Phosphorus (P) deficiency is one of the most widespread limitations to the establishment and maintenance of pastures in tropical areas. This deficiency is mainly due to the low soil P content and adsorption/precipitation processes. The purpose of this study was to evaluate the influence of manure and lime applications on the residual effect of phosphorus applied to common bean on phosphorus nutrition and yield of Brachiaria brizantha grown in succession. Four experiments were conducted in a greenhouse, in a completely […]

The distribution of phosphorus forms in the different soil compartments (labile, little labile and non-labile) is very influenced by geochemical and biological processes and by human activities. To evaluate the effect of liming and cattle manure on soil phosphorus forms, four experiments were carried out in an entirely randomized design, in a 4 x 5 factorial layout with four repetions, in a greenhouse. The treatments consisted of four liming levels (0; 0.5; 1 and 2 times the recommended dose to reach V […]

Liming and organic fertilizers can reduce P adsorption/precipitation in the soil, increasing the availability for plant uptake. To evaluate the effect of liming and cattle manure on phosphorus adsorption in the soil, four experiments were conducted in an entirely randomized design, in a 4 x 5 factorial layout with four replications, in a greenhouse. The treatments consisted of four liming levels (0; 0,5; 1 and 2 times the recommended dose to reach V = 60%) and five doses of cattle […]

This study was carried out in order to evaluate yields of wheat, lettuce and radish, as well as chemical changes in an Oxisoil due to the addition of tannery waste and hexavalent chromium. Microplots in a greenhouse, which consisted of 60 L plastic pots, received the following treatments: control; lime + NPK; primary tannery sludge + PK; chrome-tanned leather shavings + lime + NPK; finished leather shreds + lime + NPK; Cr6+ + lime + NPK; Cr6+ + lime + […]

A laboratory experiment was carried out to evaluate the hexavalent chromium reduction as affected by organic carbon amendment, Mn2+ and microbial activity. Samples of a Hapludult soil (50 g) were placed in plastic bags (50 g) and incubated during 42 days with lime (2.0 Mg ha-1), Cr6+, cattle manure(organic carbon) and Mn2+ in the doses of 20, 50 and 40 mg kg-1, respectively. Half the samples were sterilized by autoclaving to eliminate biological activity. Cattle manure and Mn sulfate amendment promoted a total soil hexavalent chromium […]

Adding simple superphosphate or phosphogypsum to piles of manure or other organic residues has been recommended to reduce losses of ammonia by volatilization during composting. However, experiments have shown discrepant results when the efficiency of these additives and the adequate rate of application are evaluated. This discrepancy could possibly be explained by differences in the residual acidity of the additives utilized in those experiments. To check this hypothesis, a laboratory experiment was carried out using samples of phosphogypsum, simple superphosphate […]

The effects of applying micronutrients, cattle manure, lime and splitting application of NPK fertilizers on the yield and the incidence of witches’ broom disease of cacao caused by Crinipellis perniciosa were determined in two experiments carried out on structured Terra Roxa soil (TR) and Yellow Latosol (LA), in Pará State, from 1988 to 1993, after the slash and burn of the forest. The hybrid (Sca 6 x Be 10) cacao crop was introduced utilizing banana (Musa spp.), as temporary shading, […]