Potassium availability for plants depends on the contents of the K forms present in the soils (non exchangeable, exchangeable and soluble K), which vary according to the degree of pedogenetic development of soils. The objective of this study was to evaluate K availability in soils with different degrees of pedogenetic development, based on the extraction of K from the soils with different extractants and with corn plants. Samples of the surface layer (0-30 cm) were collected from 12 representative soils […]

No tillage systems significantly influence the soil system, but knowledge about the effects on the mineralogy of tropical and subtropical soils is limited. This study evaluated the long-term effects (26 years) of no-tillage (NT) on aluminum hydroxy-interlayered minerals of a subtropical Oxisol in Southern Brazil (Guarapuava, PR), compared to the same soil under conventional tillage (CT). The clay fraction (< 2 µm) in soil samples of the surface horizons of a field experiment under both management systems was analyzed by […]

Soil mechanical penetration resistance exerts a strong influence on plant development since the root growth as well as crop yield are inversely related to this variable. On the other hand, soil organic matter and pH are also relevant for plant development, for being directly linked to soil nutrient availability. In the 2005/2006 growing season, the following dendrometric parameters of Eucalyptus camaldulensis were analyzed: (a) wood volume (WV), (b) perimeter at breast height (PBH) and c) plant height (PH), and the […]

The objective of this study was to analyze the spatial variability of chemical attributes of an Oxisol. The experiment was conducted with Coffea arabica L., variety Catuai, at a depth of 0-0.2 m in a grid area totaling 50 points. The studied chemical attributes were: P, K, Ca, Mg, Na, S, Al, pH, H + Al, SB, t, T, V, m, MO, ISNa, equilibrium P and micronutrients (Zn, Fe, Mn, Cu, and B). The data were analyzed by descriptive statistical […]

The use of diagnosis methods for the determination of normal nutrient ranges is efficient since it is region-specific, thus not always applicable to other regions. This study aimed to determine the optimum nutrient ranges for cotton based on the Best likelihood (ChM), Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND). The study was conducted in commercial cotton fields for the 2004/2005 growing season, in São Desidério, state of Bahia, Brazil. The total nutrient content of 65 whole […]

In no-tillage or in crop-livestock integration systems, it is common the cultivation of common bean in succession to grasses. Due to the root systems morphology, differential secretion of various organic compounds by the roots, and crop residue decomposition, grasses may affect the soil P availability and the acquisition and utilization of P sources, apparently with low agronomic efficiency, for crops in succession. This study was carried out to evaluate the use of P in common bean yield in succession to […]

The understanding and quantification of soil use and management on the soil physical quality are important to develop and select sustainable agricultural systems. The purpose of this study was to evaluate the structural quality of a clayey Brazilian Oxisol under different production and soil tillage systems by measuring the tensile strength (TS) and to quantify aggregate friability (F). The study was conducted in Castro, Paraná state, in southern Brazil, using three production systems and seven soil tillage types, in a […]

Agrosilvipastoral systems represent agro-forestry practices that allow greater diversity and sustainability of a cropping system. Soil organic matter (SOM) is one of the main indicators of the sustainability of a cropping system, especially in tropical soils. The objectives of this study were to investigate the impact of eucalypt cultivation on different C and N of SOM fractions on agrosilvipastoral systems over time. To this end, a chronosequence consisting of six implantation times of an agrosilvipastoral system was sampled. Time zero […]

Hydrological models developed to predict the impacts of non-point source pollution and land use and occupation on water quality have been extremely useful in the study of agricultural systems. For this purpose, the objective of this study was to evaluate the sensitivity of the model SWAT 2005 (Soil and Water Assessment Tool) to simulate the flow rate and total phosphorous flow mass. The research was conducted in two contiguous watersheds of the Conrado and Pinheiro rivers, affluents to the Pato […]

In restinga soils with sand-quartzous constitution the influence of the organic fraction and biological activity on soil key functions is increased, e.g., the capacity of recycling and storing nutrients. The analysis of soil attributes and edaphic fauna at sites under different vegetation cover types is important to understand the behavior of these environments. In this study, chemical, physical and microbiological soil attributes of restinga sites and their relationships with ant populations under different vegetation types in the state of Sergipe […]