3303 results

Reference values of macronutrients in eucalypt determined by DRIS and mathematical chance methods

P. G. S. Wadt, R. F. Novais, V. H. Alvarez V., S. Fonseca, N. F. Barros

01/Dec/1998

Data from 1.213 trees of Eucalyptus grandis x E. urophylla hybrids were collected between 1988 and 1994 from the Aracruz Celulose S.A. commercial plantation in the State of Espírito Santo, Brazil. Data on stand productivity and macronutrient concentration in four tree components (leaf, branch, stembark and stemwood) were used to determine the reference values of nutrient concentration by the methods of Mathematical Chance and DRIS. The formula of Jones and the population distribution based on age and selection of the […]

The method of mathematical chance to evaluate data from nutritional survey of eucalypt trees

P. G. S. Wadt, V. H. Alvarez V., R. F. Novais, S. Fonseca, N. F. Barros

01/Dec/1998

Handling a large volume of data from nutritional surveys of forest plantation is a hard task in studies of tree nutrition. A mathematical process named “Method of Mathematical Chance” was developed, based on probability calculation, to interpret such data by levels of nutrient sufficiency. By this method it is possible to identify optimum, sub-optimum and supra-optimum ranges, for each growth factor, as well as permit the classification of tree stands according to their distribution in each sufficiency level. In this […]

Matric potential and soil water content variability in irrigation management experiment

C. R. Marciano, S. O. Moraes, A. M. Saad, P. L. Libardi

01/Dec/1998

A four replicated maize (Zea mays L.) crop irrigation management experiment was carried out in a Typic Haphortox soil of Guaíra (SP), Brazil (20°27’30”S, 48°19’30”W, 495 m) from July to December, 1994. There were three treatments: tr000 – half of the recommended amount of water was applied during the crop cycle; tr0I0 – the recommended amount of water was applied only during the intermediate stage and half of it during the initial and the final stages; and trIII – the […]

Seasonal variation of colonization of eucalypt root by mycorrhizal fungi in the state of Espírito Santo, Brazil

P. H. Grazziotti, N. F. Barros, A. C. Borges, J. C. L. Neves, S. Fonseca

01/Dec/1998

This study was carried out in the field to evaluate root colonization of three Eucalyptus grandis x E. urophylla hybrids by mycorrhizal fungi as affected by soil conditions. Roots of three clonal trees, each five year old, were evaluated in regard to colonization by ectomycorrhizal and by arbuscular mycorrhizal fungi, in three areas of the State of Espírito Santo, Brazil, at four different times (July and October, 1992; January and April, 1993). The percentage of mycorrhizal colonization was dependent on […]

Heavy metals, microbial density and activity in a soil contaminated by wastes from a zinc industry

H. E. Dias-Júnior, F. M. S. Moreira, J. O. Siqueira, R. Silva

01/Dec/1998

Mining and metallurgical activities are responsible for pollution of extensive soil areas around the world, with their effects not being well known under Brazilian conditions. Total and water soluble contents of heavy metals and microbial density and activity were evaluated, in this 1996 study using samples from seven sites located in a dumping site of a zinc industry in the state of Minas Gerais, Brazil. Additionally, a non-contaminated site was used as reference. All contaminated sites presented high total and […]

Quality of soil organic matter in relation to the pedogenesis of some cambisols at Irecê, Bahia, Brazil

T. J. F. Cunha, L. P. Ribeiro

01/Dec/1998

Six calcareous soil profiles (P1, P2, P3, P4, P5 and P6) were investigated with regard to their main characteristics of soil organic matter related to structural organization. The effect of degrading processes on these soils was also considered, mainly under intensive cultivation. Based on morphological in situ observation and analytical data, the profiles P1 e P2 showed organic matter with an advanced level of evolution presenting reasonable amounts of low polymerized materials (fulvic acids). Conversely, profiles P3, P4, P5 e […]

Total and soluble boron contents and their relationships with some soil properties in the state of Ceará, Brazil

F. R. Silva, F. F. Ferreyra H.

01/Dec/1998

Total and soluble boron contents were evailable by means of three extractors, used as plant availability indexes, in order to study their relationships with soil properties in representative mapping units of the state of Ceará, Brazil. Composite soil samples from the surface soil layers (0-20 cm) of Quartz Sands (AQd), Alluvium (Ae), Planosol (PL), Bruno non Calcic (NC), Cambisol (Ce), Red-Yellow Podzol (PV), Red-Yellow Latosol (LV) and Littosol (Re) were used. Total boron was determined after fusion with sodium carbonate […]

Rainfall and runoff erosivity parameters correlated with soil losses of a haplargids (Paraiba state, Brazil)

A. W. Albuquerque, F. Lombardi Neto, A. Cataneo, V. S. Srinivasan

01/Dec/1998

Simple linear correlations among runoff and rainfall erosivity parameters and soil losses caused by erosivity rainfall in Haplargids were studied. Data related to 1986-1990 were obtained in the Experimental Station at Sumé-Brazil. The rainfall erosivity parameters were the following: a) total height of the rainfall (P) in mm; b) maximum intensity (In): I5; I10; I15; I20; I25; I30; I35; I40; I45; I50; I55; I60 and I120 minutes in mm h-1, respectively; c) total kinetic energy by the Wischmeier & Smith’s […]

Changes in chemical attributes of sandy soil under no-tillage

D. S. Rheinheimer, J. Kaminski, G. C. Lupatini, E. J. S. Santos

01/Dec/1998

No-tillage soil management does not permit incorporation of crop residues and requires surface application of fertilizers and corrective agents, thereby affecting nutrient availability and distribution. This study was carried out to evaluate the chemical changes in no-tillage system compared to conventional tillage and native grass field. Samples from a sandy/clay Red-Yellow Podzolic (Typic Hapludalf), taken at 0-5, 5-10, 10-20 and 20-40 cm depth, were used to determine zero point of salt effect (ZPSE), humic substances, permanent charge, soil pH, exchangeable […]

Nutrient potential response of eucalypt plantations as evaluated by three methods of estimating DRIS indices

P. G. S. Wadt, R. F. Novais, V. H. Alvarez V., S. Fonseca, N. F. Barros, L. E. Dias

01/Dec/1998

The aim of this study was to test the effect of three methods of estimating the DRIS indices on the nutritional status of eucalipt plantations, based on the grouping of these indices by the Nutrient Application Potential Response Method. Nutrient concentrations of tree leaf, branch, stembark and stemwood, determined in 1986 trees of Eucalyptus grandis x E. urophylla hybrids growing in the States of Espírito Santo and Bahia, Brazil, were evalued by the methods of Jones, Elwali and Gascho, and […]

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