3312 results

Mineralization of organic phosphorus in soil size fractions under different vegetation covers in the north of Rio de Janeiro

Joice Cleide de Oliveira Rita, Antonio Carlos Gama-Rodrigues, Emanuela Forestieri Gama-Rodrigues, Francisco Costa Zaia, Danielle Aparecida Duarte Nunes

01/Oct/2013

In unfertilized, highly weathered tropical soils, phosphorus (P) availability to plants is dependent on the mineralization of organic P (Po) compounds. The objective of this study was to estimate the mineralization of total and labile Po in soil size fractions of > 2.0, 2.0-0.25 and < 0.25 mm under leguminous forest tree species, pasture and “capoeira” (secondary forest) in the 0-10 cm layer of a Red-Yellow Latosol after 90 d of incubation. The type of vegetation cover, soil incubation time […]

Photosynthesis rate, chlorophyll content and initial development of physic nut without micronutrient fertilization

Elcio Ferreira dos Santos, Bruno José Zanchim, Aline Grella de Campos, Raphael Florencio Garrone, José Lavres Junior

01/Oct/2013

Few studies in Brazil have addressed the need for micronutrients of physic nut focusing on physiological responses, especially in terms of photosynthesis. The objective of this study was to evaluate the effects of omission of boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) on Jatropha curcas L.. The experimental design was a randomized block with four replications. The treatments were complete solution (control) and solution without B, Cu, Fe, Mn, and Zn. We evaluated the chlorophyll content […]

Wheat yield and physical properties of a brown latosol under no-tillage in south-central Paraná

Luiz Fernando Machado Kramer, Marcelo Marques Lopes Müller, Cássio Antônio Tormena, Leandro Michalovicz, Ronaldo do Nascimento, Marcelo Vicensi

01/Oct/2013

Soil management influences the chemical and physical properties of soil. Chemical conditions have been thoroughly studied, while the role of soil physical conditions regarding crop yield has been neglected. This study aimed to analyze the wheat yield and its relationship with physical properties of an Oxisol under no-tillage (NT). The study was carried out between 2010 and 2011, in Reserva do Iguaçu, State of Paraná, Brazil, on the Campo Bonito farm, after 25 years of NT management. Based on harvest […]

The impact of water management on iron toxicity in flooded rice

Fabiana Schmidt, Magali de Ávila Fortes, Jonas Wesz, Gerson Lubke Buss, Rogério Oliveira de Sousa

01/Oct/2013

Iron toxicity is recognized as the most widely distributed nutritional disorder in flooded and irrigated rice (Oryza sativa L.), derived from the excessive amounts of ferrous ions (Fe 2+) generated by the reduction of iron oxides. The effects of water management on the redox potential of a flooded Albaqualf soil and on iron toxicity symptoms in rice were evaluated in a greenhouse experiment. Treatments were arranged in a randomized complete block design with four replications, and consisted of five water […]

Leaching transport of naphthalene in urban soils from the metropolitan region of Recife, PE

André Inácio do Carmo, Antônio Celso Dantas Antonino, Jean Manuel Fonseca Martins, Valdinete Lins da Silva, Marie Christine Morel, Jean Paul Gaudet

01/Oct/2013

The main soil properties related to the leaching of naphthalene in soils are particle size, organic matter content and the mineralogical composition of silt and clay fractions. The aim of this study was to evaluate naphtalene reactive transfer in soil columns determinated by the dispersion and retardation of naphthalene in soil samples collected from the surroundings of fuel storage tanks in Recife, Brazil. Leaching experiments were carried out in columns containing disturbed soils and were modeled using the convection-dispersion equation, […]

Accumulation of phosphorus fractions and contamination potential in vineyard soils in the southern region of the state of Santa Catarina, Brazil

Djalma Eugênio Schmitt, Jucinei José Comin, Carlos Alberto Ceretta, Luciano Colpo Gatiboni, Tales Tiecher, Felipe Lorensini, [...]

01/Oct/2013

In vineyards, if phosphate is applied both before planting and at intervals during growth without consideration of technical criteria, the soil P fractions may be increased and their proportions altered. This study was carried out to evaluate the accumulation of P fractions and the parameters of the adsorption isotherm in a sandy Typic Hapludalf soil in vineyards with a history of successive and excessive phosphate fertilization. In December 2010, two vineyards were selected, one 4 and the other 15 years […]

Optical crop sensor for variable-rate nitrogen fertilization in corn: II – indices of fertilizer efficiency and corn yield

Jardes Bragagnolo, Telmo Jorge Carneiro Amado, Rodrigo da Silveira Nicoloso, Antônio Luis Santi, Jackson Ernani Fiorin, Fabiano Tabaldi

01/Oct/2013

Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N) fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF), based on optical spectrometry crop sensors, could increase the N use efficiency (NUE). The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF). With this purpose, three experiments […]

Soil physical properties under maize in monoculture or intercropped with summer legumes

Emerson Dalla Chieza, Thomé Lovato, Ednaldo Da Silva Araújo, Jonatan Tonin

01/Oct/2013

The use of cover crops is a practice that can improve the physical quality of soils. The objective of this work was to evaluate the potential of intercropping of summer legumes with maize to improve soil physical properties. The study was conducted in the field from September 2008 to September 2009, in an Ultisol in Santa Maria, Rio Grande do Sul. The experiment was arranged in a randomized block design with five treatments and four replications. The treatments consisted of […]

Effect of brushwood transposition on the leaf litter arthropod fauna in a cerrado area

Paula Cristina Benetton Vergílio, Fátima do Rosário Naschenveng Knoll, Daniela da Silva Mariano, Nágila Maiara Dinardi, Marcos Yukio Ueda, Osmar Cavassan

01/Oct/2013

The results of ecological restoration techniques can be monitored through biological indicators of soil quality such as the leaf litter arthropod fauna. This study aimed to determine the immediate effect of brushwood transposition transferred from an area of native vegetation to a disturbed area, on the leaf litter arthropod fauna in a degraded cerrado area. The arthropod fauna of four areas was compared: a degraded area with signal grass, two experimental brushwood transposition areas, with and without castor oil plants, […]

Optimization of the sampling scheme for maps of physical and chemical properties estimated by kriging

Gener Tadeu Pereira, Zigomar Menezes de Souza, Daniel De Bortoli Teixeira, Rafael Montanari, José Marques Júnior

01/Oct/2013

The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 […]

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