Volume 41, 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 […]

ABSTRACT The source material is one of the factors that most influence soil genesis and the mainly responsible for the nature, composition, and behavior of the soil. Given the geological complexity of the Santa Maria River basin, the objective of this study was to investigate whether the new lithologies described recently may be responsible for a greater variation in soil properties, as well as in the soil taxonomy itself. The study area is located in the municipality of Rosário do […]

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 […]

ABSTRACT Residue management in cropping systems may improve soil quality. However, there are few studies on the effects of residue management on soil aggregation and carbon content in the humin (C-HUM), humic acid (C-HAF) and fulvic acid (C-FAF) fractions in South China. Therefore, the effects on soil aggregation and on the C-HUM, C-HAF, C-FAF from incorporating winter cover crop residues in a double-cropped rice (Oryza sativa L.) system in South China fields were studied. The experiment has been conducted since […]

ABSTRACT Forest-to-agriculture conversion and soil management practices for soybean cropping are frequently performed in the Cerrado (Brazilian tropical savanna). However, the effects of these practices on the soil microbial communities are still unknown. We evaluated and compared the fungal community structure in soil from soybean cropland with soil under native Cerrado vegetation at different times of the year in the Tocantins State. Soil samples were collected in two periods after planting (December) and in two periods during the soybean reproductive […]

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 Modern maize, wheat, and soybean cultivars are usually characterized by a short cycle, high shoot-root ratio, and high responsiveness to nutrient input. Continuous no-tillage management (NTS) frequently leads to a steep gradient in soil chemical quality with depth, thus decreasing yield under conditions of acid subsoil and water stress. This study aimed to evaluate the effect of gypsum, applied separately or in combination with lime, on the yield of cultivars used in the state of Rio Grande do Sul, […]

ABSTRACT Pedological studies using X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy, and scanning electron microscopy (SEM-EDS) showed a Xanthic Ferralsol formed from the degradation of bauxite on a slope in the Caparaó region, in southeastern Brazil. We found a decrease in the number and size of bauxite fragments toward the top of the profiles, bauxite fragments that were more degraded at the top of the profiles, transformation of gibbsite into kaolinite, and absolute enrichment in silicon in the mass […]

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 […]

Abstract Plant health and nutrition are strongly influenced by the availability of water. The objective of this study was to evaluate the different patterns of initial growth and nutritional efficiency of ten drought-stressed Eucalyptus clones. Water stress conditions were induced by osmotic stress, by gradual addition of polyethylene glycol 6000 over a 20-day period. Drought stress significantly reduced the dry matter of leaves, roots, and the whole plant as well as the nutritional efficiency of most clones. Clone PL040 was […]