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| Author(s): |
Adriana Marlene Moreno Pires
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 1999-01-27 |
| Advisor: | Maria Emilia Mattiazzo |
| Abstract | |
The behaviour of zinc and copper in soils was studied in a pot experiment using sewage sludge and inorganic salts as sources of these elements. A fatorial 2 x 5 scheme was adpted for sources and Zn:Cu relationships (5:1,7:1,1:1,4:1 and control treatement with neither Zn and Cu). The test plant used was rice (Oryza sativa). The evaluation of the interaction among these two elements, was also observed in this study. The experiment was divided in two parts, each one using a different textured soil, both classified as Hapludox. Sewage sludges resuIting from different period and processing system were incorporated to soils in amount corresponding to 50 Mg ha-1 (dry weight basis). The treatments whose source was salt were constituted of the zinc and copper sulphate addition in amount corresponding to those added by the sludge. The following parameters were evaluated: pH, electric conductivity, total and soluble levels of these metaIs in soils. The availability of zinc and copper to rice was established by correlations among amounts accumulated by rice plants and those removed of the soils by the extractants HCI 0,1 moI L-1, Mehlich-3 and DTPA. It was concluded that zinc and copper availability in both soiIs was different depending on the element's source. The amount of available zinc and copper for the rice plants was mainly dependent on soil pH, as well as the sludge treatment system. Considering the extractor used for estimating bioavailability it was concluded that for both soils DTPA, HCl 0,1 moI L-1 and Mehlich-3 were representative. The results of the interaction Zinc x Copper have shown that one element didn't have influence in the absorption of the other one. (AU) | |