Correlation of properties of Brazilian Haplustalfs with magnetic susceptibility measurements

Magnetic susceptibility (chi, mass specific) is useful for easy indirect estimation of other soil properties at a low cost. The aim of this study was to assess the use of chi as measured with an analytical balance for predicting properties with a substantial influence on the management of Typic Haplustalfs in southern Brazil. To achieve this 48 topsoil samples were taken at the intersection points in a rectangular grid of 20 m x 20 m cells, with 38 of these used for calibration and 10 for validation in regression analyses. The obtained chi values were slightly higher than, and highly correlated (r = 0.970; P < 0.001) with those measured with a susceptibility meter. Highly significant (P < 0.001) correlations were also found between chi and other soil properties relevant to soil classification and management such as clay content (r = 0.68), cation exchange capacity (r = 0.62), P sorption capacity (r = 0.76) and haematite content (r = 0.82). Results from a principal component analysis of eight properties important for soil classification explained 11% of the variance in the data set. The good predictive ability of chi was consistent with current knowledge on the formation pathways for pedogenic ferrimagnets. In summary, chi, which can be readily measured with an analytical balance, has the potential for quantifying soil attributes and may therefore be used in pedotransfer functions.

Partially exchanged organophilic bentonites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial variability of soil attributes and sugarcane yield in relation to topographic location

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

Reação do solo e disponibilidade de micronutrientes, em solo de textura média, tratado com lodo de esgoto e cultivado com milho

The evaluation of micronutrient availability in agricultural soil treated with sewage sludge was developed in Field with maize cultivation on a Dystrophic Red Latosol. The experiment used a randomized complete block design, with the treatments in a split-plot scheme, in time, with six doses of sewage sludge (main-plot treatment) in relation to the five sampling periods for the soil (subplot treatment), with four replications. The sewage sludge was applied in the superficial layer (0-20 cm). The micronutrients Fe, Cu, Mn and Zn were extracted from the soils using a DTPA (diethylenetriaminepentaacetic acid) solution. The same micronutrients were analyzed in the plant tissue after the nitric-perchloric decomposition of the maize samples by spectrometric atomic absorption. The results showed an increasing amount of Fe, Mn, Zn, Cu, Cation Exchange Capacity (CEC) and a decreasing pH in the soil. The increasing doses of sewage sludge increased the Fe, Mn, Cu and Zn availability in the soil solution, and the uptake amount by maize plants were always greater than the control values.

Características químicas de solo cultivado com soja e irrigado com água residuária da suinocultura

In this work the distribution was evaluated "in situ" of phosphorus (P), organic matter (MO), potassium (K), calcium (Ca), magnesium (Mg), cation exchange capacity (CEC), aluminum (Al), sum of bases (S), base saturation (V) and pH of a soil cultivated with soybean and irrigated with swine wastewater in the 0, 25, 50 and 75% levels. The factorial scheme was constituted by the 20, 40 and 60 cm soil depths and four wastewater levels with five repetitions. The results showed that significant difference occurred only for P, K and CEC in the soil profile. However, in all parameters, the 60 cm soil depth showed that the concentrations levels are similar to before the aplication of treatments.

Efeito da aplicação de água residuária de suinocultura no solo e na qualidade dos seus lixiviados

This study evaluates the behavior of swine effluent for their effects on soil and the quality of the leachate. In the incubation of soil with effluent were used 48 units in total with experimental application rates of 0, 50, 100 and 150 m(3). ha(-1). The soil pH and leached after the application of different rates remained acid and the values of ammonia in the argisols (Pax; Ultisol) showed minor values than in the witness soil while at the nitosols the values increased due to the application rates. The cation exchange capacity increased with greater intensity in argisols. The carbon/nitrogen relation was low showing a rapid mineralization of organic waste. The values of nitrate in leachate and the first of the phosphorus nitosol were higher than in the argisols, depending on the rate of application.

Ligand Exchange Inducing Efficient Incorporation of CisPt Derivatives into Ureasil-PPO Hybrid and Their Interactions with the Multifunctional Hybrid Network

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization, feasibility and optimization of Agaricus subrufescens growth based on chemical elements on casing layer

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

NiBr2 complexes with triphenylarsine oxide (Ph3AsO). Two new interesting structures

The synthesis and crystal structure of two complexes resulting from interaction between NiBr2 and triphenylarsine oxide (Ph3AsO) is described. Green and orange complexes can be obtained from the blue, probably tetrahedral complex [NiBr2(Ph3AsO)2], depending on the solvents used for recrystallization. NiBr2·4[(C6H5)3AsO]·8H2O (green): M = 1650.2, P21/c, a = 13.731(2), b = 16.267(3), c = 17.647(2) Å, β = 112.04(1)°, V = 3651.4 Å3, Z = 2, Dx = 1.501 g cm-3, CuKα, λ = 1.54184 Å, μ = 38.67 cm-1, R = 0.039, 3741 unique reflections, 3203 with I > 3σ(I). NiBr2·4[(C6H5)3AsO]·3|2(C6H5CH3)·H2O (orange): M = 1663.7, P1, a = 12.647(8), b = 13.953(5), c = 22.853(6) Å, α = 90.91(3), β = 96.70(4), γ = 111.16(4)°, V = 3727.4 Å3, Z = 2, Dx = 1.482 g cm-3, MoKα, λ = 0.71073 Å, μ = 30.48 cm-1, R = 0.087, 8600 unique reflections, 4293 with I > 3σ(I). In the green complex the Ni(II) ion is sited on a center of symmetry and is octahedrally coordinated to six water molecules, hydrogen bonded to the Ph3AsO molecules and to the bromide anions forming a second coordination sphere in a nearly octahedral arrangement. In the orange complex the cation is pentacoordinated with the four oxygen atoms of the Ph3AsO ligands forming the basis of a tetragonal pyramid and with one Br- anion in the apical position. The absorption spectrum of the orange complex is compared with the spectra of other Ni(II) square pyramidal complexes described in the literature. © 1984.

Adsorption of various ions from acetone and ethanol on silica gel modified with 2-, 3-, and 4-aminobenzoate

Chemically bonded phases were obtained by reaction of 2-, 3-, and 4-aminobenzoate with 3-chloropropyl-silica gel. These phases were employed for metal cation adsorption in a batch method and applied to the separation of transition metal cations by chromatographic analysis.