3290 results

Volatilization of ammonia from urea compacted with sulfur and bentonite in a controlled environment

José Antônio de Oliveira, Juliano Bahiense Stafanato, Rosimar de Souza Goulart, Everaldo Zonta, Eduardo Lima, Nelson Mazur, [...]

01/Oct/2014

In recent years, new technologies have been developed to reduce N losses when using urea as a source of this macronutrient. The use of fertilizers with acidic features can reduce ammonia losses from volatilization when combined with urea. The objective of this study was to assess ammonia losses from sources of N with or without coating and/or incorporation of S and bentonite. These fertilizers were applied to the surface of a Haplic Planosol contained in trays (0.1 m2 area and […]

Decomposition and mineralization of N, P and K of cattle manure and poultry litter isolated or mixed

Valéria Borges da Silva, Alexandre Paiva da Silva, Bruno de Oliveira Dias, Josinaldo Lopes Araujo, Djail Santos, Renata Pinto Franco

01/Oct/2014

The use of organic residues in the crop fertilizations demand information about the dynamics of decomposition and release of nutrients contained therein. This study aimed to evaluate the decomposition and release of N, P and K from organic residues cattle manure and poultry litter isolates or mixed, using the method of decomposition bags (litterbag) in Alfissol of Coast Tableland in Paraiba State. The experiment was conducted in randomized block with treatments arranged in a factorial 3 × 2 × 5 […]

Chemical and physical-hydric characterisation of a red latosol after five years of management during the summer between-crop season

José Fausto Guimarães Silva, Eduardo da Costa Severiano, Kátia Aparecida de Pinho Costa, Vinícius de Melo Benites, Wellingthon da Silva Guimarães Júnnyor, José Carlos Bento

01/Oct/2014

Agricultural production systems that include the production of mulch for no-tillage farming and structural improvement of the soil can be considered key measures for agricultural activity in the Cerrado region without causing environmental degradation. In this respect, our work aimed to evaluate the chemical and physical-hydric properties of a dystrophic Red Latosol (Oxisol) in the municipality of Rio Verde, Goias, Brazil, under different soil management systems in the between-crop season of soybean cultivation five years after first planting. The following […]

Aggregate stability by the “high energy moisture characteristic” method in an oxisol under differentiated management

Érika Andressa da Silva, Geraldo César de Oliveira, Bruno Montoani Silva, Carla Eloize Carducci, Junior Cesar Avanzi, Milson Evaldo Serafim

01/Oct/2014

Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, […]

Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

Tales Tiecher, Mohsin Zafar, Fábio Joel Kochem Mallmann, Edson Campanhola Bortoluzzi, Marcos Antonio Bender, Lucas Henrique Ciotti, [...]

01/Oct/2014

Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR) spectroscopy to assess the […]

Macronutrient accumulation and decomposition of brachiaria species as a function of nitrogen fertilization during and after intercropping with corn

Nídia Raquel Costa, Marcelo Andreotti, Salatiér Buzetti, Keny Samejima Mascarenhas Lopes, Fernanda Garcia dos Santos, Cristiano Magalhães Pariz

01/Aug/2014

In regions with a tropical climate, the greatest limitations for straw maintenance on the soil surface are difficulties on its establishment and high rates of decomposition. With the aim of identifying the productive potential of Xaraes and Ruziziensis grasses, as well as subsequent straw formation for continuity of the no-tillage system, the following factors were evaluated: the dry matter yield, the lignin/total N ratio, macronutrient accumulation, and straw decomposition in two growing seasons. The treatments consisted of two Brachiaria species […]

Effect of cropping systems in no-till farming on the quality of a Brazilian Oxisol

Getulio de Freitas Seben Junior, José Eduardo Corá, Rattan Lal

01/Aug/2014

The no-till system with complex cropping sequences may improve the structural quality and carbon (C) sequestration in soils of the tropics. Thus, the objective of this study was to evaluate the effects of cropping sequences after eight years under the no-till system on the physical properties and C sequestration in an Oxisol in the municipality of Jaboticabal, Sao Paulo, Brazil. A randomized split-block design with three replications was used. The treatments were combinations of three summer cropping sequences – corn/corn […]

Changes in a Rhodic Hapludox under no-tillage and urban waste compost in the northwest of Rio Grande do Sul, Brazil

Moacir Tuzzin de Moraes, Vanderlei Rodrigues da Silva, Maurício Roberto Cherubin, Reimar Carlesso, Henrique Debiasi, Renato Levien

01/Aug/2014

The use of urban waste compost as nutrient source in agriculture has been a subject of investigation in Brazil and elsewhere, although the effects on soil physical and chemical properties and processes are still poorly known. The aim of this study was to evaluate the effect of application of urban waste compost and mineral fertilizer on soil aggregate stability and organic carbon and total nitrogen content of a Rhodic Hapludox under no-tillage in the northwestern region of Rio Grande do […]

Soil chemical atributes associated with wheat yield in a plot with different yield potentials

Luiz Fernando Machado Kramer, Marcelo Marques Lopes Müller, Cassio Antônio Tormena, Aline Marques Genú, Leandro Michalovicz, Marcelo Vicensi

01/Aug/2014

Different yield potentials between plots and within them have been verified in areas managed under no-till (NT). Precision farming (PF) techniques can help in identifying these distinct areas, but for efficient soil fertility management in areas under long-term NT, there must be representative sampling. The aim of this study was to evaluate the influence of soil chemical properties on wheat yield in accordance with the sampling layer or depth in an area under long-term NT using zones of a plot […]

Characterization and classification of soils with dark subsurface horizons derived from granite rocks in the Sul-Rio-Grandense Shield, Brazil

Márcio Ramos Botelho, Luiz Fernando Spinelli Pinto, Ana Cláudia Rodrigues de Lima, Márcio Renato Nunes

01/Aug/2014

Dark subsurface horizons with morphological characteristics similar to sombric horizons are found in higher altitude areas of the eastern portion of the Sul-Rio-Grandense Shield, Brazil. They developed in the A2, AB (or AC), and BA horizons of Ultisols, Alfisols, and Entisols. The mechanisms responsible for their genesis are still poorly understood, although most authors agree on the illuvial origin of the humus horizon and on its diagnostic character. The objective of this study was to characterize and analyze nine soil […]

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