Phosphate solubilizing microorganisms and the growth of pine and eucalypt
01/Dec/2002
Phosphate solubilizing microorganisms play an important role in supplying phosphorous to plants. This ability has stimulated research on plant inoculation. In our study, microorganisms were isolated from Pinus and Eucalyptus plantations and selected in culture medium. They were then employed in a series of 28 experiments under greenhouse conditions in substrate, forest or sterilized nursery soil, with or without phosphate fertilization, in one of the following P forms: calcium phosphate, Araxá, or Catalão phosphate. Three isolates promoted a higher dry […]
Physical and chemical properties of soils incubated with alkaline residue of the cellulose industry
01/Dec/2002
The cellulose and paper industry discards residues of varied chemical composition on a large scale. Some of these residues are being used by farmers for the adjustment of soil acidity, since they contain hydroxide. However, there are no recommendations on quantities or reapplications. Possible consequences are clay dispersion, reduction of the aggregate stability and the imbalance of nutrients, degrading the physical and chemical soil properties. This study evaluated the physical and chemical properties of two soils incubated with alkaline residues […]
Forage dry matter production of native pasture under application of liquid swine manure
01/Dec/2002
Forage dry matter production of native pastures in southern Brazil is usually low due to the restricted soil nutrient availability – a limitation that can be compensated by application of liquid swine manure. In an experiment carried out from November 1995 to November 1999, in an area near a swine farm in Paraíso do Sul County, Rio Grande do Sul State, the efficiency and frequency of liquid swine manure application in relation to dry matter production and nutrient uptake by […]
Silicon and sodium chloride effects on mineral nutrition and dry matter production of moringa (Moringa oleifera Lam.) plants
01/Dec/2002
A greenhouse experiment was conducted in the Soil Science Department of the Federal University of Lavras, Brazil, to evaluate the effect of silicon on mineral nutrition and dry matter production of moringa plants, cultivated under salinity stress. The experiments followed a randomized factorial block-type design, in three replications. In pots of 3 L capacity with one plant each, five levels of NaCl (0, 30, 60, 90, and 120 mol m-3) were combined with four levels of SiO2 (0.0, 0.5, 1.0, […]
Aggregation attribute indicators of soil quality in management systems of a cerrado region in the south of Goiás state, Brazil
01/Dec/2002
Latosols (Oxisols) under cerrado vegetation have been intensively incorporated into the agricultural production process. However, studies involving soil quality in this environment are scarce. The objective of this work was to verify alterations on aggregation attribute indicators of soil quality, as a result of the management systems adopted for the native cerrado, and to select the best attributes indicating such alterations. The samples were collected at depths of 0-10, 10-20, and 20-40 cm from a typic Dystrophic Red Latosol (Oxisol) […]
Estimation of potential soil acidity and its role in the lime demand calculation
01/Dec/2002
Lime requirement diagnostic by base saturation (H + Al) estimation methods are critical in CEC calculation since they are bound to a potential soil acidity of pH 7.0. This study was carried out in order to evaluate a relation between the H + Al obtained by direct soil incubation with calcium carbonate and the estimation by the extractors acetate salt and SMP index. Twelve south Brazilian soils, incubated with increasing calcium carbonate rates to establish the real soil acidity at […]
Influence of ammonium sulfate in mixture with urea on the volatilization of NH3-N
01/Sep/2002
The objective of this study was to evaluate the influence of addition of ammonium sulfate in mixture with urea on the volatilization of NH3-N. An experiment was carried out under controlled laboratory conditions at the Soil and Plant Nutrition Department (ESALQ/USP). The experimental design was completely randomized with five replications and five treatments. Each treatment was obtained by the mixture of urea (330 mg) with ammonium sulfate at different rates (0, 75, 150, 225 and 300 mg). The fertilizer mixtures […]
Alterations in physical properties of latosol and podzolic caused by management techniques applied between rows of rubber trees (Hevea brasiliensis)
01/Sep/2002
This experiment had the objective of assessing the influence of management practices (disk harrowing, Pueraria phaseoloides and mowing) on the soil’s bulk density and macro- as well as microporosity between the rows of rubber trees (Hevea brasiliensis) planted in 1992 in the highland of the State of São Paulo. A Dark Red Latosol, from Jaboticabal County and a Yellow Red Podzolic from Tabapuã County, São Paulo State were sampled at four depths (0-10, 10-20, 20-30 and 30-40 cm) in the […]
Micropedological characterization of altered soils after bauxite mining in Porto Trombetas (PA)
01/Sep/2002
A micropedological study was carried out in rehabilitated soils after bauxite mining, in sites dating from 1981 to 1987, compared with the Yellow Latosol, as reference, to subsidize soil indicators of rehabilitation. The study was located in Porto Trombetas, district of Oriximiná, northwestern Pará State. Micromorphological techniques, using EDS/SEM microprobe, optical and scanning electronic microscopy, were used in combination with chemical and physical analysis, at 0-10 and 40-50 cm depths. The Yellow Latosol showed a strong development of microgranular structure, […]
Nutrient losses by erosion as affected by different methods of native grassland improvement in the state of Rio Grande do Sul, Brazil
01/Sep/2002
Growth stagnation on native grassland during the winter season has stimulated the introduction of winter species in order to increase forage offer for animals in the State of Rio Grande do Sul, Brazil. To determine the nutrient losses by erosion as affected by different methods of native grassland improvement, an experiment was carried out at the Agronomic Experimental Station of the Federal University of Rio Grande do Sul, in Eldorado do Sul. A mixture of the winter forage species black […]
