[Characterization of the response of maize and sorghum to fertilization in Venezuelan soils and their relationship with the interpretation criteria of soil analysis]
1995
Rodriguez, B. | Hernandez, J. | Ramirez, R. | Tenias, J.
Results of corn and sorghum as well as available P and K in soil were compiled from 116 field experiments located in APURE, BARINAS, GUARICO, PORTUGUESA, MONAGAS, YARACUY y TACHIRA states in which five (5) levels of N, P and K were tested using a randomized block design with arrangement in a Rotable Central Composite. The data were analyzed according to the surface response methodology considering the plant number as covariant. N was the element with major response to fertilization followed by P and K. The response to P fertilization was lower in corn than in sorghum, the reverse occurred with K fertilization. The N, P and K requirements estimated from DPPR, DPPI and DPC indicated a rational use of N independently of crop; rational use of P in corn and unrationable use of K in both crops. The losses in terms of excessive quantities of applied fertilizers were 76.5 percentage for corn and 23,5 percentage for sorghum, conferring 36,5 percentage to P and 63,5 percentage to K when rankings by element. The experiments with and without response to fertilization independently of yield level showed low consistency between the field response and soil analysis prediction.
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