The Serra do Brigadeiro State Park is covered by tropical Atlantic rain forest, as part of the Mantiqueira crystaline range. In the upper areas (above 1.600 m), a type of vegetation with singular floristic composition is found, with high endemism and a number of endangered species, here called “Campos de Altitude”. A Lithosol, a Spodosol (Podzol) and a Cambisol, all associated with “Campos de Altitude”, and a Latosol under rain forest, were sampled. These soils showed high Al saturation, low […]

This work was conducted under greenhouse conditions to evaluate how doses and methods of manganese (Mn) application may affect vegetative characteristics as well as the production of upland rice. The treatments consisted of five manganese doses applied either via soil (0, 4, 8, and 16 mg dm-3) or leaf (3 4 g L-1 applications), associated with two rice cultivars (Canastra and Confiança). The experiment was randomly designed, with four replications, in a 2 x 5 factorial scheme. Each plot consisted […]

Silicon has been considered a beneficial element for plants that accumulate it, specially rice, thus it is quite common its addition to deficient soils. However, its effects seem to depend more on environmental and indirect factors related to soil and silicon sources characteristics. With the objective to study the effect of silicon as the single growth factor of rice (Oryza sativa cv. BR-IRGA 410), an experiment was carried out using nutrient solution under greenhouse conditions, with and without the addition […]

Soil fertility characteristics were evaluated on a typical dystrophic Red Latosol located in Passo Fundo, Rio Grande do Sul, Brazil, after five years of combined production systems (1993 to 1997). The effects of integrated grain production systems and with winter annual and perennial pastures under no-tillage were assessed. Four production systems were evaluated: system I (wheat/soybean, white oat/soybean, and common vetch/corn); system II (wheat/soybean, white oat/soybean, and grazed black oat + grazed common vetch/corn); system III [perennial cool season pastures […]

Humus forms allow the characterization of either a natural forest ecosystem or disturbed forests. Under this perspective, we aimed to identify the humus forms in three Tabuleiro Forest sites in northern Espírito Santo: two primary forests, “Mata Alta” and “Mata de Córrego”, and one secondary forest resulting from slash and burn, over 40 years old (Capoeira Queimada). Therefore, the holorganic horizons were studied in regard to the pedological parameters of the mineral soil. At “Mata Alta”, a mesotrophic mull was […]

Most of the silicon absorbeb by plants remains deposited on the external part of the cell walls as a layer of amorphous silica (SiO2.nH2O), probably affecting straw mineralization in soils. An experiment was performed with the aerial part of oat plants, cultivated in nutrient solution with and without silicon addition, to evaluate this hypothesis. Dried aerial parts of oat plants tissue was mixed with soil or washed quartz sand and placed in PVC tubes. Distilled water was percolated through the […]

Carbon and nutrients released from the mineralization of organic materials can interact with mineral components changing their dynamics in the soil. In this study, mixtures of corn straw, kaolinite, synthetic goethite, and quartz sand were leached with water after 7, 15, 33, 68 and 113 days of incubation at room temperature. Concentrations of soluble carbon, calcium, magnesium, and potassium were measured and accumulated over time. After 200 days, the total carbon remaining in the mixture was quantified. Total calcium, magnesium, and potassium […]

A tilled soil has increased susceptibility to raindrop impact and sediment transport by laminar surface flow and splash, but after tillage the soil reconsolidates, increasing again its resistance. Thus, an experiment was conducted on a Hapludalf with Sandy loam soil surface, under no-tillage for eight years, to evaluate interrill erosion under different tillage methods. The experiment was totally randomized with six replicates. The treatments were recent conventional tillage (RCT), two-month consolidated conventional tillage (CCT), no-tillage with mulch (NTM) with 94% […]

This study, covering 12 cultivations, was carried out at Embrapa Rice & Beans Research Center, Santo Antônio de Goiás, Goiás, Brazil, in an Oxisol, under center pivot, for six consecutive years. The effects of four soil tillage systems and six crop rotations on bulk density and soil porosity were evaluated. The experiment was conducted in a completely randomized design, using a splitplot arrangement, with three replications. The tillage treatments were: moldboard plough/harrow disc, moldboard plough, harrow disc, and no-tillage. Tillage […]

Nitrogen top dressing period affects wheat grain yields and should occur at the stages when yield potential is established. In order to determine the critical stages related to N needs, field experiments were conducted at Estação Experimental Agronômica/UFRGS, Eldorado do Sul (RS), Brazil, in 1993, 1994 and 1995. Wheat cultivars BR 23 (1993 and 1994) and Embrapa 16 (1995) were sown by the end of June at 300 seeds m-2. Nitrogen treatments (40 kg ha-1) were applied at the following stages: (a) plant emergence, (b) […]