Least limiting water range and degree of soil compaction of an oxisol after 30 years of no-tillage
01/Jun/2012
The soil physical quality is one of the factors that determine the agronomic, economic and environmental sustainability in long-term no-tillage systems (NT). Soil compaction has been discussed as a factor that contributes to a reduction in physical quality under NT. However, the use of NT can increase soil organic matter and lead to a continuous and stable porous system that mitigates the negative impacts of compaction. The purpose of this study was to evaluate the physical quality of an Oxisol […]
Structural changes in latosols of the cerrado region: I – relationships between soil physical properties and least limiting water range
01/Jun/2011
The agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected […]
Improvement of a testing apparatus for dynamometry: procedures for penetrometry and influence of strain rate to quantify the tensile strength of soil aggregates
01/Apr/2011
Soil penetration resistance (PR) and the tensile strength of aggregates (TS) are commonly used to characterize the physical and structural conditions of agricultural soils. This study aimed to assess the functionality of a dynamometry apparatus by linear speed and position control automation of its mobile base to measure PR and TS. The proposed equipment was used for PR measurement in undisturbed samples of a clayey “Nitossolo Vermelho eutroférrico” (Kandiudalfic Eutrudox) under rubber trees sampled in two positions (within and between […]
Physical properties of a rhodic haplustox under two sugarcane harvesting systems
01/Dec/2010
This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at […]
Relationships between yield of Brachiaria Brizantha and physical properties of a savannah oxisol
01/Aug/2010
Crop-livestock integration can affect soil physical properties, altering the yield and plant composition during the various no-tillage crop cycles. The objective of this study was to select the soil properties with the clearest relationship with yield and crude protein content of Brachiaria brizantha. Linear and spatial correlations were analyzed between dry matter yield and crude protein of Brachiaria brizantha and of some physical properties of a Dystroferric Red Latosol (Oxisol), in three layers (0-0.10; 0.10-0.20; 0.20-0.30 m). A geostatistical grid was […]
Structural quality of soils cultivated with coffee and pasture in an environmental protection area
01/Jun/2010
Studies of soils in Environmental Protection Areas (EPAs) are of great importance, because they are an essential component of ecosystems, directly interfering in environmental sustainability. The objective of this study was to evaluate the structural quality of soil cultivated with coffee and used as pasture in the Capituva’s River microbasin, which is located in the Environmental Protection Area in Coqueiral, south of the state of Minas Gerais. Uniaxial compression test (preconsolidation test) and soil resistance to penetration were used. Undisturbed […]
Changes in hydro- physical attributes of a typic haplustox in the Cerrado of Mato Grosso state under different forms of soil use
01/Oct/2008
The search for production forms that meet the increasing worldwide demands, maintaining the potential of the natural resources and in a systemic view of the social, economic and environmental sustainability, must be everybody’s interest and above all a concern of professionals of agrarian sciences. Aiming at a contribution in this direction, the effect of no-till and cultivated pasture production on the physical and water properties of a Typic Haplustox (Distrophic Red-Yellow Latosol) were evaluated. The study was conducted on a […]
Growth of millet and pigeon pea, performance of citrus trees, and soil physical properties in a chiselled orchard
01/Aug/2008
Chiseling and cover crops can be used in the management of orchards with the purpose of improving soil physical conditions and reducing soil compaction. This study had the objective of evaluating the influence of chiseling on the development of cover crops and citrus trees and on soil physical properties in an orchard with a compaction history in a clayey Typic Haplorthox. The soil was chiseled at 0.30 m, followed by three soil cover crops: spontaneous vegetation, pigeon pea (Cajanus cajan), […]
Efficiency of mechanical and biological chiseling in the improvement of physical attributes of a heavy clay oxisol and the increment of soybean yield
01/Aug/2008
Compaction is one of the main causes of yield decreases in agricultural soils. Mechanical chiseling has been suggested to reduce soil compaction in long-term no-tillage systems. Another option to alleviate soil compaction is the use of cover crops, such as forage radish, with a well-developed tap root system and the capacity of growing into soil compacted layers, forming stable biopores and improving the soil physical properties. This study aimed to evaluate the efficiency of a mechanical (chisel plow) and biological […]
Soil compaction and eucalyptus growth in response to forwarder traffic intensity and load
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, […]