59 results

Influence of liming on residual soil respiration and chemical properties in a tropical no-tillage system

Adolfo Valente Marcelo, José Eduardo Corá, Newton La Scala Junior

01/Feb/2012

Because of the climate changes occurring across the planet, especially global warming, the different forms of agricultural soil use have attracted researchers´ attention. Changes in soil management may influence soil respiration and, consequently, C sequestration. The objectives of this study were to evaluate the long-term influence of liming on soil respiration and correlate it with soil chemical properties after two years of liming in a no-tillage system. A randomized complete block design was used with six replications. The experimental treatments […]

Soil properties under native vegetation in Minas Gerais, Brazil: distribution by phytophysiognomy, hydrography and spatial variability

Alba Lucia Araujo Skorupa, Luiz Roberto Guimarães Guilherme, Nilton Curi, Charles Plínio de Castro Silva, José Roberto Soares Scolforo, João José Granate de Sá e Melo Marques

01/Feb/2012

One of the factors affecting the distribution of native vegetation is soil formation. Therefore, soils under native vegetation can be highly informative with regard to a region and the original soil fertility, as records of conditions found before agricultural reclamation (agrosilvopasture). The purpose of this study was to assess soil fertility and texture under native vegetation fragments sampled during the Forest Survey of the State of Minas Gerais, Brazil. In general, the variability in all soil properties was high, except […]

Chemical properties and microbial activity in castings of Chibui bari (Oligochaeta) and surrounding soil

Sergio da Silva Fiuza, Jorge Ferreira Kusdra, Denise Temporim Furtado

01/Jun/2011

Chibui bari is an edaphic oligochaeta from the Amazon region, called “minhocuçu” in view of its large size (length up to 60 cm). Their castings, in tower-shaped mounds with a height of up to 30 cm and dry weight of 2 kg, are common on the soil surface of Acre State. The objective of this study was to compare nutrient availability, organic carbon concentration and microbial activity in Chibui bari castings with soil of the surroundings under secondary forest, rubber […]

Decomposition and nutrient release from millet and sorghum biomass

Michelle Barbosa Teixeira, Arcângelo Loss, Marcos Gervasio Pereira, Carlos Pimentel

01/Jun/2011

Millet can be used as cover crop and enhance nutrient cycling in low-fertility soils. The aim of this study was to evaluate the decomposition rate and nutrient release from shoot residues of millet and sorghum left on the soil surface. The treatments consisted of pearl millet (cultivars ENA 2 and BRS 1501), and sorghum (hybrid BRS 310) plants. After cutting, at the end of the cycle, the shoot samples were placed in decomposition bags distributed on the plot surface. Plant […]

Nitrogen fertilizer use efficiency, recovery and leaching of an alexandergrass pasture

Laércio Ricardo Sartor, Tangriani Simioni Assmann, André Brugnara Soares, Paulo Fernando Adami, Alceu Luiz Assmann, Christiano Santos Rocha Pitta

01/Jun/2011

Nitrogen usually determines the productive potential of forage crops, although it is highly unstable in the environment. Studies on recovery rates and use efficiency are important for more reliable fertilizer recommendations to reduce costs and avoid environmental pollution. The purpose of this study was to evaluate N use efficiency and recovery rate of Alexandergrass pasture (Brachiaria – Syn. Urochloa plantaginea) as well as N-NO3– and N-NH4+ soil concentrations using different levels of N fertilization under two grazing intensities. The experiment […]

Spatial variability of macronutrient contents in untilled oxisols

Luiz Antônio Zanão Júnior, Regina Maria Quintão Lana, Ednaldo Carvalho Guimarães, Josefa Monteiro de Araújo Pereira

01/Apr/2010

The effectiveness of soil sampling plans may be increased if the spatial variability of soil properties is known and taken into consideration; the factors that determine it should therefore be studied. The objective of this paper was to evaluate the spatial variability of the contents P, K, Ca, Mg, and S in two Oxisols, one very clayey and the other with medium texture, managed in a similar system for eight years, in no-tillage. Soil samples were collected at regular distances […]

Spatial variability of soil chemical properties after coffee tree removal

Sidney Rosa Vieira, Osvaldo Guedes Filho, Márcio Koiti Chiba, Heitor Cantarella

01/Oct/2009

Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 […]

Radionuclides and heavy metal contents in phosphogypsum samples in comparison to cerrado soils

Vanusa Maria Feliciano Jacomino, Kerley Alberto Pereira de Oliveira, Maria Helena Tirollo Taddei, Maria Célia Siqueira, Maria Eleonora Deschamps Pires Carneiro, Marcos Roberto Lopes Nascimento, [...]

01/Oct/2009

Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and […]

Chemical and physical attributes of oxisols and their relation with irrigated corn and common bean yields

Telmo Jorge Carneiro Amado, Luciano Zucuni Pes, Claudio Luiz Lemainski, Ricardo Bergamo Schenato

01/Aug/2009

Under irrigated agriculture one of the main causes of yield variability, which is the plant-available water, is controlled. In this case, other yield limitations caused by soil attributes become more relevant. To investigate the spatial variability of soil attributes and crop yields, besides the relation between chemical and physical-hydric soil attributes and crop yields of two irrigated commercial plantations (51.8 and 58.2 ha) were studied in Trindade do Sul (TS) and Palmeira das Missões (PM) respectively, in the state of […]

Evaluating available boron and soybean response to boron in an oxisol from central-western Brazil

Ciro Antonio Rosolem, Leandro Zancanaro, Thaís Bíscaro

01/Dec/2008

Based on field observations it is often impossible to detect differences in soil B contents after the application of B fertilizers, even when increased leaf B contents are detected. This has raised doubts as to the efficacy of the B extractor used in routine soil B determinations. An experiment was conducted to study B extraction and availability to soybean in an Oxisol in the state of Mato Grosso. Boron (as boric acid) doses ranging from 0.0 to 10.0 kg ha-1 […]

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