The objective of this work was to analyze the effect of moisture content and soil management on the compressibility behavior of three soils, namely, a Red-Yellow Latosol (LV), Dusky Red Latosol (LR) and Dark-Red Latosol (LE), under annual crop, natural forest and pasture. The soils were located in the region of Lavras and Ijaci (MG). Undisturbed and disturbed soil samples were collected in two depths (0-0,03 and 0,27-0,30 m) with three replicates. The undisturbed soil samples were used in the […]

A new approach is discussed for adoption of criteria in the application of the cultural profile methodology for tropical soil conditions. The evolution of this methodology has been analyzed since its beginning in France in the 1960s, until its proposal for tropical soil management studies. The cultural profile approach can be used to make qualitative diagnosis of the physical state of soil in the field, as well as to help with soil sampling, to study the effect of agricultural machinery, […]

Using the compressibility test, the effect of soil management and moisture content on the preconsolidation pressure (σp) of three soils, a Red-Yellow Latosol (LV), a Dusk Red Latosol (LR) and a Dark-Red Latosol (LE) under annual crop, natural forest and pasture, was studied in the area of Lavras (MG) at two depths (0-0.03 and 0.27-0.30 m). For each condition, five undisturbed soil samples and a disturbed one were collected, with three replications. The undisturbed soil samples with different soil moisture […]

This work was carried out to evaluate the alterations in organic-C, microbial-C and in the activities of the enzymes cellulase and amylase in soil samples of a Rhodustalf collected in the summer at 0-10, 10-20 and 20-30 cm depths, under natural forest (NF), 20 (P20) and 25 (P25) year old pastures and 10 year old cotton cultivation. Organic-C and microbial-C contents and the amylase and cellulase activities were very similar in NF, P20 and P25. Reduction of 18% in organic-C […]

The changes in some soil chemical properties, bulk density, and microbiological activity due to the replacement of a native forest by orange cultivation were evaluated in an Yellow-Red Podzolic Soil. The study was conducted at the Cambuhy orange farm, Matão (SP) in April, 1996. Two areas were selected: (a) a native forest, and (b) a 15-year-old orange plantation. Ten sites were randomly selected in each area and soil samples were taken at 0-20 and 20-40 cm depths. In the cultivated area, […]

No-tillage soil management does not permit incorporation of crop residues and requires surface application of fertilizers and corrective agents, thereby affecting nutrient availability and distribution. This study was carried out to evaluate the chemical changes in no-tillage system compared to conventional tillage and native grass field. Samples from a sandy/clay Red-Yellow Podzolic (Typic Hapludalf), taken at 0-5, 5-10, 10-20 and 20-40 cm depth, were used to determine zero point of salt effect (ZPSE), humic substances, permanent charge, soil pH, exchangeable […]