3312 results

Forms and doses of urea to fertilize clonal cocoa tree cuttings cultivated in substrate

José Olimpio de Souza Júnior, Quirino Augusto de Camargo Carmello

01/Dec/2008

Nitrogen is the mineral nutrient required most by plants. There are, however, no studies on N fertilization calibration for rooted cocoa tree cutting production on substrate and frequent irrigation. The objective of this study was to compare the efficiency of urea fertilization on substrate and leaves for rooted cocoa tree cutting and to define N recommendable doses and foliar critical N level. The experiment was set up in a rooted cutting breeding nursery of the Cocoa Biofactory Institute, in Ilheus, […]

Physical-hydric attributes of an oxisol from the cerrado region under coffee plantation as affected by the sampling position

Ivoney Gontijo, Moacir de Souza Dias Junior, Paulo Tácito Gontijo Guimarães, Cezar Francisco Araujo-Junior

01/Dec/2008

The soil compaction, induced by different traffic intensities, can cause damage in the soil structure, reducing the coffee plantation production. The objectives of this study was to develop a model of load support capacity for a Red Latosol (Oxisol) under Cerrado and under coffee and to investigate the effect of coffee plantation management on soil pore distribution and soil water retention, in different sampling positions in the coffee plantation. The stud site is located at 18 º 59 ‘ 15 […]

Spatial variability of mineralogical attributes of an oxisol under different relief forms. I – clay fraction mineralogy

Livia Arantes Camargo, José Marques Júnior, Gener Tadeu Pereira, Renata Alves Horvat

01/Dec/2008

The distribution of the clay fraction minerals depends on specific soil-environmental conditions. The study of the relationship between properties of these minerals and specific sites of landscape occurrence is important to understand the relationship between the mineralogy and other soil attributes. This study aimed to evaluate the degree of cristallinity of goethite, hematite, kaolinite and gibbsite and the spatial pattern in an Oxisol under sugar cane for 30 years. In a grid with regular 10 m – intervals, 119 samples […]

Bearing capacity and compressibility of argisol (paleudult) as affected by traffic and winter cover crops

Henrique Debiasi, Renato Levien, Carlos Ricardo Trein, Osmar Conte, Michael Mazurana

01/Dec/2008

One of the most effective practices in preventing soil compaction is to apply stresses below the bearing capacity of the soil, often estimated by the pre-compression stress (σp). To evaluate the effects of cover crops and tractor traffic on σp and compression index (CI), a field experiment was initiated in 2002 on sandy clay loam Paleudult, in Southern Brazil (Rio Grande do Sul State). Treatments under no-tillage involved winter fallow and two winter cover crops (black oats and black oats […]

Cation leaching favored by inorganic anions and low molecular mass organic acids in soils fertilized with different poultry litters

Fabrício de Oliveira Gebrim, Ivo Ribeiro Silva, Roberto Ferreira Novais, Leonardus Vergütz, Lorena Costa Procópio, Tiago Novais Nunes, [...]

01/Dec/2008

The exponential growth in poultry farming in Brazil has led to a parallel increase in the production of manure and poultry litter. The litter generated in this activity used to be largely employed as cattle feed. However, the enactment of a law that bans the use of poultry litter as animal feed intensified its use as organic fertilizer in agriculture. Despite its importance, there are gaps in our knowledge on an adequate use to obtain high plant yields without threatening […]

Use of a geographic information system for a detailed soil survey of the Vale dos vinhedos, RS, Brazil

Eliana Casco Sarmento, Carlos Alaberto Flores, Eliseu Weber, Heinrich Hasenack, Reinaldo Oscar Pötter

01/Dec/2008

This study proposes the use of geotechnologies to support detailed soil surveys, from field surveys to the delimitation of mapping units and later the drawing of the final map. The study area corresponds to a topographic map on a scale of 1:5,000 of the Vale dos Vinhedos, in the Serra Gaúcha region, State of Rio Grande do Sul, Brazil. The material used consists of planialtimetric data derived from aerial photographs, navigation GPS (Global Positioning System), and GIS (Geographical Information System) […]

Bibliometrics, history and geography of Brazilian research on accelerated soil erosion

Alberto Giaroli de Oliveira Pereira Barretto, Marcelo Geraldo Estriga Barros, Gerd Sparovek

01/Dec/2008

Soil science history studies are rare and the Brazilian scientific community has not given substantial attention to this subject yet. The present study focused on the formation of research on accelerated soil erosion in the Brazil from a bibliometric perspective. A comprehensive database of published scientific papers was organized in a relational database and analyzed by SQL queries and GIS tools. These data were used to calculate quantitative indicators and spatial distribution patterns. Results indicate a recent development of research […]

Aluminum industry by-product as an amendment for cadmium and lead-contaminated soils

Enio Tarso de Souza Costa, Luiz Roberto Guimarães Guilherme, Nilton Curi, Luiz Carlos Alves de Oliveira, Elton Luiz Visioli, Guilherme Lopes

01/Dec/2008

Soil pollution with trace elements has been of great concern in the last years due to the increase in contaminated areas, which calls for a better understanding of trace element availability and environmental remediation. This study evaluated the performance of an aluminum industry by-product as soil amendment in Cd- and Pb-contaminated soils. Samples of a sandy (50 g kg-1 clay) and a clayey (540 g kg-1 clay) soil were mixed with polluted soil (15 %) with high Cd and Pb […]

Carbon mineralization of straw and pig manure with and without incorporation in soil

Sandro José Giacomini, Celso Aita, Ezequiel César Carvalho Miola, Sylvie Recous

01/Dec/2008

The C mineralization of pig manure and cereal straw is still relatively little studied in Brazil. The aim of this work was to evaluate C mineralization of oat straw, pig slurry and pig deep-litter, applied on the surface or incorporated in a Hapludalf soil, in laboratory conditions. The experiment was a completely randomized design with four replications of the following treatments: soil; soil + incorporated straw; soil + surface straw; soil + incorporated pig deep-litter; soil + surface pig deep-litter; […]

Assessment of the soil compaction of two ultisols caused by logging operations

Moacir de Souza Dias Junior, Sérgio Ricardo Silva, Nadívio Souza dos Santos, Cezar Francisco Araujo-Junior

01/Dec/2008

The impact of wood loads on bulk density and preconsolidation pressure and of harvester and forwarder traffic on rut depth, bulk density and preconsolidation pressure of two Ultisols were examined in this study. Our objective was to quantify the threshold beyond which significant soil compaction and rutting would occur. This study was carried out in the county of Eunápolis, state of Bahia, Brazil, (16 º 23 ‘ 17 ” S and 39 º 10 ‘ 06 ” W; altitude 80 […]

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