Determining the In Situ Apparent Thermal Diffusivity of a Sandy Soil
02/nov/2018
ABSTRACT: The thermal wave amplitude method is used to determine soil thermal diffusivity in situ for a sandy soil in Mexico (Coatzacoalcos, Veracruz). Soil diurnal temperature fluctuations were measured from depths of 0.05 to 0.65 m, in 0.01 m increments, during the months of April and August. Five mean diffusivity values were obtained experimentally, corresponding to the different depths combination. The soil thermal diffusivity ranged between 2.26 × 10−7 and 8.71 × 10−7 m2 s−1. The diffusivity values obtained are […]
Soil Water Retention Curve as Affected by Sample Height
02/nov/2018
ABSTRACT: The soil water retention curve is one of the main instruments to assess the soil physical quality and to improve soil management. Traditionally, the equipment most used in the laboratory to determine the retention curve has been Haines funnels and Richards chambers. An important factor to which little attention has been given in the use of these equipaments is the height of the undisturbed soil sample. This work proposes to evaluate the influence of different heights of undisturbed samples […]
Chemical Species and Aluminum Concentration in the Solution of Acid Soils Cultivated with Soybean and Corn under Liming
10/out/2018
ABSTRACT Chemical speciation of the soil solution is an important tool to identify Al species related to phytotoxicity. In some Brazilian acid soils, the Al extractable by the KCl 1.0 mol L -1 solution (Al-KCl) exceeds 10 cmol c kg -1 and even then, in some situations, it does not cause toxicity to the plants. This study aimed to evaluate the relationship between these high concentrations of Al-KCl found in some Brazilian acid soils and the activity of the different […]
Carbon Stocks and Pools in Relation to the Texture of Kaolinitic Soils from the Brazilian East Coast
12/set/2018
ABSTRACT: Extremely kaolinitic soils of Tertiary age elevations on the Brazilian east coast present a wide range of texture, which is recognized as one of the main factors controlling the soil organic matter contents. This study aimed to investigate the organic C storage of different compartments of kaolinitic soils. The studied soils had a wide particle size gradient, were under native forest vegetation, and located on Brazil’s eastern coast (Coruripe – CF, Umbaúba – UF, Nova Viçosa – VF, Sooretama […]
Isolation, Characterization and Symbiotic Efficiency of Nitrogen-Fixing and Heavy Metal-Tolerant Bacteria from a Coalmine Wasteland
05/set/2018
ABSTRACT: Areas affected by coal mining can be recovered by revegetation with leguminous plants associated with nitrogen-fixing bacteria. This study addressed the isolation and characterization of native nitrogen-fixing bacteria from coalmine wasteland under different vegetation restoration approaches using Macroptilium atropurpureum (DC) Urb and Vicia sativa L. as trap plants. The bacteria were characterized and identified on the basis of 16S rRNA sequences. Additionally, nitrogen-fixing strains were characterized for tolerance to high heavy metal and low pH levels, as well as […]
Morphological Diversity of Springtails in Land Use Systems
05/set/2018
ABSTRACT: Springtails (Collembola) are soil organisms with wide morphological diversity and are sensitive to alterations in the soil, regardless of whether they are human-caused or not. The aim of this study was to evaluate the influence of land use on the morphological diversity of springtails and verify their relationships with soil physical, chemical, and microbiological properties. Samples were collected in the eastern region of Santa Catarina, in three municipalities: Joinville, Blumenau, and Timbó. They included the following land use systems […]
Spiders (Arachnida: Araneae) in Agricultural Land Use Systems in Subtropical Environments
06/ago/2018
ABSTRACT Changes in land use management in agricultural areas can affect the biodiversity of spider families. This study aimed to evaluate spider diversity in different land use systems with capture by two sampling methods, and to identify soil properties that can modulate the occurrence of spiders. Five land use systems, representative of traditional agricultural areas, were evaluated in the west of Santa Catarina, Brazil, to establish a scale of land use intensity: native forest, eucalyptus reforestation areas, pastures, crop-livestock integration […]
Occurrence of Yeast Species in Soils under Native and Modified Vegetation in an Iron Mining Area
23/jul/2018
ABSTRACT Soils of the Quadrilátero Ferrífero are rich in mineral resources, especially gold and iron. Soil management and mining activities greatly impact soil biology. However, studies addressed to the diversity of microorganisms and their ecological role in the recovery of these areas are scarce. This study aimed to assess the yeast occurrence in soils with natural vegetation (Atlantic Forest, neotropical savanna, and iron outcrop) and areas with anthropogenic modifications (Eucalyptus stand and rehabilitated area) in the Quadrilátero Ferrífero region. We […]
Soil Biological, Chemical, and Physical Properties After a Wildfire Event in a Eucalyptus Forest in the Pampa Biome
17/jul/2018
ABSTRACT Wildfire events cause considerable environmental disturbance but few studies have examined changes in soil properties due to fire. This study aimed to assess the effect of a wildfire event on chemical, physical, and biological properties of the soil in a eucalyptus forest in the Pampa biome. Part of a seven-year-old eucalyptus forest was affected by a wildfire event that lasted for two days. Soil and plant litter sampling was performed in three areas: in the forest that was not […]
Ajmalicine Bioproduction in Catharanthus Roseus (L) G. Don Inoculated with Arbuscular Mycorrhiza and Fertilized with Nitrogen
17/jul/2018
ABSTRACT Catharanthus roseus (L) G. Don (Madagascar periwinkle) belongs to the Apocynaceace family and is widely spread throughout tropical and subtropical regions of the world. The plant produces several important alkaloids, such as ajmalicine and serpentine, which are used in the treatment of circulatory diseases. The potential of inoculation with arbuscular mycorrhizal fungi (AMF) and nitrogen fertilization to enhance the production of alkaloids was investigated in periwinkle. A greenhouse experiment was carried out to evaluate the effects of arbuscular mycorrhizal […]