USE OF NUTRIENTS FROM ORGANIC OR INORGANIC FERTILIZERS FOR RED HEAD CHICORY PRODUCTION

Abstract

The influence of stable manure and mineral fertilizer NPK 5-20-30 upon the status of nitrogen, phosphorus and potassium in soil, their accumulation in plants, yield of red head chicory (Cichorium intybus var. foliosum Hegi) and correlations of the studied parameters were determined during a three-year investigation period (1999-2001). Investigations were conducted on two locations in Croatia, ecologically very suitable for the vegetable crops production. Because of the nature of the research and the crop rotation, the trial was set up on a different area each year. The area selection followed detailed preliminary soil investigations. Trials were carried out according to the Latin design in live treatments: stable manure 5 kg m-2, three rates of complex mineral fertilizer NPK 5-20-30 (50, 100, and 150 g m-2), and an unfertilized control variant. Investigation results indicate that there were negative significant correlations (r=-0.772, p=<0.001) between nitrogen in the soil and nitrogen in the plant, regardless of fertilizer form and rate. In contrast, the correlation between phosphorus in the soil and in the plant, irrespective of the year and location, was positive and highly significant (r=0.613, p=0.003). An identical relation was recorded between potassium in the soil and in the plant (r=0.478, p=0.0076). Also, a positive and significant correlation was recorded between soil nitrogen and yield (r=0.367, p=0.0458) and soil phosphorus and yield (r=0.367, p=0.0462), whereas the correlation between soil potassium and yield was positive and highly significant (r=0.485, p=0.0066). Results indicate that there were no significant differences in chicory yield between fertilization with 100 and 150 g m-2 mineral fertilizer NPK 5-20-30. The highest yield was 3.73 kg m-2 in 1999 at Lika location.