the effect of vinasse application on potassium content in two classes of soils cultivated with sugarcane, and characterize the spatial variability of soil using geostatistical techniques. In the 2010 and 2011 crop year, soil samples were collected from an experimental grid at 0-0.2 and 0.2-0.4 m depth in three soils cultivated with sugarcane, totaling 90 samplings in each grid, for the determination of pH, calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P), aluminum (Al) and potential acidity (H + Al ). The data have been submitted to analysis of descriptive statistics and the K attribute was subjected to geostatistical analysis. The coefficient of variation indicated medium and high variability of K for the three soils. The results showed that the spatial dependence of K increased in depth to FRce and decreased to PHlv, indicating that the attribute could have followed the pattern of distribution of clay in depth. The investigation of the spatial variability of K on the surface and subsurface soils provided the definition of management zones with different levels of fertility, which can be organized into sub-areas for a more efficient management of the resources and the environment.