3290 results

Nutrition, dry matter accumulation and partitioning and phosphorus use efficiency of potato grown at different phosphorus levels in nutrient solution

Adalton Mazetti Fernandes, Rogério Peres Soratto

01/Nov/2012

High rates of phosphate fertilizers are applied to potato (Solanum tuberosum L.), which may cause antagonistic interactions with other nutrients and limit crop yields when over-supplied. The purpose of this study was to evaluate the influence of phosphorus (P) levels in nutrient solution on P use efficiency, nutritional status and dry matter (DM) accumulation and partitioning of potato plants cv. Ágata. The experiment was carried out in a greenhouse, arranged in a completely randomized block design with four replications. Treatments […]

Sulfur in agriculture

Adriano Reis Lucheta, Marcio Rodrigues Lambais

01/Nov/2012

Sulfur (S) deficiency in soils is becoming increasingly common in many areas of the world as a result of agronomic practices, high biomass exportation and reduced S emissions to the atmosphere. In this review, the incidence and commercial exploitation of S pools in nature are discussed, as well as the importance of S for plants and the organic and inorganic S forms in soil and their transformations, especially the process of microbiological oxidation of elemental sulfur (S0) as an alternative […]

Nodulation and nitrogen fixation efficiency of cowpea as affected by inoculum rate

Maria de Fátima da Silva, Carolina Etienne de Rosália e Silva Santos, Clayton Albuquerque de Sousa, Renata de Souza Leão Araújo, Newton Pereira Stamford, Márcia do Vale Barreto Figueiredo

01/Nov/2012

Cowpea (Vigna unguiculata (L.) Walp.) can obtain sufficient N for its own supply from the atmosphere, by the process of biological nitrogen fixation (FBN), when associated with specific and effective rhizobia bacteria. The purpose of this study was to evaluate the effect of different rhizobia inoculum rates on nodulation and biological N fixation by cowpea (cv. BRS Pujante). A complete randomized block design with seven treatments and four replicates was used. The trial was conducted in a greenhouse using 2 […]

Estimating subsoil resistance to nitrate leaching from easily measurable pedological properties

Fábio Keiti Nakagawa, Gabriel Benjamin Siqueira Forti, Marcelo Eduardo Alves, Arquimedes Lavorenti, Jarbas Honório de Miranda

01/Nov/2012

Leaching of nitrate (NO3–) can increase the groundwater concentration of this anion and reduce the agronomical effectiveness of nitrogen fertilizers. The main soil property inversely related to NO3– leaching is the anion exchange capacity (AEC), whose determination is however too time-consuming for being carried out in soil testing laboratories. For this reason, this study evaluated if more easily measurable soil properties could be used to estimate the resistance of subsoils to NO3– leaching. Samples from the subsurface layer (20-40 cm) […]

Carbon and nitrogen stocks in soil under castor bean in the semi-arid Caatinga of Brazil

Felipe José Cury Fracetto, Giselle Gomes Monteiro Fracetto, Carlos Clemente Cerri, Brigitte Josefine Feigl, Marcos Siqueira Neto

01/Nov/2012

Much of the Brazilian castor bean (Ricinus communis L.) production is concentrated in the semi-arid region (Caatinga biome) of the Northeast, as an alternative crop. The purpose of this study was to evaluate changes in C and N pools due to land use change in the Caatinga biome by castor bean production. The study was conducted on the Fazenda Floresta in the municipality of Irecê (Mid -North region of Bahia, Brazil). The climate is type BSwh (Koppen) – Semi-arid climate. […]

Micromorphology of spodic horizons of the restinga region of São Paulo State

Maurício Rizzato Coelho, Vanda Moreira Martins, Xosé Luiz Otero Pérez, Felipe Macías Vázquez, Felipe Haenel Gomes, Miguel Cooper, [...]

01/Nov/2012

The soils, especially the Spodosols, of the “restinga”, a coastal plain, are poorly studied and understood in Brazil. In this work, the micromorphology of spodic horizons was investigated at four sites of the coastal plain of the State of São Paulo (Bertioga, Ilha de Cananeia, Ilha do Cardoso, and Ilha Comprida). This allowed the characterization of different organic matter forms.  These data, together with macromorphology, were used in the analysis of the main processes involved in the genesis of spodic […]

Soil quality index associated to the groundwater recharge (SQIGR) in the Upper Rio Grande Basin, Minas Gerais

Camila Cristina Alvarenga, Carlos Rogério de Mello, José Marcio de Mello, Antônio Marciano da Silva, Nilton Curi

01/Nov/2012

In the last years, soil quality indexes for analyses of the environmental sustainability and agricultural production have been proposed in increasing numbers. However, none of these indexes is related to the groundwater recharge soil quality index for conditions in Brazil. The objective of this study was to generate a soil quality index related to the groundwater recharge (SQIGR) of the physiographical conditions of the Upper Rio Grande Basin and to draw a map of SQIGR using geostatistical procedures. The proposed […]

Soil physical properties and rice straw levels in management systems: effect on irrigated rice yield

Amauri Nelson Beutler, Janete Denardi Munareto, Cleiton José Ramão, Leandro Galon, Naimã Pinto Dias, Bruna Canabarro Pozzebon, [...]

01/Nov/2012

The State of Rio Grande do Sul is the greatest producer of flooded rice of Brazil, concentrated mostly along the western border. The objective was to evaluate soil physical properties and flooded rice yield in no-till and conventional tillage systems and rice straw levels in no-till system. The study consisted of four experiments (E), laid out in experimental design was completely randomized blocks, with four experiments (E) and 10 repetitions in experiment 1, 2 and 3 and 6 in experiment […]

Integration of ruler to measure depth in the design of a Stolf impact penetrometer

Rubismar Stolf, Jorge Hiroshi Murakami, Miguel Angelo Maniero, Marcio Roberto Soares, Luiz Carlos Ferreira da Silva

01/Nov/2012

The Stolf impact penetrometer is a dynamic cone penetrometer to measure soil resistance, in use since its release in 1982. In the original design, a centimeter scale to measure penetration depth was engraved on the proper penetration rod. The idea was to make the equipment easier to understand for farmers and to allow direct readings on the penetration rod while also avoiding additional parts. The purpose of this study was to incorporate a millimeter ruler to enable the operator to […]

Physical quality of Oxisols under no-tillage in the Savanna region of Piaui

Rossanna Barbosa Pragana, Mateus Rosas Ribeiro, Júlio César Azevedo Nóbrega, Mateus Rosas Ribeiro Filho, Juliana Alves da Costa

01/Nov/2012

The Cerrado is being increasingly exploited in production systems characterized by intensive land use, without due concern for the preservation of natural resources. The objective of this research was to evaluate the effect of no-tillage soybean on the physical properties of Oxisols. The study was carried out in the region of “Serra do Quilombo”, located in the Cerrado region of the State of Piauí.  To assess changes in soil properties caused by agricultural use, soil samples were collected from conventional […]

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