The soil penetration resistance is an important indicator of soil compaction and is strongly influenced by soil water content. The objective of this study was to develop mathematical models to normalize soil penetration resistance (SPR), using a reference value of gravimetric soil water content (U). For this purpose, SPR was determined with an impact penetrometer, in an experiment on a Dystroferric Red Latossol (Rhodic Eutrudox), at six levels of soil compaction, induced by mechanical chiseling and additional compaction by the […]

A method for determining soil hydraulic properties of a weathered tropical soil (Oxisol) using a medium-sized column with undisturbed soil is presented. The method was used to determine fitting parameters of the water retention curve and hydraulic conductivity functions of a soil column in support of a pesticide leaching study. The soil column was extracted from a continuously-used research plot in Central Oahu (Hawaii, USA) and its internal structure was examined by computed tomography. The experiment was based on tension […]

The clay fraction mineralogy and the granular structure of Oxisols in the Cerrado (Brazilian savanna) are the reason for the great volume of large pores as well as of extremely small pores, but no significant medium pore volume, resulting in low available water for plants. This study aimed to characterize and model the behavior of water retention in Oxisols with different texture classes of the Cerrado region. Samples were collected from the Bw horizon of 10 Oxisols under native vegetation. […]

Knowledge on chemical and physical soil properties provides the theoretical basis for a sustainable planning of natural resources. This study evaluated the alteration of chemical and physical soil characteristics in a Haplustox in the Zona da Mata region of the State of Minas Gerais (Brazil), under different crop systems. The systems evaluated were orange orchards, sugar-cane plantation, pasture and forest, as control. Orange orchards and pasture had been established more than 20 years before, both in succession to sugar-cane, previously […]

Relatively few studies in Brazil have investigated soil erodibility, mainly for Cambisols (Inceptisols), due to the tediousness of data collection in natural rainfall experiments. Knowledge about erodibility and erosivity is important for conservation planning, which contributes to soil sustainability. This study aimed at evaluating the rainfall erosivity and erodibility of a typic dystrophic Tb Haplic Cambisol (Inceptisol) and a typic dystroferric Red Latosol (Oxisol) under natural rainfall, in Lavras, state of Minas Gerais, Brazil, between 1998 and 2002. Pluvial precipitation […]

The objective of this work was to access spatial variations of soils from experimental plots for integrated coconut production based on the detailed mapping of soils and the construction of contour maps of soil properties. Observations and measurements were formed and samples collected in small trenches and soil profiles. The amount of soil clay from small trenches was evaluated in the field by finger touch feeling. Physical and chemical analyses were performed in all samples. Particle-size-distribution (profiles), Al, Ca and […]

Loan areas near hydroelectric power plants can be considered degraded areas since they were stripped of their soil surface horizons. This study aimed to investigate the recovery of soil chemical attributes of a Red Latosol (Oxisol) used in the embankment and fill of the hydroelectric system in Ilha Solteira, São Paulo, Brazil, by green manure, lime and gypsum. The experiment had a randomized block design with seven treatments and four replications. The treatments consisted of: one control (tilled soil and […]

Soil compaction limits grain yields. Among others factors, soil amendment with agricultural lime can contribute to micro-aggregate dispersion and the formation of compacted layers. The objective of this study was to evaluate the effect of lime on soil physical attributes related to soil compaction. The experiment was carried out in PVC columns, in a glass house, during 18 months. Sterilized and non-sterilized samples of a dystrophic Red Latosol (Hapludox) were incubated with 0, 1.9, 3.8, 5.7, 7.6 and 15.2 Mg […]

Surface lime application to an acid soil under no-till system and normal rainfall conditions increases yield and crop root growth near the soil surface, but the effects of lime sources like flue dust, sewage sludge and aqueous lime have not been fully investigated . The experiment aimed to evaluate the effects of surface application of different lime sources on soil chemical attributes of a clayey, dystrophic Oxisol and black oat root growth and yield under a no-till system. Evaluations were […]

The soil use not always result in an ecological sustainable system. An intense and inadequate soil use leads to soil degradation. In this sense, this study aimed to investigate the influence of sewage sludge on the recovery of physical properties of a degraded Oxisol, cultivated for 2.5 years with eucalyptus (Eucalyptus citriodora Hook) and Brachiaria grass (Brachiaria decumbens), in Selvíria, MS, Brazil. Six treatments were evaluated in an experiment in a randomized block design with four replications: (1) Savannah; (2) […]