ABSTRACT Root growth can be limited by physical and chemical conditions of the soil. Compacted and acidic soils, where there is an occurrence of exchangeable Al, constitute barriers to use of the soil by plant roots. The hypothesis of this study was that physical and chemical properties of the inter-row soil of a peach orchard influence the root distribution of different rootstocks. The aim of this study was to describe and register the soil physical and chemical properties and root […]

In acid soils of a more tropical environment containing smectites, as well as in highly buffered subtropical soils containing Al hydroxide interlayered smectite (HIS) or vermiculite (HIV), the values of exchangeable Al, extracted by KCl solution (Al-KCl), may be exceptionally high, but not always toxic to the crops. This “exchangeable” Al does not come solely from electrostatic sites. This study aimed to evaluate the relationship between the Al extracted from the soil by KCl and ammonium oxalate solutions, and clay […]

Nitrogen deficiency is one of the important causes of degradation of cultivated pasture, mainly in the case of Brachiaria pastures. Soil recovery is a way to restore the productive capacity of pastures in degradation. Among nutrients, nitrogen is considered essential and largely responsible for pasture area recovery. The research objective was to evaluate the effects of application of nitrogen doses and sources on marandu grass pasture over a period of three years, based on soil chemical characteristics such as pH, […]

Potential acidity is of great importance for the base saturation determination and for the recommendation of liming. The objective of this study was to evaluate the relationship between pH SMP and H + Al contents, in order to establish an equation for the potential acidity estimation of soils from Northern Minas Gerais, Brazil. The H + Al concentration (0.5 mol L-1 calcium acetate pH 7.0) and pH SMP were analysed at EPAMIG/CTNM soil fertility laboratory, in 50 soil samples. The […]

Natural grassfields developed on sandy soils from Northern Uruguay are formed by communities of forage species, composed mainly of seasonal growing grasses, with low biomass production during the fall/winter period. The objective of this study was to evaluate the effect of herbicides, applied on native grassfield to established winter forage species, on soil properties and root biomass. This experiment began in 1994 and was established as a complete block design, with three replications. In the main plots, to establish winter-growing […]

In this study the relationship between the pH SMP and H + Al concentrations was evaluated, in order to establish an equation for estimating the potential acidity of soils from Northeastern Brazil. The H + Al concentration (calcium acetate 0.5 mol L-1, pH 7.0) and pH SMP were analyzed in 81 soil samples. Soil carbon content ranged from 1.8 to 35.6 g kg-1, and clay content varied from 60 to 590 g kg-1. The equation H + Al = 31.521(pH […]

The present study was carried out in 1995 to investigate why plants cultivated in a Red-Yellow Podzolic in the State of Acre, in the Brazilian Amazon, presenting high amounts of exchangeable aluminum, have not shown symptoms of toxicity to this element or yield reduction. The exchangeable Al3+ in the B horizon is higher than 14 cmolc dm-3. Samples of the A and B horizons were incubated with increasing rates of lime and subjected to determination of pH in H2O, pH […]