ABSTRACT Management of boron fertilization depends on the magnitude of B leaching in the soil profile, which varies proportionally with the concentration of B in the soil solution, which, in turn, decreases as the soil pH increases due to the higher sorption of B on soil solid surfaces. The objective of this study was to quantify the effect of liming and rates of B applied to the soil on B leaching. The experiment was carried out in the laboratory in […]

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 […]

Continuous agricultural production in the Amazon region requires correction of soil acidity and understanding of the long-term interactions of liming with chemical soil properties. The objective of this study was to evaluate the immediate and residual effects of lime on annual crop production and soil properties of medium-textured Oxisols in the Brazilian Amazon. Field experiments were conducted at two locations in the Northeast of Pará from 2003 to 2008, one in the county of Terra Alta and the other in […]

Many studies have shown the importance of the soil microbial biomass, mainly as source/sink of carbon (C) and nitrogen (N) in forest stands. However, there are few studies focused on microbial P (MPH), especially in relation to the determination methods of MPH in these ecosystems. For an evaluation of the methods used to determine microbial P (MPH) in soils, three methods were evaluated: fumigation-extraction (FE); radiation with microwave-extraction (RE); and radiation by microwave-extraction with a membrane for anionic exchange (EMAE). […]

Morphological, physical and chemical data of 58 soil profiles of Ferralsols and low activity clay Cambisols, Lixisols, Acrisols and Nitisols and of Alisols of the International Soil Reference and Information Centre (ISRIC) collection, described and sampled in eighteen different countries of tropical and subtropical regions, were selected to analyse their consistency and, or, variability and to search for properties to better describe and differentiate them. The soil profile descriptions were based on the guidelines of FAO and the FAO endorsed […]

The existence of soil exchangeable Al in toxic levels inhibits root growth and elongation, with negative effects on water and nutrient uptake, especially of P. Thus, as soil P increases, plants become less dependent on a large root system, that may decrease crop response to liming. This study was carried out to evaluate the effect of liming and phosphorus fertilization on corn yield. The experiment was conducted in Lages, Southern Brazil, from 1994 to 1998, in a clayed Oxisol (Hapludox) […]

The screening of plants for aluminum tolerance is an alternative to soils with toxic levels of this element. Twenty five coffee genotypes were evaluated for aluminum tolerance in relation to inhibition of shoot and root growth and by the hematoxylin staining test. The aluminum accumulation in root tissues was also evaluated. After 35 and 75 days of plant growth in nutrient solution with and without aluminum, the length of the main root was evaluated. After 80 days of exposure to […]

Despite the fact that aluminum toxicity to crops is eliminated near soil water pH of 5.5, lime recommendation in many regions aims to increase soil pH up to 6.0 or even higher. For highly buffered soils, high rates of limestone are required to raise the pH from 5.5 to 6.0, resulting in additional, sometimes unnecessary, costs. The objective of this study was to evaluate the effect of soil pH on corn yield in a very acid Hapludox. The experiment was […]