Le potassium et la fumure minérale du caféier robusta dans les sols de Cote d'Ivoire
Potassium is one of the elements removed in greatest amounts by coffee. In the ferralitic soils where the clay fraction is predominantly kaolinic, the behaviour of potassium under coffee, with of without fertilizer, has been analyzed on the basis of simple ratios such as K/T, K/S, Mg/K, Ca/K and Ca + Mg/K. This study shows that during the first coffee crop cycle, these ratios change very little, whether or not fertilizer is applied. But from the second crop cycle, the best outputs are maintained when the total amount of the bases includes a high percentage of exchangeable potassium. Thus, on soils with an annual rainfall of more than 1600 mm, exchangeable potassium must account for 6 to 8 per cent of an exchangeable bases sum equal to 3 meq per cent. The same result is produced by irrigating coffee grown on soils with low rainfall. However, on soils with an annual rainfall of less than 1600 mm, the K rate is 8 to 10 per cent on schist and 3 per cent on granite, when the total bases are equal to 5 to 7 meq per cent
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
París (Francia)
1988
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| Subjects: | COFFEA CANEPHORA, FERTILIZANTES POTASICOS, MINERALES, DOSIS DE APLICACION, SUELOS, COTE D'IVOIRE, |
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