Concentraçoes relativas ótimas de nitrogenio, fósforo e enxofre, na adubaçao do cafeeiro, num latossolo vermelho-escuro de Machado, MG
The NPS equilibria in coffee (Coffea arabica L.) fertilization (Catuai cultivar) in a Dar-Red Latosol, "cerrado" phase, at Machado, MG, were studied under greenhouse conditions. The equilibria were tested in the NP and SN and SN relations and the treatments were chosen according to Richard's Cut Method. The three cut values were defined, for N and P, as a function of the phosphate maximum adsorption, and for S, as a function of the sulfate maximum adsorption. In each nutrient binary relation and each cut, four equilibria were studied. The treatment effects were evaluated 20 months after planting by measuring total dry weight. The leaf N, P and S concentrations were also determined. For each nutrient relation, the lack of the third anion limited the plant growth, mainly for N in the cuts of the PS relation. For the vegetative growth, the cut 0.4 was more effective than the cut 0.2 and equivalent or more effective than the cut 0.8. In the NP relation, when more N was added, the P requirement became higher. In the PS relation, the optimum relative concentrations indicated that the demand of S increased with the addition of P. In the same way, in the SN relation, for higher levels of N, more S was required. In general, for the best cut (0.4), the best equilibrium of the three nutrients was obtained with the application of 165 ppm of N, 80 ppm of P and 44 ppm of S. Some informations about the leaf N, P and S concentrations are presented
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
Feb
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| Subjects: | COFFEA ARABICA, CULTIVARES, FERTILIZANTES NP, AZUFRE, CONTENIDO DE NUTRIENTES, BRASIL, CATUAI, |
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