Alkaline by-products generated in the pulp and paper industry can be used to reduce soil acidity. However, the low Mg and intermediate Na values in these residues can negatively affect the bioavailability of some nutrients and soil properties. Before recommending them, it is therefore imperative that their effects on the soil be evaluated. The objective of this study was to quantify the soil chemical composition and vertical mobility of cations due to application of alkaline industrial residue in different forms, […]

Fertilization and irrigation is intensively used for seedling production in substrate, which can result in high nutrient losses. Phosphorus (P) is heavily used in the preparation of the potting mix, but studies on nutrient losses are scarce. The objective of this study was to evaluate the chemical attributes in leachate from potting mix during rooting of cocoa tree cuttings under intermittent irrigation and P fertilization in a 5 x 5 factorial, complete randomized block design with three replications. The factors […]

The low reactivity of lime below the application layer is mainly due to its low solubility, to the increase in soil negative charge in the applied zones, and to the short permanence of anions of added anions in the soil solution. This study was carried out to evaluate the effect of anions added as potassium salts on increasing the reactivity of surface-applied limestone. The experiment was carried out in 2005 on a Haplumbrept (360 g kg-1 clay, 60 g kg-1 organic matter, and […]

No-tillage systems, associated to black oat as preceding cover crop, have been increasingly adopted. This has motivated anticipated maize nitrogen fertilization, transferring it from the side-dress system at the stage when plants have five to six expanded leaves to when the preceding cover crop is eliminated or to maize sowing. This study was conducted to evaluate the effects of soil tillage system and timing of N fertilization on maize grain yield and agronomic efficiency of N applied to a soil […]

The magnitude of the vertical movement of nutrients in the soil profile determines their contact with plant roots and leaching, thus affecting the timing and method of fertilizer application. This study aimed to assess the K mobility in the soil as influenced by rate and method of potassium chloride addition. The experiment was carried out in 1998, using 7.5 cm wide and 35 cm long PVC leaching columns. Potassium was applied at rates of 0, 150 and 300 mg kg-1 […]

This experiment aimed at the evaluation of imazaquin sorption and transport in soils with different chemical, physical and mineralogical characteristics using batch and miscible-displacement techniques. The experiment was carried out with Neossolo Quartzarênico (RQ), Latossolo Vermelho-Amarelo (LVA) and Latossolo Vermelho distroférrico (LVdf) soils which were air-dried, passed through a 2 mm sieve and followed by chemical, physical and mineralogical characterization. A CaCl2 solution was applied in the miscible displacement experiment for the establishment of a Cl– elution curve that was used […]

The biodegradability and distribution of pesticides in the environment determine their pollution potential. The risk of contamination with atrazine herbicide was studied in an Ultisol under field conditions and complemented with a microcosm system study. This system allowed the use of 14C-atrazine under controlled conditions and to determine of the volatilization (0.33%), mineralization (0.25%) and leaching (4 to 11%) parameters, which are difficult to evaluate in the field. Ninety percent of the radioactivity remained in the soil, with 75% in […]

The constant use of fertilizers that does not contain sulfur, in addition to low organic matter content of some soils, may result in sulfur limitation to crops. Due to the high mobility of the sulfate ion in many soils, it is important to know the residual effect of the phosphogypsum when added to the soil as S source, in order to estimate its application frequency. Experiments were performed under field conditions, in two years, in order to evaluate the effect […]

Cadmium dynamics in the soil-plant system were evaluated in an experiment with a Typic Hapludox (320 g kg-1 of clay) PVC columns (diameter 0.10 m, height 0.80 m) were filled with soil samples (V % elevated to 70), and the surface layer (0-0.2 m) supplemented with Cd-contaminated biosolid (sewage sludge, pH 6). The biosolid treatments were contaminated as follows (in mg kg-1): 0 (control) 2,500 of Cd, 5,000 of Cd, 2,500 of Cd + 2,500 of Pb, and 5,000 of […]

Tebuthiuron adsorption was determined in samples from 0-10 to 10-20 cm layers of three soils from the county of Ribeirão Preto (SP)-Brazil: Quartzarenic Neosol (Entisol), Red Latosol dystrofic and Red Latosol dystroferric (Oxisols). Sorption data were obtained by batch equilibrium and fitted to four adsorption models: Freundlich, linear, Langmuir and Lambert. Several statistical criteria were applied for selection among these isotherms. Freundlich model showed the best fit to the data. Kd values ranged from 0.723 to 2.573 L kg-1, and […]