20 results

Soil tillage systems and cover crops in organic production of common bean and corn. II – soil biological properties

Eurâimi de Queiroz Cunha, Luís Fernando Stone, Enderson Petrônio de Brito Ferreira, Agostinho Dirceu Didonet, José Aloísio Alves Moreira, Wilson Mozena Leandro

01/Apr/2011

The influence of cover crops and their management on the maintenance of soil biological quality in areas under organic production should be better understood. This study aimed to determine the influence of the cover crops sunn hemp (Crotalaria juncea), pigeon pea (Cajanus cajan (L.) Millsp), velvet bean (Mucuna aterrima), sorghum (Sorgum technicum), and fallow on biological properties of soil under organic common bean and corn, in no-tillage (NT) and conventional tillage (CT) systems. The study was conducted in Santo Antônio […]

Variation in aggregate-tensile strength as a function of carbon content of two soils in the region of Campos Gerais

Ademir de Oliveira Ferreira, João Carlos de Moraes Sá, Neyde Fabíola Balarezo Giarola, Mônica Gabrielle Harms, Simone Miara, Marina Araujo Bavoso, [...]

01/Apr/2011

Macroscale soil behavior depends on the mechanical properties of individual aggregates. Tensile strength (TS) of soil aggregates has been used as an indicator of management effect on soil quality as related to land use. The objective of this study was to evaluate the change of TS in relation to the variation of soil organic carbon (SOC) content in two soils (Typic Hapludox) with different textures under a long term no-tillage system. The experiment was arranged in a completely randomized 2 […]

Relationship between soil oxidizable carbon and physical, chemical and mineralogical properties of umbric ferralsols

Flávio Adriano Marques, Márcia Regina Calegari, Pablo Vidal-Torrado, Peter Buurman

01/Feb/2011

The occurrence of Umbric Ferralsols with thick umbric epipedons (> 100 cm thickness) in humid Tropical and Subtropical areas is a paradox since the processes of organic matter decomposition in these environments are very efficient. Nevertheless, this soil type has been reported in areas in the Southeast and South of Brazil, and at some places in the Northeast. Aspects of the genesis and paleoenvironmental significance of these Ferralsols still need a better understanding. The processes that made the umbric horizons […]

Pedotransfer functions to estimate proctor test parameters under different tillage systems

Carina Rosa Álvarez, Federico Guillermo Micucci, Carolina Bustingorri, Miguel Angel Taboada

01/Dec/2010

The Proctor test is time-consuming and requires sampling of several kilograms of soil. Proctor test parameters were predicted in Mollisols, Entisols and Vertisols of the Pampean region of Argentina under different management systems. They were estimated from a minimum number of readily available soil properties (soil texture, total organic C) and management (training data set; n = 73). The results were used to generate a soil compaction susceptibility model, which was subsequently validated using a second group of independent data (test data […]

Soil compaction and eucalyptus growth in response to forwarder traffic intensity and load

Sérgio Ricardo da Silva, Nairam Félix de Barros, Liovando Marciano da Costa, Fernando Palha Leite

01/Jun/2008

During timber exploitation in forest stands harvesting machines pass repeatedly along the same track and can cause soil compaction, which leads to soil erosion and restricted tree root growth. The level of soil compaction depends on the number of passes and weight of the wood load. This paper aimed to evaluate soil compaction and eucalyptus growth as affected by the number of passes and wood load of a forwarder. The study was carried out in Santa Maria de Itabira county, […]

Inter-relationships between physical properties and the coefficients of soil water retention curve in an oxisol under different soil use

Jorge Luiz Machado, Cássio Antonio Tormena, Jonez Fidalski, Carlos Alberto Scapim

01/Apr/2008

Practices of soil use and management are based on the physical and hydric soil behavior. Our objective was to evaluate the inter-relationships between physical properties and coefficients of soil water retention curves in an Oxisol under different soil use systems. In 2004, three contiguous areas were selected, covered for over 20 years by forest (native), Brachiaria decumbens (fallow) and annual crops (cultivation). Twenty-five undisturbed soil samples were collected at a depth of 0-0.15 m to determine the soil water retention curves. […]

Carbon stock and carbon dioxide emissions as affected by soil management systems in Southern Brazil

Falberni de Souza Costa, Cimélio Bayer, Josiléia Acordi Zanatta, João Mielniczuk

01/Feb/2008

Carbon (C) addition through crop residues (residue-C), C dioxide emission (CO2-C) and the soil C stock (soil-C) are components of the C cycle in the soil-plant-atmosphere system. This 18-year study was conducted to identify agricultural practices that could potentially increase C retention in the soil and lessen global warming trends. The three C pools (residue-C, CO2-C and soil-C) under different tillage systems (CT-conventional tillage and NT-no tillage) and cropping systems (O/M-oat (Avena strigosa Schreb)/maize (Zea mays L.) and V/M-vetch (Vicia […]

Tensile strength and friability of an Oxisol under different land use systems

Cássio Antonio Tormena, Jonez Fidalski, Waldemar Rossi Junior

01/Feb/2008

Different physical properties are used to evaluate the soil physical quality. In this context, soil tensile strength and friability are indicators of the soil physical and structural quality. The objective of this study was to quantify the tensile strength and friability of an Oxisol under different soil use systems: forest, fallow and cultivated. Soil samples were collected from three contiguous areas of an Experimental Farm of the State University of Maringá. Two areas were cultivated: one with annual crops under […]

Simulation of organic matter dynamics in an Argisol under mineral and organic fertilization with the century model

L. F. C. Leite, E. S. Mendonça, P. L. O. A. Machado

01/Apr/2004

Simulation models are essential instruments to understand soil organic matter dynamics and the turnover of its pools in tropical soils. The objectives of this study were: (a) simulate the effects of maize production systems under organic and mineral fertilization on soil organic matter dynamics of an Ultisol using the Century model; (b) to compare total carbon (TOC) and total nitrogen stocks (TN) and the carbon pools (C) measured in the laboratory and estimated by the Century model for the surface […]

Soil properties and root system after four years of direct drilling of winter growing forage on a native grassfield dissected with herbicides

E. Pérez Gomar, J. M. Reichert, D. J. Reinert, F. García

01/Mar/2002

Natural grassfields developed on sandy soils from Northern Uruguay are formed by communities of forage species, composed mainly of seasonal growing grasses, with low biomass production during the fall/winter period. The objective of this study was to evaluate the effect of herbicides, applied on native grassfield to established winter forage species, on soil properties and root biomass. This experiment began in 1994 and was established as a complete block design, with three replications. In the main plots, to establish winter-growing […]

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