The description of the fate of fertilizer-derived nitrogen (N) in agricultural systems is an essential tool to enhance management practices that maximize nutrient use by crops and minimize losses. Soil erosion causes loss of nutrients such as N, causing negative effects on surface and ground water quality, aside from losses in agricultural productivity by soil depletion. Studies correlating the percentage of fertilizer-derived N (FDN) with soil erosion rates and the factors involved in this process are scarce. The losses of […]

Estimation of soil load-bearing capacity from mathematical models that relate preconsolidation pressure (σp) to mechanical resistance to penetration (PR) and gravimetric soil water content (U) is important for defining strategies to prevent compaction of agricultural soils. Our objective was therefore to model the σp and compression index (CI) according to the PR (with an impact penetrometer in the field and a static penetrometer inserted at a constant rate in the laboratory) and U in a Rhodic Eutrudox. The experiment consisted […]

As a result of soil management systems, like the conventional tillage system (CTS) versus the no-tillage system (NTS) for vegetable crops, modifications in soil properties occur, which change, for example, the rates of soil aggregation and the content of total organic carbon (TOC). The aim of this study was to quantify the TOC contents and evaluate the rates of soil aggregation and the distribution of aggregates by diameter classes in a soil planted to onion in NTS and CTS and […]

Total Reflection X-ray Fluorescence (TXRF) is a promising technique for analysis of trace elements (TEs), mainly because samples do not need to be digested, thereby reducing generation of waste and emission of toxic fumes. This study compared the levels of the TEs:Cr, Mn, Ni, Zn, Cu, As, Se, Hg, and Pb in soil samples collected from intensive agricultural and native vegetation areas, as determined by TXRF and by flame or graphite furnace atomic absorption spectrometry (FAAS/GFAAS). In addition, we compared […]

The State of Santa Catarina, Brazil, has agricultural and livestock activities, such as pig farming, that are responsible for adding large amounts of phosphorus (P) to soils. However, a method is required to evaluate the environmental risk of these high soil P levels. One possible method for evaluating the environmental risk of P fertilization, whether organic or mineral, is to establish threshold levels of soil available P, measured by Mehlich-1 extractions, below which there is not a high risk of […]

In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1) and Ion Exchange Resin (IER), from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed […]

Despite the considerable environmental importance of mercury (Hg), given its high toxicity and ability to contaminate large areas via atmospheric deposition, little is known about its activity in soils, especially tropical soils, in comparison with other heavy metals. This lack of information about Hg arises because analytical methods for determination of Hg are more laborious and expensive compared to methods for other heavy metals. The situation is even more precarious regarding speciation of Hg in soils since sequential extraction methods […]

Improper land use has lead to deterioration and depletion of natural resources, as well as a significant decline in agricultural production, due to decreased soil quality. Removal of native vegetation to make way for agricultural crops, often managed inadequately, results in soil disruption, decreased nutrient availability, and decomposition of soil organic matter, making sustainable agricultural production unviable. Thus, the aim of the present study was to evaluate the impact of growing irrigated mango (over a 20 year period) on the […]

The Mehlich-1 (M-1) extractant and Monocalcium Phosphate in acetic acid (MCPa) have mechanisms for extraction of available P and S in acidity and in ligand exchange, whether of the sulfate of the extractant by the phosphate of the soil, or of the phosphate of the extractant by the sulfate of the soil. In clayey soils, with greater P adsorption capacity, or lower remaining P (Rem-P) value, which corresponds to soils with greater Phosphate Buffer Capacity (PBC), more buffered for acidity, […]

Integration of chemical extraction methods and X-ray diffraction can broaden understanding of K+ forms and reserves in soil fractions, and their potential release to plants. The aim of this study was to use chemical extraction methods to estimate mineral reserves of K+ in sand, silt, and clay from subtropical soils; to associate extraction mechanisms with the forms of K+ released; and to monitor the dynamic of K+ release in a kinetics study. The sand, silt, and clay fractions of the […]