PHYSICAL PROPERTIES OF AN OXISOL WITH COVER CROPS IN NO-TILLAGE
01/Mar/2015
The use of no-tillage systems associated with the use of cover crops and crop rotation changes some soil physical properties and may indicate change in soil quality. This study aimed to use the aggregate stability index (IEA) and the sensitivity index (SI) to assess changes in soil physical attributes with the use of different plant cover after twelve years of no-tillage. We used a randomized block design with the following types of cover crops: sunn hemp, millet, sorghum, brachiaria, and […]
Aggregate stability by the “high energy moisture characteristic” method in an oxisol under differentiated management
01/Oct/2014
Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, […]
Physical quality of an Oxisol after different periods of management systems
01/Dec/2013
Management systems may lead to a loss of soil physical quality as a result of removal of the plant cover and excessive agricultural mechanization. The hypothesis of this study was that the soil aggregate stability, bulk density, macro- and microporosity, and the S index and saturated hydraulic conductivity may be used as indicators of the soil physical quality. The aim was to study the effects of different periods and managements on the physical attributes of a medium-textured Red Oxisol under […]
Soil physicall and chemical properties under different uses of marshland
01/Aug/2013
The substitution of the native vegetation of marshlands in Paraiba, initially by sugarcane and more recently by pastures, in a strongly undulated relief, has caused serious problems of soil degradation. Currently, some of these pastures are being replaced by plantations of sabiá (Mimosa caesalpiniaefolia Benth). The objective was to analyze the effect of these changes on the soil physical and chemical properties and root development. The experiment was conducted in Areia-PB, in a dystrophic Ultisol. The three treatments were represented […]
Structure quality of an oxisol submitted to compaction
01/Jun/2013
The structure change caused by soil compaction is a limiting factor to growth and development of plants. The objective of this study was to evaluate the physical parameters of an Eutrophic Oxisol in Jaboticabal, SP. Aggregate stability, hydraulic conductivity and “S” index were evaluated in a completely randomized split-plot (four levels of compaction and two depth), with four replications and an area of native forest (NF) as control. The compaction treatments consisted of C0 = 0, C1 = 2, C2= […]
Morphology and stability of soil aggregates in a red yellow argisol under different management long-term and secondary atlantic forest
01/Dec/2011
Long-term experiments testing different soil managements provide valuable information in the comparison of alterations in physical, chemical and biological soil properties with soil under natural vegetation. This long-term study was carried out to evaluate the external morphology and the stability of aggregates in the surface layer of a Yellowish-Red Argisol under different managements for comparison with secondary Atlantic Forest. Disturbed and undisturbed soil samples were collected from the 0-5 cm layer from soil under no-tillage (PD) and disk plow + […]
Content of soil organic carbon in albaqualf soil: influence of irrigated rice management
01/Oct/2011
On paddy soils in the southern region of the State of Rio Grande do Sul, Brazil, irrigated (flooded) rice is grown on 1´000´000 ha, under different soil management systems. The influence of poor drainage and alternating oxidation and reduction cycles on the content of soil organic carbon is still poorly understood. This long-term study (21 years) was conducted in Capão do Leão, RS, Brazil, to evaluate the effect of irrigated rice management systems on soil organic carbon stocks and physical […]
Aggregate stability as affected by short and long-term tillage systems and nutrient sources of a hapludox in southern Brazil
01/Aug/2009
The ability of a soil to keep its structure under the erosive action of water is usually high in natural conditions and decreases under frequent and intensive cultivation. The effect of five tillage systems (NT = no-till; CP = chisel plowing and one secondary disking; CT = primary and two secondary distings; CTb = CT with crop residue burning; and CTr = CT with removal of crop residues from the field), combined with five nutrient sources (C = control, no […]
Oxisol physical attributes affected by surface application of flue dust, aqueous lime, sewage sludges and limestone
01/Apr/2009
The residues flue dust, aqueous lime and sewage sludge (centrifuge and biodigestor) may affect soil physical attributes. The use of industrial and urban residues in soil, with emphasis to sewage sludge, was done in tilled soil, and there are no repports on soil physical attributes affected by these residues on soil surface in no-till system The goal of this study was to evaluate the physical attributes of a an Oxisol in no-till system by surface dispoasal of sewage sludge, flue […]
Humic substances, microbial activity and labile organic carbon in aggregates of a Dystrophic Red Latosol under two vegetation covers
01/Oct/2007
Organic matter is an indicator of the soil quality. Knowledge about its different components, explaining the influence of management practices on organic matter and soil aggregation, is essential for the sustainability of agricultural systems. In the present work, we evaluated humic substances, microbial activity and labile organic carbon in a Dystrophic Red Latosol from Minas Gerais state, Brazil, under natural vegetation (Cerradão) or under 30-years of conventional corn cultivation. Soil samples were collected from depths of 5-10 and 15-20 cm […]