Avaliacao de métodos químicos para extracao de zinco disponível no solo para mudas de café
The response of coffee (Coffea arabica) seedlings to applied Zn on acid soils that had been limed to give a range of pH values was investigated in the greenhouse. Zinc sulfate was mixed with soils at the rate of 0.5, 10 and 20 umg/g of Zn. The Zn content of the plants increased with Zn application and decreased with increasing pH. The solubility of Zn in the soils decreased markedly with increasing pH from four to seven. The order of extractability was 0.1N HCI>0.05N HCI + 0.025N H2S04>NH40Ac 1N pH 4.8 > DTPA > EDTA > water soluble. The 0.1N HCL and double acid extractants gave higher correlation with Zn uptake under pH < 5.5. The efficiency of these acid extractants decreased with increasing pH. The DTPA and EDTA tended to be more indicative of Zn uptake by coffee plants under pH > 6.2 than acid solutions
| Main Authors: | , |
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| Format: | biblioteca |
| Published: |
Feb
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| Subjects: | COFFEA ARABICA, PLANTULAS, CINC, SUELO ACIDO, PH, MICRONUTRIENTES, APLICACION FOLIAR, DEFICIENCIAS MINERALES, |
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