Fifty eight plots of 480 m2 (20 x 24 m) were established in stands of 5.5 year-old Eucalyptus grandis, growing in Rio Doce Valley – MG, Brazil, in order to study the relationship between growth and site characteristics. The topography of the area is hilly and the soil predominantly Oxisol, originated from granite-gnaiss parent material. A discriminant model with two linear functions was obtained and allowed to correctly classify 86.2% of the plots. The discriminant model obtained showed a holistic […]

Soil compaction process studies have more recently involved some soil tests frequently used in soil mechanics. Seeking a better understanding of the application of the Proctor normal test for agricultural purposes, this study aimed to evaluate the soil compaction curve, obtained through this test, and the effect of the degree of compaction on the soil moisture characteristic curves. For the development of this study, a Dusky Red-Latosol (LR), a Red Yellow-Latosol (LV) and a Dark Red-Latosol (LE) submitted to annual […]

The objectives of this experiment were to identify differences in the total quantity of water stored in soil, storing capacity of water available to the plants and in the water consumption of maize plants cultivated in soils of different textures. The experiment was conducted at the experimental area of the Rural Engineering Department of the Federal University of Santa Maria during the 1995/1996 growing season. A set of 12 drainage lysimeters was used. These were 156 cm long, 100 cm wide and 80 cm […]

Extraction and evaluation of active (AEM) and total (TEM) extraradicular mycelium is the first step in a comprehensive study of the interaction between host plant and arbuscular mycorrhizal fungi (AMF), since these hyphae are responsible for nutrient absorption and translocation from the soil to the host. Extraction methods for extraradicular mycelium in the literature were reviewed and reevaluated, and modifications were made, resulting in a new, simple technique. The evaluation and quantification method of AEM was tested using induced fluorescence […]

The determination of the cation exchange capacity (CEC) and the relative fractions occupied by the most common cations is crucial for soil chemical characterization and soil fertility diagnostic. These variables and the exchangeable Al3+, Ca2+ and Mg2+ concentrations have been determined in the routine soil analysis by official laboratories in the States of Rio Grande do Sul and Santa Catarina since 1994. The relationship between the SMP index and the H + Al value (potential acidity) was studied in order to establish […]

Two field experiments were conducted on a dystrophic Dark Red Latosol (Haplortox) to study the effects of lime, cobalt and molybdenum on chlorophyll contents in the leaves of peanut. Seed treatments (cobalt, molybdenum, cobalt + molybdenum and no treatment) were applied in two peanut cultivars (“Tatu” and “Tupã”) grown in four rates of lime (0, 4, 6 and 8 t ha-1), causing an increase in leaf chlorophyll contents either due to Mo or lime application. Chlorophyll contents in the leaves […]

Losses of nutrients and organic matter due to hydric erosion are highly affected by soil management. Inadequate management systems may cause pollution and eutrophication of surface waters, fertilization cost increase, and ecosystems degradation. Nutrient and organic matter losses due to erosion were evaluated during six years on a very clayey Dusky Red Latosol, with a 0.03 m m-1 slope at Dourados, Mato Grosso do Sul, Brazil under natural rainfall conditions, and different soil management systems. The treatments applied in the crop succession […]

Soil water infiltration rate may be the soil property which best reflects the general soil physical conditions, especially the structural quality. A field study was conducted at the Embrapa Trigo, Passo Fundo, Brasil in an Oxisol under long-term soil tillage systems, to evaluate the influence of these systems on soil water infiltration rate as a function of the soil cover and soil physical conditions caused by the different tillage systems. During a corn cropping period, a simulated rainfall with intensity of […]

The reaction of nitrogen compounds with ninhydrin can be used as an indicator of cytoplasmic materials released from microbial cells killed by fumigation. Total-N, ninhydrin-reactive-N (NR-N), ammonium-N (A-N), and α-amino-N in the microbial biomass of soils from the State of Rio Grande do Sul, Brazil, were determined, in 1996, in 0.5 mol L-1 K2SO4 extracts of fumigated and non-fumigated soils. Total-N varied from 20.3 to 104.4 mg kg-1 and the ninhydrin-reactive-N corresponded, in average, to 27% of this. The ninhydrin-reactive-N was made up of […]

Soil heterogeneity is known to cause variability of soil-water storage. Thus intensive sampling is required to characterize its spatial pattern. For irrigation management, it is necessary to measure the soil water content between irrigations. The objectives of this paper are to identify whether spatial patterns of soil water content in sprinkler irrigated area present temporal stability and whether this property presents spatial dependence. Temporal stability of spatial dependence structures and spatial correlation with clay content were studied. A 180 m long […]