ABSTRACT Soil structure plays an important role in water retention, infiltration capacity, porosity, and penetration resistance. The aim of this study was to evaluate the unsaturated hydraulic conductivity and physical properties of Oxisol soils (bulk density and macro-, micro-, and total porosity) in the structures identified using the profil cultural method in areas under two different management practices (perennial pasture and sugarcane). Three pits were dug in each plot to find out how homogeneous morphological structural units (HMSU) were organized […]

ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2) and 15 (B15) years cultivation, pasture (P), and a corn and beans succession (MB), as […]

ABSTRACT Soil is currently seen as the most relevant carbon sink and the most effective carbon stabilizer. In contrast, agriculture is the second largest C emitter, after burning of fossil fuels. This organic carbon (OC) introduced into the soil, mainly via organic matter (OM), is essential for several soil properties and plays an extremely important role in sandy soils. The objective of this study was to describe the changes in the amounts and pools of OC and the influence thereof […]

ABSTRACT Water erosion is the main cause of soil degradation and is influenced by rainfall, soil, topography, land use, soil cover and management, and conservation practices. The objective of this study was to quantify water erosion in a Humic Dystrudept in two experiments. In experiment I, treatments consisted of different rates of fertilizer applied to the soil surface under no-tillage conditions. In experiment II, treatments consisted of a no-tillage in natural rangeland, burned natural rangeland and natural rangeland. Forage turnip, […]

ABSTRACT The Soil Management Assessment Framework (SMAF) was developed in the U.S.A. and has been used as a tool for assessing and quantifying changes in soil quality/health (SQ) induced by land uses and agricultural practices in that region and elsewhere throughout the world. An initial study using SMAF in Brazil was recently published, but additional research for a variety of soils and management systems is still needed. Our objective was to use data from five studies in southern Brazil to […]

ABSTRACT Evaluating the decomposition dynamics of vegetative residues from cover crops can provide a better understanding of nutrient release, which is fundamental when choosing a species that is adapted to local conditions. The objective of this study was to evaluate the decomposition rates and nutrient release dynamics of the shoot phytomass of different cover crops that have potential for agricultural use in the Recôncavo Baiano, Brazil. Crop residues of the following species were analyzed: sunn hemp (Crotalaria juncea L.) – […]

ABSTRACT Agricultural land use and degradation of natural vegetation in riparian zones can impair water quality. This study was conducted in seven agricultural watersheds in Ibirubá, RS, Brazil, with the following objectives: identify relationships between concentrations of soluble phosphorus (Psol) and nitrate (NO−3) in surface water and agricultural use of soil and current vegetation in riparian zones, and assess the risk of eutrophication. Water samples from the main watercourses in each watershed were collected monthly from 10/2013 to 6/2014. Current […]

ABSTRACT The substitution of native vegetation by agricultural ecosystems can change the quantity and quality of soil organic matter (SOM), and the intensity of these changes depends on the soil type, climate, and land use. The objective of this study was to evaluate the quality of organic matter in chronosequences of Jatropha cultivation in contrasting soil and climatic conditions. Soil samples were evaluated at depths of 0.00-0.10, 0.20-0.30, and 0.80-1.00 m in chronosequences located in Planaltina, Distrito Federal (Cerrado-Pasture-Jatropha), Dourados, […]

ABSTRACT Rice monoculture in lowlands can cause problems for management practices in crop fields, for example, in weed control. For this reason, corn in rotation with irrigated rice in lowlands may be advantageous, despite problems with soil compaction and water excess. The objective of this study was to evaluate soil physical properties and corn performance in soil management systems in an Albaqualf soil (lowlands). Two experiments were conducted in the field, in the 2013/14 and 2014/15 crop seasons. The experimental […]

ABSTRACT Water erosion degrades the soil and contaminates the environment, and one influential factor on erosion is slope length. The aim of this study was to quantify losses of soil (SL) and water (WL) in a Humic Cambisol in a field experiment under natural rainfall conditions from July 4, 2014 to June 18, 2015 in individual events of 41 erosive rains in the Southern Plateau of Santa Catarina and to estimate soil losses through the USLE and RUSLE models. The […]