In order to study sampling techniques useful for digital soil mapping (DSM), we evaluated the effect of changes in sampling density, based on data from areas already mapped by traditional methods, in regard to the accuracy of decision trees models for generating soil maps using DSM. In two watersheds in northwestern Rio Grande do Sul, Brazil, 1:50,000 scale conventional soils maps were used as reference maps. From the ASTER – GDEM Global Digital Elevation Model and the hydrographic network, maps […]

The use of diazotrophic bacteria can help to achieve higher yields and reduce negative environmental impacts caused by N fertilizers. The aim of this study was to evaluate the effects of seed treatment with Azospirillum bacteria and the application of different rates of mineral N on maize agronomic performance at two levels of yield management. A field experiment was set up in Lages, SC, Brazil, in the 2011/2012 and 2012/2013 growing seasons. A randomized block experimental design arranged in split-split […]

The identification of variability patterns through soil properties allows land use and occupation in a sustainable manner. The aim of this study was to ascertain the potential of magnetic susceptibility of the soil and landscape models in defining areas for specific management practices through the use of mathematical tools. The study area is in the municipality of Guariba, SP, Brazil. We chose an area of 110 ha in which three geomorphic surfaces (I, II, and III) had been identified and […]

The soils used to grow irrigated rice in the State of Santa Catarina have different mineralogical and chemical characteristics from the soils used for calibration studies of the Mehlich-1 extractant, for estimating soil phosphorus availability to plants. Thus, the aim of this study was to evaluate the effectiveness of Mehlich-1, Mehlich-3, Resin, Olsen and EDTA extractants in predicting P availability to flood irrigated rice in soils of State of Santa Catarina. The experiment was carried out in a greenhouse in […]

Common bean (Phaseolus vulgaris L.) may benefit from biological N 2 fixation, but inconsistent responses of the crop to rhizobium inoculation indicate the need for supplemental mineral N fertilization. In this study, we aimed to evaluate the response of the common bean crop to rhizobium inoculation in association with supplemental mineral N in the Cerrado (Brazilian tropical savanna) and Atlantic Forest biomes. Four field experiments were carried out, two in Santo Antônio de Goiás (State of Goiás), one in Valença […]

The use of pig slurry (PS) as fertilizer can affect the soil quality and increase total stocks of soil organic carbon (TOC). However, the effects of PS on TOC amount and forms in the soil are not fully understood, particularly in areas under no-tillage (NT). The purpose of this study was to determine TOC contents and stocks in the particulate (POC) and mineral-associated C fractions (MAC) of an Oxisol after nine years of maize-oat rotation under NT, with annual applications […]

Preharvest burning is widely used in Brazil for sugarcane cropping. However, due to environmental restrictions, harvest without burning is becoming the predominant option. Consequently, changes in the microbial community are expected from crop residue accumulation on the soil surface, as well as alterations in soil metabolic diversity as of the first harvest. Because biological properties respond quickly and can be used to monitor environmental changes, we evaluated soil metabolic diversity and bacterial community structure after the first harvest under sugarcane […]

Soil aggregation and the distribution of total organic carbon (TOC) may be affected by soil tillage and cover crops. The objective of this study was to determine the effects of crop rotation with cover crops on soil aggregation, TOC concentration in the soil aggregate fractions, and soil bulk density under a no-tillage system (NTS) and conventional tillage system (CTS, one plowing and two disking). This was a three-year study with cover crop/rice/cover crop/rice rotations in the Brazilian Cerrado. A randomized […]

Tin mining in the Serra da Onça in the Jamari National Forest, State of Rondônia, Brazil, caused severe chemical, physical, and biological changes in the soil. In 1997, the area was divided into plots and a rehabilitation program was begun, which consisted of land surface modeling, construction of terraces, liming, fertilization, and planting of leguminous crops and native plants. In subsequent years, new plots were set up in the rehabilitation program so that at the time of sampling the different […]

Conservation tillage systems in orange groves can increase soil load-bearing capacity minimizing their risks of soil compaction. The objective of this study was to evaluate load-bearing capacity through preconsolidation pressure and its dependence on water content, bulk density, and organic carbon of a Typic Paleudult soil 18 years after setting up permanent plant cover between the rows of an orange grove. A randomized block experimental design was used, with three replications. Three groundcover treatments subjected to mowing between the rows […]