Nitrogen is an important nutrient, due to its soil dynamics and crop demand. The amount of N supplied by the soil is however frequently insufficient, and N fertilization is required to obtain maximum yields. This study was conducted with the objective of evaluating different sources and periods of N application in no till wheat. A randomized block design was used in a factorial scheme 2×6 with four replications. The treatments consisteded of the combination of two N sources: Urea and […]

The use of organic residues as fertilizers and soil conditioners requires their maturation and the quality monitoring of the final product. Vermicomposting is a technique which, along with the composting process, eliminates the potential harmful effect of manure residues to human health and soil. The stability and maturity degrees of a given vermicompost are usually inferred from the quantity and quality of the humic substances in the resulting compost. This study aimed to evaluate the quality and maturity of vermicomposts […]

Soil fertility is defined as the capacity of the soil to supply nutrients, in a balanced proportion for plant growth and productivity, in the absence of toxic elements. This concept, based on the mineralist theory, is widely used around the world. With the shift away from conventional systems, high crop yields are frequently obtained under no-tillage, even where soil fertility indexes are considered inadequate, according to soil fertilizer recommendations for the conventional system. It is possible that the traditional evaluation, […]

Models of soil water erosion prediction and estimation are generally based on a series of parameters, normally determined by applying simulated rainfall in the field or laboratory. The use of simpler, faster and cheaper parameters such as texture, content and oxide type and aggregate water stability may contribute to facilitate the estimation of the factor interrill soil erodibility (Ki). The purpose of this study was: i) to determine the interrill soil erodibility of three Brazilian Oxisols; ii) evaluate the use […]

Based on field observations it is often impossible to detect differences in soil B contents after the application of B fertilizers, even when increased leaf B contents are detected. This has raised doubts as to the efficacy of the B extractor used in routine soil B determinations. An experiment was conducted to study B extraction and availability to soybean in an Oxisol in the state of Mato Grosso. Boron (as boric acid) doses ranging from 0.0 to 10.0 kg ha-1 […]

Pig slurry serves as plant nutrient source, but may cause phosphorus accumulation in the soil when used improperly, which later can be transferred to the aquatic environment causing eutrophication. The objective of this study was to evaluate the potential risk of environmental contamination by continuous use of pig slurry, measuring alterations in phosphorus content in the soil and in the sorption isotherms. The study was carried out at the Universidade Federal de Santa Maria, in a Typic Hapludalf. The effects […]

Each soil tillage system has its proper characteristics, which have distinct effects on the chemical, physical and biological soil properties, and may require adaptations of fertilization recommendations and management. This study was conducted to evaluate the performance of three maize cultivars with fertilizer application before and at sowing in two soil tillage systems. The experiment was carried out at the “Faculdade de Ciências Agronômicas”, UNESP, Botucatu-SP campus, from November 2003 to May 2004, in a Dystric Nitosol (FAO). The experimental […]

Soil contamination by heavy metals is a current concern that requires a suitable approach, taking the needs of modern societies into account. In mined areas the evaluation of soil contamination is an important tool for the management of degraded areas. This study was carried out in order to establish local reference values (LRV) for Zn in soils surrounding mining areas in the county of Vazante-MG (Brazil), with a view to evaluate the environmental contamination. Soil profiles were collected in the […]

It is convenient to apply nutrients in fertigation at an appropriate depth, in order to locate those elements at a convenient place for plant uptake. So, an experiment was carried out under laboratory conditions using percolation columns, to establish the irrigation lamina fraction in which N (NH4+ e NO3–), K+, and H2PO4– doses must be applied as well as the optimum dose fractioning of these nutrients so as to locate their adequate depth and determine the distribution of fertigated NH4+, […]

Changes in the physical properties of soil, mainly related to water retention and soil aggregation, may be linked to changes in electrochemical soil properties. The purpose of this study was to determine the effects of liming on the relationship between soil and water. In 1994, an experiment was installed in the experimental area of the Departamento de Solos da Universidade Federal de Santa Maria, in a dystrophic plinthic Gray Acrisol. Treatments consisted in surface liming and lime incorporation at 0, […]