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Classical Methods and Calculation Algorithms for Determining Lime Requirements

André Guarçoni, Fabrício Moreira Sobreira


ABSTRACT The methods developed for determination of lime requirements (LR) are based on widely accepted principles. However, the formulas used for calculation have evolved little over recent decades, and in some cases there are indications of their inadequacy. The aim of this study was to compare the lime requirements calculated by three classic formulas and three algorithms, defining those most appropriate for supplying Ca and Mg to coffee plants and the smaller possibility of causing overliming. The database used contained […]

Mercury Content in Soils of Southeastern Brazil Without Anthropogenic Influence and its Correlation with Soil Characteristics

Liliane Catone Soares, Lucília Alves Linhares, Fernando Barboza Egreja, Cláudia Carvalhinho Windmoller, Maria Irene Yoshida


Correlation between physical and chemical characteristics of soils and their natural mercury content is important for identifying the parameters that most influence Hg retention in these soils and its distribution in different environmental compartments. The aim of this study was to quantify the Hg content of tropical soils without anthropogenic influence and correlate it with physical and chemical soil characteristics. The present study is relevant because most research focuses on contaminated soils and, in the case of tropical soils, research […]

Effect of rock powder and vinasse on two types of soils

Otavio Mitsuhiro Motizuki Lopes, Elma Neide Vasconcelos Martins Carrilho, Maria Leonor Ribeiro Casimiro Lopes-Assad


Can vinasse accelerate the change of minerals in rock dust to obtain fertilizers, using residues from alcohol agro-industries and mining? Answering this question was the main objective of this study. Therefore, an experiment was set up in the laboratory in a completely randomized design using Polyvinyl Chloride (PVC) columns, in which the 0-50 cm layers of a clayey soil (eutroferric Red Oxisol) and sandy soil (Typic Quartzipsamment) were reproduced. We applied three different rates of basalt powder (0.0; 2.0, and […]

Changes in chemical properties of a latosol by weed management in coffee plantions

Cezar Francisco Araujo-Junior, Paulo Tácito Gontijo Guimarães, Moacir de Souza Dias Junior, Elifas Nunes Alcântara, Aretusa Daniela Resende Mendes


Weed control is one of the most intensive management practices in coffee plantations resulting in changes in soil chemical properties. The objectives of this study were: a) to assess the effects of weed management in a coffee plantation on the chemical properties of a Dystroferric Red Latosol (Oxisol) compared to soil under native forest; b) to verify the relationship between soil organic carbon content (COS) and the effective cation exchange capacity (effective CEC) and the cation exchange capacity at pH […]

Ammonia volatilization following soil application of conventional urea or urea with urease inhibitor

Francis Alex Tasca, Paulo Roberto Ernani, Douglas Antonio Rogeri, Luciano Colpo Gatiboni, Paulo Cézar Cassol


Ammonia volatilization is an important process of N loss which decreases the use efficiency of N by plants when urea is applied on the soil surface. To overcome this problem, some chemical compounds were mixed with urea to inhibit the urease action. The purpose of this study was to compare applications of an alternative fertilizer with urease inhibitor to reduce ammonia volatilization with conventional urea, under certain environmental and soil conditions. Four experiments were carried out in 2007 and 2008, […]

Contribution of soil constituents to the cation exchange capacity as determined by different extraction methods

Edson Campanhola Bortoluzzi, Danilo dos Santos Rheinheimer, Claudia Petry, João Kaminski


The cation exchange capacity (CEC) is a physicochemical property dependent on mineral and organic soil constituents. Despite the use of different procedures and extractors the CEC is normally expressed considering only the pH control or not of the extracted solution. This study aims to discuss the significance of the contribution of organic carbon and clay to the CEC of an Acrisol, using different determination methods. For this purpose, 75 samples of an abruptic Red-Yellow Acrisol from the Universidade Federal de […]

Organic nitrogen mineralization rate following the fifth sewage sludge application in an Oxisol

Rita Carla Boeira, Viviane Cristina Bettanin Maximiliano


In agricultural systems treated with sewage sludge, the management ought to seek an adequate N supply to plants, while avoiding nitrate enrichment because of its potential to pollute subsurface water bodies. Thus, when determining the maximum amounts to be applied to a specific crop, some sewage sludge and soil properties should be known. One is the fraction of organic N of the waste that will be mineralized (NMF) during the crop cycle. This quantity, combined with mineral N in the […]

Nitrogen mineralization after sewage sludge applications to four corn crops

Rita Carla Boeira, Viviane Cristina Bettanin Maximiliano


The available N in sewage sludge-amended soils is one of the restrictive factors for residue application in great amounts. This criterion must be considered in regulations for agricultural use of sewage sludge to avoid environmental pollution of soil and water bodies. The availability of mineral N from native soil organic-N is not considered in the calculation of the maximum rate of sewage sludge application, when these residues are applied for the first time, and this procedure is usual in the […]

Nitrogen doses and sources in marandu pasture. I – changes in soil chemical properties

Kátia Aparecida de Pinho Costa, Valdemar Faquin, Itamar Pereira de Oliveira, Cristiane Rodrigues, Eduardo da Costa Severiano


Nitrogen deficiency is one of the important causes of degradation of cultivated pasture, mainly in the case of Brachiaria pastures. Soil recovery is a way to restore the productive capacity of pastures in degradation. Among nutrients, nitrogen is considered essential and largely responsible for pasture area recovery. The research objective was to evaluate the effects of application of nitrogen doses and sources on marandu grass pasture over a period of three years, based on soil chemical characteristics such as pH, […]

Ammonium and nitrate seasonal and daily fluctuation in a Typical Red Dysthropic Argisol

Naracelis Poletto, Daniel Santos Grohs, Claudio Mario Mundstock


Ammonium and nitrate ions from soil organic N mineralization are the predominant N mineral forms available to plants. The ion ratio and distribution along the soil profile show daily fluctuations and oscillate seasonally. NH4+ and NO3– soil content were evaluated in two adjacent plots, one of them farmed continuously with barley, soybean and barley in a no-tillage system for more than 10 years, with pH 6.0 and fertilized with P and K. A second plot was maintained undisturbed, with native […]

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