3290 results

Nutrient uptake and chemical changes in Oxisols planted to cover crops in rotation with soybean and corn

Wander Luis Barbosa Borges, Rogério Soares de Freitas, Gustavo Pavan Mateus, Marco Eustáquio de Sá, Marlene Cristina Alves

01/Feb/2014

The effects on soil chemical properties brought about by cover crops vary considerably. This study was conducted to evaluate nutrient uptake by five cover crops used for grain, seed and forage production at different seed densities per hectare, as well as uptake by spontaneous vegetation, and their effect on the chemical properties of two Oxisols when grown in rotation with soybean and corn. The experiments were set up in Votuporanga, SP, Brazil and Selvíria, MS, Brazil in March 2008 after […]

Rice straw incorporated just before soil flooding increases acetic acid formation and decreases available nitrogen

Ronaldir Knoblauch, Paulo Roberto Ernani, Francisco Carlos Deschamps, Luciano Colpo Gatiboni, Timothy Wayne Walker, Késia Silva Lourenço, [...]

01/Feb/2014

Incorporation of rice straw into the soil just before flooding for water-seeded rice can immobilize mineral nitrogen (N) and lead to the production of acetic acid harmful to the rice seedlings, which negatively affects grain yield. This study aimed to evaluate the formation of organic acids and variation in pH and to quantify the mineral N concentration in the soil as a function of different times of incorporation of rice straw or of ashes from burning the straw before flooding. […]

Soil aggregation and organic carbon of Oxisols under coffee in agroforestry systems

Gabriel Pinto Guimarães, Eduardo de Sá Mendonça, Renato Ribeiro Passos, Felipe Vaz Andrade

01/Feb/2014

Intensive land use can lead to a loss of soil physical quality with negative impacts on soil aggregates, resistance to root penetration, porosity, and bulk density. Organic and agroforestry management systems can represent sustainable, well-balanced alternatives in the agroecosystem for promoting a greater input of organic matter than the conventional system. Based on the hypothesis that an increased input of organic matter improves soil physical quality, this study aimed to evaluate the impact of coffee production systems on soil physical […]

Dry matter and macronutrient accumulation in fruits of Conilon coffee with different ripening cycles

Fábio Luiz Partelli, Marcelo Curitiba Espindula, Wellington Braida Marré, Henrique Duarte Vieira

01/Feb/2014

The period between anthesis and fruit ripening varies according to the Conilon coffee (Coffea canephora) genotype. Therefore, the time of the nutritional requirements for fruit formation may differ, depending on the formation phase and the genotype, and may directly affect split application of fertilizer. The aim of this study was to quantify the accumulation of dry matter and N, P, K, Ca, Mg and S at several stages in the fruit of the Conilon coffee genotype with different ripening cycles, […]

Estimation of water percolation by different methods using TDR

Alisson Jadavi Pereira da Silva, Eugênio Ferreira Coelho

01/Feb/2014

Detailed knowledge on water percolation into the soil in irrigated areas is fundamental for solving problems of drainage, pollution and the recharge of underground aquifers. The aim of this study was to evaluate the percolation estimated by time-domain-reflectometry (TDR) in a drainage lysimeter. We used Darcy’s law with K(θ) functions determined by field and laboratory methods and by the change in water storage in the soil profile at 16 points of moisture measurement at different time intervals. A sandy clay […]

Effects of traffic control on the soil physical quality and the cultivation of sugarcane

Gustavo Soares de Souza, Zigomar Menezes de Souza, Reginaldo Barboza da Silva, Ronny Sobreira Barbosa, Fernando Silva Araújo

01/Feb/2014

The cultivation of sugarcane with intensive use of machinery, especially for harvest, induces soil compaction, affecting the crop development. The control of agricultural traffic is an alternative of management in the sector, with a view to preserve the soil physical quality, resulting in increased sugarcane root growth, productivity and technological quality. The objective of this study was to evaluate the physical quality of an Oxisol with and without control traffic and the resulting effects on sugarcane root development, productivity and […]

Perennial grasses for recovery of the aggregation capacity of a reconstructed soil in a coal mining area in southern Brazil

Lizete Stumpf, Eloy Antonio Pauletto, Flavia Fontana Fernandes, Luis Eduardo Akiyoshi Sanches Suzuki, Tiago Stumpf da Silva, Luiz Fernando Spinelli Pinto, [...]

01/Feb/2014

The construction of a soil after surface coal mining involves heavy machinery traffic during the topographic regeneration of the area, resulting in compaction of the relocated soil layers. This leads to problems with water infiltration and redistribution along the new profile, causing water erosion and consequently hampering the revegetation of the reconstructed soil. The planting of species useful in the process of soil decompaction is a promising strategy for the recovery of the soil structural quality. This study investigated the […]

Iron oxidation on the surface of adventitious roots and its relation to aerenchyma formation in rice genotypes

Marquel Jonas Holzschuh, Filipe Selau Carlos, Felipe de Campos Carmona, Humberto Bohnen, Ibanor Anghinoni

01/Feb/2014

Establishment of the water layer in an irrigated rice crop leads to consumption of free oxygen in the soil which enters in a chemical reduction process mediated by anaerobic microorganisms, changing the crop environment. To maintain optimal growth in an environment without O2, rice plants develop pore spaces (aerenchyma) that allow O2 transport from air to the roots. Carrying capacity is determined by the rice genome and it may vary among cultivars. Plants that have higher capacity for formation of […]

Genotypic variability in seed accumulation of foliar-applied molybdenum to common bean

Rogério Faria Vieira, Trazilbo José de Paula Júnior, José Eustáquio de Souza Carneiro, Marina Viana Queiroz

01/Feb/2014

The genotypic variability in molybdenum (Mo) accumulation in common bean seeds has been demonstrated in cases in which soil is the main Mo source, but this variability is yet unknown when Mo is foliar-applied. Therefore, seed Mo concentrations (SMoCc) and seed Mo contents (SMoCt) of 12 genotypes were determined in four experiments in the Zona da Mata, Minas Gerais, Brazil, in which plants were sprayed with 600 g ha-1 Mo. For comparison, two additional experiments without external Mo were conducted. […]

Mineral assemblage of soils developed from different lithologies in southern Minas Gerais, Brazil

Marla Alessandra Araujo, Alessandro Vitor Pedroso, Douglas Carvalho Amaral, Yuri Lopes Zinn

01/Feb/2014

Systematic studies on of soil formation factors are relatively scarce in Brazil since comprehensive samplings of a variable factor while keeping others constant are difficult to perform. Near Lavras, Minas Gerais, there is wide geological diversity over a small area, which offers a chance to assess the control exerted by different lithologies on mineral suites and other soil properties. Thus, eight soils overlying quartzite, mica-schist, gabbro, itabirite, serpentinite, meta-limestone, gneiss and phyllite, under similar climate and tropical, semideciduous forest conditions […]

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