In tropical regions there is rapid decomposition of plant material deposited on the soil, and the ability to recycle nutrients through this decomposition is one of the most important aspects of cover crops. The aim of this study was to evaluate the yield and nutrient release from forage crops intercropped with maize for silage, and soybean in succession. The study was conducted in the experimental area of Universidade Estadual Paulista, Ilha Solteira campus, Brazil. The experiment consisted of maize for […]

Arbuscular mycorrhizal fungi (AMF) play an important role in natural ecosystems as they influence plant nutrition and soil structure. The aim of this study was to determine the mycorrhizal inoculum potential and the relationship between mycorrhizal mycelium length of AMF and aggregation of riparian soils. Soil samples were collected in riparian areas in the Itajai Açu river watershed, between the municipalities of Gaspar and Navegantes, Santa Catarina, Brazil. Eight areas were sampled within three soil classes: Cambissolo (Inceptisol) (C), Gleissolo […]

The Shape of sand grains plays an important role in evaluation of soil particle size distribution. However, in most sieving techniques it is assumed that grains are spherical and can be described by a single parameter, diameter. Moreover, the subjectivity of the tests used to estimate sand roughness makes it difficult to obtain data that accurately represent reality. The aim of this paper was to study the use of image analysis together with the degree of sphericity and fractal theory […]

Associated with the benefits of the no-till system for the soil, there may be the formation of a vertical gradient of fertility and a compacted layer caused by heavy farm machine traffic, which may modify the root growth of crops. The aim of this study was to evaluate the effect of rates and forms of phosphate fertilizer application and soil compaction by machine traffic on the physical properties and root system of soybeans and maize. The study was conducted in […]

Inorganic phosphorus (Pi) usually controls the P availability in tropical soils, but the contribution of organic P (Po) should not be neglected, mainly in systems with low P input or management systems that promote organic matter accumulation. The aims of this study were to evaluate the changes in the Po fractions over time in soil fertilized and not fertilized with cattle manure and to correlate Po forms with available P extracted by anion exchange resin. The experiment was carried out […]

The spatial correlation between soil properties and weeds is relevant in agronomic and environmental terms. The analysis of this correlation is crucial for the interpretation of its meaning, for influencing factors such as dispersal mechanisms, seed production and survival, and the range of influence of soil management techniques. This study aimed to evaluate the spatial correlation between the physical properties of soil and weeds in no-tillage (NT) and conventional tillage (CT) systems. The following physical properties of soil and weeds […]

Inoculating wheat seeds with nitrogen-fixing bacteria such as Azospirillum brasilense may be beneficial to the crop and reduce the need for N application. Nevertheless, few studies have measured the benefit of this practice on irrigated wheat with the expectation of high yield and demand for N. The objective of this study was to evaluate the yield and N content of irrigated wheat under different N application rates, with and without inoculation with A. brasilense. Two experiments were carried out in […]

To produce reliable analytical data in a laboratory, all the stages of the analysis protocol must be properly understood and controlled. Extraction of soil P may thus be compromised by the conditions of analysis, and this may explain variability in results. Therefore, the objective of this study was to verify the effect of deviations in agitation speed, time of soil/ solution contact, and environmental temperature on extraction of soil P by Mehlich-1 (M-1) and Mehlich-3 (M-3). The study was conducted […]

Soil compaction is an undesirable consequence of land use for crop production, especially under cultivation with minimum soil turnover as in the no-tillage system (NTS). However, the compaction caused by machine traffic on soils under NTS does not make crop production unviable, indicating that some intrinsic mechanisms promote the reversion of soil compaction. In this study, the influence of alternate contraction and expansion cycles was evaluated with regard to the bulk density (ρ) of a Latossolo Vermelho argiloso (clayey Oxisol) […]

The predictive models used in digital soil mapping (DSM) need to be trained with data that most fully capture the variation of terrain and soil properties in order to generate adequate correlations between environmental variables and the occurrence of soil unities. Several methods have been used in DSM to evaluate the accuracy of these models. The aims of this study were to compare the use of three sampling procedures for training a classification and regression tree (CART) algorithm, and evaluate […]