Influence of phosphorus and potassium fertilizers on permanent and temporary pastures in relation to application frequency
1988
Motca, G. (Institutul Agronomic Nicolae Balcescu, Bucuresti (Romania)) | Barbulescu, C. | Cardasol, V. | Chiper, C. | Simtea, N. | Pavel, C. | Razec, I. | Ionescu, I. | Lapusan, A. | Tucra, I. | Dragomir, N. | Dinca, F. | Ionel, A. | Panait, V. | Iacob, T. | Dumitrescu, O. | Capsa, I. | Capsa, S. | Petcu, N. | Stefan, D.
During 1977-1982 the investigations performed in permanent and temporary grasslands located at altitudes between 125 and 1,200 m, aimed to determine the effects of a low frequency of application of phosphorus and potassium fertilizers. Fertilization variants were as follows: 50 kg/ha anually, 100 kg/ha every 2 years and 150 kg/ha every 3 years, for each fertilizer as P2O5 and K2O, under 3 rates of nitrogen fertilization (100, 150 and 200 kg/ha nitrogen) fractionally applied. By administering every 2-3 years PK fertilizers, dry matter yield decreased by up to 12 % in Festuca valesiaca grasslands, by maximum 20 % in those with Festuca rubra on pseudogleyed albic luvisols, and by maximum 9 % in temporary grasslands on pseudogleyed albic luvisols. In all the other grasslands under study yield was not significantly influenced. Simultaneously with the increase of the intervals between PK fertilizer applications, the coefficient of yield variation in Festuca rubra grasslands decreased, in those with Festuca valesiaca and in temporary grasslands located on pseudogleyed albic luvisols increased and remained unchanged in all the other grasslands. In soils with low to medium supply of K Al, potassium content in plants and soil decreased in the years characterized by persistence of the effect of potassium fertilizers
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