The lack of information concerning the variability of soil properties has been a major concern of researchers in the Amazon region. Thus, the aim of this study was to evaluate the spatial variability of soil chemical properties and determine minimal sampling density to characterize the variability of these properties in five environments located in the south of the State of Amazonas, Brazil. The five environments were archaeological dark earth (ADE), forest, pasture land, agroforestry operation, and sugarcane crop. Regular 70 […]

Information underlying analyses of coffee fertilization systems should consider both the soil and the nutritional status of plants. This study investigated the spatial relationship between phosphorus (P) levels in coffee plant tissues and soil chemical and physical properties. The study was performed using two arabica and one canephora coffee variety. Sampling grids were established in the areas, and the points georeferenced. The assessed properties of the soil were levels of available phosphorus (P-Mehlich), remaining phosphorus (P-rem) and particle size, and […]

In analysis of the spatial and temporal variability of the factors inherent to agricultural production, geostatistics is the basis for the application of the concepts of precision agriculture. Thus, this study was developed to evaluate the spatial variability of soil physical and water properties and to delineate homogeneous zones in a vineyard using geostatistical tools. A field experiment was carried out in Petrolina, Pernambuco, Brazil (in the Lower Middle São Francisco Valley) in a grape vineyard, irrigated by microsprinklers. In […]

The national and international demand for maps of soil properties has increased. The aim of this study was to characterize cohesive soils and associate their variability of particle size, chemical properties, and color to different landforms in agricultural areas and native vegetation using geostatistical techniques. To set up the experiment, we selected three areas of soil consisting of an area planted to soybeans and, contiguous to it, another area with plant cover remaining from three types of cerrado (tropical savanna), […]

Heavy machinery traffic on cropped soils applies different tensions that, combined with high values of soil moisture, can result in soil compaction. The aim of this study was to evaluate the variation in some physical properties of an Argissolo Amarelo (Ultisol) due to farm tractor traffic with different numbers of passes. The study was conducted at UNIVASF in Petrolina, State of Pernambuco PE, Brazil, in an experiment in strips with two factors: tractors of 2,650, 2,795, and 3,540 kg; and […]

The use of geostatistical techniques allows detection of the existence of dependence and the spatial distribution of soil properties, thus constituting an important tool in the analysis and detailed description of the behavior of soil physical properties. The aim of the present study was to use geostatistics in assessment of physical properties in a Latossolo (Oxisol) dystrophic under native forest and pasture in the Amazon region of Manicore. Grids with of 70 x 70 m were established in native forest […]

In the subtropical regions of southern Brazil, rainfall distribution is uneven, which results in temporal variability of soil water storage. For grapes, water is generally available in excess and water deficiency occurs only occasionally. Furthermore, on the Southern Plateau of Santa Catarina, there are differences in soil properties, which results in high spatial variability. These two factors affect the composition of wine grapes. Spatio-temporal analyses are therefore useful in the selection of cultural practices as well as of adequate soils […]

In agriculture, the search for higher crop yields based on sustainable soil management has led to a gradual pursuit of knowledge of the variables related to production systems. The identification of the causes of variability of these properties has become a part of strategic planning in the sugar and ethanol industry. This study investigated the spatial variability of iron oxides in the clay fraction and its relationship to soil physical and chemical properties in different sugarcane cultivation systems in the […]

The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 […]

Considering the importance of knowledge of the spatial distribution of soil properties, the purpose of this study was to evaluate the spatial variability of physical properties in a Cambisolunder different land uses in the southern Amazon region. The study was conducted on three farms with cassava, sugarcane, and agroforestry, in the region of Humaitá, in the south of the State of Amazonas. In these areas, 70 x 70 m grids were established, with a regular spacing of 10 x 10 […]