401 results

RELATIONSHIP BETWEEN SOIL PHYSICAL AND CHEMICAL PROPERTIES AND YIELD OF GOLDEN GRASS IN THE JALAPÃO REGION, TO, BRAZIL

Helena Maria de Paula Santana, Edson Eyji Sano, Manuel Pereira de Oliveira, Marilusa Pinto Coelho Lacerda, Juaci Vitoria Malaquias

01/Jul/2015

In the Jalapão region, State of Tocantins, Brazil, there are large contiguous areas of Neossolos Quartzarênicos (Tropsamments). Golden grass (Syngonanthus nitens) is a native species widely used as material for handicrafts in the region, and it is therefore of great importance for the local economy. The aim of this study was to analyze the relationship between soil physical and chemical properties and golden grass yield in Campos Limpos Úmidos within Jalapão State Park (Parque Estadual do Jalapão). We collected soil […]

EUCALYPTUS PRODUCTIVITY, SOIL PHYSICAL PROPERTIES AND ORGANIC MATTER FRACTIONS INFLUENCED BY TRAFFIC INTENSITY AND HARVEST RESIDUES

Guilherme Luiz de Jesus, Ivo Ribeiro Silva, Luís Fernando Januário Almeida, Mateus Alves dos Santos, Fernando Palha Leite, Júlio César Lima Neves

01/Jul/2015

The number of machine passes, types of wheels, and high soil moisture during harvest operations affect the soil compaction process. The impacts of these factors and alternatives to reduce them must be better understood. This study evaluated the impact of different traffic intensities of a loaded forwarder and the effect of different management conditions of eucalyptus harvest residues on productivity, soil physical properties, and organic matter at the end of the subsequent rotation in two Oxisols in the State of […]

NITROGEN LOSS BY EROSION FROM MECHANICALLY TILLED AND UNTILLED SOIL UNDER SUCCESSIVE SIMULATED RAINFALLS

Julieta Bramorski, Paulo Cesar Ocheuze Trivelin, Silvio Crestana

01/Jul/2015

The description of the fate of fertilizer-derived nitrogen (N) in agricultural systems is an essential tool to enhance management practices that maximize nutrient use by crops and minimize losses. Soil erosion causes loss of nutrients such as N, causing negative effects on surface and ground water quality, aside from losses in agricultural productivity by soil depletion. Studies correlating the percentage of fertilizer-derived N (FDN) with soil erosion rates and the factors involved in this process are scarce. The losses of […]

TOTAL ORGANIC CARBON AND SOIL AGGREGATION UNDER A NO-TILLAGE AGROECOLOGICAL SYSTEM AND CONVENTIONAL TILLAGE SYSTEM FOR ONION

Arcângelo Loss, Alex Basso, Bruno Salvador Oliveira, Leôncio de Paula Koucher, Rodolfo Assis de Oliveira, Claudinei Kurtz, [...]

01/Jul/2015

As a result of soil management systems, like the conventional tillage system (CTS) versus the no-tillage system (NTS) for vegetable crops, modifications in soil properties occur, which change, for example, the rates of soil aggregation and the content of total organic carbon (TOC). The aim of this study was to quantify the TOC contents and evaluate the rates of soil aggregation and the distribution of aggregates by diameter classes in a soil planted to onion in NTS and CTS and […]

SOIL PHOSPHORUS THRESHOLDS IN EVALUATING RISK OF ENVIRONMENTAL TRANSFER TO SURFACE WATERS IN SANTA CATARINA, BRAZIL

Luciano Colpo Gatiboni, Thomas Jot Smyth, Djalma Eugenio Schmitt, Paulo Cezar Cassol, Clovisson Menotti Boeira de Oliveira

01/Jul/2015

The State of Santa Catarina, Brazil, has agricultural and livestock activities, such as pig farming, that are responsible for adding large amounts of phosphorus (P) to soils. However, a method is required to evaluate the environmental risk of these high soil P levels. One possible method for evaluating the environmental risk of P fertilization, whether organic or mineral, is to establish threshold levels of soil available P, measured by Mehlich-1 extractions, below which there is not a high risk of […]

Phosphorus Fertilization for High Yield of Soybean, Maize, and Winter Cereal Crops in Rotation in Oxisols under Long-Term no-Till in the South Central Region of Parana, Brazil

Renan Costa Beber Vieira, Sandra Mara Vieira Fontoura, Cimélio Bayer, Renato Paulo de Moraes, Eduardo Carniel

01/May/2015

Although the State of Parana, Brazil, has adopted crop rotation and no-till (NT) systems, fertilizer application is still based on recommendations developed more than 30 years ago for monocropping under conventional tillage because fertilizer recommendations developed specifically for crop rotation under NT are lacking. The objective of our study was to consolidate P calibration and evaluate crop responses to P fertilization so as to propose a system of technical recommendations for P fertilization for soybean, maize, wheat, and barley grown […]

Differential Behavior of Young Eucalyptus Clones in Response to Nitrogen Supply

Eric Victor de Oliveira Ferreira, Roberto Ferreira Novais, Greice Leal Pereira, Nairam Félix de Barros, Ivo Ribeiro da Silva

01/May/2015

Eucalyptus requires large amounts of nitrogen (N); however, it responds in diverse manners to the application of this nutrient. The aim of this study was to evaluate the differential performance in growth, mineral nutrition, and gas exchanges of N-fertilized Eucalyptus clones. The treatments consisted of two Eucalyptus clones (VM-01 and I-144) and six N application rates (0, 0.74, 2.93, 4.39, 5.85, and 8 mmol L-1 NH4NO3) arranged in a randomized complete block design with five replications. VM-01 had greater plant […]

Relationship Between Edaphic Factors and Vegetation in Savannas of the Brazilian Midwest Region

Michellia Pereira Soares, Paula Reys, Daniel Salgado Pifano, Janaílson Leônidas de Sá, Patrícia Oliveira da Silva, Thailliny Moraes Santos, [...]

01/May/2015

The Brazilian savanna is a mosaic of phytophysiognomies influenced by edaphic and topographic factors that range from the occurrence of fires to anthropic disturbance. The goal of this study was a comparative analysis between two cerrado areas in southeastern Goiás, relating the floristic composition and structure of the vegetation to soil properties to better understand the physiognomic characteristics of the region. Twenty-five 20 × 20 m plots were used. All plants with circumference at breast height of more than 15 […]

Changes in the Structure of a Nigerian Soil under Different Land Management Practices

Joshua Olalekan Ogunwole, Luiz Fernando Pires, Bello Muhammed Shehu

01/May/2015

Quantification of soil physical quality (SPQ) and pore size distribution (PSD) can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system), and contrast the effects of these practices on the structure of PSD […]

Air Permeability of the Soil Seedbed under a No-Tillage System

Osvaldo Guedes, Alvaro Pires da Silva, Neyde Fabíola Balarezo Giarola, Cássio Antônio Tormena

01/May/2015

Air permeability may be used as a soil physical quality indicator. The objective of this study was to determine the air permeability and pore continuity index for the seedbed of an Oxisol cultivated under a no-tillage system that underwent mechanical chiseling and biological promotion of pore formation using the forage radish crop. The study was carried out in an experimental area of the Universidade Estadual de Ponta Grossa (Ponta Grossa State University), Parana, Brazil. The treatments were 18 consecutive years […]

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