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Biometric Responses of Soybean to Different Potassium Fertilization Management Practices in Years with High and Low Precipitation

Michel Esper Neto, Evandro Antonio Minato, Marcos Renan Besen, Tadeu Takeyoshi Inoue, Marcelo Augusto Batista


ABSTRACT Brazilian soybean producers commonly apply maintenance potassium (K) fertilization during cultivation to restore the K taken up by plants; however, this measure can modify the morphophysiological plant characteristics, since the functions of K are closely related with plant growth and development. This study assessed the morphological changes in soybean plants in response to K rates, sowing fertilization, and the application periods of K fertilization in a Latossolo Vermelho eutroférrico (Oxisol) under a no-tillage system, located in the municipality of […]

Is Composting a Route to Solubilize Low-Grade Phosphate Rocks and Improve MAP-Based Composts?

Henrique José Guimarães Moreira Maluf, Carlos Alberto Silva, Everton Geraldo de Morais, Leonardo Henrique Duarte de Paula


ABSTRACT: In alkalinized and Ca-rich composts, solubilization of apatite from phosphate rocks (PRs) is not guaranteed; however, chelating agents and humified substances produced during composting may alter the soluble contents and P forms of monoammonium phosphate (MAP)-based composts. These effects may depend on the proportions of organic wastes and P source used in the compost piles. The aim of this study was to evaluate the effect of composting chicken manure, coffee husk, and Araxá PR, Bayóvar PR, or MAP in […]

Nutrient Release, Plant Nutrition, and Potassium Leaching from Polymer-Coated Fertilizer

Henrique Bley, Clesio Gianello, Lenio da Silva Santos, Lisiane Priscila Roldão Selau


ABSTRACT The increase in food consumption and limitations in food production areas requires improved fertilizer efficiency. Slow- or controlled-release fertilizers are an alternative for synchronizing nutrient availability with the plant demands, reducing losses to the environment. The aim of this study was to evaluate the efficacy of polymer-coated KCl compared with conventional KCl. The products were incubated in soil under controlled conditions to evaluate the time required for nutrient release. A greenhouse experiment was performed with corn plants in pots […]

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 […]

Addition of Urease Inhibitor Has No Effect on Ammonia Volatilization Following Soil Application of Poultry Litter or Organomineral Fertilizer, Unlike Urea

Késia Silva Lourenço, Paulo Roberto Ernani, Juliano Corulli Corrêa, Sulian Junkes Dal Molin, Lucas Silva Lourenço


ABSTRACT Quantification of ammonia volatilization after addition of animal residues and nitrogen (N) mineral fertilizers to the soil is important for N management in fertilization programs. The objective of this study was to evaluate the effect of adding a urease inhibitor to N fertilizers to minimize ammonia losses following soil application. The experiment was carried out in a laboratory with samples of a Brazilian Oxisol containing 790 g kg-1 clay and 23 g kg-1 organic matter. Treatments consisted of addition […]

Soil Solution Nutrient Availability, Nutritional Status and Yield of Corn Grown in a Typic Hapludox under Twelve Years of Pig Slurry Fertilizations

Marco André Grohskopf, Paulo Cezar Cassol, Juliano Corulli Corrêa, Jackson Adriano Albuquerque, Paulo Roberto Ernani, Maria Sueli Heberle Mafra, [...]


ABSTRACT Nutrient content in soil solution may vary in response to the applied amount of pig slurry (PS). Thus, the aim of this research was to evaluate the nutrient content in soil solution and its relationship to nutritional status and yield of corn under 12 years of annual fertilization with increasing doses of PS, soluble mineral fertilizer (MF) and PS combined with MF. The experiment was conducted under field conditions in a Latossolo Vermelho Distroférrico (Typic Hapludox). The treatments consisted […]

Effectiveness of Five Biosolids as Nitrogen Sources to Produce Single and Cumulative Ryegrass Harvests in Two Australian Soils

Rodrigo Studart Corrêa, Douglas José da Silva


ABSTRACT Biosolids have been produced by various stabilization processes of sewage sludge, but little attention has been given to the effects of such treatments on their effectiveness to supply nitrogen for plant growth. Here, we investigated these effects by cultivating Lolium perenne (ryegrass) in two Australian soils, a sandy Spodosol and a clayey Oxisol. Biosolids stabilized by either aerobic digestion, composting, CaO-liming, 250 oC heat-drying or solar irradiation of domestic sewage sludge were applied to soils at 10 increasing rates […]

Characterization of Ornamental Rock Residue and Potassium Liberation Via Organic Acid Application

Ramires Ventura Machado, Felipe Vaz Andrade, Renato Ribeiro Passos, Roberto Carlos da Conceição Ribeiro, Eduardo Sá Mendonça, Luiz Felipe Mesquita


ABSTRACT Organic acids present in organic matter and, or, exudates by microorganisms and plants can increase the liberation of potassium present in minerals. The objective of this study was to characterize the residue from ornamental rocks and evaluate the release of K from these residues after the application of organic acids. The experiment was conducted under laboratory conditions and followed a 2 × 3 × 5 factorial design with three replicates. The studied factors were: two organic acids (citric acid […]


Maik Barbosa Rodrighero, Gabriel Barth, Eduardo Fávero Caires


ABSTRACT To reduce acidity in no-till systems, lime is broadcast on the soil surface without incorporation. Two experiments were carried out, one in a clayey Latossolo Vermelho Distrófico (Rhodic Hapludox) and another in a sandy loam Neossolo Litólico Húmico (Lithic Hapludoll), to test the hypothesis that the source and particle size of lime influence soil reaction in the short term, and crop response to surface liming under a no-till system. A randomized complete block design was used in a 2 […]


Fernando Viero, Cimélio Bayer, Renan Costa Beber Vieira, Eduardo Carniel


ABSTRACT Nitrogen losses by ammonia (NH3) volatilization can be reduced by appropriate irrigation management or by alternative N sources, replacing urea. The objective of this study was to evaluate the efficiency of irrigation management and N source combinations in decreasing NH3 volatilization from an Argissolo Vermelho Distrófico típico cultivated for 28 years with black oat (Avena strigosa) and maize (Zea mays), under no-tillage in the region of Depressão Central, Rio Grande do Sul, Brazil. The experiment was arranged in a […]

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