The spatial variability of soils under a same management system is differentiated, as expressed in the properties. The spatial variability of aggregate stability of a eutrophic Red Latosol (ERL) and a dystrophic Red Latosol (DRL) under sugarcane was characterized. Samples were collected in a regular 10 m grid, in the layers 0.0-0.2 and 0.2-0.4 m, with 100 points per area, and the following properties were determined: geometric mean diameter (GMD) of aggregates, mean weight diameter (MWD) of aggregates, percent of aggregates in […]

Soil compaction is a limiting factor to increase yields and to develop long-term no-till, especially in clayey soils. The objective of this study was to evaluate the effect of compaction levels on soil bulk density, porosity and penetration resistance, as well as the consequences on root growth, leaf area index and yield of common bean and wheat in crop succession. The treatments were: NT – continuous no-till for six years; NTc – NT with additional compaction; Chi – chisel plow […]

There are various methods for assessing data on infiltration rates, but it is important to know how these methods interact with soil properties. The objective of this paper was to analyze four methods for infiltration measurement in different soil types under a no tillage system. Field experiments were performed in Campinas, Campos Novos Paulista and Pindorama, in São Paulo State, on Eutrudox, Hapludox and Hapladult soils, respectively. Infiltration rates were measured from September to November 2000, by the evaluation methods: […]

The effects of irrigation and cropping on the properties of soils were studied in the region of the low-medium São Francisco river basin. Six sites were selected, three of them involving Oxisols collected at the Senador Nilo Coelho Project, in Casa Nova, BA, while the remaining three involved Ultisols collected at the Curaçá Irrigation Perimeter in Juazeiro, BA. The selected sites involved non irrigated and irrigated land, different crops and irrigation methods. The soils were morphologically characterized and samples were […]

The term soil compaction refers to the compression of an unsaturated soil during which an increase of the bulk density of soil occurs in consequence of the reduction of its volume, due to the expulsion of the air caused by inadequate management. To study the effect of different soil management systems on maximum dry bulk density and optimum moisture content, an experiment was conducted in a Dusky Red Latosol of the Lavras (MG, Brazil) region, submitted to the following management […]

A field experiment, arranged in a four-replication split-plot design, was conducted in a Dark-Red Podzolic (Paleudult) to study infiltration rates, ponding time and initial runoff under conventional and no-tillage methods, plots cultivated with oats (Avena strigosa) and soybeans (Glycine max), using simulated rainfall with constant mean intensities of 63.0 and 87.0 mm/h. A small rainfall simulator with 80-100 and 80-150 Veejet nozzles was used, and the test sites had 0.81 m2. Smith’s model was adjusted to the observed data. Ponding […]

The effects of continuous sugarcane cropping on the properties of a clayey Yellow Latosol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, AL, involving a native forest (Tn) and sugarcane fields cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized and undisturbed samples of the A, AB, and BA horizons of each profile were collected […]

The effects of continuous sugarcane cropping on the physical and morphological properties of a clayey xanthic ferralsol were studied in the region of the Low Coastal Tablelands of Alagoas State, Brazil. Four sites were selected at Caeté mill, São Miguel dos Campos, State of Alagoas, Brazil, involving a native forest (Tn), and sugarcane fields, cultivated for periods of two (T2), eighteen (T18) and twenty-five (T25) years. The soils were morphologically characterized, and samples were taken from each horizon to determine […]

Face the planosols (Albaqualf) importance to the agricultural activities in the South Region of the State of Rio Grande do Sul, Brazil, the effect of chiselling on physical parameters of this soil was studied. Experiments were carried out at the Agricultural Machines Experimental Area of EMBRAPA – CPACT, in Capão do Leão, RS, November, 1994. It was analysed the effect of chiselling at three operating speeds (4.76; 3.63 and 2.58 km h-1), in two levels of soil moisture content (119.6 […]