Soils with brown or yellowish brown hues are dominant in the high altitude areas of southern Brazil. This feature is a consequence of the cool weather and high humidity conditions, which contribute for the formation of goethite and complete soil xantization. However, in some sites, soils present brown and yellowish brown hues in surface and transitional horizons, yet preserving red colors in subsurface horizons what may represent a relic of a drier and hotter climate condition from the past. In […]

An experiment was carried out under green house conditions to evaluate the effects of the inoculation with arbuscular mycorrhizal fungi (AMF), associated with the addition of formononetin (5, 10 µ mol L1), quercetin and morin (5, 10 and 15 µ mol L1), on the growth and nutrient content of passion fruit plants in the phase of seedlings cultivated in sterile substrate and after transplanting to a non-sterile substrate. The fungi utilized were Glomus clarum (Gc), Glomus fasciculatum (Gf) and a […]

In the region of Lavras, Minas Gerais, Brazil, soils profiles with argillic horizons were selected to evaluate the alterations which occurred during the process of soil formation and to investigate pedogenetic characteristics related to the parent material. Within this region, these soils occur on sloping and hilly landscapes. They were selected for this study because they preserve characteristics inherited from the original bedrocks. Three profiles formed from geologic material with different chemical composition were selected: Profile 1 – Red-Yellow Argisol […]

Some of the leguminous tree associated to fixing bacteria and micorrizal fungi have good development in degraded soils. Aiming to evaluate the influence of these species on soil fertility level, dry matter production and the nutrient contents of litter originated from these plants were measured during 1995. The rate of litter decomposition was evaluated by analysing the material collected in 1995 and 1996. Homogeneous stands of Caesalpiniifolia mimosa (‘Sabiá’), Acacia mangium and Acacia holosericea established at the experimental station of […]

Based on the hypothesis that antecipating of nitrogen application can increase corn grain yield due to more N availability in the initial stages of development, field studies were conducted for three agricultural years (1996/97, 1997/98, and 1998/99) to evaluate different types of management of N application for corn cultivated after winter soil cover crops. This work was developed on a Hapludalf soil, at the experimental area of the Soil Science Departament at the Federal University of Santa Maria (RS, Brazil). […]

The boron supply to plants can be accomplished by the soil, by foliar application or by treatment of the seeds. Seed treatment advantages are: application uniformity, readiness for plant use and reduction of the application costs. Theoretically, the initial reserve of boron can be increased by application in the seeds. However, high boron concentrations close to the seeds interfere with germination. The objective of this experiment was to evaluate the germination of seeds treated with increasing doses of B and […]

The aim of this work was to evaluate the effects of human intervention, i. e., jungle clearing and introduction of pasture (Brachiaria sp), on the total-N and organic-C contents and humic acids, fulvic acids and humina fractions. This research was carried out in a forest near Porto Velho – Rondônia (Amazo Forest) and Senador Canedo – Goiás (“cerrado”). The soil samples were collected in 1995, from areas of primary vegetation and planted pasture, obeying a line with 24 points every […]

This study was carried out to assess the influence of Winter plant cover on the physical soil properties in a Structured Terra Roxa soil in the state of Santa Catarina. The plant cover consisted of an association of black oats (Avena stirgosa Schreb) with pasture turnip (Raphanus sativus L.) and organic fertilization with poultry manure and 2 mineral fertilization. Soil samples collected in August 1994 and January 1995, at depths of 0-10, 10-20 and 20-30 cm, from an experiment started […]

The aim of this study was to evaluate the effects of soil organic matter on the sorption and desorption of glyphosate in three soils with different mineralogical attributes. The experiments were carried out at the Laboratório de Ecotoxicologia of the Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). The soils were classified as: Rhodic Kandiudalf (NVef), Anionic Acrudox (LAw) and Typic Humaquept (G). In order to evaluate the influence of organic matter on the ghyphosate sorption, the soils […]

The aim of this work was to evaluate the influence of P levels and arbuscular mycorrhizal fungi (AMF) on growth and mineral nutrition of Citrus limonia. The experiment was conducted under greenhouse conditions, with a completely randomized 6 x 3 factorial design, with six P levels (0, 50, 100, 150, 200 and 250 mg kg-1 of substrate), two species of AMF (G. etunicatum and G. intraradices) and a control without AMF, with three replicates per treatment, using 1.7 dm-3 pots. […]