The spatial variability of some physical and chemical characteristics of a compound of soils under grapevine (Vitis vinifera-L) cultivation was studied in the county Vitória Brasil, State of Sao Paulo, Brazil. Main objective was research into the spatial dependence of these soil characteristics and their variability, frequency distribution and minimum number of soil subsamples for grapevine crop. Soil data were collected in grid sampling at 156 points, using geoestatistics for the data analysis. Highest variability was found for macroporosity (MA), […]

In a natural landscape, the soils present a wide variation on morphological, physical, chemical and mineralogical properties due to several soil formation factors. In a cultivated landscape others sources of variation may be present, such as anthropogenical processes. The knowledgement of these variations is important to soil survey, development of sampling designs and soil management practices. This work aimed to study the spatial variability of some physicals attributes of a Dystrophic Red Latosol cropped in no tillage system. It was […]

The objective of this work was to studying the spatial variability of some chemical properties of a saline-sodic soil of alluvial origin, in the Irrigated Perimeter of São Gonçalo, district of Sousa-PB, Brazil. At an experimental area of 2912 m2, soil samples were collected in a grid with a spacing of 4 x 4 m, at a layer depth of 0 to 0.30 m. The data analysis was carried out by means of descriptive statistics and geostatistics. The results showed […]

The spatial variability of the soil characteristics colour, clay content, pH and penetrometer resistance was evaluated in seven areas on which strongly weathered and intensively cropped soils occur, in the Planalto Médio region, State of Rio Grande do Sul, Brazil. Nested analysis of variance was performed with the objective of assessing their homogeneity and optimal soil sampling density. Representative soil profiles were characterized and classified in these areas. Field work was performed from August to November, 1989. Kandiudox, Hapludox and […]

The variability of leaf nutrient concentrations (nitrogen, phosphorus, potassium, calcium, magnesium, zinc, copper, manganese, and iron) was assessed in a twelve-year-old orange orchard, cv. Pêra, grown on a dystrophic Yellow Latosol of medium texture plain relief, in Governador Mangabeira, State of Bahia, Brazil, 1990. A transect consisting of 50 trees, spaced four meters apart, was sampled. Twenty leaves were collected from each tree. The leaves were taken from four different points of the crown, opposite two by two, and from […]

With the objective of assisting sampling systems and planning orange experiments, soil variability was assessed in a twelve-year-old orange orchard, cv. Pera, grown on a dystrophic Yellow Latosol of medium texture plain relief, in Governador Mangabeira, State of Bahia, Brazil, 1990. A transect consisting of 50 trees, spaced 4 m apart, was sampled. Soil samples were taken from a fixed point under the tree drip line on the successively fertilized strip. Results showed that only phosphorus and gravimetric soil moisture […]