In areas of intensive pig production, pig slurry is used as an important nitrogen (N) source of crops, but is also a major cause of soil, air and water pollution. Strategies are required to reduce N losses from this organic material to the environment and to improve the agronomic efficiency as plant N source. The purpose of this study was to evaluate the effect of the use of a nitrification inhibitor (NI) and the split application of pig slurry (PS) […]

When conventional tillage is replaced by no-tillage (NT) changes occur in the dynamics of soil nutrients and acidity, which may influence the soil-plant relationships and consequently, the criteria for soil fertility management. This study determined the criteria for liming as well as the soil critical levels for P and K in a crop rotation of soybean, maize, wheat, barley, and white oat, widely used in the South-Central region of the State of Parana, in Southern Brazil. The study involved 13 […]

Studies of heavy rainfall are of practical interest for the conservation management of natural resources such as watersheds and soil and water. The spatial distribution of these natural rainfall events allows conclusions about regions where the occurrence of heavy rain is more frequent and to estimate their magnitude for locations without rainfall data sets. Thus, the purpose of this study was to map heavy rainfall data from 177 meteorological stations, using a geostatistical approach, for Minas Gerais, identifying the most […]

In the Amazon region, pastures provide a satisfactory grass yield in the first years. Over time, overgrazing by livestock, the lack of pasture maintenance and choice of regionally unsuitable forage species can lead to soil degradation. The objective of this study was to evaluate the effect of different soil management systems on some soil physical properties of a Red-Yellow Oxisol (LVA) under degraded pasture, in the State of Rondônia (RO). The soil management systems were T = control; G = […]

Rainfall erosivity is one of the main factors related to water erosion in the tropics. This work focused on relating soil loss from a typic dystrophic Tb Haplic Cambisol (CXbd) and a typic dystrophic Red Latosol (LVdf) to different patterns of natural erosive rainfall. The experimental plots of approximately 26 m2 (3 x 8.67 m) consisted of a CXbd area with a 0.15 m m-1 slope and a LVdf area with 0.12 m m-1 slope, both delimited by galvanized plates. […]

Much of the organic matter of a typical peat consists of humic substances, mainly formed via humification of organic residues, decomposed by soil microorganisms, and by the polymerization of organic compounds to functional macromolecules, which are normally more resistant to degradation. The fundamental pathways governing the humification of soil organic matter (SOM) are not well understood so far, and most available data about the identified chemical precursors of humic substances and the main chemical routes by which they are transformed […]

To model the water flow and solute transport in soils, hydrodynamic and hydrodispersive parameters are required as input data in the mathematical models. The axisymmetric infiltration experiment using a single-ring infiltrometer with a conservative tracer (KCl) is a simple and efficient method for the determination of these parameters in the field. The objective of this study was to characterize hydrodynamic and hydrodispersive parameters of some soils in a marshy region, in Areia-PB, in the field, based on single-ring infiltration tests. […]

Successive applications of pig slurry to soils under no-tillage can increase the nutrient levels in the uppermost soil layers and part of the nutrients may be transferred to deeper layers. The objective was to evaluate the distribution of nutrients in the profile of a soil after 19 pig slurry applications under no-tillage for 93 months. The experiment was conducted from May 2000 to January 2008 in an experimental area of the Federal University of Santa Maria, southern Brazil, on a […]

The use of SMP pH to estimate the potential acidity (H + Al) is more practical than the method of 0.5 mol L-1 calcium acetate for routine laboratory analyses. The objective was to fit an equation to estimate the H + Al from SMP pH values of soils of the State of Pará. From various regions of the state, 177 soil samples were collected, in which the SMP pH was determined in 0.01 mol L-1 CaCl2 solution and H + […]

Soil infiltration is a key link of the natural water cycle process. Studies on soil permeability are conducive for water resources assessment and estimation, runoff regulation and management, soil erosion modeling, nonpoint and point source pollution of farmland, among other aspects. The unequal influence of rainfall duration, rainfall intensity, antecedent soil moisture, vegetation cover, vegetation type, and slope gradient on soil cumulative infiltration was studied under simulated rainfall and different underlying surfaces. We established a six factor-model of soil cumulative […]