PHOSPHORUS AND POTASSIUM ABSORPTION IN ZEA-MAYS SUPPLIED WITH ORGANO-MINERAL FERTILIZERS

Torrefied leather-PK and peat-PK fertilizers were compared with chemical PK trials to improve phosphorus and potassium absorption in maize grown in an open-field experiment. The application rates were 0, 50 and 100 kg P2O5 ha-1, supplying 0, 84 and 167 kg K2O ha-1, respectively. All experimental plots received a split application of 300 kg N ha-1. Organo-mineral fertilizers at half-rate were as effective as the chemical fertilizer at the whole dose to provide the highest P concentration and uptake in the grain. K absorption in the stalks and its translocation to the seeds were higher in the PK-leather than in the chemical PK trials. These results suggest that the rate of 100 kg P2O5 ha-1 exceeded the crop nutrient requirements thus being fertilizer-consuming. Therefore the best PK fertilizer efficiency can be achieved when chemical fertilizers are properly used to manufacture organo-mineral fertilizers.