Soil organic matter is constituted by a vast array of compounds that include active and more stable fractions, with different cycling rates. Management practices affect organic carbon and nitrogen contents, organic matter quality, and soil aggregation. The present study aimed to characterize organic carbon and nitrogen in aggregates of a Dystrophic Red Latosol of Minas Gerais State, Brazil, in an area of native vegetation (Cerradão) and another one that has been for 30 years under conventional corn cultivation. Soil samples […]

The improvement in the structural soil quality under continuous no-tillage occurs concomitantly to soil (re)acidification. Surface compaction can sometimes occur, owing to machinery traffic, which has to be corrected by soil tilling. In a 12-year experiment under different soil management systems we evaluated the time it takes to recover the initial soil physical attributes that are affected by soil tillage by the occasion of lime reapplication. The experiment was set up on a Rhodic Paleudult (Ultisol) at the Agronomical Experimental […]

The no-tillage system improves the structural soil quality. However, machinery traffic can cause surface soil compaction. In this situation, soil tilling for lime incorporation not only corrects soil acidity problems, but also decreases possible negative effects of soil compaction. The effects of tilling or not tilling the soil at the moment of lime reapplication on physical attributes in the soil profile and crop yields under different soil management systems were therefore evaluated. A long-term experiment was conducted on a Rhodic […]

Soil degradation under cultivation results mainly from the inadequate management and it reflects in low crop yields. With the purpose of evaluating the effect of legumes on physical attributes and organic carbon content of an Alfisol, an experiment was conducted in the Alagoinha County-PB, Brazil, between 1997 and 1999, with the following species: Crotalaria juncea L, Cajanus cajan L, Cajanus cajan (L) Millsp, Calopogonium mucunoides L, Canavalia ensiforme L, Dolichos lab lab L, Pueraria phaseoloides L, Macroptilium atropurpureum L, Leucaena […]

The input of organic compounds in agriculture and the soil wetting and drying cycles have a strong influence on soil aggregation. This study investigated the effect of incubation periods and the influence of wetting and drying cycles with the addition of organic compounds of distinct hydrophobic and hydrophilic characteristics on the aggregation of a Red-Yellow Latosol. The experiments were arranged in an incomplete factorial design 2 x 3[(4-1) + (4-1)]. The factors were: air-dried soil of A and B horizons, three incubation periods (40, […]

A greenhouse experiment was conducted to examine the structural modifications engendered by wetting-drying cycles in Latosol samples (Oxisols) with different mineralogical properties submitted to dry grinding, compared with bulk samples. Air-dried soil samples were sieved through a 1.00 mm sieve and separated in two groups. One was kept as control group and the other ground in a mortar and sieved through a 0.105 mm sieve. This second was also split in two groups, one of which received particulate humic acid […]

The wetland soils in the state of Rio Grande do Sul present wide variation in their morphological, physical, chemical and mineralogical characteristics due to the heterogeneity of the parent material and different degrees of hydromorphism. Since their main uses for flooded rice and cattle breeding are frequently low-profit activities, the introduction of dry land crop species in rotation and/or succession with flooded rice has been called for. By broadening the spectrum of wetland soil use, a better weed control for […]

Aluminum (Al) is one of the most abundant elements in weight in Brazilian soils, found in different minerals and forms. Considering the lack of information about its participation in the physical behavior of soil, the present study aimed to evaluate the relationship between the mineralogy of the clay fraction, different forms of Al and physical attributes of different soils. Disturbed and undisturbed samples of A and B horizons of representative soils from the South and Campos das Vertentes physiographic regions […]

This study aimed at evaluating changes in the physical properties of an alic sandy-clay loam Yellow Latosol (Haplortox), located at Cruz das Almas, Bahia, Brazil, cropped for 15 years with banana, 38 years with citrus, 15 years with mango, and 14 years with cassava, compared with soil covered by native forest. In 1991, soil samples were collected for the A, AB, Bw1 and Bw2 horizons and soil bulk density, soil density, macroporosity, microporosity were determined, as well as the distribution […]

This study aimed to evaluate the relationship between the mineralogical constituents of clay fraction and the development of micro and macrostructure of Latosols (Oxisols) from southeastern Brazil. For that purpose, samples of oxic horizons were obtained from seven Latosols representative of this group, from Minas Gerais and Espírito Santo states. The different soil samples were submitted to morphological, chemical, physical, mineralogical and micromorphological characterizations. From the different results it was possible to conclude that kaolinite and gibbsite are the main […]