Humic substances (HS) are the main pool of total soil organic carbon (TOC). They are partitioned in different fractions according to its solubility in alkali or acid medium, which can be related to soil type and management. This work aimed to compare HS partitioning in Brazilian soils according to soil depth, soil type, biome, and land uses. In a literature review of theses, dissertations, journal articles, and abstracts in proceedings, quantitative data on TOC partitioning in humic acids (HA), fulvic […]

Several advances have been made in the field of diffuse spectroradiometry in the last decades. In agriculture, the search for quantification methods of physical and chemical properties of the production environment, based on soil reflectance, has been constantly researched. The aim of this study was to evaluate the possibility of estimating the silt, sand, clay, sum of bases, total iron and organic matter content in soil samples based on the reflected energy. The samples were collected in a 2500 ha […]

Considering the importance of knowledge of the spatial distribution of soil properties, the purpose of this study was to evaluate the spatial variability of physical properties in a Cambisolunder different land uses in the southern Amazon region. The study was conducted on three farms with cassava, sugarcane, and agroforestry, in the region of Humaitá, in the south of the State of Amazonas. In these areas, 70 x 70 m grids were established, with a regular spacing of 10 x 10 […]

Organic acids play an important role in the nutritional conditions of plants. Their relevance is related to their formation dynamics, mineralization rate and adsorption by soil colloids. This study was carried out to evaluate the dynamics of mineralization and adsorption of organic acid (acetic acid – AA, citric acid – CA and humic acid – HA) applied to the soil. Samples of two Oxisols were used: Rhodic Haplustox (LV) and Typic Haplustox (LVA). The mineralization experiment was arranged in a […]

Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of […]

Araucaria angustifolia (Bert.) O. Kuntze is the main component of the Mixed Ombrophilous forest and, in the State of São Paulo, it is associated with a high diversity of soil organisms, essential for the maintenance of soil quality, making the conservation of this ecosystem a major and pressing challenge. The objective of this study was to identify the physical and chemical properties that are most closely correlated with dehydrogenase enzyme activity, basal respiration and microbial biomass under native (NF) and […]

The least limiting water range (LLWR) is one of the best indicators of soil physical quality in intensive production systems. The objective of this study was to evaluate the physical quality of a Typic Haplorthox by the LLWR after three crop growing seasons and the first year of crop-livestock integration in Xambrê, northwestern Paraná, Brazil. The experiment was established in a randomized block design with three replications. Treatments consisted of four brachiaria heights before grazing (0.10; 0.20; 0.30, and 0.40 […]

Histosols are formed under geomorphic and climate conditions that allow the accumulation of organic material, and their drainage for agriculture leads to the subsidence process and changes in the content of soil organic matter (SOM), with implications in the sustainability of these soils. The objective of this study was to evaluate some physical properties of Histosols and their relationship to SOM content and degree of decomposition in soils formed under hydromorphic conditions in the states of Rio de Janeiro (Aw […]

Soil management systems, as those that integrate crop and livestock production, aiming at maintenance or recovering of soil quality, are indispensable for a sustainable agricultural management. Our hypothesis is that the land use for integrated crop-livestock systems improves soil physical properties, thus contributing to a sustainable agricultural soil use in the southwestern Cerrado region. The aim of this study was to investigate the influence of different tillage systems on some soil physical properties of the Cerrado. The soil under study […]

Coffee farmers from the physiographic region known as the Upper San Francisco River, MG, Brazil, have been adopting a new conservation management system with effects on the soil physical quality that require evaluation. The objective of this work was to study the physical quality of a Latosol and a Cambisol in contiguous areas under commercial coffee plantations. The soil of a transition area at the top of the landscape was classified as latossolic dystrophic Tb Haplic Cambisol (Inceptsol) and the […]