Composted Tannery Sludge Research Articles

English

Experiments were carried out under field conditions to evaluate the effects of composted tannery sludge (CTS) on soil pH, electric conductivity (EC) and soil organic matter (SOM) content after three years of amendment. The CTS was applied at 0, 2.5, 5.0, 10.0 and 20.0 ton ha-1. In each year, soil samples were collected 60 day after CTS amendment. After three years, the CTS increased about 5, 46 and 69% of the soil pH, EC and SOM content as compared with the control. Consecutive amendment of crescent rates of CTS promotes linear increases in soil pH, electric conductivity and organic matter content.   Key words: Composting, industrial wastes, salinity soil.

Disponibilização de fósforo, correção do solo, teores foliares e rendimento de milho após a incorporação de fosfatos e lodo de curtume natural e compostado

Solubilization of phosphorus, soil correction and corn yield after addition of phosphates and natural and composted tannery sludge. The objective of this study was to evaluate the effect of tannery sludge associated with fosforita (rock phosphate) on the availability of phosphorus and correction of soil, leaf levels and maize yield. The experiment was conducted on the field during twelve months (October 2005 to October 2006) with the incorporation of 2.5 and 5.0 Mg ha -1 of tannery sludge (natural and composted) and 100 kg of P2O5 ha -1 in the form of soluble and natural phosphate (fosforita). During the months of November 2005 to April 2006, maize was grown in the experimental area. Treatment with tannery sludge naturally, at a dose of 5.0 Mg ha -1 associated with fosforita, incremented the levels of phosphorus, calcium and base saturation in the soil for 360 days after implementation. This treatment provided increases in levels of phosphorus in the leaves of maize. The composted tannery sludge treatment, compared to natural tannery sludge, was deficient in the absorption of phosphorus by maize and soil correction. Increased yield of maize was verified by the incorporation of fosforita associated with the natural and composted tannery sludge at a dose of 5.0 Mg ha -1 .

The influence of soil treatment by untreated and composted tannery sludge on yield, nutrient status, and chromium content in selected crops

 The research is aimed to determine the effect of fertilization with untreated or composted tannery sludge on yielding, macroelement and chromium contents in plant biomass. The biggest yield diversification was observed in the first and second year of the experiment, whereas in the subsequent years no major differences in yields were discerned. The mechanism of diversified plant response to organic fertilizers supplied to the soil resulted from their different ability to utilize nutrients but was also due to crop succession and different tolerance of subsequent species to the amount of supplied chromium. Nitrogen contents in plants were diversified, despite supplementing its dose to an equal level in all treatments (except the control). It may be concluded that the nitrogen in the applied materials occurred mostly in organic forms and its availability depended on the mineralization rate. Phosphorus and magnesium content depended on the plant species and applied fertilization. Potassium was more available if applied in a mineral form whereas calcium and sodium contents increased significantly in the plant biomass after fertilization with tannery sludge containing materials. Chromium content in tannery materials did not affect the content of this element in the aboveground plant parts and the absorbed chromium was retained mainly in the plant root system.