The objective of this field experiment was to evaluate the effect of liming and phosphorus application on the structural stability of a clayey acid soil with high organic matter content, a typical feature of the southern Brazilian plateau. The study was carried out on a Brown Latosol (Haplohumox), in Lages, State of Santa Catarina, Brazil, in a split plot arrangement of a completely randomized block design. Treatments consisted of lime application at rates of 0, 4.5, and 9.0 Mg ha-1 at the […]

Field assessments of the water redistribution process are time consuming and costly because hydraulic soil properties vary extensively in space and time. The present work proposes two analytical models to estimate the dynamics of this process, based on the use of the hydraulic unit potential gradient of Richard’s equation. The first model estimates the soil water content and the second flow density, both as functions of time for internal drainage at a given depth. From statistical and physical points of […]

The effects of inoculation with arbuscular mycorrhizal fungus (AMF), substratum fumigation, and addition of soluble phosphate on papaya plant cultivar “Sunrise Solo” parameters (height, leaf number, and stem diameter) were studied. Separate treatments with AMF inoculation (Glomus macrocarpum) and increasing phosphorus levels (60, 120, 240, and 480 mg kg-1 of P in soil) influenced these parameters significantly, while the factor substratum fumigation had no significant effect. The inoculation effect was most expressive when 60 mg kg-1 of P in soil was added. Such was […]

To select a method for the evaluation of a root system the research goals, crop of interest, and its growth conditions must be taken into consideration. The study of roots is highly important in the understanding of various phenomena of the shoot growth and development, but requires an extremely careful proceeding since evaluation methods are laborious and the roots are affected by the physiochemical variability of the soil. The objective of this research was to compare five evaluation methods for […]

Increased phosphorus availability in the top soil layer of no-tillage systems can lead to a higher transformation from inorganic into organic phosphorus fractions of different labilities. The preferential phosphorus accumulation forms and fractions under the application of soluble phosphate rates in a no-tillage system were determined. During five and a half years, the following accumulated P2O5 rates: 0, 130, 180, 260, 360, 540, 720, 980, and 1.240 kg ha-1 of P2O5, were applied in the winter and/or summer, whereupon samples of the […]

To design hydraulic structures, a sound estimation of rainfall parameters is necessary, in order to ensure the technical and economical feasibility of the project. Equations to predict intense rainfall are widely used to estimate runoff peak discharge. The difficulty to obtain estimates for sites where no rainfall data are available can be overcome by the interpolation of precipitation data, based on neighboring meteorological stations, through statistical procedures. The objective of this work was to compare the two most accurate statistical […]

A greenhouse experiment was carried out to evaluate the effect of the Ca/Mg ratio in the cation exchange capacity on common bean growth. Samples of a typic ferric aluminum Red Latosol (LVat) and a psamitic dystrophic Red Latosol (LVdp), both Haplortox (U.S. Soil Taxonomy) in pots containing 3.5 dm3 of soil were treated with Ca:Mg ratios of 1/2, 1, 2, 4, 6 and 8. The experiment was arranged in a completely randomized block design with six replications. Three replications were harvested […]

Soil organic matter and its different pools have key importance in nutrient availability, soil aggregation, and in the greenhouse gas fluxes between the earth surface and the atmosphere. The objectives of this study were: a) to evaluate the effect of maize production systems under organic and mineral fertilization on total organic carbon (TOC) and total nitrogen (TN) stocks and on organic carbon pools (C) in an Acrisol; and b) to estimate the contribution of these systems in the atmospheric CO2 […]

Studies into the nutritional efficiency of grafted coffee plants is essential for the selection of graft/rootstock combinations for a maximum development and production. Our objective was the evaluation of the influence of rootstocks on the efficiency of uptake, translocation and use of Ca, Mg, and S in young Coffee arabica L. plants in hydroponic cultivation. The experiment was conducted in a greenhouse and lasted 170 days, using sand as substratum and circulating nutritive solution. Four genotypes of Coffea arabica L. were […]

Soil management has an impact on soil cover and roughness, and, together with other variables, affects water erosion. In São José do Cerrito, State of Santa Catarina, Brazil, three simulated rainfall tests were evaluated during the soybean cycle March 2000 through June 2001 in combination with the five tillage systems: plowing + disking (bare soil) (BS); plowing + disking and soybean crop on dry oat residues (PD); chiseling + disking and soybean crop on dry oat residues (CD); soybean crop […]