Seeds with a high concentration of P or Mo can improve the growth and N accumulation of the common bean (Phaseolus vulgaris L.), but the effect of enriched seeds on biological N2 fixation has not been established yet. This study aimed to evaluate the effect of seeds enriched with P and Mo on growth and biological N2 fixation of the common bean by the 15N isotope dilution technique. An experiment was carried out in pots in a 2 x 3 x 2 x 2 factorial design […]

Crop residues on the soil surface act mainly as protection against raindrop impact, reducing aggregate disruption, runoff, sediment transport and consequently, erosion. This protection can have significant effects on the corn plant characteristics. The objective of this study was to evaluate the effect of the amount of black oat residues on no-tillage root development, nutrient uptake and grain yield of corn genotypes. The experiment was conducted in an Oxisol, in a randomized block design in split plots with three replications. […]

A very active and influential parameter in the erosive process is the R factor, called rainfall erosivity. This factor is one of the components of the universal soil loss equation. Studies in spatial variability have been conducted in an attempt to define the spatial distribution of the R factor for a given region. This study aimed to calculate the rainfall erosivity (R factor – EI30) to generate spatial maps. The study was conducted in experimental areas of eucalyptus stands in […]

Irrigation with treated domestic sewage wastewater (TSE) is an agricultural practice to reduce water requirements of agroecossystems and the nutrient load impact on freshwaters, but adverse effects on soil chemical (salinization, sodification, etc.) and soil physical properties (alteration in soil porosity and hydraulic conductivity, etc.) have been reported. This study aimed to define some relationships among these changes in an Oxisol using multivariate analysis. Corn (Zea mays L.) and sunflower (Helianthus annuus L.) were grown for two years, irrigated with […]

Evaluating plant root capacity in extrating water from the soil is important for transpiration modeling and to understand crop growth and yield and soil water and nutrient balance. Aiming to test a macroscopic root water extraction model based on the microscopic process description, an experiment was described in which the root system of plants penetrated different soil layers with contrasting hydraulic properties. Four lysimeters containing two physically divided compartments were built and filled with material of two soils with different […]

Cropping systems modify soil attributes and can affect their quality. Traditionally evaluated by laboratory analytical methods, soil attributes have been used as indicators of its quality and are very accurate. However, many times, analytical methods are of difficult access by the producer and high cost. Visual Soil Assessment (VSA) has been developed to help land managers to assess soil condition easily, reliably and cheaply on a field scale. The objective of this study was to evaluate the performance of the […]

The effects of humic substances on soil properties are known. However, little is known about the effects of these materials on plants. Depending on the concentration and chemical nature of the humic molecules applied, the effect may be expressed by an expansion of the root system, increase of nutrient absorption and increased crop growth. To evaluate the effects of C-humic acid concentrations on nutrition and growth of eucalyptus seedlings, a greenhouse experiment was carried out in nutrient solution. The treatments […]

The eutrophication of aquifers is strongly linked to the mobility of P in soils. Although P mobility was considered irrelevant in a more distant past, more recent studies have shown that P, both in organic (Po) and inorganic forms (Pi), can be lost by leaching and eluviation through the soil profile, particularly in less weathered and/or sandier soils with low P adsorption capacity. The purpose of this study was to determine losses of P forms by leaching and eluviation from […]

Rill erosion begins with the concentration of surface runoff on depressions of soil surface, evolving into the formation of channels or ravine, increasing soil degradation by water erosion. The objectives of this study were to evaluate the hydraulic conditions of the water flow in rills and characterize the water flow regime, and to measure the induced changes in the geometry of the preestablished rills. An experiment was conducted in which outflows of 17.5; 47.0; 60.0; 77.0 and 110.0 L min-1 were applied […]

The information obtained through the humic fractions distribution can be used in brazilian soil studies as a diagnostic attribute or differential characteristic and therefore, contribute to the evolution of Brazilian System of Soil Classification (SiBCS). The objective of this study was to quantify the organic carbon in humic fractions of surface and subsurface diagnostic soil horizons and propose the use in the brazilian system of soil classification. A total of 169 diagnostic horizons distributed between Folistic Epipedon (O hístico), Histic Epipedon (H hístico), […]