Mineralogy of the Clay Fraction and Chemical Properties of Soils Developed from Sedimentary Lithologies of Pirambóia, Sanga-the-Cabral and Guará Geological Formations in Southern Brazil
24/Aug/2017
ABSTRACT Quali-quantitative and crystallographic characterizations of the different minerals of a soil are essential for the best evaluation of its genesis, degree of weathering, active pedogenetic processes, physical and chemical properties, and its potential reserve of mineral nutrients. This study presents the results of mineralogical investigations carried out to verify the influence of the different lithologies of three geological formations of a sedimentary nature on the mineralogical composition of the soils and the relation of this mineralogical composition to soil […]
Performance of a Distributed Hydrological Model Based on Soil and Moisture Zone Maps
24/Aug/2017
ABSTRACT The scarcity of field data to develop soil maps through a pedological survey is one of the main limitations to using distributed hydrological models, especially in small and medium-sized watersheds. The aim of this study was to compare a distributed hydrological model prediction to a soil map based on a pedological survey and a moisture zone map obtained using the Height Above the Nearest Drainage – HAND model. The Distributed Hydrology Soil Vegetation Model – DHSVM, which is a […]
Nitrogen Transfer from Cover Crop Residues to Onion Grown under Minimum Tillage in Southern Brazil
24/Aug/2017
ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT) and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and […]
Diversity and Efficiency of Rhizobia Communities from Iron Mining Areas Using Cowpea as a Trap Plant
01/Aug/2017
ABSTRACT Mining is an important economic activity. However, its impact on environment must be accessed, mainly on relevant processes for their sustainability. The objective of this study was to evaluate the diversity and efficiency of symbiotic nitrogen fixing bacterial communities in soils under different types of vegetation in the Quadrilátero Ferrífero: ironstone outcrops, Atlantic Forest, neotropical savanna, and a rehabilitated area revegetated with grass. Suspensions of soil samples collected under each type of vegetation were made in a saline solution […]
Anthropization Effects on the Filamentous Fungal Community of the Brazilian Catimbau National Park
01/Aug/2017
ABSTRACT The Caatinga biome features an exclusive endemic biodiversity, and is characterized by the presence of xerophytic, deciduous vegetation, high temperatures, and low rainfall. This important park has undergone anthropization, especially through extraction of firewood and timber and growing plants for raising goats. The objectives of this study were to compare the communities of filamentous fungi present in the preserved area and in the anthropized soil of the Catimbau National Park in Buíque, PE, Brazil, and to evaluate the impacts […]
Water Erosion in a Long-Term Soil Management Experiment with a Humic Cambisol
01/Aug/2017
ABSTRACT Water erosion, the main factor in soil degradation, is strongly influenced by soil cover and management. The objective of this study was to determine soil and water losses under natural rainfall conditions from 1993 to 2012 in the southern Santa Catarina Plateau, Brazil, in 3.5 × 22.1 m plots with crops in rotation to study the following management treatments: conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and a treatment with bare soil (BS). The soil cover remaining […]
Management Systems Effect on Fertility Indicators of a Ferralsol with Vegetable Crops, as Determined by Different Statistical Tools
01/Aug/2017
ABSTRACT The intensive nature of soil use in vegetable production areas has led to a marked decrease in soil quality. The objective of this study was to evaluate the effects of adoption of soil management systems on vegetable production with regards to the chemical properties of a Rhodic Ferralsol after five years and to evaluate the use of the Principal Component Analysis (PCA) statistical tool in discriminating the different treatments. The experiment was conducted under field conditions in central Brazil […]
Clay Mineralogy of Brazilian Oxisols with Shrinkage Properties
01/Aug/2017
ABSTRACT Shrinkage capacity (caráter retrátil in Portuguese) is a new diagnostic characteristic recently introduced in the Brazilian System of Soil Classification (SiBCS) to indicate shrink and swell properties observed in subtropical soils from highland plateaus in southern Brazil, specifically in Oxisols with brown colors. In soils located in road cuts exposed to drying for some weeks, strong shrinkage of soil volume is observed in these soils, resulting in the formation of pronounced vertical cracks and large and very large prismatic […]
Sediment Morphology, Distribution, and Recent Transport Dynamics in a Reforested Fragment
01/Aug/2017
Abstract Erosion generates large amounts of sediment, which may be deposited at the site of origin, on the slope of a hill, or along waterways. The transportability of each type of sediment by runoff and its potential for subsequent deposition largely depends on its morphological features and particle size distribution. The aim of this study is to describe and characterize the morphology and micromorphology of sediments deposited in a reforested area and to understand the dynamics of the transport process. […]
Effect of Mineral Nitrogen on Transfer of 13C-Carbon from Eucalyptus Harvest Residue Components to Soil Organic Matter Fractions
21/Jul/2017
ABSTRACT The amount of harvest residues retained in Eucalyptus plantations strongly influences soil organic matter (SOM), but the efficiency of conversion to SOM may vary according to the type of residue. This study evaluated the recovery of C from Eucalyptus residue components – leaves, bark, branches, roots, and a mix of all residues – in different SOM fractions with or without mineral-N supplementation (200 mg kg-1 of N). Variation in natural 13C abundance was used to trace the destination of […]