EFFECT OF N FERTILIZATION ON THE N-CONTAINING GASES OF THE SOIL

Recently more and more attention is given to the need to reduce nutrie nt losses of fertilizer origin. This is important from both the econom ic and the environmental point of view. In the soil N fertilizer is su bject to migration and transformation, owing to its solubility and par ticipation in microbiological processes. According to the results of e xperiments,only about 50% of the N fertilizer applied is utilized by t he plants, the rest may be leached, immobilized or lost in gaseous for m due to denitrification processes depending on the soil characteristi cs (pH, moisture, biological activity, etc.). A model experiment was s et up in pots containing 40 kg of clay-illuviated brown forest soil wi th or without maize as a test crop. 150 mg/kg NO3-N and NH4-N fertiliz ers were (with basic PK) added to the soil, and the soil moisture leve l was adjusted to 80% and 65% of the water-holding capacity. Gas-colle cting traps were built in to the soil at a depth of 20 cm. After the s tart of the experiment, soil gas samples were taken from the traps thr ough silicon pipes on the 6th, 20th, 34th, 48th and 68th days. The N-c ontaining gases (NO, NO2, N2O, N-2) were analysed by gas chromatograph y.