39 results

Application of zinc doses via soil to irrigated banana “Prata Anã” (AAB) in northern Minas Gerais, Brazil

Enilson de Barros Silva, Múcio Mágno de Melo Farnezi, Paulo Jorge de Pinho, Maria Geralda Vilela Rodrigues, Janice Guedes de Carvalho

01/Dec/2007

A field experiment was conducted in Nova Porteirinha, MG, Brazil, in a dystrophic Red Yellow Latossol, to detect the response of the banana tree ‘Prata Anã’ to Zn doses through soil and critical Zn levels in soil and leaves. Four Zn doses were applied, corresponding to 0, 10, 20 and 40 kg ha-1 year-1 , using zinc sulfate as source. The treatments were arranged in a randomized block design, with three repetitions per block, totaling 36 experimental plots. The following traits were evaluated: […]

Spatial variability of chemical attributes of a soil under different uses and managements

Eloiza Gomes Silva Cavalcante, Marlene Cristina Alves, Zigomar Menezes de Souza, Gener Tadeu Pereira

01/Dec/2007

The use and management of soil and crop condition the variability of soil attributes directly. This study was conducted in Selvíria-MS, Brazil with the objective of evaluating the spatial variability of pH, potassium (K), calcium (Ca), magnesium (Mg) and base saturation (% BS) in an Oxisol under different use and management conditions. Soil samples were collected in a grid, in regular 2 m intervals, at 64 grid points, at depths of 0.0-0.1 m and 0.1-0.2 m, from areas of: native cerrado vegetation (savannah), […]

Effect soil compaction on root growth and maize yield

Onã da Silva Freddi, José Frederico Centurion, Amauri Nelson Beutler, Ricardo Garcia Aratani, Cristian Luarte Leonel

01/Aug/2007

The structural soil modifications caused by different tillage systems can result in more or less intense compaction, which interferes with soil penetration resistance, bulk density and porosity, influencing root growth and crop yields. The objective of this work was to evaluate the effect of compaction on particular characteristics of a Red Latosol and associate them with root growth and maize yield. The main treatments consisted of six compaction levels, induced by controlled tractor traffic and the secondary treatments of two […]

Geoecological drivers of cerrado heterogeneity and 13C natural abundance in oxisols after land-use change

Henry Neufeldt

01/Oct/2006

The 13C natural abundance technique was applied to study C dynamics after land-use change from native savanna to Brachiaria, Pinus, and Eucalyptus in differently textured Cerrado Oxisols. But due to differences in the d13C signatures of subsoils under native savanna and under introduced species, C substitution could only be calculated based on results of cultivated soils nearby. It was estimated that after 20 years, Pinus C had replaced only 5 % of the native C in the 0-1.2 m layer, in which substitution […]

Spatial soil fertility variability in a homogeneously managed corn field

Zaqueu Fernando Montezano, Edemar Joaquim Corazza, Takashi Muraoka

01/Oct/2006

Insights on the variability of soil fertility in cultivated areas can contribute significantly to a rationalized use of fertilizers and soil amendments. The objective of this study was to determine the soil fertility variability through the fractionation of a commercial corn field into small management cells. The study was carried out on the farm Alto Alegre, Planaltina, GO, Brazil, on an Oxisol previously under Cerrado (savannah) in an area of 373 ha under corn in the 2003/2004 growing season. A polygon […]

Soil water dynamics in a toposequence under Savanna Woodland (Cerradão) in Assis, SP, Brazil

Carlos Eduardo Pinto Juhász, Patrícia Ribeiro Cursi, Miguel Cooper, Thalita Campos Oliveira, Ricardo Ribeiro Rodrigues

01/Jun/2006

The aim of this study was to characterize the morphological, physical and hydraulic soil properties in a toposequence under native plant cover in a permanent observation plot of 320 x 320 m installed in the Assis Ecological Station, São Paulo State, Brazil. The plot is covered by a remnant Savanna Woodland (Cerradão) vegetation of the southern border zone of the great Cerrado domain. The bi-dimensional geometry (horizontal and vertical) of the soil horizons in a toposequence provided details on the […]

Agricultural machinery traffic and alterations in biopores under an orange orchard

Herdjania Veras de Lima, Cláudia Liane Rodrigues de Lima, Tairone Paiva Leão, Miguel Cooper, Alvaro Pires da Silva, Ricardo Espíndola Romero

01/Oct/2005

Soil micromorphological studies enable a detailed observation of the modifications in soil pore structure and space imposed by cultivation and agricultural machinery traffic. This study tested the hypothesis that compaction caused by machinery affects the form and class distribution of pores in a distinct way and that such alterations can be used as soil quality indicators. The objectives of this study were to evaluate and quantify, through micromorphological studies, the modifications in porosity caused by biological activity (biopores) in a […]

Relationships between soil class and nutritional status of coffee plantations

Paulo Guilherme Salvador Wadt

01/Apr/2005

Farm planning requires an assessment of the soil class. Research suggest that the Diagnosis and Recommendation Integrated System (DRIS) has the capacity to evaluate the nutritional status of coffee plantations, regardless of environmental conditions. Additionally, the use of DRIS could reduce the costs for farm planning. This study evaluated the relationship between the soil class and nutritional status of coffee plants (Coffea canephora Pierre) using the Critical Level (CL) and DRIS methods, based on two multivariate statistical methods (discriminant and […]

Water balance in the soil volume of a citrus plant root system

Antônio Carlos Rodrigues Cruz, Paulo Leonel Libardi, Laércio Alves de Carvalho, Genelício Crusoé Rocha

01/Feb/2005

Crop yields, associated to weather and soil conditions, depend on the availability of water and nutrients in the soil at the appropriate time and amounts. Lack and excess of water in the soil are limiting factors for plant growth and can reduce the productivity. Therefore, studies leading to a better understanding of how water behaves within the root zone of a field crop are of unquestionable importance for an adequate agricultural management. Objectives of this study were the evaluation of […]

Potassium-bearing minerals in two oxisols of Rio Grande do Sul State, Brazil

G. W. Melo, E. J. Meurer, L. F. S. Pinto

01/Aug/2004

The objective of this study was to identify the K-bearing minerals as well as the granulometric fraction of the soil with potential to supply K to the plants from two basaltic Oxisols (Hapludox and Kandiudox). The mineralogical analyses of the granulometric fractions of the Hapludox soil revealed the probable occurrence of a mica mineral in the fine silt and coarse clay fractions, while feldspar minerals occurred in the sand, coarse silt, and fine silt fractions. In the Kandiudox soil, a […]

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