Contamination of wetland soils and floodplain sediments from agricultural activities in the Cerrado Biome (State of Minas Gerais, Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Phosphorus fractions in soils of the mangrove, restinga and Atlantic forest ecosystems from Cardoso Island, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Available nitrogen and responses to nitrogen fertilizer in brazilian eucalypt plantations on soils of contrasting texture

Eucalyptus plantations have seldom responded to N fertilization in tropical and subtropical regions of Brazil. This implies that rates of N mineralization have been adequate to supply tree needs. However, subsequent crop rotations with low N fertilization may result in declining concentrations of organic and potentially mineralizable N (N-0), and consequent loss of wood productivity. This study investigated (a) in situ N mineralization and N-0 in soils of eucalypt plantations in Sao Paulo state, Brazil; (b) tree growth responses to N fertilizer applied 6-18 months after planting; and (c) the relationships between N-0,N- other soil attributes and tree growth. We established eleven N fertilizer trials (maximum 240 kg ha(-1) of N) in E. grandis and E. grandis x urophylla plantations. The soil types at most sites were Oxisols and Quartzipsamments, with a range of organic matter (18 to 55 g kg(-1)) and clay contents (8% to 67%) in the 0-20 cm layer. Concentrations of N-0 were measured using anaerobic incubation on soil samples collected every three months (different seasons). The samples collected in spring and summer had N-0 140-400 kg ha(-1) (10%-19% total soil N), which were best correlated with soil texture and organic matter content. Rates of in situ net N mineralization (0-20 cm) ranged from 100 to 200 kg ha(-1) year(-1) and were not correlated with clay, total N, or N-0. These high N mineralization rates resulted in a low response to N fertilizer application during the early ages of stand growth, which were highest on sandy soils. At the end of the crop rotation, the response to N fertilizer was negligible and non-significant at all sites.

Management Impacts on Soil Organic Matter of Tropical Soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tropical soils with high aluminum concentrations cause oxidative stress in two tomato genotypes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modeling the formation and propagation of desiccation cracks in soils

The problem of desiccation cracks in soils has received increasing attention in the last few years, in both experimental investigations and modeling. Experimental research has been mainly focused on the behavior of slurries subjected to drying in plates of different shapes, sizes and thickness. The main objectives of these studies were to learn about the process of crack formation under controlled environmental conditions, and also to better understand the effect of different factors (e.g. soil type, boundary conditions, soil thickness) on the morphology of the crack network. As for the numerical modeling, different approaches have been suggested lately to describe the behavior of drying cracks in soils. One aspect that it is still difficult to describe properly is the crack pattern observed in desiccated soils. This work presents a novel technique to model the behavior of drying soils. The crack patter observed in desiccation tests on circular plates are simulated with the main objective of predicting the effect of soil thickness on crack pattern. Good agreement between experimental results and model prediction are observed.

Ultramafic complexes and associated mineral deposits in the Precambrian of eastern Minas Gerais, Brazil

Based on field work, prospection and petrographic studies ultramafic complexes and their mineral deposits from eastern Minas Gerais in southeastern Brazil are generally outlined to form a basis for future investigations in this region. The bodies dealt with occur at Ipanema, Córrego Novo, Bela Vista de Minas, Rio Pomba and Liberdade. These ultramafic bodies are generally enclosed in high-grade gneisses and consist of serpentinized peridotites and harzburgites which were metamorphosed together with their country rocks in upper amphibolite to granulite facies. Weathering of these rocks gives rise to nickeliferous laterite, while metamorphism has resulted in anthophyllite asbestos and talc deposits. © 1985 Springer-Verlag.

Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physico-chemical properties of starches isolated from potato cultivars grown in soils with different phosphorus availability

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Go/N ratio in tropical soils from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of stillage biodegradation by respirometry in sandy and clay soils

The stillage, which is a liquid residue from the distillation of the sugarcane ethanolic fermentation, contains organic matter and can be a big source of pollution when it is discarded in the wrong way. Its application as fertilizer has been extended, which is reason to cause concerns regarding the environment. The aim of this work was to evaluate and quantify the biodegradation of stillage in sandy and clay soils, besides verifying the efficiency of the Embiotic Line®inoculum as an accelerator of the biodegradation. Bartha and Pramer respirometric technique was used to determine the production of CO2 during the 50 days of the biodegradation process, and the quantification of the initial and final microorganisms was also conducted. Results were analyzed using the Friedman statistical test. Clay soils were significantly better on stillage decomposition when compared to sandy soils (p=0.0153). Clay soils presented greater efficiency in stillage biodegradation, with higher field capacity, better water, organic matter and microbial retention. Regarding the use of the embiotic line, the experiment has shown this product does not interfere positively in the stillage biodegradation for both soils, possibly needing adjustments in its composition.

Availability of nutrients, productive properties, and quality of sunflower ( L.) seeds in acid soils amended with different molar ratios between Ca and Mg

Liming is indispensable in acid soils for amending acidity; however, the technique may alter the cation balance in soil and, consequently, may limit the availability and uptake of nutrients. We aimed to evaluate different molar ratios between calcium (Ca) and magnesium (Mg) on the availability of soil nutrients and their influence on the productive properties of sunflower and seed quality. The experiment was carried out in a greenhouse under two types of contrasting soils and six molar combinations of CaCO3and MgCO3 in amendment of soil acidity to raise base saturation to 70%. After incubation, soil analysis was undertaken to verify the ratios obtained and nutrient availability. Morphological and production variables were analyzed at the end of the experiment, as well as accumulation of nutrients in the achenes and their physiological quality. In spite of equal base saturation between the types of soil, there were differences in the available contents of these cations. The increase in the Ca contents limited the Mg contents to the critical level of the sunflower. This result had a negative influence on the production properties of sunflower and physiological quality. In contrast, there was a compensation of the crop with greater accumulation of nutrients in the achenes under lower yield.

Variation of soil and water volumes in riparian jungle soils of Brazil

The objective of this work is to study the relation between humidity, density, porosity and shrinkage of the floodplain soil and riparian vegetation and their ability to store water. For this purpose, two locations for every type of soils were evaluated. Both were placed at the Agronomy University (Faculdade de Ciências Agronômicas) in São Manuel, State of São Paulo, Brazil. The floodplain soil was vegetated with Southern Cattail (Typha domingensis). In both places, soil samples were collected from several depths: 0, 30, 60 and 100 cm. Results show that lower soil density values (0.15 g/cm3) with organic texture and high porosities values (up to 86.2%) were found in samples with the highest organic material content in the floodplain soil. For this field experiment, flood plains soils (characterised as basin gley soils) presented high volumetric instability with a retratibility of 67.49% and higher water storage capacities compared to riparian stands soils (characterised as fluvic neosoils).

EC31-133 The Management of Nebraska Soils (Revised March 1936)

The agricultural lands of this country are its greatest natural resource. History points out that nations with vast areas of good farm land are most likely to prosper and survive over long periods of time. Local communities, too, prosper and flourish in proportion to the productiveness of the surrounding land. Schools, social life, and business develop best in areas where the land is productive and properly managed and conserved. Nebraska, in common with other states, has suffered by the depletion of soil fertility. The reduction in acres in legumes and grasses, and the deplation of the organic matter in the surface soils, has likewise had its effect on the run-off of precipitation, soil blowing, and damage from drouth. In order to know what elements of fertility may become deficient and how soil fertility may be restored and maintained, we should understand the composition, character, and management of soils. In the following pages, some fundamentals of soil feritlity are given, followed later by a discussion of practical soil-management practices.

Review of Soils in Archaeological Research by Vance T. Holliday

When I teach geoarchaeology, I tell students on the first day of class that "soils are the canvas for much of the archaeological record." Just as an artist's canvas holds and affects the paint, soils hold archaeological materials, and soil-forming processes strongly influence the preservation and spatial pattern of cultural deposits. Given this close relationship between soils and the material remains of humans, we have long needed a treatise that addresses all aspects of soils from an archaeological perspective. Vance Holliday's latest book, Soils in Archaeological Research, does this and more.